Categories
WW2 German SPGs

Geschützwagen IVb für 10.5 cm leFH 18/1

German Reich (1939)
Self-Propelled Artillery – 12 Built (2 Prototypes
+ 10 Pre-Production Vehicles)

The development of the Panzer division concept in Germany during the 1930s played a significant role in creating an effective offensive force. The mass concentration of tanks within these divisions provided considerable firepower, allowing them to overcome most enemy opposition. However, engaging well-fortified defensive positions posed a challenge even for Panzer divisions. To address this issue, half-track towed artillery guns were attached to these divisions. These guns were mobile but required some time to set up for firing. Recognizing the need for more mobile and rapidly deployable artillery, Germany started developing self-propelled artillery vehicles. The first attempt to develop such a vehicle would lead to the Geschutzwagen IVb für 10.5 cm le.F.H.18/1.

The Sfl.IVb was the first specially designed German self-propelled artillery vehicle. Source: https://live.warthunder.com/feed/images/

History

To supplement the firepower of newly created Panzer divisions, an artillery regiment was attached to them. This allowed the divisions to have their own dedicated artillery support to provide firepower against fortified enemy positions. These regiments were equipped with 24 10.5 cm le.F.H. 18 and 12 larger 15 cm s.F.H. 18 field howitzers. Occasionally, the latter were replaced with one battery with four 10.5 cm K18 guns.

The 10.5 cm le.F.H. 18 and the larger 15 cm s.F.H. 18 field howitzers were the standard artillery pieces used by the German ground forces during the war. Source: Wiki

Given that mobility was a key part of the Panzer division concept, these had to be mobile to provide the necessary fire support against fortified enemy points. To maintain the required mobility, the German forces employed half-tracks to transport and support the artillery guns, which had good overall mobility. These half-tracks were capable of keeping up with the Panzers in various types of terrain. However, despite their mobility advantages, the half-tracks still required some time to properly set up for combat. When preparing to fire, the guns had to be uncoupled from the towing transport vehicles and the crew had to manually tow the guns to their designated firing positions. The time required for this preparation would depend on the crew’s training and the specific combat situation. It is worth noting that the crew operating these guns were exposed to the risk of enemy return fire during this process. Another drawback of this setup was that the transport vehicles were parked at a distance from the firing positions. In case of an emergency or the need to rapidly relocate, the guns could not be easily moved away. This limitation could potentially leave the artillery crews vulnerable if they were under direct enemy attack or if the situation required a quick change of position. Overall, while the addition of an artillery regiment with mobile half-tracks provided valuable firepower to the Panzer divisions, there were trade-offs in terms of setup time, crew exposure to enemy fire, and limited mobility once the guns were in position.

To increase the mobility of artillery detachments, half-tracks were used. They offered much better drive performance over wheeled trucks. But this was not an ideal solution and a fully mobile self-propelled artillery vehicle was desirable. Source: Wiki

Increasing the mobility of these guns while offering some level of protection could only be achieved in the form of self-propelled artillery. Even before the war, German Army officials were aware that such a vehicle was desirable. In 1934, the early Panzer division concept was meant to include an artillery battalion equipped with 12 self-propelled artillery vehicles. Given the limitations of the German industry at that time, this was only wishful thinking.

The Germans partially addressed the need for close fire support with the introduction of the 7.5 cm armed Panzer IV. In 1935, Krupp was instructed by Wa Prw 6 (German Army’s Ordnance Department office responsible for designing tanks and other motorized vehicles, later renamed to Wa Prüf 6) to build a Panzer IV turret armed with a 10.5 cm L/16 gun. This test vehicle was designated as a 10.5 cm Panzerwagen Nebeltank (Eng. Fog tank). Its purpose was to fire either smoke or high-explosive rounds against enemy positions. The British used a similar concept in their early Cruiser tank designs. Krupp did complete a prototype with the 10.5 cm gun in 1938, but the project did not progress beyond that stage. The exact reasons for the cancellation are not well-documented, and it is unclear why the development of tanks with a 10.5 cm low-velocity gun did not proceed further. It is possible that the German Army’s focus shifted towards other priorities or that technical challenges and resource limitations played a role. In addition, there were some in the German Army who fiercely opposed this concept. Overall, while the Germans did experiment with the idea of mounting a 10.5 cm gun in a tank turret, such projects did not progress beyond the prototype stage.

The Panzer IV was intended to provide support fire for other advancing Panzers. Its 7.5 cm gun could effectively deal with enemy-fortified positions. Attempts to install an even larger 10.5 cm gun ultimately lead nowhere and the 7.5 cm caliber remind a standard armament of the Panzer IV up to the end of the war. gun.
Source: www.worldwarphotos.info

Still, the idea of using self-propelled artillery was not fully discarded. Following a large military exercise undertaken by the 1st Panzer Division, a report (dated December 1935) was issued regarding the artillery support.

“ …During the rapidly increasing pace of the (mock) battles, it proved impossible to gather exact statistics for the possible deployment of a self-propelled gun battalion in combat. Principally, the missions presented to motorized artillery are comparable to those for towed artillery units in an infantry division. However, it must be demanded that ready-to-fire preparations must be made quicker and a change of position to be achieved more rapidly.
Any mission directed by the Panzer brigade to the supporting artillery cannot be fulfilled by horse-drawn units. After a successful breakthrough, the horse-drawn artillery is too slow in getting into position, which significantly reduces their ability to open supporting fire. Any artillery support for the Panzer brigade requires it to have the ability to immediately follow the tank advance, also the type must have high mobility over all terrain and protection against enemy fire: an armored fully tracked vehicle mounting an artillery piece…”

In addition, this report highlighted the importance of deciding which caliber should have been used for this role.

“…Furthermore, it must be decided as to whether this vehicle will be armed with a 7.5cm or 10.5cm gun. Trials using both weapons will have to be conducted in the near future. A 10.5cm gun will have a greater impact in the target, but inevitably will make the vehicle heavier and give it a conspicuous superstructure. Due to the size of the gun, ammunition storage will be considerably limited. Until trials with 10.5cm self-propelled guns have been completed, the tank brigade will have to continue to use the 7.5cm-armed tanks of the heavy companies. The crews will have to be trained on how to use this weapon as artillery…”

In 1936, several steps were taken to develop more suitable self-propelled artillery vehicles. However, the development of these vehicles faced consistent delays. One primary factor was the limited production capacity of the German industry, which was struggling to produce an adequate number of tanks and had little spare capacity for other projects. As a result, the development of self-propelled artillery vehicles languished.

Furthermore, there was a belief that the Luftwaffe, the German air force, would provide sufficient close operational fire support to the Panzer divisions. In the early years of the war, the Luftwaffe effectively fulfilled this role, which further diminished the immediate need for mobile artillery vehicles and alleviated some of the pressure for development.

Additionally, it should be noted that some officials within the German Army were against the concept of self-propelled artillery vehicles. They might have held the belief that traditional towed artillery and close air support were sufficient, or they had concerns about the feasibility or effectiveness of such vehicles. These differing opinions among army officials also contributed to the delays in developing self-propelled artillery vehicles.

It was not until 1939 that work on such a vehicle finally began to gain traction. That year, Krupp presented a drawing (designated W 1324) of such a vehicle to the Army. In contrast to the later designs built during the war, this vehicle was dedicated for this sole purpose. The engine was mounted to the rear, while the turret with the gun was placed in the central section of the hull. The Krupp engineers did not want to place the engine in the middle of the hull, as this would increase the overall vehicle height. Wa Prüf 6 was interested in this project but requested some structural changes. They agreed that the engine should be positioned to the rear. Other suggestions included that the traversing arc had to be increased without changing the traverse mechanism, the ammunition load was to consist of at least 40 rounds, the elevation of -10° to +15°, frontal armor protection had to be at least 20 mm, etc.

During a new meeting held in October 1939, further changes were requested. For example, it was ordered that the SSG 46 transmission had to be used. The pivoting point of the main weapon was proposed to be moved slightly to the rear and raised up. It was hoped that, by doing this, the elevation and traverse of the main gun would be improved. With these suggestions, the production of the first prototype known as Sfl.IVb was scheduled to be completed at the start of 1941.

In the meantime, another meeting was held in late January 1940 to discuss further details. During this meeting, great attention was focused on how to best use the limited turret interior space. Especially of great interest was if the elevation and traverse controls could be positioned on the left side of the main armament, as it would be the most effective in this arrangement. The possible use of a diesel engine was discussed.

A month later, Krupp informed Wa Prüf 6 that the wooden mock-up was ready for inspection. Obersltl. Olbrich was part of the first group that inspected the mock-up. He was one of the major opponents of mounting a 10.5 cm howitzer in a tank turret. While the overall design was deemed sufficient for the job, Olbrich requested some changes. First, he demanded that this vehicle should not have a fully rotating turret, as it would resemble a tank. This decision may seem absurd due to the benefits of having a fully rotating turret, however, during the early development of tanks, there were individuals in various countries, including Germany, who held obsolete or unrealistic notions about how tanks should function and their specific design. This backward and conflicting thinking was not unique to the German army but was present in other nations as well.

Obersltl. Olbrich’s opposition to a fully rotating turret might have stemmed from such notions or his personal beliefs. It is possible that he had concerns about the vulnerability of a fully rotating turret or the complexity it would add to the vehicle’s design. Without further information, it is difficult to ascertain his exact reasoning.

In any case, additional changes, including redesigning the turret were requested. The side armor would slope down toward the rear. The turret walls would be placed at an angle to provide additional protection. The Germans were quite aware of the benefits of using angled armor. Storage area and the radio would be placed in the turret rear to act as a counterweight to the main armament. Despite Olbrich’s reservations, the project was gaining enough interest within the German Army, and production orders for the first vehicles followed soon after the inspection of the wooden mock-up.

Name

The vehicle was initially designated as Sfl.IVb. Sfl was short for Selbstfahrlafetten (Enbg. Self-propelled). The Roman numeral IV was related to the Panzer IV chassis and the latter ’b’ served to distinguish it from other self-propelled projects, such as the Sfl. IVa, ahistorically better known as the Dicker Max. Sometimes in sources, it is also referred to as Selbstfahrlafetten mit Fahrgestell des Panzerkampfwagen IVb.

In August 1941, Krupp was informed that the designation was to be changed to le.F.H.18 (Sfl). In 1942, it was once again changed to Pz.Sfl.F.le.F.H.18 Ausf.A. This article will continue using the short Sfl.IVb designation for the sake of simplicity.

First Production Orders

Following the inspection of the wooden mock-up, Krupp received a production order for two prototype vehicles designated V1 and V2 in November 1940. Rheinmetall was awarded a contract for the delivery of four guns. Krupp then received another production order for 10 pre-production vehicles. The production schedule for these 10 vehicles was:

Date Number
1941
December 1
1942
January 2
February 3
March 4

If these vehicles proved to be successful, a production order of 200 vehicles was to be awarded to Krupp. The estimated mass production was to commence in October 1941. Of course, as with many other projects, there were delays in the production of these vehicles. Krupp was reported to have finished the two prototypes at the start of 1942. These were then transported to the secret test center at Kummersdorf. One of the two prototypes received some damage, probably during firing trials, and was sent back to Krupp to be repaired. It was reported to be fully repaired by 4th February 1942.

As these two were being tested, the necessary components for the assembly of the 10 pre-production vehicles slowly arrived at Krupp. It was estimated that these would be completed by April 1942 and that serial production would start at the end of the year. These were once again delayed and Krupp finally completed them during the period of August to December 1942.

Krupp obviously lacked the proper production facilities to deliver all promised vehicles. It was instead decided to award the production order to Stahlindustrie GmbH from Mulheim-Ruhr.

A newly produced Sfl.IVb. Source: https://www.tankarchives.ca/2017/03/pzsflivb-halfway-to-hummel.html

Specifications

This vehicle shared a number of visual resemblances with the Panzer IV. In truth, many components were not interchangeable, for example, the suspension. It is not clear why these components were not taken directly from the Panzer IV production lines, as it would have made the construction of the whole vehicle much simpler and cheaper.

Chassis

The Sfl.IVb chassis shared its overall layout with other German tank designs. The front part of the hull served as a housing point for the transmission, followed by the crew compartment and the engine. The front hull, where the transmission and steering systems were located, was fully enclosed, providing protection to the vital components housed within. To allow access for repairs and maintenance, a square-shaped transmission hatch was positioned in the middle of the angled plate. This hatch would allow the crew to reach the transmission without having to dismantle the entire hull. Additionally, two rectangular steering brake inspection hatches were included in the design. The presence of these inspection hatches made it easier for the crew to check and service the steering system when needed.

The overall configuration of the Sfl.IVb‘s front hull was similar to that of the Panzer IV’s design. However, there was a difference in the size of the transmission hatch. The Panzer IV utilized a larger transmission hatch compared to the Sfl.IVb. This discrepancy in size could be attributed to the specific requirements and design choices made for each vehicle.

Suspension and Running Gear

The suspension was another element that was similar to that of the Panzer IV. Pairs of road wheels were placed on bogies. Only the last assembly was provided with a bump stop. These, in turn, were suspended using self-dampening leaf spring suspension. In contrast to the Panzer IV’s suspension, this vehicle had only six road wheels. In addition, these were somewhat larger, having a diameter of 520 mm in contrast to the Panzer IV’s 470 mm road wheels. The Sfl.IVb used three return rollers, a rear idler, and a front-mounted drive sprocket. The tracks were 40 cm wide. This suspension, while not perfect, had a simple design and was easy to build and maintain.

The suspension consisted of six road wheels suspended on three bogie assemblies. It was more or less taken directly from the Panzer IV. Source: Digital Collection of Armin Freitag

Engine and Transmission

For the engine, Krupp’s engineers decided to use the Maybach 6-cylinder HL 66P which produced 188 hp@3200 rpm. Why they used this weaker engine instead of an original Panzer IV engine is unclear. It is possible that this was done in order to reduce the height of the hull and, thus, the whole vehicle as much as possible. It is somewhat ironic that, for the anticipated mass production, this engine was to be replaced with the much stronger 320 Maybach HL 90 P20K engine, which actually never occurred.

With the HL 66P engine and a weight of 18 tonnes, this vehicle had a maximum speed of 35 km/h. The fuel load of 470 l provided an operational range of 210 km and 130 km cross-country. The engine was coupled to the front-mounted SSG 46 six-speed (and one reverse) transmission.

The engine itself was fully protected by armor. The rear part of the engine compartment curved down slightly. On top of it, there were two ventilation ports. Two more were positioned to the rear, with a large exhaust being placed in the middle. The engine was separated from the crew compartment by a fire-resistant wall. Spare equipment, such as road wheels, were stored on top of the engine compartment.

Rear view of the engine compartment. Note the two protected ventilation ports and the large exhaust placed between them. The armored box on the right side is the Nebelkerzenabwurfvorrichtung, a smoke grenade rack system. Source: https://www.tankarchives.ca/2017/03/pzsflivb-halfway-to-hummel.html

Superstructure

The vehicle superstructure was box-shaped and had a quite simple overall design. The front armor plate had two vision ports. The left one was used by the driver, while the right one was a fake port meant to confuse enemy gunners about the driver’s position. This tactic was also employed on other German vehicles, such as the Panzer II Ausf.F. On both sides of the superstructure armor, there were two smaller vision ports.

The driver accessed his position through a hatch located on top of the superstructure. The last noticeable features on the superstructure were the two turret rail extensions, with one on each side. These rails were used to mount and stabilize the turret.

While the turret did not have any observation ports, four were placed in the superstructure. The one on the right-front side of the superstructure is fake and was intentionally added to confuse enemy gunners. Source: Digital Collection of Armin Freitag
The extension added to the left and rear side of the superstructure for the turret can be seen in this picture. Source: Digital Collection of Armin Freitag

Turret

The turret was open-topped. This had several advantages.

Firstly, it provided the crew with a good view of their surroundings, which was important for an artillery vehicle that needed to identify targets and adjust fire accurately. This increased situational awareness could enhance the effectiveness of the crew in engaging enemy targets within sight.

Secondly, the open-topped turret made ammunition resupply easier. Since the crew could access the ammunition storage directly from the top of the turret, reloading the artillery gun with additional rounds was simpler and more efficient. This could contribute to faster firing rates and sustained operations on the battlefield.

Lastly, removing the roof of the turret helped in reducing the overall weight of the vehicle. By eliminating the need for heavy armored roofing, the vehicle’s weight was reduced, which could have positive effects on its mobility and maneuverability.

The turret was constructed using eight angled armored plates that were welded together. The front plate featured a large opening where the gun assembly was bolted. The height of the side plates tapered downward towards the back. This design choice was not uncommon in German self-propelled vehicle designs of the time. By tapering the side armor, the weight of the turret was further reduced while still maintaining sufficient protection for the crew.

Inside the turret, the working space was rather cramped. To address this issue and provide more room, both the commander and gunner seats could be folded when not in use. This folding feature likely allowed the crew members to move around more comfortably and perform their duties effectively.

By tapering the side armor, the weight of the turret was further reduced while still maintaining sufficient protection for the crew. Spare track links and other equipment were stored to the rear of the turret, in order to act as a counterbalance to the main armament. Source: https://live.warthunder.com/feed/images/

Observation ports were not placed on the turret since they were deemed unnecessary. Presumably, the open-topped design already provided the crew with sufficient visibility, eliminating the need for additional observation ports. This could have contributed to a simpler and more streamlined turret construction.

To serve as a counterbalance to the main armament, additional spare track links and other equipment were stored to the rear of the turret. This placement of equipment helped balance the weight distribution of the turret and the overall vehicle, maintaining stability during firing and movement.

A good view of the turret interior. The wall of the turret was used to store various equipment, ranging from the crew’s personal belongings, defense weapons, and ammunition for them. Also, note the radio position (the actual radio is missing in this photograph) and the loudspeaker next to it. Source: https://www.armedconflicts.com/10-5-cm-leFH-18-1-Sf-auf-Geschuetzwagen-IVb-t31692

Armament

The main armament for this vehicle was the 10.5 cm le.F.H. 18 light howitzer. This was the most common field artillery piece that the Germans employed during the war. It was designed by Rheinmetall and put into service in 1930. The designation “18” was intentionally misleading, as the Germans were prohibited from developing new artillery after World War I. By using designations that falsely implied it was a World War I design, they were able to bypass these restrictions. While a good overall design, it would be improved a few times during the war, mainly in order to increase its range and reduce the construction costs.

The 10.5 cm le.F.H. 18 in its original configuration. Source: https://www.armedconflicts.com/10-5-cm-leFH-18-10-5-cm-light-field-howitzer-t678

In order to fit inside this particular vehicle, the 10.5 cm howitzer had to undergo a redesign. The howitzer was removed from its carriage and placed on specially designed mounting points located on the front part of the turret. To accommodate the limited space, the original recoil cylinders and recuperators were replaced with smaller ones. These modified components were positioned farther back, located just above the breach block. To further reduce the recoil force during firing, a large muzzle brake was added. Thanks to these modifications, it was possible to use a much smaller armored gun mantlet. In order to avoid accidentally injuring the gunner on the left side of the breach block, a large protective gun shield was added. With these changes, the modified howitzer was designated as 10.5 cm le.F.H. 18/1.

In the turret, it had an elevation of -10° to +40°. The traverse of the whole turret was limited to 35° in both directions. The gunner operated the elevation of the main armament by hand. The manual traverse handwheel was located on the right side of the turret and operated by the loader. It was hoped that, on the production vehicles, a fully traversable turret would be used. The maximum firing range of 10,650 m could be achieved by using the 14.8 kg heavy high-explosive round. For aiming the 10.5 cm le.F.H. 18/1, the gunner would use the Z.E.34 and Rfl.F.36 gun sights. This vehicle did not use travel locks.

The two-part (round and propellant charge) ammunition was stored inside the hull. In total, the ammunition load capacity was 60 rounds and propellant charges.

While no secondary machine gun was incorporated, the crew members were equipped with 3 MP 40 submachine guns for close self-defense purposes. These submachine guns were s, accompanied by 18 32-round capacity magazines.

The Sfl.IVb did not have a fully rotating turret. Instead, it was limited to 35° traverse in both directions. Source: https://www.tankarchives.ca/2017/03/pzsflivb-halfway-to-hummel.html
The 10.5 cm howitzer on this vehicle had an elevation of -10° to +40°. Source: Digital Collection of Armin Freitag
A close-up view of the 10.5 cm breach block. In order to fit this weapon inside the turret, the original recoil cylinders and recuperators of the 10.5 cm howitzer were replaced with smaller ones, located just above the breach block. Also, notice the gunner and the commander’s sights. At the bottom of the photograph, spare rounds and propellant charges can be seen too. Source: https://live.warthunder.com/feed/images/
To protect the gunner, a large gun shield was placed to the left of it. The loader was responsible for traversing the turret. The traverse handwheel mechanism can be seen here. Source: Digital Collection of Armin Freitag

Armor

Given its specific role, this vehicle was only lightly protected. The front hull and superstructure armor was 20 mm thick. The sides were even less protected, being only 14.5 mm thick. The turret armor was mirrored, being the same armor thickness. The top armor was 8 mm thick, the same as the hull’s bottom. The driver’s protective vision port was 30 mm thick and, in addition, he was extra protected with a 90 mm thick armored glass.

Such self-propelled artillery vehicles were meant to provide long-range fire support. Thus, they would be, ideally, but combat conditions are not always predictable, firing from afar, without fear of enemy retaliation. For this reason, mobility had greater importance than armor thickness.

Crew

Given its relatively small size and cramped interior, the crew of the vehicle consisted of four members, namely the commander, driver, gunner, and loader. The driver enjoyed full protection, as he was situated in the front hull compartment. The commander occupied the position on the left side of the gun and was equipped with a doppelscheren Turmspaehfernrohr scissor periscope for observing the surroundings. The periscope offered a 3x magnification and a 20° field of view. As on all German armored combat vehicles, the gunner was seated to left of the gun. On the right of the gun sat the loader.

The Sfl.IVb had a crew of four, with only the driver being fully protected, Source: Digital Collection of Armin Freitag

In Service

Once the 10 pre-production vehicles were fully completed, some of these were allocated to the Feldversuchs Batterie (Eng. Field trial battery) of the Artillerie Regiment 16 (Eng. Artillery regiment) in late 1942. The battery was part of the 16th Panzer Division. Six vehicles were used to form a single battery. The remaining four vehicles and the prototypes stayed behind to serve as training and replacement vehicles.

While these saw service on the Eastern Front, no record of their performance survived to this day. The 16th Panzer Division was almost completely destroyed at Stalingrad, so it is likely that the six vehicles were lost there too.

One Sfl.IVb with Balkenkreuz painted on its turret side being transported by rail, possibly to the frontlines. Source: Digital Collection of Armin Freitag
Another photograph of one Sfl.IVb, possibly somewhere on the Eastern Front during 1942. Source: Digital Collection of Armin Freitag
Six vehicles were used for troop trials as part of the 16th Panzer Division, which saw service during the German advance toward Stalingrad. Source: Digital Collection of Armin Freitag
The remaining vehicles, including the prototypes, stayed behind to be used as training vehicles. This vehicle appears to be located at some unidentified training center, next to a few captured French tanks. Source: Digital Collection of Armin Freitag
A Sfl.IVb located at the Jüterbog artillery training center in 1943. Source: Panssarikilta Facebook group

Further Plans and the End of the Project

The discovery that a modified Panzer II chassis could be reused for a similar purpose led to the decision to prioritize that option instead. By late 1942, due to the challenges faced by the German industry in producing enough tank chassis, introducing yet another completely new chassis would only cause additional delay and confusion. The Panzer II components were already available and were much easier to be reused. While the self-propelled vehicle based on the Panzer II chassis lacked a rotating turret, the urgency of the situation necessitated the use of available components.

The introduction of the self-propelled vehicle based on the Panzer II best known by its nickname Wespe was one of the reasons why the Sfl.IVb project was canceled. The Wespe did the same job but used parts and chassis that were already available. Source: panzerserra

However, the Sfl.IVb project was briefly revived when Krupp was instructed to test if a 15 cm s.F.H.18 could be used on the chassis. Despite the efforts of Krupp engineers, it was determined that the chassis was not suitable for the installation of such a large weapon. Consequently, the project was shut down in November 1942. Krupp then attempted to repurpose the Sfl.IVb chassis as an anti-tank vehicle similar to the Jagdpanzer IV project, known as Panzerjager IVb E39. However, it appears that these proposals also did not progress further.

The ultimate fate of the 12 vehicles remains unknown. At the end of the war, one of the vehicles (possibly one of the two prototypes) without a gun was discovered by the Allies at the Rheinmetall facility in Hillersleben.

The remains of one Sfl.IVb was found by the Allies at the end of the war at the Rheinmetall facility in Hillersleben. Source: S.J. Zaloga Panzers In The Gunsights
Alleged schematic of the Krupp proposed anti-tank version. Source: https://panzerpedia.fandom.com/wiki/Jagdpanzer_E_39

Conclusion

The Sfl.IVb was part of Germany’s efforts to design a dedicated self-propelled artillery vehicle for their tank formations. The Sfl.IVb featured a partially rotating turret, which was considered a novel feature compared to later designs introduced by the Germans. The vehicle had a well-designed overall structure, and its ammunition storage was relatively large and somewhat protected. These features made it a potentially suitable option for meeting the artillery needs of the German Panzer divisions.

However, the Sfl.IVb faced significant drawbacks that led to the termination of the project. One major issue was the extended development and production time, which resulted in delays. Additionally, the design did not make effective use of components that were already in production. As a result, by the time it was planned to enter production, the Germans opted for a simpler but less sophisticated design: the Wespe self-propelled artillery gun, based on the Panzer II chassis.

The decision to switch to the Wespe was driven by the Germans’ lack of capacity for the introduction into production of yet another chassis, considering the demands of the war by 1942. Consequently, the Sfl.IVb project was effectively abandoned, and no combat reports or real-world performance data exist to evaluate how the vehicle performed on the battlefield.

Geschützwagen IVb für 10.5 cm le.F.H.18/1. Illustrations by Godzilla

Geschützwagen IVb für 10.5 cm le.F.H.18/1 Technical specifications

Crew Commander, gunner, loader, and driver
Weight 18 tonnes
Dimensions Length 5.9 m, Width 2.87 m, Height 2.25 m
Engine Maybach HL 66P six-cylinder liquid-cooled 188 hp@ 3,200 rpm
Speed 35 km/h
Range 240 km
Primary Armament 10.5 cm l.F.H. 18
Secondary Armament Three 9 mm MP 40 submachine guns
Elevation -10° to +40°
Armor 8-20 mm

Sources

D. Doyle (2019) The Complete Guide To German Armored Vehicles, Skyhorse Publishing books
T. Anderson (2019), Panzerartillerie, Osprey Publishing
D. Doyle (2005). German military Vehicles, Krause Publications.
T.L. Jentz and H.L. Doyle (2001) Panzer Tracts No. 10-1 Artillerie Selbstfahrlafetten
P. Chamberlain and H. Doyle (1978) Encyclopedia of German Tanks of World War Two – Revised Edition, Arms and Armor press.
D. Nešić, (2008), Naoružanje Drugog Svetsko Rata-Nemačka, Beograd
S.J. Zaloga Panzers In The Gunsights

Categories
WW2 German SPGs

10.5 cm K gepanzerte Selbstfahrlafette “Dicker Max”

German Reich (1941-1942)
Heavy Tank Destroyer/Bunker Buster – 2 Built

The “10.5 cm K (gp.Sfl.)” (Eng. 10.5 cm cannon (armored self-propelled gun)) or “10 cm K. Pz.Sfl.IVa” (Eng. 10 cm cannon self-propelled gun IVa), more commonly known as the “Dicker Max” (Eng. Fat Max), was a German self-propelled artillery gun. Development started in 1939, with the Army requesting a mobile “bunker buster” to destroy the fortifications on the French border. However, it would never fulfill that role, since the only two vehicles ever built were completed in early 1941, well after the end of the Battle of France.

The tank was based on the reliable Panzer IV chassis and used the standard K.18 German heavy artillery gun. The ammunition used consisted of Tungsten core rounds, which, in combination with the high velocity of the gun, had great penetration capabilities. Both vehicles were sent to the Eastern Front as tank destroyers, where one of the two would prove itself very successful, destroying a large number of Soviet tanks.

Colorization of the second “10.5 cm K (gp.Sfl.)”, part of “Panzerjäger Abteilung 521” (Eng. Anti-Tank Battalion 521). Photograph taken in the Summer of 1942 in the Soviet Union. Colorized by Johannes Dorn. Source: Digital Collection of Armin Freitag

Context: The Need for a “Bunker Buster”

One of the main problems that the German High Command faced during preparation and planning for what would become the Second World War was how to defeat France. The German-French border was heavily fortified on both sides, with the French Maginot Line in the Alsace-Lorraine province and the German Siegfried Line mirroring it. In the end, two plans were prepared. The first plan was to revisit the Schlieffenplan that was already used during WW1. The idea was to invade the neutral Benelux states and invade France through the Belgian border.

British Soldiers of the British Expeditionary Force (BEF) enter a bunker complex of the Maginot Line in 1939. Source:
https://de.m.wikipedia.org/wiki/Datei:Troops_of_51st_Highland_Division_march_over_a_drawbridge_into_Fort_de_Sainghain_on_the_Maginot_Line,_3_November_1939._O227.jpg

The second plan was to power through the heavily fortified Maginot Line on the French-German border. However, this plan was only to be executed if the first plan failed. For this purpose alone, Germany started development of multiple heavy mortars, such as the 60 cm heavy mortar Gerät 40/41.

A map showing the strong and weak fortifications on the French border around 1940. Source: https://www.landofmemory.eu/de/sujets-thematiques/die-maginot-linie-und-die-deveze-bunker/

Beside this immense self propelled mortar, the Germans also intended to reuse the 8.8 cm Flak gun in this role. This gun was quite cumbersome to move, and in order to increase its mobility, two different proposals would be adopted.

The first would be created by placing the gun on a half-track chassis, creating the 8.8 cm Flak 18 Sfl. auf schwere Zugkraftwagen 12 t (Sd.Kfz.8) als Fahrgestell. The second variant was more orthodox in design, consisting of an armored half-track prime mover and a slightly modified 8.8 cm Flak 18 gun.

Both of these were built in limited numbers and saw use in their designated roles. Alongside the previously mentioned projects, the need arose for a much more compact self-propelled tracked chassis mounting a powerful gun that could deal with enemy concrete bunkers.

Some 10 8.8 cm Flak 18 Sfl. auf schwere Zugkraftwagen 12 t (Sd.Kfz.8) als Fahrgestell would be built. While having a number of issues with their overall design, these vehicles would prove to have excellent firepower against tanks and bunkers. Source: https://en.wheelsage.org/daimler-benz/db_s8/daimler-benz_db_s8/pictures/jy7d0g
Another proposal that was adopted in limited numbers was the Gepanzerter 8t Zugkraftwagen and Sfl.Flak. It was a more orthodox design, consisting of an armored half-track prime mover and a slightly modified 8.8 cm Flak 18 gun They would see action in France during 1940, after which they would be removed from service. Source: T.L. Jentz and H.L. Doyle Panzer Tracts No. 22-5 Gepanzerter 8t Zugkraftwagen and Sfl.Flak

Development of the ‘Panzerselbstfahrlafette IVa

Because Krupp had previously developed most German tanks, the Wa Prüf 6 (Eng. Army Design Office 6) once again contacted the firm in 1938. However, because Krupp had never designed a large caliber self-propelled gun, there were many different concepts and ideas on how this SPG would look. After having agreed on some specifications, Krupp started the development in 1939.

One of the first problems that occurred was where to place the engine. Krupp submitted two drawings in April 1939. In the first drawing, the engine was placed under the gun, in the front, which resulted in a shorter overhang, reduced by 800 mm compared to the second drawing, in which the engine was placed in the center. However, putting the engine below the gun resulted in numerous disadvantages that Krupp listed:

  • poor access to the engine
  • unfavorable installation of the radiator and cooling air fans
  • crew encumbered by heat and fumes
  • noise from the engine
  • complicated operation of the transmission
  • firing height increased to at least 2 m
  • nose-heavy vehicle

On the other hand, placing the engine in the center of the hull would result in a lower firing height of 1.7 m and easier access to the engine. Additionally, the center of gravity would be better placed. In the end, the Wa Prüf 6 went with the first plan, because they thought that 800 mm of additional overhang with the second engine location was too much to handle for such an SPG.

Next, it was settled that a 180 hp V-6 engine would be installed instead of a 320 hp V-12 engine. However, the drawbacks were an increased height of 100 mm. By May 1939, Krupp had to design a new variant of the SPG with the engine below the gun, a torsion bar suspension, and a 6-cylinder engine. On May 2nd, 1939, Krupp presented their new design. This design included the V-12 Maybach HL 120 engine instead of the agreed V-6, because they thought the V-6 would not be powerful enough.

Additionally, it offered easier access to the cylinders. The problem was that the V-12 was heavier and was planned to go out of production. In addition, Krupp proposed that they would use the steering unit and transmission of the VK9.01, but with dry-pin tracks and not lubricated ones. Lastly, a muzzle brake was installed. This reduced the recoil from 1,000 mm to 800 mm, which meant the gun could be moved 200 mm more to the rear. It was also specified at this point that the 10.5 cm K 18 gun was to be installed in the new SPG.

On May 15th, 1939, Krupp again met up with the representatives of the Wa Prüf 6, who decided in favor of a new design with a 200 hp Maybach HL 66 placed in the middle of the hull, with an estimated total weight of 22 tonnes. Krupp added a radiator behind the engine for better cooling. Additionally, the Wa Prüf 6 requested the recoil cylinder and recuperator be moved back to save space in the armored housing. It was also at this point that it was settled that a regular panoramic gunsight was to be used for indirect firing and a new periscope gunsight would be added for direct firing. After this, approval for constructing a full-scale wooden mock-up model was given to Krupp.

Later, Krupp would inform the Wa Prüf 6 that a weight increase could not be avoided if they intended to use a torsion bar suspension. Because of this, Krupp suggested using the Panzer IV’s leaf spring suspension to save weight. This caused a problem, as the Wa Prüf 6 had originally planned to use the torsion bar interleaved suspension with lubricated tracks with rubber pads to achieve the maximum possible speed. However, the Design Office knew that the excess weight that came with the torsion bar suspension could not be reduced from anywhere else and that, due to this excess weight, lubricated tracks without rubber pads would not work due to ground pressure limitations. The Wa Prüf 6 then thought about simply using a regular torsion bar suspension with dry pin tracks, like on the Panzer II Ausf.D1/2.

On August 10th, 1939, when the wooden mock-up model was completed, Wa Prüf 6 suggested reducing the hull width to match the one of the Panzer IV. Later, the final decision was made to limit the weight to 20 tonnes by using the 8-wheel leaf suspension and chassis of the Panzer IV. The Panzer IV was chosen over the Panzer III because, at that time, it was more readily available and lighter.

On August 21st, 1939, the decision was made to use the Maybach HL 66 P engine together with the transmission and steering unit of the VK9.02, after previously being proven to be compatible. This was very important, because higher turning power was needed, as the Panzer IV normally had a width to length ratio of 1:1.46 compared to 1:1 for the VK9.02. A maximum speed of 35 km/h was requested.

Krupp was then awarded a contract to produce two trial vehicles, with all necessary equipment and real armor. The gun was to be provided by the Wa Prüf 4 (Department for Artillery). On September 4th, 1939, Krupp presented the construction drawings. The SPG did not have a turret and the hull and superstructure were constructed as one unit. The two trial vehicles were to be completed by May and June 1940, with the armor hulls completed eight weeks prior so the gun could be mounted in time.

On the same day, the final changes before production were made. These included minor changes to the gun sights, mounts for the periscopes, changes to the gun shield, and the gunner’s hatch being made to be rectangular and counter sunk. Additionally, the range finder was omitted.

The second SPG in front of the barracks in 1942, after undergoing repairs. Source: Ebay, unknown seller
A “10.5 cm K (gp.Sfl.)” stuck in the mud of the Soviet Union in autumn 1941. Source: Digital Collection of Armin Freitag

Name

The designation for the “10.5 cm K (gp.Sfl.)” is quite complicated. First off, this article is referring to the vehicle as an SPG, because that was its original intended role, even though it was eventually used and classified as a tank destroyer.

During the entirety of the development and production, it was referred to as “10 cm K. Pz.Sfl.IVa”, which stands for “10 cm Kanone Panzer Selbstfahrlafette IVa” (Eng. 10 cm canon self-propelled gun IVa). On August 13th, 1941, the name was changed to “10.5 cm K (gp.Sfl.)” which stands for 10.5 cm Kanone (gepanzerte Selbstfahrlafette) (Eng. 10.5 cm canon (armored self-propelled gun)). After the war, the name “Dicker Max” appeared, which is nowadays the most popular name for the vehicle, presumably due to its simplicity and funny connotations.

Interestingly, in a diary entry of the commander of the second SPG, Kurt Hildebrandt, he gives the vehicle’s nickname as “Brummbär”.

The article iwill use the original designation when referring to the development/production/design sections and the second description when referring to everything after August 1941.

One of the two SPGs in the Soviet Union in August 1941. Source: Digital Collection of Armin Freitag

Production

During production, on October 11th, 1939, Wa Prüf 6 again met up with Krupp. They informed Krupp that the transmission of the VK9.02 would not be installed and the regular SSG 46 transmission should be used instead. However, this significantly reduced the speed to 25 km/h, as the gear ratio was only 1:8 at 188 hp.

During a production report in April 1940, Krupp stated that they were working on the next generation of AFVs, which included the “10 cm K. Pz.Sfl.IVa”. The completion date was extended to August 1940, since the need for such an SPG was reduced after the invasion of France, as the Germans attacked around the heavy fortifications of the Maginot Line. However, Krupp would only complete the two SPGs in January 1941. During a demonstration for Hitler on March 31st, 1941, it was decided that serial production could begin in spring 1942. However, this was never implemented and only the two AFVs were ever produced.

Presumably the second “10.5 cm K (gp.Sfl.)” after it returned to the frontlines in summer 1942. Source: Ebay, unknown seller

Design

Hull

The 10.5 cm K (gp.Sfl.)’s hull was slightly redesigned in comparison to a standard Panzer IV hull. The forward-mounted transmission was unchanged. The difference was that it received a new angled top armor plate cover that completely enclosed it. The two hull frontal brake access hatches, including the large square-shaped bolted hatch, were retained. The engine and driver’s positions were moved to the center of the hull. The gun and its mount were placed directly above the enclosed engine. Lastly, to the rear, was the crew fighting compartment.

Presumably the first SPG in the Soviet Union in mid 1941. Source: Kurmark – Antik via Ebay

Suspension

Given that this vehicle was based on a Panzer IV chassis (unspecified version, but likely the Ausf.D or E), it used the same suspension. This consisted of eight small double wheels placed on each side, suspended in pairs, and placed on four bogie assemblies. The small road wheels were suspended by leaf-spring units. There were also four return rollers on each side. Finally, the drive sprocket was at the front and the idler at the rear.

The suspension was to be taken from the Panzer IV Ausf.E, while the drive sprocket appear to be taken from Ausf.D. The difference was in the covering caps. This basically changed nothing, as these were only minor mostly changes and performed the same. It also does not help that the Germans often mixed older and newer components on their vehicles.

The 10.5 cm K (gp.Sfl.) used a standard Panzer IV suspension. While not perfect, it was simple and easy to maintain. Source: https://www.tankarchives.ca/2016/12/dicker-max.html
Comparison between early type and Ausf.E type covering caps. Source: K. Hjermstad Panzer IV

In its early development phase, Wa Prüf. 6 and Krupp engineers often discussed what type of suspension to use. Several different proposals were made. This included the use of a torsion bar suspension and lubricated tracks without rubber pads. Ultimately, at the insistence of Krupp engineers and with the aim of saving weight and easing production, the use of the Panzer IV’s suspension was chosen. It weighed 430 kg less than a Panzer III’s torsion bar suspension. In addition, it provided more internal room and was generally easier to maintain. It was already in production, so there would be enough spare parts and it would also help save development time. Krupp still proposed that the Army should test a prototype that used a six-wheel bogie suspension. While Wa Prüf 6 considered and even issued a production order for a prototype equipped with this suspension for testing, it was eventually canceled, and no such vehicle was built.

The second SPG after arriving back at the front in 1942, giving a great view of the suspension. Source: Koelsch333 via Ebay

Engine

For the construction of this vehicle, the Panzer IV’s original Maybach HL 120 TRM engine, giving out 265 hp@2,600 rpm, was replaced with a much weaker Maybach HL 66 P, providing 180 hp@3,200 rpm. The engine was then connected to a forward mounted SSG 46-type transmission. Initially, a MAN Cletrac-type steering unit was to be used. However, this was replaced with a standard Panzer IV steering unit to simplify production.
With these changes, the maximum speed dropped considerably to 27 km/h. Krupp engineers were alarmed by the reduction of speed and requested that the transmission be changed. A possible replacement was the A.K.6 S 55, but this was not yet properly tested. To avoid delaying the project, it was decided to keep the SSG 46 transmission despite the reduction in speed. The change of engine also reduced the overall operational range, which was 170 km on road and 120 km cross-country. The fuel tanks were located in the front part of the hull, but their capacity is not specified in the sources.

The engine itself was moved to the center of the hull in order to allow for the necessary room for the crew. The engine was placed in a fully enclosed casing. Two ventilation ports were placed above the engine compartment. This arrangement would later be used on many German vehicles adapted for various roles, including the 15 cm armed Hummel self-propelled artillery, which was also based on the Panzer IV.

The decision to replace the engine with a weaker one was mainly motivated by the need to keep the vehicle’s overall height as low as possible. This decision would greatly and negatively affect the overall drive performance of the 10.5 cm K (gp.Sfl.). Given the reduction of speed, the whole point of providing a mobile support vehicle was lost. In order to engage a target, the whole vehicle had to change positions often, and, together with a weaker engine, often led to overheating problems.

Superstructure

For the construction of the superstructure of this vehicle, the Germans especially wanted to avoid using complex-shaped armor plates. Instead, they went for the simplest design possible. Starting from the front, the Germans added an enclosed housing to the left of the gun, where the driver was positioned. It was a simple box-shaped compartment with a front mounted pivoting driver vision port, vision slit to the left, and a hatch on top. The driver’s protective visor, the Fahrersehklappe 50, was 50 mm thick. When the visor was closed, the driver would use a binocular periscope to see through two small round ports located just above the visor. Opposite this compartment, the Germans placed another fake one. It was meant to confuse enemy gunners, so that they had a harder time hitting the driver.

The front superstructure plate armor was made of one large piece with a hole in the center for the gun itself. The side armor consisted of four welded armor plates. The lower two were placed straight up, while the upper two were slightly angled toward the center of the vehicle. The upper part of the side armor was cut down as it went toward the rear part of the vehicle. This was done intentionally to reduce the weight of the vehicle and would appear commonly on many later German vehicles of similar design. The rear part of the vehicle was protected by one larger armor plate. Two escape hatches were placed there.

The top part of the vehicle was mostly open. The exception was the front part of the vehicle, where the gunner’s periscope was positioned. In front of it was a small bullet splash protector. The rear part of the vehicle was also lightly protected in order to provide the loaders with some level of protection against aerial attacks. The crew fighting compartment was left open to facilitate ventilation of the smoke created during gun firing. It also provided a good view of the surroundings, reduced production cost, and overall weight. The downside though is obvious, as the crew was exposed to enemy fire and the elements.

In order to confuse the enemy, the Germans added a fake driver compartment on the right side. Opposite it is the real driver position, which was enclosed in a small box-shaped superstructure. While the driver would normally use the front pivoting vision port, if it had to be closed down, he would then use a binocular periscope to see through two small round ports located just above the visor. Source: https://www.tankarchives.ca/2016/12/dicker-max.html
The rear view of the vehicle. Notice the two hatches (the right one is open) which provide the crew with an entry point to their positions and to restock ammunition. Given that the vehicle was open-topped, the crew could easily just jump out of the fighting compartment. Source: https://www.tankarchives.ca/2016/12/dicker-max.html
A view of the fighting compartment. The internal space was rather cramped and only a limited amount of ammunition, important equipment, and the crew’s personal belongings could be carried inside. Source: https://www.tankarchives.ca/2016/12/dicker-max.html

Armor Protection

The thickness of the armor, like many other components, was determined by the weight limitations of the vehicle. To prevent the vehicle from becoming too heavy, the armor was kept relatively light. To enhance protection, the front armor plates were face-hardened.

The front hull had a thickness of 50 mm, while the upper front superstructure armor measured 30 mm. The box-shaped gun mantlet had a thickness of 50 mm. In contrast, the side hull and superstructure armor were thinner, measuring only 20 mm. The rear armor was even lighter at 10 mm. The upper armor varied between 10 and 20 mm in thickness.

The Germans made an intriguing addition to the vehicle by including a thin armor cover for the ammunition bins, even though the crew compartment was open-top. This feature aimed to offer some protection against potential attacks from enemy aircraft. However, doubts remain regarding the actual effectiveness and practicality of this measure.

In general, the armor thickness of the vehicle was considered relatively insufficient when compared to the standards of 1941. Nonetheless, the presence of a powerful and long-range gun helped alleviate this concern to some extent. The vehicle had the ability to engage targets from a distance, potentially preventing them from mounting effective counterattacks, at least in theory.

Main Armament – The 10.5 cm K18 Gun

The main armament chosen for this vehicle was the 10.5 cm K18 gun, which had been developed in the late 1920s. The designation “K18” was intentionally misleading, as the Germans were prohibited from developing new artillery after World War I. By using designations that falsely implied it was a pre-World War I design, they were able to bypass these restrictions. The K18 gun incorporated elements from both Krupp (carriage) and Rheinmetall (gun), which were merged together into a single design. Production began in 1933 after a successful testing phase, following a standard pattern similar to other modern German artillery pieces.

The gun featured a split-trail carriage and was connected to two large leaf-spring-suspended solid rubber-rimmed wheels. The barrel, housed in a protective jacket, was a single-piece design connected to a horizontally sliding breech. The gun was designed for towing by trucks or half-tracks, and if necessary, it could also be towed by horses, although in this case, the barrel had to be removed and placed on another trailer. It had a traverse range of 64° and an elevation range of 0° to +48°. With the strongest charge, it had a maximum firing range of just over 19 km. The gun weighed 5,640 kg when in action.

Despite its relatively long-range capabilities, the 10.5 cm K18 gun was considered to have a small caliber, despite its large size. However, it remained in use until the end of the war. An interesting aspect is that in the early stages of the war and during the invasion of the Soviet Union, it was often employed in anti-tank roles.

The 10.5 cm K18 gun was used as long-range artillery and, in an emergency, even as an anti-tank weapon. Source: https://ru.pinterest.com/pin/9781324180303270/

In order to fit inside this particular vehicle, the 10.5 cm gun had to undergo redesign. The gun was removed from its carriage and placed on specially designed mounting points located on top of the engine compartment. To accommodate the limited space, smaller recoil cylinders and recuperators were utilized. These modifications allowed for the omission of a large gun mantlet. Despite the reduced size, the gun maintained a sustained rate of fire of 120 rounds per hour (2 rounds per minute). A large muzzle brake was incorporated into the design, although it was later replaced by a smaller one when the gun was deployed on the frontlines. Additionally, a large travel lock was added to the front of the gun to support its heavy weight and long barrel.

In order to fit inside the vehicle, the original recoil cylinders and recuperators of the 10.5 cm gun were replaced with smaller ones. These modified components were positioned farther back, removing the need for a large gun mantlet. In the image, you can see the new recoil cylinder and recuperator located just above the breach block. Notably, ammunition bins for the rounds and propellant charges can be observed on the right side of the image. Additionally, the vehicle features a scissor periscope, which the commander used to assist in spotting targets. Source: https://www.tankarchives.ca/2016/12/dicker-max.html

The design of the vehicle’s gun system had some shortcomings, particularly in terms of its limited traverse and elevation capabilities. The gun had a traverse of only 16° and an elevation range of -15° to +10°. To operate the gun, the control wheels for both elevation and traverse were positioned on the left side of the vehicle, ensuring convenient access for the gunner. Each full rotation of the traverse wheel resulted in a traverse speed of 0.7°, while the elevation speed ranged between 0.7° to 0.8° per wheel turn.

The 10.5 cm gun exhibited remarkable anti-tank capabilities that served as a notable strength despite its design limitations. With a muzzle velocity of around 822 m/s (this varies slightly in different sources), it could penetrate up to 155 mm of armor at a range of 500 m. At a distance of 1 km, it was capable of defeating 128 mm of armor, and at 1.5 km, it could pierce 111 mm of armor. These exceptional performance characteristics established it as one of the most effective anti-tank weapons during the early years of the war.

The 10.5 cm gun employed a two-part ammunition system, comprising a propellant and a round. Although this type of ammunition slightly reduced the firing rate, it offered several advantages. It facilitated convenient storage within the vehicle and allowed for loading regardless of the gun’s position. Additionally, during firing, the gunner had the flexibility to utilize one or more charges as required. The ammunition load for the vehicle consisted of a total of 26 rounds, which were stored both on the right side of the crew compartment and in close proximity to the driver’s position.

Another ammunition bin was installed next to the driver due to the lack of internal space. Source: https://www.tankarchives.ca/2016/12/dicker-max.html

The gunner would employ the Selbstfahrlafetten-Zielfernrohr for direct firing, specifically targeting enemy armor. However, when fulfilling the role of mobile artillery for firing support at long distances, the Rundblickfernrohr 34 would be utilized instead. The effective range for direct firing was limited to 3 km, providing the 10.5 cm gun with substantial firepower to engage distant targets. Nevertheless, due to various factors such as poor visibility, adverse weather conditions, ammunition quality, or sheer luck, engaging enemy armor at longer ranges was infrequent.

While no secondary machine gun was incorporated, the crew members were equipped with 4 MP 40 submachine guns for close self-defense purposes alongside two magazine pouches for each weapon.

The newly built vehicles were initially supplied with a massive muzzle break which was, at some point, replaced with a smaller design. Source: https://www.tankarchives.ca/2016/12/dicker-max.html
Given the large size of the gun, it was necessary to install a forward-mounted travel lock. Source: https://www.worldwarphotos.info/gallery/germany/tanks-2-3/dicker-max/

Crew

The crew of the vehicle consisted of five: commander, driver, gunner, and two loaders. The driver enjoyed full protection as he was situated in the small driver compartment. The commander occupied the position on the right side of the gun and was equipped with a doppelscheren Turmspaehfernrohr scissor periscope for observing the surroundings. The periscope offered a 3x magnification and a 20° field of vision. Positioned opposite the commander was the gunner, while the two loaders stood behind them, prepared to load the gun.

The vehicle required a crew of five. Four of them were positioned in the rear, while the driver was alone in his small compartment. Source: https://www.tankarchives.ca/2016/12/dicker-max.html
A close-up view of the interior. The crew seats show the crew positions, with the gunner and the commander being placed forward and the loaders to the rear. Source: https://www.tankarchives.ca/2016/12/dicker-max.html

Organization and Doctrine

The two 10.5 cm K (gp.Sfl.) were assigned to one of the most famous German early to mid-war anti-tank units, Panzerjäger Abteilung 521 (Anti-Tank Battalion 521). This battalion fielded various anti-tank weapons, including the Panzerjäger I and the larger Panzerselbstfahrlafette für 12,8 cm Kanone 40. During Operation Barbarossa, the unit was initially part of the XXIV. Army Corps and later came under the command of the 3rd Panzer Division in September 1941. It was later incorporated into the XVII. Army Corps and participated in the Battle of Stalingrad, where it was ultimately destroyed as part of the 6th Army.

Within the Anti Tank Battalion, the two 10.5 cm K (gp.Sfl.) were organized into a new platoon, which consisted of a fighting column and an ammunition transport column. The fighting column included two 10.5 cm K (gp.Sfl.) vehicles, two Kfz.4 anti-air defense cars, and a Kfz.15 radio communication vehicle. This composition allowed for both direct and indirect fire capabilities, contributing to the battalion’s effectiveness in combat.

A great photo for showing what followed the SPGs around during an advance. In front are multiple cars with ammunition trailers. Source: Digital Collection of Armin Freitag

The primary purpose of this particular self-propelled gun was to engage and destroy heavily fortified concrete bunkers at long distances, all while maintaining its mobility on the battlefield. Additionally, it served as a formidable weapon against heavy tanks that were impervious to other anti-tank weapons. However, due to its delayed deployment, it did not have the opportunity to fulfill its original intended role during the events in France in 1940. Instead, when it was eventually sent into the Soviet Union in 1941, its focus shifted primarily to its secondary role of engaging and combating enemy tanks.

The second 10.5 cm K (gp.Sfl.) after it was sent back to the battlefield in mid 1942 with members of the Panzerjäger Abteilung 521. Source: Digital Collection of Armin Freitag

Combat Results

First stage – Operation Barbarossa and Early Losses

The following reports come from Panzerjäger Abteilung 521, which participated in the invasion of the Soviet Union on 22nd June 1941. The first operational report comes from 24th June 1941.

One of the two 10.5 cm K (gp.Sfl.) of Panzerjäger Abteilung 521 relatively early in the campaign against the Soviet Union, together with the ammunition column and a Panzerjäger I. Source: Digital Collection of Armin Freitag

The platoon was employed in a vanguard in the fight around the area east of Kobryn, where it fired HE rounds at infantry positions. In the evening, the platoon was supporting an attack by motorcycle gunners that crossed over a river. The SPGs engaged open artillery at a range of 1,100 to 1,700 m and successfully disabled them.

One of the two SPGs during the very early stages of Operation Barbarossa in a Polish village in 1941. Source: Auction-factory.de

During the advance on Slutsk on June 26th, 1941, an unfortunate incident occurred which resulted in the destruction of one of the self-propelled guns. Although the exact cause was not definitively determined, it is believed that the intense heat generated from the engine, combined with the exceptionally high temperatures outside on that day, led to a buildup of heat. Within the area, a small quantity of high-explosive (HE) grenades was stored, which likely ignited as a result.

Fortunately, the crew members were quick to react when they noticed a small burst of flame, allowing them to promptly evacuate the vehicle. All five crew members observed the SPG continuing to move for a short distance before coming to a halt. However, shortly thereafter, the flames spread and reached the main ammunition storage, causing a catastrophic fire. As a result, the vehicle was completely destroyed and had to be abandoned at the roadside. Remarkably, despite the loss of the vehicle, it was reported that the gun of the SPG remained intact and was still usable.

The first SPG after it burned out. Interestingly, this wreck would later turn out to be a popular photoshoot point, as many photos exist of different units passing by the wreck and examining the remnants. This also says a lot about how long a wreck would sit on that road side. Source: Digital Collection of Armin Freitag
Wehrmacht soldiers of presumably another unit examine the remnants of the SPG. The large opening and missing plates were not damaged by the fire but presumably the result of scrapping by other units. Source: Digital Collection of Armin Freitag
The report noted that the gun was still intact, which can be seen in this photo. Source: Digital Collection of Armin Freitag
At some point, a recovery vehicle pushed and tipped the wreck over. Source: Digital Collection of Armin Freitag
At another point in 1941, the wreck was recovered and driven into the woods for better examination. Source: Digital Collection of Armin Freitag
The first SPG at its new location in the woods, presumably to protect the scraping crew from Soviet aircraft. Source: Digital Collection of Armin Freitag
The same vehicle, presumably also photographed around the same time as above from a distance. Source: Digital Collection of Armin Freitag
What is likely to be the last photo of the first SPG destroyed. Looking at the last two photos, it appears that the SPG was either almost entirely blown up or scrapped for metal plates. Source: Digital Collection of Armin Freitag

On June 30th, 1941, the final remaining self-propelled gun confronted a Soviet armored train but was unable to halt its escape to safety. The SPG encountered an internal problem with one of its components, specifically a broken bolt in the slide mechanism of the steering brakes. This malfunction significantly impeded the gun’s ability to aim accurately at the target. Consequently, the team lost approximately 5 minutes of crucial time, during which the armored train managed to elude capture and find a secure location.

On August 20th, 1941, the self-propelled gun found itself engaging an enemy column from a considerable distance of over 4,000 m. This was primarily due to the absence of a closer firing position that would ensure the SPG’s safety. As the enemy tanks opened fire, their long-range shots and the continuous movement of the column hindered their ability to aim accurately, providing relative safety for the SPG.

To engage the column, the SPG employed high-explosive (HE) grenades with delayed fuzes set to the maximum range of 2,400 m. Although the crew initially estimated the distance to be 3,000 m instead of the actual 4,000 m, they skillfully targeted the column with well-placed hits and multiple spotting shots. Following the German tank crew’s training protocol for column destruction, the gunner aimed at the first tank in the column using a pre-loaded HE grenade. While a direct hit was not achieved, subsequent observation revealed damage to the tank’s tracks.

Continuing the engagement, the SPG fired three additional rounds of regular armor-piercing ammunition at the same tank. However, none of the shots hit their mark, as the gunner had to rely on trial and error to adjust the gun’s elevation beyond the effective range of 2,400 m. Later, it was observed that the crew of the enemy tank, identified as a KV-1, intentionally destroyed their own tank and managed to escape.

The second SPG with its kill markings (7 T-34 tanks destroyed) relatively late during its short expedition. In the background appears to be an ammunition carrier based on a Panzer IV. Source: Digital Collection of Armin Freitag

In addition to the destruction of the first tank in the column, two more tanks, likely T-34/76 mod.1941s, met a similar fate. The rounds fired by the SPG caused damage to the suspension of these tanks, rendering them immobile. Subsequently, the crew of each tank took the decision to set their vehicles on fire, effectively destroying them.

During a defensive battle on August 29th and 30th, 1941, the Battalion encountered Soviet tanks. On the 29th, the gunner and commander of the SPG scouted the area to identify suitable defensive positions and gain a better sense of the distances to specific points, making the aiming process easier. Upon returning to the tank, a Soviet T-34 approached their position, unaware of the presence of the SPG. Exploiting this advantage, the crew successfully destroyed the tank at a close range of 100 m. Subsequently, they engaged a second T-34 at approximately 1,000 m, managing to immobilize it. However, the Soviets recovered the disabled tank under the cover of darkness later that night.

On August 30th, 1941, the SPG encountered a T-34 tank and two T-26 light tanks positioned approximately 1,200 m away. However, the SPG was unable to advance closer due to the presence of Soviet anti-tank positions in the area. Despite the challenging circumstances, the SPG successfully immobilized the T-34 tank but failed to hit the T-26 tanks, which managed to escape into a nearby forest.

Regrettably, the available records for the 10.5 cm, K (gp.Slf.) conclude at this point. Towards the end of 1941, the sole surviving vehicle was withdrawn from the frontlines.

The only surviving 10.5 cm, K (gp.Slf.) on a rail wagon on the way back to the factories. Note the damaged road wheels. Source: Digital Collection of Armin Freitag

Second stage – Into Stalingrad

After being withdrawn from the frontlines, the SPG underwent extensive repairs and maintenance at the Krupp facilities. The vehicle required significant repairs and was repainted, resulting in the loss of its kill markings. During this time, Krupp proposed using a new Panzer IV chassis, but the Army Design Office rejected the offer, stating that the existing suspension would suffice.

In spring 1942, the SPG was deployed back to the frontlines, once again assigned to Panzerjäger Abteilung (Sfl.) 521, which had survived the unsuccessful attack on Moscow in the winter of 1941. Alongside two similar vehicles, known as the Panzerselbstfahrlafette für 12,8 cm Kanone 40, the SPG was expected to be combat-ready by June 1st, 1942. It subsequently participated in operations such as Case Blue and the assault on Stalingrad, with the objective of capturing the oil fields near Stalingrad.

The second 10.5 cm, K (gp.Slf.) repaired and ready to be sent back into action together with its larger partner tank destroyers, the Panzerselbstfahrlafette für 12,8 cm Kanone 40, that would also later meet their fate in Stalingrad. Source: Ebay, unknown seller

During this period, from spring to October 1942, the recorded history of the SPG is scarce, suggesting that the Army Design Office had less interest in its performance. It is likely that the vehicle was seen more as a reserve vehicle to plug equipment gaps in the Wehrmacht, rather than a subject for further testing or development. By this time, the Army Design Office had likely accumulated sufficient knowledge and experiences from previous operations, diminishing the need for detailed documentation of the SPG’s activities during this period.

The SPG met its demise in October 1942, as indicated by the absence of any mention of the vehicle in inventory reports from November and December of that year. The last known photograph of the tank was taken in December 1942 by Soviet soldiers. In the photo, the vehicle is seen in its original dark gray color with patches of sand yellow applied over it. Additionally, the tank underwent white washing, resulting in an interesting camouflage pattern. This type of camouflage was commonly employed by vehicles entering combat during the summer of 1942. The SPG featured a total of 18 kill rings and a small tank symbol painted on the barrel, reminiscent of the markings added by the crew in 1941.

What appears to be the last photo ever taken of the second SPG, around Stalingrad in December 1942, being examined by a Soviet soldier. Interestingly, in this photo, the exterior equipment differs greatly from the one above. Also, the small tank symbol and the 18 kill rings are not shown in the photo above. Colorized by Johannes Dorn. Source: World War Photos

Lessons Learnt

According to the Army Design Office’s request, the crews and unit were tasked with closely monitoring and describing the flaws and performance of the 10.5 cm, K (gp.Slf.) during combat. The following points are based on reports from July to September 1941, shortly before the second vehicle was sent back to Germany:

  1. The vehicle’s effectiveness in the vanguard was limited due to its lack of maneuverability. With a combined traverse of only 18°, the entire tank needed to turn even for minor adjustments. This, combined with the vehicle’s weak engine and heavy weight, significantly slowed down the aiming process. Furthermore, since only the frontal armor provided adequate protection, the tank crew had to constantly be vigilant to avoid being flanked and always keep its front facing the enemy. The nature of vanguard operations demanded the ability to engage targets from any direction without encountering such challenges.
  2. The tank had proven its effectiveness in providing support to infantry attacks from open positions through direct fire. However, a significant challenge arose from the large dust cloud generated in front of the gun, which hindered the observation of the tank’s own shots. To overcome this issue, it was deemed crucial to deploy an observation post or a dedicated team led by a fire control non-commissioned officer (NCO) who possessed knowledge of both the crew and the vehicle. This team’s role was to provide accurate observations and assist in adjusting fire, thereby maximizing the tank’s effectiveness in combat situations.
  3. The tank had not yet been utilized in its intended role as a concrete bunker destroyer with direct fire. However, its large caliber and high penetration demonstrated in the destruction of medium tanks indicated its effectiveness.
  4. The transmission and engine did not encounter any major issues. However, there were concerns regarding the overstressing of the steering brakes, leading to bolts in the steering slide tearing out.
  5. Achieving direct hits on heavy tanks like the KV-1 at ranges of 4,000 m proved challenging. Destruction or damage to the suspension primarily resulted from shell fragments, which sometimes led the crew to abandon and destroy their tank. However, this occurrence was not consistent, with instances where the enemy crew managed to tow their tank away during nighttime.
  6. Due to the gun’s capability in engaging soft skin targets up to 4,000 m, it was recommended to mark the range scale accordingly. However, most armored targets could only be effectively engaged at a range of 1,500 m.
  7. Prior to each firefight, it was crucial to scout the terrain in order to identify an optimal firing position. This task could be carried out by either the commander or the gunner.
  8. Engaging moving targets proved challenging, especially at longer distances. The limited traverse of 9º on either side was insufficient for pre-aiming at targets over large distances.
  9. It was not recommended to engage heavy tanks directly at ranges exceeding 1,000 m, as achieving penetration became increasingly challenging. Additionally, there was limited visibility monitoring the impact location of projectiles. Therefore, it was advised to engage tanks only within a range of up to 1,000 m.
  10. In order to facilitate indirect fire with high-explosive grenades, the inclusion of a rangefinder was seen as crucial, especially for ranges exceeding 1,000 m.
  11. The commander’s observation periscope proved insufficient and had to be replaced with a standard Scherenfernrohr (scissor telescope) for improved observation capabilities.

The encountered challenges and experiences played a vital role in the development of subsequent German self-propelled guns (SPGs), such as the Wespe and Hummel. These vehicles incorporated several of the necessary upgrades derived from the lessons learnt.

A great panorama shot of the second SPG in autumn 1942 and multiple support vehicles, including an observation Sd.Kfz.253. Source: Digital Collection of Armin Freitag
The second 10.5 cm, K (gp.Slf.) in autumn 1941 with its commander standing in front of it. Source: Digital Collection of Armin Freitag

Conclusion

The 10.5 cm, K (gp.Slf.) served as a well-conceived initial endeavor to create a specialized self-propelled gun (SPG) dedicated to the destruction of heavy bunker positions. However, like many first attempts, it exhibited several design flaws and performance concerns on the battlefield. Nonetheless, the project held significant importance for both Krupp and the Army Design Office, as it provided valuable insights and lessons in terms of combat performance. These experiences proved instrumental in the development of subsequent SPGs during the war. Moreover, the knowledge gained alone rendered the vehicle useful for the German Army, despite its imperfections.

Furthermore, the vehicle’s actual combat performance demonstrated its effectiveness as a tank destroyer, as the second vehicle showcased its capability by successfully destroying numerous Soviet medium tanks with its powerful gun. However, it is important not to overlook the negative aspects, which significantly impacted the vehicle’s mobility and overall performance. The design flaws, in particular, played a pivotal role in the destruction of the first vehicle, highlighting a potential recurring problem if larger numbers had been produced, akin to the issues faced by many Ferdinand tank destroyers in 1943.

An interesting photo of one of the two SPGs at an early stage of Operation Barbarossa in 1941. Source: Digital Collection of Armin Freitag
10.5 cm K gepanzerte Selbstfahrlafette. Illustration by Pavel Alexe.
10.5 cm K gepanzerte Selbstfahrlafette in winter camo. Illustration by Pavel Alexe.

10.5 cm, K (gp.Slf.) Specifications

Dimensions (L-W-H) 7.47 x 2.86 x 2.53 m
Total Weight 22 tonnes
Crew 5 (driver, 2 loaders, gunner, commander)
Speed On roads 27 km/h, off-road 17 km/h
Range On roads: 170 km, off-road: 120 km
Armament 10.5 cm Kanone L/52
3x 9 mm MP 40
Armor 10-50 mm
Engine Maybach HL 66 P, 6 cylinder water cooled, 6.6-liter gasoline, 180 hp
Ammunition 26 10.5 cm (HE and AP) shells
576 9 mm rounds
Elevation -15° to +10°
Steering ratio 1.48
Gunsight Sfl.Z.F.1, 2x 20 degrees, 3400 m for AP, 2400 m for HE
Power Ratio 8.2 hp/tonne
Ground clearence 40 cm
Total Production 2

Sources

D. Doyle (2005). German military Vehicles, Krause Publications.
D. Nešić, (2008), Naoružanje Drugog Svetsko Rata-Nemačka, Beograd
T. Anderson (2018) History of the Panzejager, Volume 1 Origin and evolution 1939-42, Osprey Publishing.
P. Chamberlain and H. Doyle (1978) Encyclopedia of German Tanks of World War Two – Revised Edition, Arms and Armor press.
T.L. Jentz and H.L. Doyle (1997) Panzer Tracts No.4 Panzerkampfwagen IV
T.L. Jentz and H.L. Doyle (2004) Panzer Tracts No.7-1 Panzerjager

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15 cm sIG 33 auf Panzerkampfwagen I ohne Aufbau Ausf.B Sd.Kfz.101

German Reich (1940)
Self-Propelled Artillery – 38 Built + At Least 5 Modified

The concept of mounting a heavy infantry gun on a tank chassis was born out of the need for providing the German infantry formations with more mobile artillery support. In order to test the whole concept, the German firm Alkett designed and built a small series of 38 self-propelled vehicles. These consisted of a Panzer I Ausf.B chassis armed with a 15 cm sIG 33 infantry support gun. Despite its primitive construction, this vehicle, named 15 cm sIG 33 auf Panzerkampfwagen I ohne Aufbau Ausf.B, would see extensive action up to 1943.

A 15 cm sIG 33 auf Panzerkampfwagen I ohne Aufbau Ausf.B. Source: http://www.panzernet.net/panzernet/stranky/samohybky/spanzer1.php

Rise of the Infantry Support Guns

The First World War brought a series of military reforms and the introduction of new technologies and weapons. One of these was the concept of artillery units put directly under infantry control, which were meant to provide close-up fire support. On the Western Front, the use of such artillery was highly desirable, but their employment was heavily hindered by the extensive entrenched lines. On one hand, the use of close support fire at key points on the battlefield would offer a chance to break the enemy line. On the other hand, the difficult terrain greatly reduced their mobility during advances. Another major problem was that these guns were not specifically designed for this role. Any available small caliber gun or mortar would be reused for this purpose. Because of this, these early ‘assault guns’ were too heavy or had insufficient mobility to be used more directly during assaults.

After the First World War, the Germans especially showed interest in designing and producing infantry support guns. Despite being forbidden from doing so by the Treaty of Versailles, which prohibited the development of such weapons, the Germans bypassed this by often simply adding fictitious design years to their guns, misleading the Allies into believing that they were old World War One designs. After some time spent testing and perfecting the design, two new infantry support guns would be developed. These Infatteriegeschutz (Eng. Infantry guns) included the lightweight 7.5 cm leIG 18 and the much heavier, larger caliber 15 cm sIG 33. Both of these proved to be excellent designs, serving the German infantry up to the end of the war. The 15 cm sIG 33 proved to be especially effective in combat. It had good elevation, was easy to maintain, and had excellent firepower. The range of both of these guns was rather limited but, given the specialized role that they were to perform, this was not seen as an issue. The divisional artillery formation armed with 10.5 and 15 cm guns was to provide long-range fire support.

The 7.5 cm LeIG 18 light infantry support gun. Source: Wiki
The larger 15 cm sIG 33. Source: http://panzerserra.blogspot.com/2021/04/15-cm-sig-33-sf-auf-panzerkampfwagen-i.html

Panzer I Ausf.B

The Panzer I was the first mass-produced German tank and entered service in 1934. The first version, known as Panzer I Ausf.A, while vital in providing experience regarding tank design and crew training, had many shortcomings. A year later, another improved version was introduced to service, the Ausf.B. It had a more powerful engine and an improved suspension, while the armor and armament remained the same. By the time production ended in June 1937, some 1,500 of both versions were built. While additional versions would see service in the following years, these would be built in limited numbers only.

Despite its obsolescence as a combat tank, with its weak armament of two machine guns, the Panzer I remained in frontline service up to late 1941. The German industry could not sufficiently produce an improved design, so the Germans were forced to use the Panzer I as a frontline tank. Due to its obsolescence, the Panzer I chassis would be reused for a series of adaptations for other roles. This included a small production run of a self-propelled version armed with the 15 cm infantry support gun.

A Panzer I Ausf.B. Source: https://warspot.net/579-pz-kpfw-i-ausf-b-all-grown-up

Self-Propelled Version

While the 15 cm sIG 33 offered great firepower to the German infantry, its weight severely limited its mobility. Infantry units of the German Army were not very mobile formations given the general lack of towing vehicles, mostly relying on horses to pull their equipment. In rarer cases, a Sd.Kfz.10 or 11 half-track was used to tow this gun. Depending on the means of towing, different road wheels were used. For example, when towed by horse, all-metal wheels were used. When towed by a half-track, metal wheels with solid rubber tyres were used. Despite this, moving a heavy gun was tiresome and took some time to set up properly. In addition, during retreats, the guns were often abandoned, as they could not be moved fast enough.

These shortcomings became obvious after the Polish campaign in 1939. Shortly after that, WaPrüf 6 issued orders to develop a self-propelled version armed with such a gun. According to original plans, this vehicle was to be a completely new design. These envisaged a fully tracked vehicle with 50 mm frontal and 20 mm side armor. The total combat weight was to be slightly over 12 tonnes and the maximum speed was to be 67 km/h. The last but most important requirement was that the gun could be easily dismounted and used in its original configuration.

Given that designing a brand new chassis would take time, the Germans went for the simplest possible solution. In parallel with this vehicle’s development, an anti-tank vehicle armed with a 47 mm gun was being developed using the Panzer I Ausf.B chassis. The choice to use this chassis was made in order to maximize the efficient utilization of existing resources. Larger chassis, such as the Panzer III or IV, would be more suited for this task, but, given their limited numbers and the lack of production capabilities of the German industry, there was no other choice than to reuse the Panzer I tank for this project. Another fact is that the Panzer I was, by that point, an obsolete combat vehicle, but it remained in service, as there was nothing available to replace it.

In any case, the overall design of the new self-propelled vehicle was quite simple. The Panzer I’s upper superstructure was removed and replaced with the entire 15 sIG 33 gun, which was provided with box-shaped armor protection, open to the rear and top. While this simple approach left much to be desired, it made the whole construction easy to repair and maintain, and any damaged part could be easily replaced or salvaged.

The first working prototype was completed at the start of 1940. It was designed and built by Almarkische Kettenfabrik G.m.b.H from Berlin. Following successful testing, a production order for 37 (chassis numbers 10456 to 16500) such vehicles was given. These were completed by the end of February or March 1940, depending on the source.

According to some sources, this is the prototype vehicle during testing in early 1940. Source: https://warspot.ru/9376-malye-da-udalye

Name

This vehicle was designated as 15 cm sIG 33 auf Panzerkampfwagen I ohne Aufbau Ausf.B Sd.Kfz.101. As with other German armored vehicles of WWII, other sources use slightly different designations for this vehicle, such as 15 cm sIG 33 PzKpfw I Ausf.B. For the sake of simplicity, this article will use sIG 33 auf Pz. I, although this was not an official name.

The nickname ‘Bison’ is often associated with this vehicle, but the Germans never referred to it as such. It is also sometimes referred to as Sturmpanzer I, which was another false name, given the incorrect belief that the vehicle was designed to be used as a direct fire support weapon. While occasionally it did happen, it was not its primary purpose.

Design

Hull

The sIG 33 auf Pz. I’s hull consisted of a frontal-mounted transmission, a central crew compartment, and a rear-positioned engine. Its overall design was unchanged from the original Panzer I Ausf.B.

Suspension

The suspension was another element that remained unchanged the original Panzer I Ausf.B. It consisted of five road wheels per side. The first wheel used a coil spring mount design with an elastic shock absorber in order to prevent any outward bending. The remaining four wheels were mounted in pairs on a suspension cradle with leaf spring units. There was a front drive sprocket, rear idler, and four small return rollers. Given the added weight, the sIG 33 auf Pz. I’s suspension was very prone to malfunctions and breakdowns.

The suspension of this vehicle consisted of five road wheels, four return rollers, a front-drive sprocket, and the rear idler. Source: https://www.worldwarphotos.info/gallery/germany/artillery/sig33-bison/
Due to the extensive weight of the gun, crew, and the gun shield, the sIG 33 auf Pz. I’s suspension was prone to breakdowns. Source: https://www.worldwarphotos.info/gallery/germany/artillery/sig33-bison/

Engine

With the added crew and the gun, the weight increased from the original 5.8 tonnes to 7 tonnes. Depending on the source, the weight of this vehicle is sometimes described as being 8.5 tonnes. The Panzer I Ausf.B was powered by a new water-cooled Maybach NL 38 Tr, which was able to supply 100 hp@ 3,000 rpm. The maximum speed, depending on the source, ranged between 35 to 40 km/h, while the cross-country speed was only 12-15 km/h.

The fuel was located in two tanks, with one holding 82 liters and the other 62 liters. Both were located to the rear right side, separated from the crew compartment. The operational range was 170 km on good roads and 115 km/h cross-country. Sources, such as Tank Power Vol.XXIV 15 cm sIG 33(Sf) auf PzKpfw I/II/III, mention that the operational range was only 100 km. Author W. Oswald (Kraftfahrzeuge und Panzer) mentions that the operational range was 160 km on good roads and 120 km cross-country.

Superstructure

While the chassis remained unchanged, the original superstructure and turret were removed. A small frontal driver plate was retained. While it kept its driver visor port located on the left side, another smaller vision port was added next to it. Despite this, the driver’s vision would be severely limited by the added upper superstructure, which protruded slightly on both sides in front of the driver.

The driver’s front plate with its two visor ports is visible here. Source: Digital Collection of Armin Freitag

On top of the vehicle, a simple three-sided box-shaped armored superstructure was added for crew protection, which was open from the back and the top. The sides and lower parts of the front armor were flat. The upper front plates were slightly angled inwards at a 25º angle. On the front armor, there was a large U-shaped opening to allow the gun to be placed there. It was enclosed by the gun shield itself, so it did not leave the crew exposed. There was a large hatch located to the front upper left, which served to provide a clear view for the gunner’s sights.

The frontal gun shield that covered the large opening on the front superstructure armor. Source: https://www.worldwarphotos.info/gallery/germany/artillery/sig33-bison/

The side armor plates had few noticeable features. On top of them, small observation ports were added. The rear sections of the two side walls could, if needed, be opened to provide the crew with more working room and some protection during ammunition resupply. Lastly, on the sides of the armor plates, there was a noticeable bulge that protruded out of the vehicle. Its purpose was to provide slightly more working space during the mounting or dismounting of the main gun.

The rear sections of the side walls could, if needed, be opened to provide the crew with more working room. Source: https://www.worldwarphotos.info/gallery/germany/artillery/sig33-bison/

With this new superstructure, the sIG 33 auf Pz. I was a fairly large target. There are conflicting recollections on the precise turret dimensions. For example, D. Nešić (Naoružanje Drugog Svetskog rata-Nemačka) mentions a length of 4.42 m, width of 1.68 m, and height of 3.35 m. According to T.L. Jentz and H.L. Doyle (Panzer Tracts No.10 Artillerie Selbsfahrlafetten) the length was 4.42 m, width of 2.17 m, and height of 2.7 m. Lastly, Tank Power Vol.XXIV 15 cm sIG 33(Sf) auf PzKpfw I/II/III gives slightly different numbers of 4.42 m length, 2.65 m width, and 3.35 m height.

The sIG 33 auf Pz. I’s large size in comparison to one of its crew members. Source: https://www.worldwarphotos.info/gallery/germany/artillery/sig33-bison/

Armor

The original Panzer I Ausf.B’s armor was quite thin. Its front hull ranged between 8 to 13 mm. The side armor was 13 mm, the bottom 5 mm, and the rear 13 mm. The armor was made of rolled homogenous hardened plates with a Brinell hardness of 850. It was welded and formed the body of the superstructure and hull. Although not protected from even small caliber anti-tank guns, it could provide protection against small arms fire and SmK bullets (steel-cored rifle bullets).

An illustration showing the armor thickness around a Panzer I Ausf.A. Source: Panzer Tracts

For crew protection, the vehicle received a large box shaped superstructure. Its armor thickness was only 4 mm thick according to T.L. Jentz and H.L. Doyle (Panzer Tracts No.10 Artillerie Selbsfahrlafetten). Authors, such as D. Nešić (Naoružanje Drugog Svetskog rata-Nemačka), mention it being 10 mm thick. This basically provided the crew protection only against regular small caliber ammunition. Armor-piercing ammunition of the same caliber could easily penetrate this armor. With its open rear and top, its large silhouette, and a powerful gun, the sIG 33 auf Pz. I was a magnet for enemy return fire. This alone indicates that using this vehicle in a close support role was dangerous for the crew and completely suicidal.

The sIG 33 auf Pz. I’s armor did not offer any real protection besides small caliber bullets and shrapnel. Being hit by any properly designed anti-tank weapons could easily take it out of action or completely destroy it, like in this picture. This also shows the round platform on which the 15 cm sIG wheels were placed. Source: Digital Collection of Armin Freitag
This sIG 33 auf Pz. I’s upper superstructure armor was completely shattered, possibly being hit by an enemy artillery round. This photograph clearly shows how its armor protection was quite poor. Source: Achtung Panzer. 150-мм САУ Bison I Военные машины 62 Торнадо
Additional spare parts would sometimes be added to the front to act as extra armor. Their effectiveness is questionable. Source: https://www.worldwarphotos.info/gallery/germany/artillery/sig33-bison/

Armament

The main armament of this vehicle was 15 cm sIG (schwere Infanteriegeschutz – Heavy infantry gun) 33. Rheinmetall began its development in 1927 and it entered service in 1933. With a total weight of approximately 1,700 kg, it was one of the heaviest guns ever to be used for infantry support. It was a reliable and robust gun that was easy to build and required very little maintenance.

In terms of construction, it was a quite conventional design. It had a two-wheeled carriage and the older type of box trail equipped with a hydropneumatic recoil system placed under the gun barrel. The gun possessed a high elevation and used a horizontal sliding-block breech mechanism. To help counteract the muzzle weight, two balancing springs (one on each side) were installed. The 15 cm sIG was considered a satisfactory weapon by the Germans, but the greatest issue was its weight. It would remain in use throughout the whole of World War II in both its original form and as the main weapon of many German self-propelled guns.

A gun crew loading a 15 cm sIG 33. Source: Wiki

The gun installation was quite simple. The gun was not modified in any way and was simply placed on top of the modified Panzer I chassis. To hold the wheels in place during firing the gun, they were placed in a metal housing located on top of the mudguards and held in place by two large screws. In addition, there were two large metal rings that housed the two gun wheels, providing further stability. The gun was also secured by a vertical pin connected to the gun tow hitch (towing eye) and a triangular-shaped armored plate that was welded to the engine compartment.

A sIG 33 auf Pz. I without its armored superstructure. Source: Digital Collection of Armin Freitag
Close-up view of the metal housing located on top of the mudguards, which held the wheels in place. Source: https://warspot.ru/9376-malye-da-udalye
The gun was also secured by a vertical pin connected to the gun tow hitch and a triangular-shaped armored plate that was welded to the engine compartment. Source: Digital Collection of Armin Freitag

If needed, the gun could be easily removed, which made performing maintenance and repairs much simpler. For removing the gun, a sufficiently strong crane (either specially designed or a simple improvisation) would be needed. As mentioned earlier, for this purpose, on both sides of the armored superstructure, there were two oval projections. The right-hand side oval was slightly closer to the front of the vehicle, in contrast to the left side. This allowed the gun to be turned anti-clockwise and, with the help of some kind of crane or a winch system, the gun could be removed without dismantling the rest of the superstructure.

The gun could be easily replaced using any kind of sufficiently strong crane. Source: Digital Collection of Armin Freitag

The 15 cm sIG 33 fired a 38 kg heavy high-explosive round at a maximum range of 4.7 km. This high-explosive round, during explosion, created a lethal area of around 100-120 m wide and 12-15 m deep. While the 15 cm sIG used several different ammunition types, on the sIG 33 auf Pz. I configuration, only the high-explosive rounds were used. The main gun elevation was -4° to +75, while the traverse was 5.5° in both directions. These numbers differ depending on the source used. The rate of fire was low, at only 2 to 3 rounds per minute. This was due to the heavy weight of the shells and the use of separate two-part ammunition (shell and charges). The 15 cm sIG 33 used the Zeiss Rblf 36 gun sight.

Close-up view of the Zeiss Rblf 36 gun sight. Source: Achtung Panzer. 150-мм САУ Bison I Военные машины 62 Торнадо

Due to its cramped interior and the large size of the ammunition required for the gun, only three spare rounds were transported in the vehicle. This would limit the effectiveness of the sIG 33 auf Pz. I if the supporting ammunition carriers could not reach them for whatever reason. It is possible that the crew would store additional rounds inside the vehicle. There are photographs that show that an additional fourth round was carried under the gun itself, making it difficult to spot. Spare rounds were held in woven containers. Two were usually located on the left rear mudguard and one on the right side, plus the one under the gun. Author D. Nešić (Naoružanje Drugog Svetskog rata) states that the ammunition load of this vehicle consisted of up to 18 rounds. This is highly unlikely given the limited internal space.

Besides the crew’s personal weapons, no secondary armament was provided for self-defense. As this vehicle was designed to fire from a distance, this was not a significant issue.

The round that was placed under the gun can be seen here. In addition to this, the right round is also visible. Two more round containers (possibly empty) are held on top of the gun’s box trail. Source: https://www.tapatalk.com/groups/missinglynx/sig-33-auf-pz-i-ausf-b-ohne-aufbau-4th-ammo-basket-t42129.html
The crew of this vehicle appears to have stored at least 6 spare rounds. Source: T. Anderson Panzerartillerie
The crew of this vehicle have stockpiled additional rounds and various spare parts on their vehicle. Source: Achtung Panzer. 150-мм САУ Bison I Военные машины 62 Торнадо

Using a lighter gun may seem to have been a better choice due to the overburdened chassis, but the Germans chose not to for a number of reasons. The two main infantry support guns used by the German Army were the 7.5 and the 15 cm guns. The much smaller 7.5 cm leIG 18 was lighter. On the other hand, the gun was highly mobile, so placing it on a self-propelled chassis was not seen as urgent or providing enough advantages. The 15 cm sIG 33 was very heavy and mobility was a major issue. Using it in a more mobile configuration was deemed more important. In addition, it had much stronger firepower than its ‘smaller’ ‘cousin’. Using other artillery pieces, such as the 10.5 cm howitzer, may also have been an alternative. However, as it was not directly under the control of the infantry, the use of this caliber would have caused some logistical problems.

Crew

According to authors T. L. Jentz and H. L. Doyle (Panzer Tracts No.10 Artillerie Selbsfahrlafetten), this vehicle was operated by a crew of five. During relocation to other positions, three of them were stationed inside the vehicle. The two remaining crew were transported by the auxiliary vehicles belonging to the unit. Somewhat confusingly, the same sources later mentions a crew of four including the commander, two gun operators, and the loader in the specifications table. It is unusual, but the driver is not mentioned, which might explain the difference.

Sources such as Tank Power Vol.XXIV 15 cm sIG 33(Sf) auf PzKpfw I/II/III mention a crew of four: commander/gunner, driver, and two loaders. This is a significant difference between sources, especially regarding the commander’s role. To complicate the matter, older photographs show this vehicle with both four and five crew members.

The driver was positioned on the vehicle’s left side and was fully protected. As there was no hatch available for him, the driver would have had to squeeze around the gun to get to his position. The gunner was positioned to the left of the gun and the loader right of him. The last crew member was likely positioned behind them, ready to assist the gun’s loading.

The crews from the supply vehicles (usually three people per vehicle) would also help with delivering the ammunition. As there was little room for all of the crew members, on long marches, the crew, with exception of the driver, were usually transported by the support vehicles (but this depended on the situation in the field). As an open-topped vehicle, the crew was also exposed to the weather. A canvas cover could be placed over the vehicle, but it limited the crew’s view of the surroundings.

This vehicle appears to have a crew of five, with the driver and three more crew inside the vehicle, and one more further back. Some of them may have not been part of the crew, but rather part of the auxiliary personnel. Source: https://www.worldwarphotos.info/gallery/germany/artillery/sig33-bison/
Another vehicle with a crew of five. Source: F. V. de Sisto Early Panzer Victories
This vehicle appears to have had four crew members. Source: Bobban-Militaria via Ebay

Organization

With the completion of all 38 vehicles, it was possible to begin creating the first units equipped with this vehicle during spring 1940. These were allocated to six vehicle strong Schwere Infanteriegeschütz (Motorisiert) Kompanie – s.I.G.(mot.) Kp (Eng. self-propelled heavy infantry gun companies). With the available vehicles, six such companies were formed, numbered 701 to 706. The remaining two vehicles were allocated for training, but also acted as replacement vehicles.

These companies were attached to the Schütze-Brigade (Eng. rifle brigade) of various panzer divisions just prior to the German invasion of the West in May 1940.

s.I.G.(mot.) Kp Panzer Division
701st 9th
702nd 1st
703rd 2nd
704th 5th
705th 7th
706th 10th

The structural organization of each company consisted of a command unit that was equipped with four military cars, such as the Kfz.15 Horch, as well as four motorcycles. One of these motorcycles was provided with a sidecar. The companies were divided in three two-vehicle strong platoons. These were supplemented by four Sd.Kfz.10 half-track vehicles with two trailers and two motorcycles. Additional trucks would be used to transport ammunition, fuel, and spare parts from designated army storage bases to the unit at the front. After 1941, some structural changes were made to address this unit’s lack of radio equipment, enlarging the command unit with additional vehicles and radio equipment. In later years, some vehicles may have been provided with radio equipment, like some photographs indicate.

Each of the 6 self-propelled heavy infantry gun companies received 6 sIG 33 auf Pz. I vehicles. These appear to be undergoing training, as some vehicles lack the upper armor protection. At least one even lacks its gun, or is acting as an ammunition carrier. Source: Digital Collection of Armin Freitag
Due to their low ammunition capacity, additional auxiliaries vehicles were needed to transport ammunition, spare parts, and even some of the crew members. Source: Digital Collection of Armin Freitag
While the sIG 33 auf Pz. I was initially not provided with radio equipment, later in the war, some of them appear to have been equipped with such devices. Source: http://www.panzernet.net/panzernet/stranky/samohybky/spanzer1.php

In Combat

Conquest of the West, May 1940

The sIG 33 auf Pz. I self-propelled heavy (motorized) infantry gun companies, numbered from 701 to 706, were allocated to six panzer divisions that were preparing for an attack on the Westin May 1940.

During the German offensive in France, the vehicle proved to be an effective weapon, but was not without its flaws. While the firepower was deemed excellent, other characteristics, such as mobility, armor protection, and reliability were deemed insufficient. The mechanical breakdowns, especially of the transmission, were common, and many vehicles were put out of action because of this. For example, the 703rd Company only had one operational sIG 33 auf Pz. I after the first week of fighting. In total, only two were lost due to enemy fire during this offensive. One of these two was hit by an artillery shell and destroyed.

In a report about the sIG 33 auf Pz. I’s performance by the 706th Company, it was noted that:

“ … The sIG 33 auf PzKpfw I Ausf B, in its present form, has not performed well. However, the gun, if it could be used in action, was very effective and fully met our expectations. The PzKpfw I chassis proved to be too weak. The running gear, although overhauled at Alkett, was still considerably worn out after many years in service. Most failures (up to 60 percent) occurred with the clutches, the brakes and the tracks. Most sIG companies could not keep pace with the marching speed of the tank division, which often exceeded 30 kph. For this reason, we advise to attach the sIG companies to infantry divisions for the coming combat… Combat usually involved a single sIG 33 gun firing from a concealed position at ranges varying from 50 to 4,000 m. But, the front gun shield was repeatedly penetrated by armor-piercing infantry ammunition…. “

A sIG 33 auf Pz. I during the advance in the West. Somewhat unusually for the German standards, the crews of these vehicles often added various painted names on them. Source: T. Anderson Panzerartillerie
Due to its weak armor protection and sheer size, the sIG 33 auf Pz. I was an easy target for enemy gunners. At least two vehicles were lost during the invasion of the West in 1940. Source: T. Anderson Panzerartillerie

In the Balkans

During the Axis invasion of Yugoslavia in April 1940 and later the invasion of Greece, only the 701st, 703rd, and 704th companies would see action. There is little to no information about their use in this campaign, as the war reports of the panzer divisions they were attached to (2nd, 5th, and 9th) barely mention them. Yugoslavia was defeated very quickly (the war lasted less than two weeks) with minimal German losses. The sIG 33 auf Pz. I may have seen some limited action there. Following the capitulation of Yugoslavia, the Germans successfully invaded Greece. They were likely used to bombard the heavily defended Greek Metaxa Line. As with their service in the Balkans, due to lack of information, it is unknown whether these units suffered any losses, but it is likely none were lost.

A sIG 33 auf Pz. I during the German offensive in Greece. Source: J. Engelmann Bison und andere 15 cm-Geschutze auf Selbstfahrlafetten

Although not a single vehicle is recorded as having been lost in direct combat, as many as six were lost in a highly unusual accident. After the successful campaign in the Balkans, the Germans began to withdraw their forces in preparation for the upcoming attack on the Soviet Union. On 19th May 1941, the 703rd Company, together with other armored vehicles of the 2nd Panzer Division, was meant to be transported by the ships Kybfels and Marburg from Patras (Greece) to Taranto (Italy). On 21st May, unbeknown to the Axis forces, the British HMS Abdiel (M39) minelayer secretly laid down some 150 mines near the planned route. Close to Cape Dukato, Kybfels struck a mine at around 14:00. The damage was so extensive that the whole ship sank very quickly. Shortly after, the Marburg would also run into a mine, and the explosion caused a huge fire. The ship did not sink immediately, but it also shared the fate of the first Axis ship. In this action alone, the Germans lost 226 personnel, including all the equipment and weapons stored inside these two ships. While not completely clear, it appears that at least some vehicles and equipment from the 2nd Panzer Division may have been unloaded a few days before this accident. Whatever the case, the 703rd Company lost all of its six-vehicles. As a replacement, it received towed 15 cm sIG guns instead.

The sIG 33 auf Pz. I from the 703rd Company being loaded on ships to be transported to Italy. All six were lost when the ships carrying them were sunk by mines. The 703rd Company was not disbanded, but was instead equipped with towed 15 cm sIG 33. Source: https://www.forosegundaguerra.com/viewtopic.php?t=20226

In the East, 1941-1943

By the time of the German invasion of the Soviet Union in June 1941, there were at least 30 sIG 33 auf Pz. I available for action. Although the German forces did not expect any serious resistance from the Soviet Army, the first month of the invasion proved to be different from their expectations. All six self-propelled heavy infantry gun companies were heavily engaged in combat.

In a combat effectiveness report (as found in T. Anderson Panzerartillerie) made by the 702nd Company dated from 18th September 1941, there are few quite interesting comments regarding the use of these vehicles.

“.. Despite being thoroughly aware of the shortcomings of the type, the sIG (mot S) [referring here to sIG 33 auf Pz. I] has performed very well as an assault gun during the campaign in Russia. This is in contrast to the first combat deployment in France, when the unit was afflicted by a number of serious problems. However, our troops have benefited from the long training phase and become accustomed to all mechanical vagaries and adept at correcting any faults.

The sIG (mot S) is the ideal assault gun for the lead echelon of a Kampfgruppe in the Panzer division. The low trajectory of the gun, when firing with a No.4 charge, is very effective for attacking a point target, such as a bunker or dug-in artillery, or machine-gun nests and mortar positions, with a minimal expenditure of ammunition. Due to having a fully tracked chassis, the vehicle can be moved quickly to attack a fresh target. Also, by being armored, the sIG (mot S) can also be deployed in an open position, and this can have a demoralizing effect on enemy forces; many cease firing and give away their positions. The gun is not suitable for use as an anti-tank gun, but it must be emphasized that in an emergency situation, it can be used to attack enemy armor. Just the massive effect of a 15 cm high-explosive shells detonating near enemy tanks will normally cause the attack to turn away; this was even applicable to the 52 tonnes heavy tank [KV heavy tank] . A stationary tank or any that approaches head-on can be destroyed at 300 to 400 m range by firing two or three shells propelled by the No.4 charge. In most instances, a combat company was supported by a single self-propelled gun, but any action involving the platoon would be the exception: the guns would be concealed in a covered position: Some 80 percent of all rounds were fired from an open position… “

This report shows that the crew of some units prefered to use the sIG 33 auf Pz. I in a role for which it was not designed for. Thanks to its excellent firepower, enemy targets, such as fortified positions, could be easily taken out. The report even mentions the possibility to use it as an improvised anti-tank vehicle in desperate situations

This report also mentions the logistical problems, something that the Germans always faced during the war and which were never fully solved.

“ … The workshop facilities for the company must be improved and enlarged. The lack of an 8-ton Zugmaschine [Sd.Kfz.7] and a flatbed trailer to enable the recovery of damaged guns or repair, is a very serious problem. Recovery services at divisional level were insufficient and extremely slow at recovering any damaged gun. This was observed when two were lost during the advance and, despite of their exact positions being reported (as required in regulations), neither vehicle was recovered immediately. However, both were later recovered by crews from the Speer organization, but were not returned to the company. If a tractor and flatbed trailer had been available, these precious guns would have been returned directly to our workshop unit for repair and be available for service after seven days. The resupply to our guns worked satisfactorily, this was due to the dedication to his task by the leader of the ammunition squad. However, it has become obvious that the standard Opel Blitz truck has poor cross-country mobility and a lack of cargo capacity. Since a large stock of ammunition cannot be carried on the gun, the resupply team has to follow in close proximity. As a consequence, the delivery of heavy cross-country trucks must be considered a vital necessity.’’

Lastly, the unit report also mentions the numbers of destroyed enemy targets during the advance toward Leningrad. The enemy losses, at the cost of some 1,640 rounds, were 24 bunkers, 31 guns, 13 anti-tank guns, and 6 tanks. Interestingly, the report also mentions the list of repairs undertaken during a four-day march, which included the replacement of 68 road wheels, 392 track links, 1,057 track bolts, 8 idler wheels, 2 drive sprockets, 5 return rollers, 9 leaf springs, etc. The source for this report is T. Anderson (Panzerartillerie).

While the use of the sIG 33 auf Pz. I by the 702nd Company may indicate that this vehicle could be quite effectively used in more aggressive and direct combat actions, a few things should be remembered. In the early period of the war in the East, the Soviet forces were often poorly led and trained. This affected their overall combat performance greatly, to the point that they would often run from the Germans, thinking the enemy was superior to them. As the war progressed and the Soviet soldiers became more experienced with fighting the enemy, the German advance slowed down. The sIG 33 auf Pz. I’s armor was minimal at best, and the Soviets possessed a great number of anti-tank guns and anti-tank rifles that could easily take out this vehicle.

To prevent the inadequate use of the lightly protected self-propelled artillery, in late 1942, the Waffenamt (German Army Weapon Agency) issued a series of orders that essentially banned their use in more direct attacks. With the rising losses, the surviving crew members were often relocated to the infantry school at Döberitz. There, they trained and helped with the formation of new units. The last unit to operate this vehicle was the 5th Panzer Division (704th), which still listed two operational vehicles on 30th June 1943.

A sIG 33 auf Pz. I am from the 702nd Company somewhere in the Soviet Union, possibly during the winter of 1941/42. Source: https://www.worldwarphotos.info/gallery/germany/artillery/sig33-bison/

New Vehicles

While the sIG 33 auf Pz. I chassis was overburdened and prone to malfunctions and breakdowns, its simplicity allowed an easy replacement of damaged parts. Another benefit of its overall design was that, in case the chassis was damaged beyond repair, the gun could simply be dismounted and used in its original configuration, or the other way around. Easy removal of the gun allowed the German crews to fabricate additional vehicles, if the components for it were available, with minimal equipment. This was the case of the 701st Company, which received 5 Panzer I chassis and two 15 cm guns. While, officially, only 38 vehicles were built, additional conversions were undertaken in the field. At least a few were documented, although others may have not. This somewhat complicates determining the precise number of such conversions used, but it is highly unlikely that many additions were completed.

The Germans somewhat overcomplicated their self-propelled artillery design by having the possibility to use the gun in its original towing configuration. The sIG 33 auf Pz. I actually achieved this with minimal work needed on its overall design.

A pair (or even more) sIG 33 auf Pz. Is without their armament. These were under repair or even possibly newly rebuilt vehicles. Source: Bobban-Militaria
Thanks to its simple mechanical nature, the replacement of the gun was relatively easy. Source: T. Anderson Panzerartillerie

Was This Vehicle Used as an Assault Gun?

There is some confusion about the precise role of this vehicle. Often, in some sources, this vehicle is described as the performing role of an assault vehicle. The well-known and only footage of this vehicle in action shows it firing at French buildings at close range supported by infantry. It is important to note that this was likely a propaganda film made by the Germans. In general, the self-propelled artillery guns developed and used by the Germans, such as this vehicle and later models (Wespe, Hummel, and the 15 cm armed Grile based on the Panzer 38(t) chassis) were provided with limited armor protection, giving more priority to their mobility and firepower. Their role was not to charge at the enemy and fire at close range, but instead to follow up fast motorized German units and support them from a distance. For close firing support, the German employed the well-known StuG III series, but also the 15 cm armed Sturmpanzer III and IV. These were much better protected and able to resist enemy return fire. While the sIG 33 auf Pz. I could be and probably was used as an assault gun on some occasions, this kind of deployment was highly risky for its crew. If the enemy had any kind of anti-tank weaponry or were even positioned above, they could easily take out the sIG 33 auf Pz. I’s crew or the vehicle itself. The effectiveness of its firepower can be seen in a contemporary German propaganda video, where it is filmed destroying a house during one German offensive action (possibly somewhere in France).

Despite being often portrayed and sometimes used as a close support vehicle, the sIG 33 auf Pz. I was best used from a relatively safe distance. Source: https://www.worldwarphotos.info/gallery/germany/artillery/sig33-bison/

Conclusion

The sIG 33 auf Pz. I self-propelled gun solved the problem of the low mobility of towed artillery guns. It could engage enemy positions and then disengage, change position, or retreat to safety much faster than towed artillery. But, due to its overburdened chassis, breakdowns were common, which led to a reduction of its mobility. The firepower of the main 15 cm sIG 33 guns was considered to be satisfactory, being able to destroy most targets and even, in rare cases, enemy tanks. The sIG 33 auf Pz. I also had a very simple design, which allowed for quick and easy repairs and replacement of any damaged or worn-out parts. The simple installation of the 15 cm sIG gun also allowed it to be dismounted (if the tank chassis was damaged beyond repair) and to be used as an ordinary towed gun.

The weight of the 15 cm gun and the additional armor plates was simply too much for the weak Panzer I tank’s chassis. This overloading often resulted in many transmission and suspension breakdowns. A common problem was the frequent malfunction of the shock absorbers fitted to the front road wheels. Breakdowns of entire wheels and tracks were also common. The main gun recoil during fire was so strong that the vehicle would wildly shake and could be thrown back. This also increased the chance of damaging the chassis.

The high profile was a big problem for the sIG 33 auf Pz. I too, making it an easy target for enemy artillery gunners. The armor was also quite light and offered only limited protection from small arms fire and shrapnel.

It must be noted that this vehicle was not designed to be used as an assault weapon. Instead, it was intended to be used in a supporting role from a distance, where the lack of armor was not so important. Regardless, heavy camouflage and a well-selected combat position were necessary for the crew’s survival, but this was not always possible or easy to achieve successfully.

Low ammunition capacity was a major issue, especially during prolonged fighting, as the gun could quickly run out, which limited its combat potential. The sIG 33 auf Pz. I, therefore, needed constant support from a supply vehicle for the delivery of additional ammunition, which were themselves in short supply. Moreover, the crew compartment was too cramped, meaning that some of the vehicle’s crew had to be transported by these ammunition vehicles.

Despite its flaws, the sIG 33 auf Pz. I would become an example of how the Germans would (especially in the later part of the war) reuse obsolete or captured tank chassis and combine them with the 15 cm sIG gun. Later models would use more fitting tank chassis, such as the Panzer 38(t), which would be built in much greater numbers. The sIG 33 auf Pz. I may not have been a perfect weapon, but it influenced the future development of similar vehicles used by the Germans during the war. It not only helped German designers and engineers gain experience in making similar vehicles, but also contributed to the development of adequate tactics.

The author of this article would like to thank Guillem Martí Pujol for providing valuable data and Smaragd123 for providing photographs.

15 cm sIG 33 (Sf) auf Geschüetzwagen I Ausf.B Sd.Kfz.101 of the schwere Infanteriegeschütz-Kompanie 701, France, May 1940.
15 cm sIG 33 (Sf) auf Geschüetzwagen I Ausf.B Sd.Kfz.101 of unit 704, attached to the 5th Panzerdivision.
Both illustrations were produced by Tank Encyclopedia’s own David Bocquelet.
sIG 33 auf Pz. I Specifications
Weight 7 tonnes
Crew 4 to 5 (driver, commander/gunner, loader, and radio operator)
Engine Maybach NL 100 hp ​​@ 3,000 rpm
Speed 35-40 km km/h / 12-15 km/h (cross-country)
Range 170 km / 115 km (cross-country)
Armament 15 cm sIG 33
Armor 4 to 13 mm

Sources

T. Anderson (2020) The History of the Panzerwaffe, Osprey Publishing
J. Engelmann, Bison und andere 15 cm-Geschutze auf Selbstfahrlafetten, Podzun-Pallas-Verlag GmbH
P. Chamberlain and H. Doyle (1978) Encyclopedia of German Tanks of World War Two – Revised Edition, Arms and Armor press.
Ian V. Hogg (1975) German Artillery of World War Two, Purnell Book Services Ltd.
T. L. Jentz and H. L. Doyle (1998) Panzer Tracts No.10 Artillerie Selbsfahrlafetten
H. Doyle (2005). German Military Vehicles, Krause Publications
F. V. De Sisto (2010) Early Panzer Victories, Condor Publication Company
Tank Power Vol.XXIV 15 cm sIG 33(Sf) auf PzKpfw I/II/III, Wydawnictwo Militaria
D. Nešić (2008) Naoružanje Drugog Svetskog rata-Nemačka, Beograd
W. Oswald (2004) Kraftfahrzeuge und Panzer Motor Buch Verlag
T. Anderson (2019) Panzerartillerie, Osprey publishing
D. Predoević (2008) Oklopna vozila i oklopne postrojbe u drugom svjetskom ratu u Hrvatskoj, Digital Point Tiskara

Categories
Has Own Video WW2 German SPGs

Gepanzerter 8t Zugkraftwagen and 8.8 cm BuFlak ‘Bunkerknacker’

German Reich (1938-1940)
Armored Towing Vehicle – 25+ Built
Anti-Aircraft Gun – 33 to 50 Modified

Prior to the Second World War, the Germans were aware that they would need weapons that could deal with enemy fortified positions, such as bunkers. Their anti-tank guns and most of the artillery were not suited for this task. During the Spanish Civil War, the 8.8 cm Flak anti-aircraft gun proved to be quite effective when used against ground targets. Thanks to its large caliber and high velocity, the German Army officials came up with the idea of modifying some of them for use against enemy bunkers. Around 50 or so guns would be modified and used during the invasion of the West in 1940.

Heavily modified Sd.Kfz.7 half-track with the specialized 8.8 cm Flak gun.Source: https://www.worldwarphotos.info/gallery/germany/halftracks/sdkfz-7/

A Brief  8.8 cm Flak History 

In search of a new anti-aircraft gun, Krupp was contacted by German Army officials to develop such a design. In 1931, Krupp engineers returned to Germany after spending years cooperating with the Swedish Bofors company to begin construction of the gun under the most secret conditions. By the end of September 1932, Krupp delivered two guns and 10 trailers. After a series of firing and driving trials, the guns proved to be more than satisfying, and, with some minor modifications, were adopted for service in 1933 under the name 8.8 cm Flugabwehrkanone 18 (Eng: anti-aircraft gun) or, more simply, Flak 18.

Its overall anti-aircraft performance was similar to other nations’ heavy anti-aircraft guns. It gained its fame as an excellent anti-tank weapon in the early years of the war. This gun helped the Germans when other weapons failed them in this role. It would remain in German use up to the war’s end, with over 20,000 such guns being built. Many, including copies, would see service for several more decades.

The 8.8 cm Flak 18. Source: Pinterest

Not a Ground Attack Weapon 

Despite its fame as an excellent anti-tank weapon during the war, the 8.8 cm Flak was not intended to fulfill this role. Proof for this can be seen in a Wa Prw document dated October 1935. In it, a list of all available anti-tank weapons that were in use or under development was mentioned. In addition, weapons and guns that could be used in this manner were noted too. This included some 2 cm and 3.7 cm caliber anti-aircraft weapons. Somewhat surprisingly, the 8.8 cm Flak gun was not mentioned for potential use as an anti-tank weapon. Two years later, armor-piercing rounds for the 2 cm and 3.7 cm anti-aircraft guns were included in the anti-aircraft development program. The 8.8 cm caliber was once again not included, and thus, no armor-piercing rounds for it were to be developed.

The Germans at this point did not consider the 8.8 cm Flak to be a viable anti-tank weapon. The main reasons for this were its sheer size, the difficulty of movement once employed, and concealment. The only German anti-tank gun that was in service during this time was the 3.7 cm PaK 36. It could be easily moved by only a few crew members, was a small target, and had sufficient firepower to deal with most of the tanks from that era.

When the war in Spain broke out in 1936, the Germans responded to Francisco Franco’s call for aid. The Germans dispatched both ground and air forces to Spain, including a small number of the 8.8 cm Flak guns. As the Nationalists gained the upper hand in the air, the 8.8 cm guns were employed for the destruction of ground targets, where their firepower showed that it had great potential in this role. Thanks to their half-track towing vehicles, mobility was not a major issue, as these possessed good overall drive on-road and off-road.

Even before the Spanish War ended, in 1938, the Heereswaffenamt (German Army weapons agency) and, more importantly, Adolf Hitler himself, requested that the 8.8 cm Flak 18 be adapted for use against ground targets. Their primary missions would be to destroy enemy fortified positions, such as bunkers, but also tanks if any came into range. Mobility was a major factor, as the gun had to be quickly positioned to take action against enemy targets. Two proposals would be adopted. The first would be by placing the gun on a half-track chassis, creating the 8.8 cm Flak 18 Sfl. auf schwere Zugkraftwagen 12 t (Sd.Kfz.8) als Fahrgestell. The second variant was more orthodox in design, consisting of an armored half-track prime mover and a slightly modified 8.8 cm Flak 18 gun.

Some 10 8.8 cm Flak 18 Sfl. auf schwere Zugkraftwagen 12 t (Sd.Kfz.8) als Fahrgestell would be built. While having a number of issues with their overall design, these vehicles would prove to be effective anti-tank weapons during the war. Source: en.wheelsage.org

The latter version was known as the 8.8 BuFlak (Bunker Flak). Given its purpose, the destruction of enemy bunkers, these 8.8 cm guns are sometimes referred to as Bunkerknacker (Eng: bunker destroyer). It is important to note that this name was not only used to describe the 8.8 cm gun, but also for other weapons that performed similar roles, such as the 10.5 cm K 18 guns. The term  Gepanzerte Flak is also sometimes used. The towing vehicle was designated as Gepanzerter 8t Zugkraftwagen.

Increasing the 8.8 cm Flak gun’s mobility was to be achieved by firing the gun while still connected to its two-wheeled bogies. In this way, the crew would not need to waste time lowering the gun and removing the bogies. A new shield was to be added to the gun for crew protection, albeit minimal in scope. In addition to protecting the crew, their towing vehicle would be armored as well. The vehicle chosen for this conversion was the Sd.Kfz.7, which was the standard towing half-track for the 8.8 cm Flak gun prior to and during the war.

The first wooden mock-up of the modified Flak gun. Source: T.L. Jentz and H.L. Doyle Panzer Tracts No. 22-5 Gepanzerter 8t Zugkraftwagen and Sfl.Flak

Production

In order to implement what was seen as an urgent project, Rheinmetall was contacted in August 1938. Rheinmetall engines worked hard, completing the wooden mock-up by 19th August. Only a week later, the first prototype was completed and tested at Kummersdorf. By the end of September, around 50 such modified guns would be built. Authors, such as  T. Anderson (History of Panzerwaffe Volume 1 1939-42), mention that 33 guns were modified this way.

While the number of the modified guns is known, the precise number of modified towing vehicles is unknown. Authors T.L. Jentz and H.L. Doyle (Panzer Tracts No. 22-5 Gepanzerter 8t Zugkraftwagen and Sfl.Flak) mention that, thanks to photographic evidence, it is known that at least 25 such vehicles were built, though possibly more. The first vehicles were completed in mid-1938.

Design of the 8.8 cm BuFlak Gun

The Gun 

The 8.8 cm Flak 18 used a single tube barrel which was covered in a metal jacket. The barrel itself was some 4.664 meters (L/56) long. The gun recuperator was placed above the barrel, while the recoil cylinders were placed under the barrel.

The 8.8 cm gun had a horizontal sliding breechblock which was semi-automatic. It meant that, after each shot, the breach opened on its own, enabling the crew to immediately load another round. This was achieved by adding a spring coil which was tensioned after firing. This provided a good rate of fire of 15 rounds per minute when engaging ground targets. Despite its maximum range of 15.2 km (with a muzzle velocity of 840 m/s), modified Flak guns were meant to engage enemy bunkers and positions in ranges of less than 1 km.

The modified Flak guns received a slightly changed Flakzielfernroht 20E telescopic sight. Its original use of degree grading was replaced with meters. The gunsight was positioned some 71 cm to the right and 20 cm below the gun. The gunner had to take this into account during firing. The gunsight had to be accordingly positioned slightly to the right and below the target.

The crew manual for this weapon notes that the best and most stable firing position was when the gun was facing forward or to the rear. When fired to the sides, great care had to be taken so that the gun could take the firing recoil. No source provides a precise weight of this gun, but given that it received minimal modifications, it would likely remain the same or quite similar to the original, which had a weight in firing position of 5,150 kg, while the total weight was 7,450 kg.

Controls

Initially, the Flak 18 had two handwheels, one responsible for elevation or one for the traverse. These were located on the right side of the gun. In essence, this meant that two crew members were needed to fully control the movement when tracking targets. The Flak gun that was intended to be solely used for ground operations had to have changed controls. The two separate handwheels were replaced with a single operating unit that contained both of these controls. This new control unit was placed on the forward right side, close to the shield. Essentially, this meant that only one crew member, the gunner, was needed to fully engage targets. Due to its primary mission of engaging ground targets, the elevation was limited to -4° to +15°.

Carriage

Given its size, the gun used a large cross-shaped platform. It consisted of the central part, where the base for the mount was located, along with four outriggers. The front and the rear outriggers were fixed to the central base. The gun barrel travel lock was placed on the front outrigger. The side outriggers were shorter in contrast to those originally used. On these two side outriggers, the round-shaped leveling jacks were replaced with a new square-shaped jack. Their purpose was to prevent the gun from digging into the ground and to keep the gun level on uneven ground.

The modified 8.8 guns had side outriggers that were shorter in comparison to those of normal guns. Also note the new square-shaped jacks. Source: www.worldwarphotos.info  
In comparison, the original side outriggers were longer and had round-shaped leveling jacks. Source: T.L. Jentz and H.L. Doyle Panzer Tracts No. Dreaded Threat The 8.8 cm FlaK 18/36/47 in the Anti-Tank role

Bogies

The whole gun was moved using two-wheeled bogies designated as Sonderanhanger 201. The front bogie had single wheels, while the rear one consisted of a pair of wheels per side. Another difference between these two included that the front bogie had 7 and the rear 11 transverse leaf springs. The wheel diameter was the same for the two, at 910 mm. These were also provided with air brakes. In contrast to ordinary guns, this version was to be fired while the two bogies were still connected to the gun carriage.

These guns were to be fired by still connected to the two bogies. This made them rather tall targets for enemy gunners. Source: T.L. Jentz and H.L. Doyle Panzer Tracts No. 22-5 Gepanzerter 8t Zugkraftwagen and Sfl.Flak

Shield 

Another new implementation was the introduction of a slightly modified armored shield. It had a simple rectangular shape and was placed at an angle. To the right, there was a hatch that could be closed if needed. Its purpose was to provide the gunner an opening to spot his targets. While an ordinary 8.8 cm Flak front armor shield had a small opening on top for the gun to elevate to the sky, this gun shield did not have it, and it was instead covered with a plate. To somewhat further increase the gun operator’s protection, two smaller triangle-shaped side armor plates could be expanded to both sides. When on the move, these were folded to the front armor shield. The precise armor thickness is not listed in the sources, but it is mentioned that it was slightly thicker than the 10 mm used on the original 8.8 cm Flak shield. While not particularly thick, it was intended to protect the crew from small-caliber rounds and shrapnel.

Front view of the new gun shield, which was slightly enlarged. As the upper part of the shield was enclosed, the gun could not be used to target enemy aircraft. Source: T.L. Jentz and H.L. Doyle Panzer Tracts No. 22-5 Gepanzerter 8t Zugkraftwagen and Sfl.Flak  
For comparison, the armored shield used on ordinary 8.8 cm guns had an opening at the top which enabled the crew to elevate the gun barrel to engage air targets. In addition, it was somewhat smaller in dimensions. Source: www.deviantart.com

Ammunition

The modified Flak gun was mostly meant to fire high-explosive and anti-tank rounds. The 8.8 cm Sprgr Patr was a 9.4 kg high-explosive round with a 30-second timed fuze. The 8.8 cm Pzgr Patr was a 9.5 kg standard anti-tank round. With a velocity of 810 m/s, it could penetrate 95 mm of 30° angled armor at 1 km. At 2 km, at the same angle, it could pierce 72 mm of armor. Using an armor-piercing round, at 70° angle, it could penetrate 1 m of concrete at 1 km distance. As these guns could not be used in their original role, the fuse setting device was replaced with a box-shaped ammunition bin that contained 6 rounds of ammunition.

Another modification was the introduction of ammunition storage for six rounds, which was placed where the fuse setting device was originally located. The ammunition box on this gun is currently empty. Due to its high rate of fire, the ammunition could be easily spent in a short amount of time. Source: T.L. Jentz and H.L. Doyle Panzer Tracts No. 22-5 Gepanzerter 8t Zugkraftwagen and Sfl.Flak

Crew

The vehicle with the gun had a crew of 7. This consisted of the commander, loader, gunner, and four additional gun assistants. The gunner was placed on the right side of the gun and was responsible for operating the gun traverse, elevation, and firing mechanism. Left of the gunner was the loader’s position. Due to the use of bogies during firing, the height of the gun was raised. In order for the loader to be able to load a new round, a metal platform was welded on this side to stand on. The commander and the remaining crew were responsible for moving the gun, carrying additional ammunition, and spotting targets.

Due to its increased height, it was necessary to add a platform for the loader. Also, note the smaller shape of the lowered side outrigger. Source: T.L. Jentz and H.L. Doyle Panzer Tracts No. Dreaded Threat The 8.8 cm FlaK 18/36/47 in the Anti-Tank role  
Another view of the loader’s positions. The loader was put in a quite precarious and somewhat exposed position, where a well-placed enemy bullet could easily end his life while loading the gun. Source: T.L. Jentz and H.L. Doyle Panzer Tracts No. 22-5 Gepanzerter 8t Zugkraftwagen and Sfl.Flak

The Gepanzerter 8t Zugkraftwagen 

The primary towing vehicle for the 8.8 cm Flak guns was the Sd.Kfz.7 half-track, although it was also not uncommon to see heavy 6×6 wheeled trucks being used in this role. The Sd.Kfz.7 was developed in the mid-1930 by Krauss-Maffei. During its production run, some changes to its design would be implemented, mostly in an attempt to increase its overall performance. This would lead to the installation of a stronger engine and adding two more road wheels per side. The performance was deemed satisfactory and some 12,000 such vehicles would be built up to 1945. The Sd.Kfz.7 also saw limited export success, being sold in small numbers to Brazil, Hungary, Japan, the Soviet Union even Great Britain after the war. It was also built in Italy under the Breda 61 designation.

As the previously mentioned 8.8 cm guns were to be used for destroying enemy fortified positions at relatively close ranges, a soft-skin towing vehicle was deemed undesirable for this task. For this reason, unknown numbers of Sd.Kfz 7 was modified, receiving an armored body to protect the engine, crew, and ammunition.

The Sd. Kfz. 7 half-track in its original configuration. Source: wwiitank.wordpress.com

Chassis and Suspension

The Sd.Kfz 7 chassis and its suspension seem to have been unchanged. The suspension consisted of 6 road wheels, a rear idler, and a front positioned drive sprocket. The front four wheels were suspended using a balance suspension. The remaining wheels were placed on a pivoting arm suspended using a semi-elliptic leaf spring unit.

The armored Sd.Kz. 7’s suspension and overall chassis construction seem to have been unchanged. Also, note the side hatch door located beneath the driver compartment. Source: T.L. Jentz and H.L. Doyle Panzer Tracts No. 22-5 Gepanzerter 8t Zugkraftwagen and Sfl.Flak

Crew

The crew of this vehicle consisted of only the driver, who was positioned on the front left side of the driver compartment. During the drive, the commander would sit next to the driver. The remaining crew were located in the rear crew compartment.

Armored Body

The armored body of this vehicle resembles that used on the Sd.Kfz.251 armored half-track. It was well angled and covered the whole length of the rear compartment. In addition, it was open-topped. The armor thickness of the plates used for this vehicle was 15 mm. With this thickness and with the angled sides, it provided sufficient protection from small-caliber rounds and artillery shrapnel only.

The armored body of this vehicle could basically be divided into a few sections: the engine compartment, the driver compartment, the crew compartment, and the ammunition storage bin. The engine’s sides and front were fully enclosed with an armored shield. On both sides, there were four large hatches. These could be opened to provide better ventilation for the engine. The top of the engine compartment was not protected.

The engine front and side were fully protected. On each side, there were two hatch doors that could be opened for better engine ventilation. Source: www.armedconflicts.com

The drive compartment was slightly raised up from the rest of the armored body. It was open-topped and had four protective hatches, two at the front and one on each side. In addition, on the bottom of the sides of the driver compartment, two larger hatches were located. Their purpose is not clear, and they served either for some kind of storage or to allow the driver and the commander to exit the vehicle. Behind was the gun crew compartment. The crew was positioned on two benches placed opposite each other. In order to exit the vehicle, there was a hatch at the rear of this compartment. Lastly, to the rear of the vehicle, box-shaped armored ammunition storage was located. It contained some 24 spare rounds of ammunition.

The top of the engine compartment was left unprotected. Source: T.L. Jentz and H.L. Doyle Panzer Tracts No. 22-5 Gepanzerter 8t Zugkraftwagen and Sfl.Flak  
Top view of the driver’s position. Source: T.L. Jentz and H.L. Doyle Panzer Tracts No. 22-5 Gepanzerter 8t Zugkraftwagen and Sfl.Flak  
The ammunition storage could hold 24 rounds to the rear of the vehicle. Source: T.L. Jentz and H.L. Doyle Panzer Tracts No. 22-5 Gepanzerter 8t Zugkraftwagen and Sfl.Flak

Performance

The ordinary Sd.Kfz.7 vehicles had a 140 hp HL 62 TUK engine and could reach up to 50 km/h. With a fuel load of 213 liters, the operational range on roads was 250 km, and 135 km off-road. The length of this vehicle was 6.85 meters, width 2.4 meters, and height 2.62 meters. While the performance of the Gepanzerter 8t Zugkraftwagen is not mentioned in the sources, the additional weight from the armor plates probably affected its overall performance. To which extent this was the case it is quite difficult to know.

Either due to losses or some other reasons, ordinary unarmored Sd.Kfz 7 half-tracks would sometimes be used as towing vehicles, like in this case. Source: T. Anderson History of Panzerjager Volume 1 1939-42

Training and Organization  

By the order of the Oberkommando des Heeres (Eng. German High Command), the training of the first crews that were to operate these guns was to commence during September 1938. The main training center was to be at the Juterbog artillery school.

Nominally, these were intended to be attached to heavy motorized artillery or anti-tank battalions. The order for the employment of these vehicles was to be issued by the command of an infantry regiment.

Prior to the engagement, the commander, along with two assistants, would go ahead to observe its target, find the best firing position, and the best way to retreat if needed. Once the location was found, the gun was moved to that position. Despite the 8.8 cm gun’s good firing range, targets were to be engaged at less than 1 km. In addition, due to its somewhat limited elevation, great care had to be taken by the crews to choose good firing positions. Given that the crew had to come rather close to the target, hiding and camouflaging the gun was seen as essential. Because of its sheer size, in practice, this would be a difficult task to undertake in close proximity to the target. Smoke screens were meant to be used while the gun was preparing to fire.

These units were to be primarily used in destroying enemy fortified positions, such as bunkers. Since the target hit rate was expected to be around 30%, shooting at greater ranges than that had to be avoided. If enemy tanks came into range, these were also to be targeted.

Some 11 vehicles were attached to the 525th, 560th, and 605th schwere Panzer Jäger Abteilung (Eng. heavy anti-tank battalions) each. Each of these battalions were divided into three companien (Eng. Company).

In Combat

Occupation of The Sudetenland 

The first ‘combat’ use of the Gepanzerter 8t Zugkraftwagen and Sfl.Flak was during the occupation of the Sudetenland in 1938. This operation was peaceful and the 8.8 cm guns did not have to fire in anger. While its self-propelled cousin saw service in Poland, use of the Gepanzerter 8t Zugkraftwagen and the 8.8 cm BuFlak in this campaign is not recorded, which likely suggests that it was never employed there.

The Gepanzerter 8t Zugkraftwagen and Sfl.Flak in the occupied Sudetenland. Source: T.L. Jentz and H.L. Doyle Panzer Tracts No. 22-5 Gepanzerter 8t Zugkraftwagen and Sfl.Flak

In France

The 525th, 560th, and 605th heavy anti-tank battalions would see service during the German West campaign of 1940. During this campaign, they were attached to various units depending on the combat needs. Unfortunately, their overall performance and usage is rather poorly documented.

The 525th heavy anti-tank battalion saw its first action while helping clean Allied road barricades at Trois Ponts on 10th May 1940. The following day, it provided its firepower to the 49th Infantry Regiment that was attacking a bunker. After firing several rounds, the bunker crew surrendered. On 19th May, while driving toward Dinant, two vehicles from the 525th heavy anti-tank battalion ran into an enemy ambush and were hit by machine gun and anti-tank fire. One armored Sd.Kfz 7 was hit by an anti-tank round and was set on fire. The fire would expand to its ammunition storage, igniting it into an explosion. The second vehicle was hit with machine gunfire. Its crew abandoned the gun and used the armored towing vehicle to retreat. An hour later, they returned to recover the damaged gun.  The gun would be repaired that evening and the unit advanced toward Clairefontaine.

The following day, another vehicle arrived to support the attack of the 49th Infantry Regiment at the Allied held Assevent. Elements of the 525th heavy anti-tank battalion participated in this engagement with two guns. One gun was positioned to protect the infantry against enemy armor, which had been spotted. The second gun proceeded forward, but its towing vehicle hit a metal bar which immobilized it. The crew had to sit by this vehicle and wait for a replacement. Soon, the replacement vehicle arrived and the crew continued the advance. Once in a designated position, at least three enemy machine gun positions were destroyed. The crew of this gun noticed that friendly infantry was retreating under fire from enemy B1 bis tanks. One was engaged at a distance of 300 m and destroyed. The second vehicle was hiding behind a wooden hut. As it emerged to target the 8.8 cm gun, it was hit, exploding in the process. Seeing the two tanks destroyed, the German infantry made a counter-attack. These guns were also used to support the 51st Infantry Regiment advancing toward Dunkerque during May 1940.

The Gepanzerter 8t Zugkraftwagen towed an 8.8 cm gun at the start of the German attack in May 1940. Source: /www.armedconflicts.com  
An 8.8 cm firing at Allied positions near Dunkerque in May 1940. Source: W. Muller The 8.8 cm FLAK In The First and Second World Wars  
Despite their armor, the Gepanzerter 8t Zugkraftwagen could still be taken out by almost any anti-tank weapon. Source: www.armedconflicts.com

Following the successful conclusion of the West campaign, the 525th, 560th, and 605th heavy anti-tank battalions were equipped with ordinary towed 3.7 cm anti-tank guns. The reason for this decision is not known. The order for the reorganization of these units did not include an explanation for this decision. Other units (both Heeres and Luftwaffe), which operated normal 88 mm Flak guns were more than satisfied with their overall performance. This is also supported by the German General Staff, which even argued that the 8.8 should be incorporated into each infantry division. A possible reason for the removal from service of the BuFlak may have been poor training and use. Another issue may have been related to the gun’s limited elevation, which prevented it from being operated in anti-aircraft use.

The fate of the guns and towing vehicles is unknown. It is likely that both types which survived the West campaign were converted back to their original configurations.

Conclusion

The Gepanzerter 8t Zugkraftwagen and its modified Flak gun were an attempt to provide the German ground forces with an effective anti-bunker and anti-tank vehicle. Its overall performance is quite difficult to describe due to the lack of sources and information about its use.

While the 8.8 cm gun was unquestionably an effective weapon when used against fortified targets or tanks, this design was rather questionable. The 8.8 cm Flak in its original configuration was already a tall target. The modified gun was even taller, which made it even easier for the enemy to see. The  Gepanzerter 8t Zugkraftwagen, while protected, in contrast to the ordinary towing variant, was often easily taken out due to the required close proximity to the target.

Due to a lack of information, the precise reason why this vehicle and its gun were removed from service is not known. It is likely that this was done more due to its poor organizational usage than due to any major flaws in its design, as the 8.8 cm Flak and the soft-skin towing vehicles would see major action up to the war’s end.

Gepanzerter 8t Zugkraftwagen. Ilustration made by Godzilla  

8.8 cm BuFlak ‘Bunkerknacker’. Ilustration made by Godzilla

8.8 cm BuFlak Specifications

Dimensions 7.7 x 2.2 x 2.9 m
Weight in firing position:  5.150  tonnes
Crew  7 (Commander, loader, gunner, and four additional gun assistants)
Primary Armament: 8.8 cm L/56 gun
Elevation: -4° to +15°

 

Gepanzerter 8t Zugkraftwagen Specification

Dimensions (l-w-h) 6.84 x 2.4 x 2.62 m
Total weight, battle-ready 23.6 tonnes
Crew 1 (Driver)
Propulsion 140 hp HL 62 TUK
Speed  50 km/h
Range (road/off-road) 250 km, 135 km
Armament None
Armor 15 mm

Sources

 

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10.5 cm leFH 18/2 (Sf.) auf Fahrgestell Panzerkampfwagen II ‘Wespe’ (Sd.Kfz.124)

German Reich (1943)
SPG – 662-753 Built

The greatest strength of the German Panzer Divisions during World War II was their rapid speed and ability to engage the enemy with concentrated force. But, sometimes, this was not enough, and additional firepower was needed to soften designated targets. This was the job of the Panzer Division’s own towed artillery. This was not always possible, as the mechanized towed and horse-drawn artillery could not always keep up with the advancing Panzers. They also needed time to properly set up for firing and were prone to enemy return artillery fire.

The le.F.H.18/2 auf. Fgst.Pz.Kpfw.II (Sf) (Sd.Kfz.124). Source: warspot.ru

A more suitable solution was a tank-based self-propelled artillery vehicle. This was not possible to achieve in the early stages of the war, as the German tank industry was barely keeping up with the demand for tanks. It was not until 1942 that the first proper steps were undertaken in developing such vehicles. While initially, dedicated vehicle designs were considered, due to a lack of time, the Germans went for a stopgap solution. Originating from this, two different designs would emerge: the larger 15 cm armed Hummel and the smaller 10.5 cm armed Wespe. While intended as interim solutions, both would be built in relatively great numbers and used up to the end of the war.

History

During the early stages of World War II, German Army officials were aware that having mobile self-propelled artillery that could keep up and support the Panzer Divisions was desirable, but no major attempt was made in that direction. There were a number of reasons why this was never implemented during the first few years of the war or before it. One fact was that the German industry was unable to produce enough tanks, let alone have spare production capacity for other projects. The Luftwaffe provided the Panzer Divisions with adequate close operational fire support to compensate for the lack of a mobile artillery vehicle.

From 1940 to 1942, there were a number of different but limited attempts to build such vehicles. These included the Panzer I and Panzer II-based self-propelled vehicles equipped with the 15 cm sIG 33 infantry gun, which were built in small numbers. French captured tanks and tracked artillery tractors were also modified for this role. As these were built on captured chassis and without the possibility of mass-producing necessary parts, these would be built in smaller numbers and their use would be limited. Smaller numbers of British Vickers Light Tanks were modified with 10.5 cm guns and saw some use on the Eastern Front.

By 1942, it was obvious that the development of self-propelled artillery was urgent, as the Luftwaffe was losing control of the skies. For this reason, in the same year, Wa Prüf 6 (the office of the German Army’s Ordnance Department responsible for designing tanks and other motorized vehicles) issued requests for a new self-propelled artillery vehicle.

15 cm sIG 33 (Sf) auf Panzerkampfwagen I Ausf B, of which less than 40 would be built. This was one of the earliest German attempts at increasing the mobility of towed artillery. Source: Wiki

The initial request may have been somewhat overcomplicated, as it was requested that the new vehicle should have a full 360° firing arc (something that no other self-propelled artillery had during the war). The second major request was that it should have had the possibility of removing its main weapon and using it in a static emplacement. The Germans had a few such projects in development, like the ones based on the Panzer IV chassis (the Heuschrecke, for example). However, these would take too much valuable time to be properly developed and adopted for production. So, the German High Command (Oberkommando des Heeres-OKH) decided to proceed with a simpler solution for the time being. The so-called Zwischenlösung (interim solution) was to include chassis and other components that were already in production and available. After a short deliberation, in mid-July 1942, a decision was made by a Panzercommision to reuse the Panzer II Ausf.F chassis for this purpose. The Panzer II tank was already obsolete and used mostly in the reconnaissance role. Its chassis was also being reused for the Marder II anti-tank project.

To design this new vehicle, a contract was awarded to Rheinmetall-Borsig and Alkett. The Panzer II Ausf.F chassis had to be modified by moving the engine to the center of the vehicle, thus making room for a rear fighting compartment. It was to be lightly protected and armed with a 10.5 cm howitzer. When the vehicle was completed and tested, a report was presented to Hitler, in which it was noted that this modification was feasible to enter production by the end of July 1942.

The first Wespe prototype. It incorporated some elements, like the large muzzle brake, round-shaped driver compartment cover and one headlight, that would not be implemented on the production vehicles. Source: warspot.ru
Another view of the first prototype. Source: warspot.ru

Name

The first official name given to this vehicle was Leichte Feldhaubitze 18/2 (Sf) auf Geschützwagen II, dated from July 1943. During its service life, the vehicle received several slightly different designations. These included G.W. II ‘Wespe’ für le.FH 18/2 (Sf) auf Gw II from August 1943, Geschützwagen II in November 1943, leichte Panzerhaubitze auf Sd.Kfz.123 in May 1944, and le.F.H.18/2 auf. Fgst.Pz.Kpfw.II (Sf) (Sd.Kfz.124) in October 1944.

The name by which this vehicle is best known, Wespe (wasp), was actually only a suggestive name that was officially discontinued after February 1944. For the sake of simplicity only, this article will use the Wespe designation.

Production

For the production of the Wespe, FAMO (Fahrzeug und Motorenwerke GmbH) factories, located in Breslau, and the Ursus (which was also part of FAMO) ones from Warsaw were chosen. FAMO was already involved in Panzer II and Marder II production, so it possessed the production capabilities necessary for the new project. According to the German Army production plans for this project, some 1,000 vehicles were to be built by May 1944. After that, better designed mobile artillery was to replace it, something which never happened.

The first two production vehicles would be built by FAMO in February 1943. In order to speed up the production of the Wespe, the Marder II production would be terminated. The FAMO main production line at Breslau would be included in Wespe production up to August 1943, after which it was to focus solely on the production of the large Sd.Kfz.9 half-tracks. Following this decision, it was also decided to reduce the overall production order to 835 vehicles. With FAMO leaving the Wespe project, the only manufacturer remaining was Ursus. The total production price of each Wespe was 65,628 Reichsmarks (49,228 for the chassis and 16,400 for the gun).

Monthly production in 1943
February 2
March 40
April 136
May 37
June 34
July 59
August 57
September 49
October 37
November 38
December 38
Monthly production in 1944
January 37
February 33
March 35
April 19
May 20
June 19
Total 676

These production numbers are from T.L. Jentz and H.L. Doyle’s book, Panzer Tracts No.10-1 Artillerie Selbstfahrlafetten. As with many other German vehicles, production numbers differ between sources. Authors F. Koran and J. Starosta (Wespe in detail) list that 685 vehicles were built. According to author J. Engelmann (Wespe-Heuschrecke), 682 vehicles were built. Interestingly, author P. P. Battistelli (Panzer Divisions 1944-45) gives a production range between 662 and 753 being built.

The design

Hull

The Wespe was constructed using a heavily modified Panzer II chassis. Its hull consisted of the forward-mounted transmission, centrally positioned engine, and the rear fighting compartment for the crew and the main gun. The Wespe hull was slightly longer than the original Panzer II hull, by some 220 mm. Depending on the source, this lengthening was either introduced at the start of production or at some point in the later months of production.

An illustration of the Wespe’s internal components. Source: http://panzerserra.blogspot.com/2020/05/wespe-105-cm-lefh-182-auf-gii-sdkfz-124.html

Suspension

The suspension of the Wespe was, in essence, the same as that of the original Panzer II, with some changes implemented during the production. It consisted of five large 550 x 98 x 455 mm road wheels (on each side) which had rubber rims. Above each wheel, on a rocker arm, a quarter elliptical leaf spring unit with a movable roller was placed. With the addition of the new gun, more crew members, ammunition, and such, it led to an increase of the weight from 9.5 to 11 tonnes. To cope with this extra weight, the Wespe suspension was additionally strengthened by widening the leaf springs above the wheels.

There was also a front-drive sprocket (with a diameter of 755 mm), a rear positioned idler (650 mm diameter), and three return rollers (220 mm x 105 mm) on each side. The track had a width of 300 mm and consisted of 108 links. The ground pressure was 0.76 kg per square centimeter.

The Wespe shared, with some changes, the same Panzer II suspension. Source: panzerserra.

The first Wespes produced had the same bump stops as the original Panzer II. After only a few months of production, new stronger bump stops with vertical volute springs were added on the first two wheels on both sides. The vehicles produced after November 1943 had one more bump stop added to the last wheel. This was one of the few modifications added to the Wespe vehicles during production.

During production, some changes were implemented, like adding two (and later one more) bump stops with vertical volute springs on the first two wheels per side. For some unknown reason, the last road wheel is lacking its rubber rim. Source: warspot.ru

Engine and transmission

The Wespe’s engine was positioned in the center of the Panzer II Ausf.F hull. This was done to provide more working space for the crew and provide better stability during the firing of the gun. The powerplant was unchanged, using the same Maybach HL 62 TR 6-cylinder water-cooled engine giving 140 hp@2600 rpm. The two fuel tanks, with a total 170-liter capacity, were placed under the crew compartment. The maximum speed with this engine was 40 km/h and the cross-country speed was 20 km/h. The Wespe’s operational range was 140 km on good roads and 95 km cross-country. The engine and the crew compartment were separated by a 12 mm thick protective firewall.

As the engine was moved to the center, the drive shaft that connected it to the forward-mounted transmission system was shortened. The Zahnradfabrik SSG 46 type transmission had six forward and one reverse gears.

Superstructure

On top of the modified Panzer II hull, a new superstructure was placed. The front part of it consisted of a simple armored plate placed at a steep angle. On the left side, a fully enclosed driver compartment was added. The original prototype had a more rounded driver compartment cover. The actual production vehicles had a simpler three-sided design with angled armor. Some sources indicate that, during the production, both models of driver compartment design were used. This is false, as the round-shaped driver compartment was used only on the prototype vehicle. Interestingly, the surviving prototype vehicle has the production version of this compartment, which means that, at some point, it was changed.

On the sides of the driver’s compartment were two (one on each side) vision slits. In front, there was a square-shaped hatch that could be opened up. When his hatch was closed, the driver would use the front-mounted slit. All the slits were protected by a thick armored glass block. On top of the driver compartment, a two-piece escape door was placed. To have some access to the transmission, a round-shaped hatch (held in place by two bolts) was placed on the right side of the front superstructure plate.

The top positioned two-piece escape door for the driver compartment is visible here. Source: www.worldwarphotos.info
The top positioned two-piece escape door for the driver compartment is visible here. Source: www.worldwarphotos.info

The remainder of the superstructure covered the centrally positioned engine and served as a base for the rear crew compartment. On both sides, there were two cooling air grilles for the engines. The superstructure had mostly simple and flat sides. The central part of the superstructure sides curved slightly inward. Just behind the engine (toward the crew compartment to the rear), an opening for the gun mount was left.

The engine was provided with four cooling air grilles for better ventilation. The remainder of the rear positioned superstructure serves as the base for the new fighting compartment. Source: www.worldwarphotos.info

Fighting compartment

To the rear of the vehicle, a new open-top fighting compartment was placed. It consisted of several armored plates bolted together. The two front plates were angled toward the gun and were additionally reinforced by the gun shield. The height of the side armor plates lowered to the back, mostly to reduce weight. To the rear, a rectangular-shaped door was placed. It could be easily lowered to provide more working room and easy access to additional spare ammunition from auxiliary vehicles. Inside the crew compartment, on both sides, there were a number of brackets for various equipment, such as the radio, fire extinguisher, canvas cover, MP submachine guns and their ammunition, etcetera. The radio and its aerial antenna were positioned on the left side of the fighting compartment. Shells were stored to the rear and the propellant on the sides inside the fighting compartment.

The fighting compartment had a simple but cramped design. Source: Panzer.net
The rear door could be hinged down to provide additional working space, as here, during maintenance. Source: Panzer.net
Top view of the Wespe. The ammunition storage bins to the rear can be seen in the fighting compartment. Source: warspot.ru

Armor

The Wespe was only lightly protected, but this was intentionally done in order to reduce the overall weight and speed up the production as much as possible. The armor thickness was also limited in order to not adversely affect the vehicle’s overall driving performance, as this was the main point of this new vehicle. The use of the Panzer II light tank chassis was another reason why the armor thickness had to be kept minimal, as the added weight could significantly affect its performance.

The front armor of the hull was 30 mm thick and placed at a 75° vertical angle. The sides were 14.5 mm thick, the rear 14.5 mm at 10° horizontal and the bottom was only 5 mm thick. The front superstructure armor was 15 (or 20 mm) thick and placed at a 30° vertical angle. The sides and rear of the superstructure were 15 mm and the top 10 mm thick. The fighting compartment was protected by only 10 mm thick all-around armor. The front armor was placed at 66°, side 73°, and rear 74° vertical angle.

While good mobility was the Wespe’s greatest defense, once cornered, its armor offered no real protection against enemy fire. The Wespe in the foreground is completely destroyed, likely by a direct hit. Source: warspot.ru

The Wespe’s overall armor thickness was never intended to protect against direct hits, but mainly from small-caliber fire, shrapnel, etcetera. The Wespe’s greatest defense was its ability to quickly reposition to another firing position without any fear of returning enemy fire. A good camouflage was also handy for increasing its chances of surviving.

The crews would also camouflage their vehicles to avoid being spotted by the enemy. Source: http://panzerserra.blogspot.com/2020/05/wespe-105-cm-lefh-182-auf-gii-sdkfz-124.html

Armament

For the main weapon of the Wespe, the proven 10.5 cm le.F.H. 18/2 field howitzer was chosen. This was the most common field artillery piece that the German employed during the war. It was designed by Rheinmetall and put into service in 1930. The 10.5 cm le.F.H. 18 had good overall performance, but the range was somewhat lacking. For this reason, it was improved during the war in order to increase its range, mobility, and ease of production.

The 10.5 cm le.F.H. 18 in its original configuration. Source: https://www.armedconflicts.com/10-5-cm-leFH-18-10-5-cm-light-field-howitzer-t678

For the installation of the 10.5 cm le.F.H. 18/2 in the Wespe, the wheels, trails, and the shield were removed. The 10.5 cm le.F.H. 18/2 was then placed in the center of the vehicle, on a specially designed mount. The main weapon had an elevation of -5° to +42° and a traverse of 20° in both directions (or 17°, depending on the source). The maximum firing range, of 10,650 m, could be achieved by using the 14.8 kg heavy high-explosive round. To help with the recoil, the 10.5 cm le.F.H. 18/2 was provided with a muzzle brake. The barrel had to be replaced after firing 10,000 rounds. The Wespe’s uncomplicated construction made such a replacement an easy job, which could be achieved with a simple crane. For aiming the 10.5 cm le.F.H. 18/2, the gunner would use the Rblf 36 gun sight. The recoil distance during firing was 1.15 m, with the maximum allowed being 1.17 m.

During long marches, the Wespe’s main gun could be locked in place by two travel locks. One was placed in front of the gun’s shield and one to the rear. The Wespe’s main weapon was flanked by two curved armored shields.

A close-up view of the Wespe’s modified mount. Source: warspot.ru
The front travel lock was located just outside of the gun’s shield. Source: Parada, M. Suliga and W. Hryniewicki Wespe Sd.Kfz 124, Kagero
As the Wespe was a simple vehicle, the replacement of damaged parts (like the main gun, in this case) was quite easy to achieve. Source: warspot.ru
A heavily camouflaged Wespe battery firing at designated targets. Note the main gun recoiling to the rear. Source: Unknown
This particular Wespe was completely destroyed, exposing the 10.5 cm le.F.H. 18/2, which stayed in its place. Source: pinterest

In some sources (like D. Nešić, “Naoružanje Drugog Svetsko Rata-Nemačka”), the main weapon of the Wespe is described as the le.F.H. 18M. This was actually a slightly improved version of the 10.5 cm le.F.H. 18. The 10.5 cm le.F.H. 18M introduced an improved recoil system, had a muzzle brake, and had a new type of long-range shell, but otherwise, it was the same artillery piece. The modified main gun of the Wespe and the 10.5 cm le.F.H. 18M are quite similar due to the muzzle brake and could have been easily misidentified as the same weapon.

The improved 10.5 cm le.F.H. 18M howitzer. Source: WIki

The 10.5 cm le.F.H. 18/2’s two-part ammunition consisted of the shell and charge. There were three different types of shells that could be used. These included the standard High Explosive (HE), Armor Piercing (AP), and smoke rounds. The charges acted as the propellant for the shells, and there were six different types (marked as 1, 2, 3, etcetera), depending on the desired range.

Initially, the ammunition load consisted of 32 rounds and cartridges. This was officially changed to 30 rounds on 28th June 1943. Of these, 18 HE rounds had normal fuzes and 4 had double fuzes. The remaining 8 rounds were AP rounds. Regarding the charges, 45 were carried inside the vehicle. There were 30 cartridges in the 1-5 range and 15 additional 6 charge cartridges.

For close protection, the crew had at their disposal a 7.92 mm MG 34 or 42, and two 9 mm MP 38 submachine guns. But, given that these vehicles were supposed to act as artillery fire support vehicles from longer ranges, these would ideally be rarely used.

For self-defense, the crew could use either an MG 34 or 42 (mounted on the armored side of the crew compartment) or two MP submachine guns. As these vehicles were designed to provide firing support at longer ranges, it was rare that the crew had to use these in close combat. Source: Pinterest

Crew

The Wespe had a crew of five, which included the commander, gunner, loader, radio operator, and driver. The driver was positioned in the front hull and was the only crew member that had all-around protection. The remaining crew were positioned in the fighting compartment. The gunner was located to the left of the main gun, with the radio operator behind him. The radio equipment consisted of a FuG Spr transmitter and receiver. Interestingly, authors G. Parada, M. Suliga, and W. Hryniewicki (Wespe Sd.Kfz 124) note that the gunners (possibly referring to the gunner and loader) were additionally trained in driving and operating the radio equipment, so that, in case of emergency, if the driver or the radio operator were unable to perform their duties, the other crew members could temporarily take over their roles. To the right of the gun were positioned the commander and the loader.

Despite its small size, the Wespe had a crew of five. Source: https://imgur.com/a/1YTcyOy http://panzerserra.blogspot.com/2020/05/wespe-105-cm-lefh-182-auf-gii-sdkfz-124.html

Due to the Wespe’s small size and cramped fighting compartment, the crews were left with no room to carry extra equipment and spare parts. There was not even room for their personal belongings. It was quite common to see external modifications, such as added storage boxes, spare tracks (although there were standard holders for spare track links on the lower front hull), road wheels, and all sorts of other equipment that the crew may have needed.

These vehicles had a wide selection of added storage boxes, spare wheels and other equipment, something that was quite common among Wespe crews. Source: Wiki

Organization

The Wespes were mainly issued to the Panzer or Panzer Grenadier Divisions of the German Army, but also in some quantities to the SS Panzer Divisions. Six artillery vehicles plus two ammunition Wespes were used to form a Batterie (Battery) which was allocated to the Artillery Regiment of the Panzer Divisions. On average, each Panzer Division would have 12 Wespes while, in rarer cases, some had 18 vehicles (for example, the 3rd Panzer Grenadier Division). These would be further reinforced by a battery of six 15 cm Hummel self-propelled guns.

A Wespe battery consisted of six combat vehicles and two ammunition supply vehicles. As the ammunition supply vehicles were not presented from the start, other soft-skinned vehicles, like trucks, were probably used in the ammunition supply role. Source: Unknown

The first distribution to units

For the upcoming German Kursk Offensive, six divisions were to be equipped with Wespes by the end of May 1943. These included the 17th Panzer Division with 12 vehicles, the 3rd and 29th Panzer Grenadier Divisions, each with 18, Panzer Grenadier Division Grossdeutschland with 12, SS Das Reich with 12 and the LSSAH also with 12 Wespes. The following month, 9 more Divisions were supplied with Wespes. By the end of 1943, over 30 Armored Divisions would be equipped with Wespes, with the majority having 12 and, in rare cases, 6 or 18 vehicles.

In Combat

The Wespe first saw combat action during the German offensive at Kursk in 1943. As the German progress was slow, the Wespes were mostly employed as static artillery support elements. But, thanks to their mobility, they could easily avoid any return artillery fire and minimize their losses.

While not intended to engage tanks other than in an emergency, the Wespes could repel such an attack under ideal circumstances. Such a thing happened some 50 km northwest of Orel, when a group of 8 Soviet tanks tried to overrun a Wespe battery. The Wespe crews opened fire at ranges of over 1.5 km, targeting the Soviet tanks with a mix of AP and HE rounds. Due to the rapid artillery fire, the Soviet tanks decided to abort their attack and retreated without losses.

Not many problems were noted by the crews of the Wespes, with one of the few being the wear of the teeth in the steering gear. There were also problems with oil leaks in the drive housing unit. By the end of 1943, very few Wespes were lost in combat. Of the over 30 Divisions which employed them, only a few had less than 10 operational vehicles, with most being at full strength or close to it.

In Italy, the Wespe performed somewhat more poorly, but this was mainly due to the terrain. In a report made by an unnamed German officer, who was sent to Italy to examine the Wespe’s performance on this front, he noted that the terrain was the Wespe’s greatest enemy:

“….The planned employment of the Sfl.-Artillerie (self-propelled artillery) within a Panzer Division practically never occurred in Italy. This was due to the peculiarity of the terrain and the combat situation. In actual fact, the Sfl. were preponderantly employed in platoons or only as individual guns. Therefore, in no way were useful experiences obtained on the tactical employment of the Sfl. ..”

He also noted several problems with the Wespe that were a consequence of the difficult terrain. These included engines that were too weak and unable to effectively overcome the steep terrain, the final drive units often broke, and that there were a number of breakdowns of other parts like brakes, brake linings, etcetera. He also mentioned that the 3rd Panzer Grenadier Division had 11 vehicles operational out of 18, while the 26th Panzer Division had only 2 operational out of 12. The Wespe would also participate in the battle for France in 1944. In March 1945, there were still some 307 operational Wespes.

A group of mixed German armored vehicles, including four Wespes, two Panzer IIIs, and four Tigers in the background during the Kursk Offensive. Source: www.worldwarphotos.info
A Wespe battery ready to engage enemy positions. Source: Wiki
The Wespe would also see action against the Western Allies in France and Italy. Source: Wiki

Geschützwagen II für Munition

The lack of a tracked ammunition supply vehicle was something that the Germans never managed to solve completely. In the case of the Wespe (and the larger Hummel), they came up with a simple solution. What the Germans did was simply reuse the Wespe chassis by removing the gun to provide room for spare ammunition. The gun opening on the fighting compartment was simply covered with a sheet of metal. This modified vehicle was able to carry some 90 rounds of ammunition. These vehicles could be repurposed back into mobile artillery vehicles quite quickly. The crew consisted of a driver and two additional crew members responsible for ammunition resupply. Between June 1943 and June 1944, some 159 such vehicles would be built.

The ammunition carrier based on the Wespe could be easily identified by the lack of the main weapon and the sheet metal plate that replaced it. Source: warspot.ru

Surviving Wespes

Today, there are a few surviving Wespes in the world. There is one Wespe in the Munster Panzer Museum in Germany. This particular vehicle is actually the first prototype. Another one is in the Russian Patriot Park Museum and one more is at the Saumur Musée des Blindés in France.

The surviving Wespe at the Munster Panzer Museum in Germany. Source: WIki

There are also a number of Wespe wrecks, like the one at the Battle of Normandy Museum in France. In Germany, there is one at the Westwall Museum at Pirmasens. Two more are in Andre Becker’s private collection in Belgium.

Conclusion

Despite being designed as a temporary solution until properly designed self-propelled artillery vehicles would be introduced, the Wespe proved to be a successful vehicle. It provided the German armored units with a fire support vehicle that was able to keep pace with them. While less than 700 were produced, these were widely distributed to various armored Divisions. They were not perfect and had a number of issues, mostly related to their original intended design as a temporary solution and the use of an old lightweight chassis. As the Wespe was meant to be quickly pushed into production, some things, like the working room and armor, had to be sacrificed.

Wespe from the 2nd PanzerArtillerie Regiment, Russia, June 1944
Wespe from the 2nd Panzerartillerie Regiment, Russia, June 1944 – HD picture.
Wespe 146th Panzer Artillerie Regiment, Normandy.
Wespe from the 146th Panzer Artillerie Regiment, PanzerLehr Regiment, Normandy, summer 1944.
Wespe, 8th Panzerdivision, Ukraine, summer 1944
Wespe from the 1st Abteilung, Panzerartillerie regiment, 8th Panzerdivision, Ukraine, summer 1944.
Wespe, Italy, summer 1944.
Wespe from an unidentified unit, Italy, summer 1944.
Wespe, Hermann Göring Panzer Division, Anzio, January 22, 1944
Wespe from an unidentified Abteilung, perhaps part of the Hermann Göring Panzer Division, Anzio, January 22, 1944.
Wespe, Hungary, March 1945
Wespe of an unidentified unit, Hungary, March 1945.
Munitionschlepper auf Wespe
Munitionschlepper auf Wespe, Fallschrimpanzerdivision Hermann Göring, East Prussia, winter 1944-45.

le.F.H.18/2 auf. Fgst.Pz.Kpfw.II (Sf) (Sd.Kfz.124)

Dimensions (L-W-H) 4.81 m x 2.28 m x 2.3 m,
Total weight, battle-ready 11 tonnes
Crew 5 (Commander, Gunner, Loader,Driver and Radio operator)
Propulsion Maybach HL 62 TR 140 HP @ 3000 rpm
Speed (road/off-road) 40 km/h, 20 km/h
Range (road/off-road)-fuel 140 km, 95 km
Primary Armament Armament:10.5 cm le.F.H18/2
Secondary Armament One 7.92 mm M.G.34 machine guns
Elevation -5° to +42°
Armor 5 mm – 30 mm

Sources

Categories
WW2 German SPGs

Hummel-Wespe 10.5 cm SPG

German Reich (1944)
SPG – 12+ Built

The 10.5cm Hummel-Wespe Artillery SPG

There is only one known photograph of a Hummel self-propelled gun (SPG) chassis and body fitted with an artillery 10.5cm le.F.H. 18/40 L/28 howitzer rather than the normal 15cm s.FH 18/1 L/30 howitzer. It was officially called the Hummel-Wespe. This name was used on the Stahlindustrie construction company’s documentation. It was also known as the 10.5cm le.F.H. 18/40 (Sf) auf Geschützwagen III/IV, or LeichtPanzerhaubitzen (lePzHaub – light armoured howitzer) or the the Ersatz-Wespe (Replacement Wasp). The photograph was taken after World War Two during the winter of 1945/46 at Košťaty near Teplice, Czechoslovakia, close to the factory that assembled the vehicle.
German WW2 10.5 cm le.F.H. 18/40 GW III/IV Hummel Wespe artillery SPG
Hummel-Wespe 10.5 cm le.F.H 18 Artillerie Selbstfahrlafetten (Artillery SPG) – Photo: Petr Dolezal and Marek Solar
The Hummel SPG used an extended tank chassis called the Geschützwagen III/IV to mount the 15cm s.FH 18/1 L/30 howitzer. The engine was moved from the rear of the tank to the center of the vehicle to make room for the gun and the armored fighting compartment at the back of the SPG.
The 10.5cm leFH 18/2 (Sf) auf Geschützwagen II ‘Wespe’ (Sd.Kfz.124) artillery SPG used a Panzer II tank chassis. Production began in February 1943 and ceased in June 1944, when the main factory in Warsaw, Poland was captured by the Red Army. The German Army Panzer-Artillerie batteries still needed more self-propelled guns that could keep up with the Panzer Divisions, fitted with 10.5cm le.F.H. 18/40 howitzers.
The Geschützwagen III/IV was still in production and being used for the Nashorn 88mm anti-tank self-propelled gun as well as the 15cm Hummel SPG. A decision was made to mount the 10.5cm le.F.H. 18 howitzers gun used on the Wespe SPG onto the Geschützwagen III/IV chassis.
The German armaments company Deutsche Eisenwerke (D.E.W) were constructing Geschützwagen III/IV chassis at their assembly plant in Duisburg, Germany. Allied bombing was making production difficult. It was moved to the D.E.W plant Werke (Deutsche Eisenwerke AG Werk) Teplitz-Schönau in Czechoslovakia (now known as Teplice, Czech Republic). The building of armored vehicles for the German Army continued until the end of the war in May 1945.
Plans to fit a 10.5 cm Le.F.H 18/40 light field howitzer to the s.Pz.Haubitze Fahrgestell extended and modified Panzer III/IV tank chassis, as a stop-gap solution to send more 10.5 cm artillery SPGs on the battlefield, were discussed in a meeting on 2nd December 1944. The factory was expected to produce 40 in February, 50 in March and 80 in April. A further report documents the demand for a further 250 to be built in June 1945. That report was dated 9th January 1945.
A Stahlindustrie report dated 30th of August 1945 stated that one Hummel-Wespe artillery SPG had been built in December 1944, a further 9 in January 1945 and a further one before the end of the war, bringing the total to eleven. No German Army documents have been found that show these vehicles entering operational service or being used on the battlefield.

The anti-grenade screen

Another unusual feature visible in the photo of the Hummel/Wespe is the hand grenade protection screen that was added over the open fighting compartment on a metal hinged frame.
Hummel with wire screen
This is a photograph of an early version Hummel, not a Hummel/Wespe. It is fitted with the same wire mesh top screen to prevent grenades and mines from being thrown into the fighting compartment. Notice the large exhaust muffler/silencer box under the rear hatches. It was removed on the later version of the Geschützwagen III/IV chassis that was used on the 10.5 cm le.F.H. 18/40 Hummel-Wespe artillery SPG.

Proposed production figures – German Archives

A GenArt (General der Artillerie) report dated 11 December 1944, kept in the German Archives, reports that documentation for the 10.5 cm Hummel-Wespe design had been signed and a production order for 250 units for delivery in June 1945 issued.Production was to start in February 5. It was intended that 80 vehicles would be completed each month.
On 10 February 1945 the Oberkommando der Wehrmacht (OKH – Supreme Command of the German Armed Forces) issued the following instructions, ” “Due to the drop in light field howitzer (LeFH) production, delivery of the 250 le Panzerhaubitze auf Fahrgestell Hummel is no longer anticipate. Instead of the 80 lePzHaub scheduled for February only 10 will be completed, followed by another 20 in March. To compensate, production of Panzerhaubitzen will proceed as follows.”
“In parallel with the highest possible output of lePzHaub, some 50 sPzHaub (15 cm sFH Hummel SPGS) will be produced. The available 80 sFH guns from the Hummel production wil be mounted on Beutelafetten (captured gun mounts). Production of lePzHaub (the 10.5 cm leFH Hummel-Wespe) will be fixed at 200 and not 250 units.”
Due to the end of the war being close, the continued bombing of German factories and supply routes, this production figure was never meet.

Proposed production figures – Russian Archives

A German document was captured by the Red Army. It showed predicted production numbers of vehicles like the Jagdpanther, Jagdtiger, Flakpanzer, Hummel and Hummel-Wespe from March 1945 to August 1945. It was translated by Senior Lieutenant Rubinshtein into Russian and kept in the Soviet archives.
On line 345, it shows that planned production of the heavily armed howitzer, the Hummel, was for 50 vehicles: 20 in March and 10 in April, May, June 1945 with production stopping in July. On line 346, it shows that planned production of the light armed howitzer, the Hummel-Wespe, was for 190 vehicles: 20 in March and 30 in April, May, June and 40 in July, August 1945.
There was a side note that an additional 10-20 new type Hummel/Wespe would be added to the number on April and May. This would have brought the planned production numbers of the 10.5cm Hummel-Wespe Artillery SPG to 220 vehicles by August 1945. Obviously, that did not happen as the war ended in May 1945.

Czechoslovakian Army 1948-54

Surviving Hummel-Wespe artillery self-propelled guns were used by the Czechoslovakian Army after WW2. They had twelve, but only eight vehicles underwent renovation and entered service in 1948. Between 1948-1949 they were officially called “Samohybné děla so 105 mm húfnicou”. Between 1949-1954 the official designation in army records changed to “105 mm samohybná húfnica vz.18/40”. They were withdrawn from Army service in 1954 and presumably scrapped. (Source – Vojenská história 4/2009 ISSN 1335-3314, VHÚ Bratislava)
Czechoslovakian Army records recorded the original German production chassis number (Fgst.Nr) of the eight Hummel-Wespe artillery SPGs that entered their service.
German Fahrgestellnummer 84407, date in service 4th May 1949,
Battery number R114, army registration number 79.651
German Fahrgestellnummer 84412, date in service 4th May 1949,
Battery number R107, army registration number 79.652
German Fahrgestellnummer 340003, date in service 4th May 1949,
Battery number R108, army registration number 79.653
German Fahrgestellnummer 84410, date in service 4th May 1949,
Battery number R3397, army registration number 79.654
German Fahrgestellnummer 84422, date in service 20th October 1949,
Battery number R113, army registration number 79.655
German Fahrgestellnummer 84419, date in service 20th October 1949,
Battery number R109, army registration number 79.656
German Fahrgestellnummer 84420, date in service 20th October 1949,
Battery number R106, army registration number 79.657
German Fahrgestellnummer 84421, date in service 20th October 1949,
Tactical unit number R105, army registration number 79.658

The German self-propelled howitzers

The full designation of this self-propelled artillery gun was Panzerfeldhaubitze 18M auf Geschützwagen III/IV (Sf) Hummel, Sd.Kfz.165. The German word ‘Hummel’ means bumblebee. This armored fighting vehicle had a nasty sting. There were two main types of self-propelled guns in the German Army during WW2. One was fitted with an anti-tank gun and the other with an artillery howitzer, like the Hummel. A vehicle fitted with an artillery field howitzer was called a ‘Geschüetzwagen’, which is literally translated as a ‘gun vehicle’. The letters ‘Sf’ stand for ‘Selbstfahrlafette’ – self-propelled carriage. ‘Panzerfeldhaubitze’ means armored field howitzer.
Self-propelled artillery guns were developed to enable fast moving attacks to have artillery support that could keep up with the speed of advancing Panzer Divisions. They could use direct fire mode at targets they could see or, more commonly, use indirect fire at targets plotted on a map.
They were not designed to be in the front line or engage in combat with tanks. They were motorized artillery guns that could fire high explosive HE shells over the heads of friendly troops. Most targets would have been given to the crew as map grid references by forward observation officers or infantry units under attack.
Quite often, the gun crews could not see where their shells landed, as the target was so far away. They would have to rely on the forward observer to tell them if adjustments had to be made.
The open-topped back design of these self-propelled guns had a number of advantages. The elevated commander’s position when standing in the crew compartment, behind the protective armored shield, meant that he had a good view on all sides. If there was the threat of enemy small arms fire, then the crew could use a twin lens range finder telescope that could peak over the top of the armored casement.
There was enough room for the crew to be transported towards the battlefield whilst protected from small arms fire and shell shrapnel. The vehicle had good mobility and could follow the infantry almost anywhere. The gun was quicker to get ready for action and fire on targets than towed artillery guns.
Putting the 10.5 cm le.F.H. 18/40 howitzer on top of a tank chassis was a more efficient use of manpower from the traditional form of German artillery battery transportation. Even in WW2, horse power was still widely used although tracked vehicles were also employed when available. Each field gun would require a six-horse team to pull the gun and limber. The ammunition, supplies and kit would be kept in the limber, which was a very large box on a pair of wheels with seats on the top. Three men would ride on the left-hand horse of each pair to control them. The remaining six men of the gun crew would ride on top of the limber. Only a relative few were towed by the 3-ton halftracks.
High explosive HE shells came in two parts. The explosive shell was loaded first, followed by the variable charge canister. This meant that the Hummel/Wespe could only carry 18 rounds of HE. It could fire armor-piercing AP rounds but they were only effective at short ranges and used in self defense. The Hummel/Wespe was not meant to be on the battlefield front line. It was a support vehicle that provided artillery support from behind the infantry and tanks.

The Geschützwagen III/IV chassis

The powerful 10.5 cm le.F.H. 18/40 light field howitzer was mounted on a specially designed Alkett/Rheinmetall-Borsig lengthened German tank chassis called the Geschützwagen III/IV. Components were adopted from both the Panzer III and Panzer IV tank chassis. The more robust final drive wheels, front drive wheels and steering units plus the Zahnradfabrik SSG 77 transmission gearbox were adopted from the Panzer III Ausf.J.
The Maybach HL 120 TRM engine with its cooling system, the suspension, and idler with track tension adjustment were adopted from the Panzer IV. The engine was moved from the rear of the tank to the center of the vehicle to make room for the gun and the armored fighting compartment at the back of the SPG.
On early versions of the Geschützwagen III/IV chassis, the front top of the hull had sloping armor with a raised armored compartment for the driver on the left of the vehicle. The front hull superstructure and driver’s armored compartment were redesigned in early 1944 and enlarged, covering the whole width of the vehicle. The radio operator and driver now had more space to work in. This design was used on all Hummel/Wespe artillery SPGs.
The exhaust system was also changed on the later model. It was moved from the original location below the rear double doors. The exhaust mufflers were dropped and the ends of the exhaust pipes were cut at a slant away from the tracks to avoid stirring up additional dust.
The Geschützwagen III/IV tank chassis did not have a hull mounted machine gun. Crews were issued with a single MG34 or MG42 machine gun, carried inside the fighting compartment, for self-defense.
The Hummel/Wespe was designed to be operated by a crew of six: commander, driver and four gunners. They were protected by an enclosed high silhouette armored fighting compartment. Although it was open topped, the crew were issued with a thick canvas tarpaulin cover that could be used in bad weather.
In front of the driver, a metal wire grid was fixed into position to aid the driver maneuvering the vehicle in the correct fire position. These were designed to prevent grenades and mines being thrown into the vehicle as it moved through towns and cities.
A metal louvered cover ventilated the engine, but many later versions were fitted with an angled shield that opened upward. On the photograph of the Hummel/Wespe the metal louvered engine vent can not be seen on the sides of the vehicle. It looks like it has been fitted with one of the armored angled shields.
Three aiming stake poles would have been carried in brackets below the rear door. The gunner would use a large ZE 34 sight. The top lens aperture would point to the rear of the vehicle. The gunner used this aperture of the sight to locate the aiming sticks that a member of the crew had pounded into the ground at the rear at a known bearing from the vehicle, having used a compass (compasses did not work inside a metal vehicle in 1943). By lining up the red and white fire aiming stake, subtracting 180 degrees, he would be able to work out the correct bearing the gun barrel is pointing towards.
The upper fighting compartment superstructure walls were constructed using 10 mm (0.39 in) thick E11 chrome-silicon armor plates hardened to 153 kg/mm2 for protection against shell fragments. The 30 mm (1.18 in) thick front hull was made using face-hardened FA32 armor plates. The rest of the hull was made out of cheaper rolled SM-Stahl (carbon steel) that was hardened to 75-90 kg/mm2. It took 20 mm (0.78 in) thick plates of SM-Stahl to provide equivalent protection against penetration by SmK (7.92 mm AP bullets) as 14.5 mm (0.57 in) of E11 armor plate.
The early Geschützwagen III/IV chassis used the standard 1943 38cm wide SK18 track that had three smooth metal pads visible on the front face of the track. In winter some vehicles were fitted with track width extenders called Winterketten (winter track). These triangular pieces of metal were bolted onto the outer edge of the track to extend the width of the track and help the vehicle move across snow and mud by spreading the load over a larger area. They were problematic: they fractured and often fell off. In 1944, vehicles started to be fitted with the wider Ostketten (east track) to cope with the conditions found on the Eastern Front. The Winterketten extensions made the SK18 tank track 55cm wide. The one-piece Ostketten was 56cm wide and did not have bits falling off it.

The Hummel-Wespe - Illustration by David Bocquelet
The Hummel-Wespe – Illustration by David Bocquelet

Early version Hummel SPG Eastern Front Winter 1943
A regular Hummel SPG with the wire mesh protective cover

Wespe 146th Panzer Artillerie Regiment, Normandy.
A Wespe SPG with its 10.5 cm gun.

10.5cm Hummel-Wespe SPG model
A model of the 10.5cm Hummel-Wespe SPG made by Danis Stamatiadis

Hummel-Wespe artists impression of the SPG on the Eastern Front battlefield during 1945
Hummel-Wespe artists impression of the SPG on the Eastern Front battlefield during 1945 (Art work – Cyber-Hobby)
The Hummel-Wespe 10.5 cm SPG had the louvered engine vents protected by an armoured shaped cover
The Hummel-Wespe 10.5 cm SPG had the louvered engine vents protected by an armored shaped cover (Photo – Cyber-Hobby)
The front hull superstructure and driver's armored compartment were redesigned in early 1944
The front hull superstructure and driver’s armored compartment were redesigned in early 1944 and enlarged, covering the whole width of the vehicle. The radio operator and driver now had more space to work in. (Photo – Cyber-Hobby)

The rear exhaust system was removed on the Hummel-Wespe SPG. The three aiming stake poles were stored below the rear hatch doors.
The rear exhaust system was removed on the Hummel-Wespe SPG. The three aiming stake poles were stored below the rear hatch doors. (Photo – Cyber-Hobby)

Fighting compartment of the Hummel-Wespe Spg
Fighting compartment of the 10.5 cm le.F.H 18 Hummel-Wespe SPG. (Photo – Cyber-Hobby)

The 10.5 cm le.F.H. 18 light field howitzer

The 10.5 cm leFH 18 gun was a German light howitzer used in World War II. The abbreviation leFH stands for the German words ‘leichte FeldHaubitze’ which, translated, means light field howitzer. It was fitted with a ‘Mundungbremse’ muzzle brake to allow longer range charges to be fired and reduce the amount of recoil on the gun. This increased the operational life of the gun barrel.

German Army 10.5 cm le.F.H. 18 light field howitzer on display at the Finnish Artillery Museum, Finland
German Army 10.5 cm le.F.H. 18 light field howitzer on display at the Finnish Artillery Museum, Finland
The 105 mm (4.13 in) high explosive HE shell weighed 14.81 kg (32.7 lb). The armor piercing shell weighed 14.25 kg (31.4lb). It had a muzzle velocity of 470 m/s (1,542 ft/s) and a maximum firing range of 10,675 m (11,675 yds). With a good gun crew, it had a rate of fire between 4-6 rounds per minute.
The 10.5cm leichte Feld Haubitze 18 gun was not very useful in the direct-fire mode against enemy armored vehicles. It could only penetrate 52 mm (2 in) of armor plate at a very short range of 500 meters.
The high explosive shell was in two pieces. It was a ‘separate loading’ or two part round. First, the high explosive HE projectile would be loaded and then the cartridge propellant case. Depending on the range of the target different sized bags of propellant were inserted into the cartridge. More bags were used for longer range targets.

An article by Craig Moore

Hummel-Wespe specifications

Dimensions (L x W x H) 7.17 m x 2.97 m x 2.81 m (23ft 5in x 9ft 7in x 9ft 2in)
Total weight, battle ready 23 tonnes (24.25 tons)
Crew 6 (commander, driver, 4x gun crew)
Propulsion 12-cylinder water cooled Maybach HL 120 TRM 11.9 litre petrol engine, 265 hp at 2600 rpm
Fuel capacity 400 litres
Top speed 42 km/h (26 mph)
Operational range (road) 215 km (133 miles)
Armament 10.5 cm le.FH 18/40 howitzer
7.96 mm (0.31 in) MG 34 machine gun
7.96 mm (0.31 in) MG 38/40 machine gun
Armor Front 30 mm (1.18 in), sides 20 mm (0.79 in), rear 20 mm (0.79 in)
Superstructure front 10 mm (0.39 in), sides 10 mm (0.39 in)
Total production 10-20?

Sources

Panzer Tracts No.10 Artillerie Selbstfahrlafetten by Thomas L. Jentz
Panzer Tracts No.10-1 Artillerie Selbstfahrlafetten by Thomas L. Jentz
German self-propelled guns by Gordon Rottman
Panzer-Grenadier Division Grosssdeutschland by Bruce Quarrie
Panzerartillerie by Thomas Anderson
Restricted July 1944 – Allied Expeditionary Force – German Guns – Brief notes and range tables for allied gunners. SHAEF/16527/2A/GCT
Czechoslovakian Army records
Germans Tanks of ww2
Germans Tanks of ww2

German Self-Propelled Artillery Guns of the Second World War
German Self-Propelled Artillery Guns of the Second World War

By Craig Moore

One towed artillery gun required a team of six horses and nine men. WW2 German engineers came up with the idea of mounting an artillery gun on top of a tank chassis. This new technology reduced the amount of resources required to deploy one artillery gun. Artillery self-propelled guns only needed a four or five man crew. They could also be made ready to fire more quickly. This book covers the development and use of this new weapon between 1939 and 1945. One type was successfully used in the invasion of France in May 1940. More were used on the Eastern Front against Soviet forces from 1941 until the end of the war in 1945.

Buy this book on Amazon!

Categories
WW2 German SPGs

10.5 cm leFH 18/3 (Sf.) auf Geschützwagen B2(f)

German Reich (1942)
SPG – 16 Built

The Giant SPG

With the fall of France in May 1940, the German Army captured a lot of French Army tanks and vehicles. They called them Beutepanzer (trophy tanks). The approximate numbers of French AFVs captured by the German Wehrmacht are as follows: 300x Panhard-178; 3,000 Renault-UE; 350 to 360x Lorraine 37L and 38L; 1700x Renault FT Tanks (various versions); 843x Renault R35; 550 to 600x Hotchkiss H-35 and H-39; 50x FCM-36 tanks; 297x SOMUA S-35 tanks and 161x Char B1 bis tanks. More than 5,000 captured French army armoured fighting vehicles were repaired or converted in French factories. Vehicle manuals were translated into German and the vehicle spare part production initiated.
One such Beutepanzer trophy tank was the very large Char B1 bis heavy tank. Many of them had been abandoned by their crews after running out of ammunition or fuel. The French Army supply system was poorly organized in 1940. Very few of these monster tanks were knocked out by enemy action.
10.5cm le.F.H.18/3 (Sf) auf Geschuetzwagen B2(f) factory fresh having just been driven out of the workshop doors.
Factory fresh 10.5cm le.F.H.18/3 (Sf) auf Geschuetzwagen B2(f), having just been driven out of the workshop doors.
They were given the German designation Panzerkampfwagen B2 740(f) shortened to Pz.Kpfw. B2 740(f). The letter ‘f’ signified that it was a French built tank. Hitler issued a directive in March 1941 that sixteen of these tanks were to be converted to self-propelled artillery guns and used to support the Flammenwerfer auf Pz.Kpfw.B2(f) flamethrower tanks as they assaulted Soviet positions on the Eastern front.
It took longer than initially planned to convert the Char B1 tanks to self-propelled artillery guns. Lack of equipment, vehicles, guns and parts were blamed. The Flammenwerfer auf Pz.Kpfw.B2(f) flamethrower tanks went into action without supporting artillery SPGs in June 1941.
The Panzer-Abteilung (Flamm).103 was disbanded by mid-July 1941. The B2 Flammenwerfer tanks were a disappointment to the Germans. They kept on breaking down with mechanical problems. They were not reliable and could not be depended upon to get to an enemy strong point and neutralize it.

Livery

Most of the 10.5cm leFH 18/3 (Sf) auf Geschützwagen B2(f) artillery self-propelled artillery guns were painted ‘Panzergrey’ at the factory but a few were repainted in the standard late war paint scheme of sandy yellow ‘Dunkelgelb’ with brown and yellow mix.
10.5cm le.F.H.18/3 (Sf.) auf G.W.B2 in the Rheinmetall-Borsig factory with bad weather tarpaulin on the top
10.5cm le.F.H.18/3 (Sf.) auf G.W.B2 in the Rheinmetall-Borsig factory with bad weather tarpaulin on the top painted in ‘Dunkelgelb’ sandy yellow not ‘Panzergrey’.
The following photograph ends the discussion as to what colour the 10.5cm leFH 18/3 (Sf) auf Geschützwagen B2(f) artillery self-propelled artillery guns were painted. The first vehicle is painted in the sandy yellow ‘Dunkelgelb’ and the one following it is painted in the earlier ‘Panzergrey’.
10.5cm le.F.H.18/3 (Sf.) auf G.W.B2 painted sandy yellow

Design and Production

The design contract was given to Rheinmetall-Borsig, which was based in Dusseldorf. They created blueprints for a mount placed on top of the tank chassis that could take the 10.5 cm leFH 18/3 artillery howitzer. The gun crew would be protected from small arms fire by an open top armored casement. Its armor plate thickness ranged between 30–40 mm (1.18-1.57 in) thick at the front and 20–30 mm (0.79-1.18 in) at the sides. Tarpaulins would cover the open top to give the crew shelter from bad and hot weather.
It had a five-man crew: commander, driver and three gunners. The Char B1 main gun in the hull had been removed. It was not replaced with a hull mounted machine-gun. For self-defence, a 7.92 mm (0.31 in) MG 34 machine gun was available to be fitted to the top of the gun casement. The crew also had access to handheld 9 mm (0.35 in) machine pistols.
The Char B2 tanks already had a very high profile. With the mounting of the 10.5cm leFH 18/3 howitzer on the top, it was very tall. Its height was 3 m (9ft 11in). This made it easy for the enemy to spot, so it had to be deployed behind the initial front line of tanks.
The French army radios were replaced. Some could only send messages by Morse code. Modern German Fug.5 radios, that could provide voice communication, were fitted in the machines. The removal of the hull mounted 75 mm (2.95 in) gun increased the amount of room there was available for the storing of extra equipment and ammunition.

Operational Service

Five were produced by January 1942, five in the following February and six in March. The sixteen 10.5cm le.F.H.18/3 (Sf) auf G.W. B2(f) were issued to Artillerie-Regiment 93, 1.Abteilung (1st Battalion) of the 26.Panzer-Division which was in France. The 1st Battalion had three batteries with four self-propelled artillery guns in each battery. The four remaining vehicles were issued to the HQ battery on reserve. Reports stated that the vehicle was prone to frequent mechanical breakdowns.
An Artillerie-Regiment 93’s combat strength report dated 31st May 1943 reported that they had fifteen 10.5cm le.F.H.18/3 (Sf) auf G.W. B2(f) SPGs of which 14 were in an operational condition. This report also recorded that twelve Wespe 10.5cm SPGs had been issued to the 1.Abt./Artl.Rgt.93 as replacement vehicles for the mechanically unreliable 10.5cm le.F.H.18/3 (Sf) auf Geschuetzwagen B2(f) SPGs. These were then used as training vehicles to teach new tank drivers, gunners and mechanics their trade skills. The 26.Panzer-Division was sent to Italy in July 1943.
Orders had been issued to send these vehicles to Sardinia to be part of the strength of the 90.Panzergrenadier-Division. No records have been found to confirm that the fifteen remaining vehicles were transferred to Sardinia or what their ultimate fate was. The 90.Panzergrenadier-Division withdrew to Corsica from Sardinia and was then sent to northern Italy. It fought at Anzio, Rome, the Caesar and Gothic Lines and the Po River. It was destroyed near Bologna, Italy, April 1945.

The 10.5cm LeFH 18/3 howitzer

The 10.5 cm leFH 18 gun was a German light howitzer used in World War II. The abbreviation leFH stands for the German words ‘leichte FeldHaubitze’ which, translated, means light field howitzer. It was fitted with a ‘Mundungbremse’ muzzle brake to allow longer range charges to be fired and reduce the amount of recoil on the gun. This increased the operational life of the gun barrel.
The 105 mm (4.13 in) high explosive HE shell weighed 14.81 kg (32.7lb). The armor piercing shell weighed 14.25 kg (31.4 lb). It had a muzzle velocity of 470 m/s (1,542 ft/s) and a maximum firing range of 10,675 m (11,675 yds). With a good gun crew, it had a rate of fire between 4-6 rounds per minute.
The high explosive shell was in two pieces. It was a ‘separate loading’ or two-part round. First, the high explosive HE projectile would be loaded and then the cartridge propellant case. Depending on the range of the target different sized bags of propellant were inserted into the cartridge. More bags were used for longer range targets.
The 10.5cm leichte Feld Haubitze 18 gun was not very useful in the direct-fire mode against enemy armored vehicles. It could only penetrate 52 mm (2 in) of armor plate at a very short range of 500 meters (550 yd).
A HEAT-round for the 10.5cm leFH 18 was developed in June 1940. It went into service in a large number in winter 1941/42, probably as a reaction to the T-34s and KV-series tanks appearing on the Eastern Front. There were 3 different types of HEAT-rounds, the GR H1/A, GR H1/B and GR H1/C. The GR H1/A was the first one developed in June 1940, followed by the GR H1/B sometimes in 1941 and the final GR H1/C in 1942.

An article by Craig Moore

Geschützwagen B2(f) specifications

Dimensions (L,W,H) 7.62 x 2.4 x 3 m (25′ x 7’10” x 9’11”)
Total weight, battle ready 32.5 tons
Crew 5 (commander, driver, gunner, 2x loaders)
Propulsion Renault 307 water cooled, 6-cylinder gasoline/petrol engine, 272 hp
Top road speed 28 km/h (17 mph)
Off road speed 21 km/h (13 mph)
Operational range (road) 135 km (84 miles)
Main Armament 10.5 cm (4.13 in) leFH 18/3 howitzer
Secondary Armament 7.92 mm (0.31 in) MG34 machine gun
Armor (chassis) Front 40-60 mm (1.57-2.36 in)
Sides and rear 55 mm (2.16 in)
Total production 16

Sources

Beute-Kraftfahrzeuge und panzer der deutschen Wehrmacht by Walter J. Spielberger
Beutepanzer der Wehrmacht by Alexander Lüdekes
Die Feldartillerie des Heeres in der Panzerabwehr 1939–1945 (Militärgeschichte” issue 1/1994, page 9–15) by Wolfgang Fleische.
Profile AFV Weapons 55 – German Self Propelled Weapons by Peter Chamberlain and H.L.Doyle.
German Heavy Field Artillery 1934-1945 by Joachim Engelmann
German Artillery at War 1939-45 Vol 1 vy Frank V. de Sisto.
German Army S.P. Weapons 1939-45 part 2. handbook No1 by by Peter Chamberlain and H.L.Doyle.
Panzer Tracts by Thomas L.Jentz and H.L.Doyle
Assistance of Marcus Hock and Steve Osfield

German Army 10.5cm leFH 18/3 (Sf) auf Geschuetzwagen B2(f) self-propelled artillery gun
German Army 10.5cm leFH 18/3 (Sf) auf Geschuetzwagen B2(f) self-propelled artillery gun by David Bocquelet

10.5cm leFH 18/3 (Sf) auf Geschuetzwagen B2(f) in Dunkelgelb livery by David Bocquelet

Gallery

Two 10.5cm le.F.H.18/3 (Sf.) auf G.W.B2(f) self-propelled artillery guns on the move.
Two 10.5cm le.F.H.18/3 (Sf.) auf G.W.B2(f) self-propelled artillery guns on the move. They were designated alphabetically in capital letters (A – P).
Gun crew standing next to a 10.5cm le.F.H.18/3 (Sf) auf Geschuetzwagen B2(f)
Gun crew standing next to a 10.5cm le.F.H.18/3 (Sf) auf Geschuetzwagen B2(f)
10.5cm le.F.H.18/3 (Sf) auf Geschuetzwagen B2(f) N
The fighting compartment that surrounded the gun of 10.5cm le.F.H.18/3 (Sf) auf Geschuetzwagen B2(f) N had an open top. In bad or very hot weather, a tarpaulin covered the top.
10.5cm le.F.H.18/3 (Sf) auf GW B2(f) SPG 'D' is carrying a large wooded box on the back
Notice that 10.5cm le.F.H.18/3 (Sf) auf GW B2(f) SPG ‘D’ is carrying a large wooded box on the back.
10.5cm le.F.H.18/3 (Sf) auf GW B2(f) Artillery Self-propelled Gun, with vehicle identification letter D
10.5cm le.F.H.18/3 (Sf) auf GW B2(f) Artillery Self-propelled Gun, with vehicle identification letter D (source: ebay)
10.5cm le.F.H.18/3 (Sf) auf GW B2(f) SPG 'D' is carrying a large wooded box on the back
Here is a side view of another 10.5cm le.F.H.18/3 (Sf) auf GW B2(f) SPG carrying a large wooded box on the back.
The 75mm gun was removed from the Char B1 hull when the tank was converted into an artillery self-propelled gun.
The 75 mm (2.95 in) gun was removed from the Char B1 hull when the tank was converted into an artillery self-propelled gun.
10.5cm le.F.H.18/3 (Sf) auf GW B2(f) SPG N
Side view of 10.5cm le.F.H.18/3 (Sf) auf GW B2(f) Artillery Self-propelled Gun, with vehicle identification letter N, being inspected by senior officers (Giuseppe Bianco)
10.5cm le.F.H.18/3 (Sf) auf GW B2(f) SPG N
Front view of 10.5cm le.F.H.18/3 (Sf) auf GW B2(f) Artillery Self-propelled Gun, with vehicle identification letter N, being inspected by senior officers (Giuseppe Bianco)

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10.5cm le.F.H.18/3 (Sf) auf GW B2(f) Artillery Self-propelled Gun, with vehicle identification letter C (source: ebay)

Germans Tanks of ww2
Germans Tanks of ww2
German Self-Propelled Artillery Guns of the Second World War
German Self-Propelled Artillery Guns of the Second World War

By Craig Moore

One towed artillery gun required a team of six horses and nine men. WW2 German engineers came up with the idea of mounting an artillery gun on top of a tank chassis. This new technology reduced the amount of resources required to deploy one artillery gun. Artillery self-propelled guns only needed a four or five man crew. They could also be made ready to fire more quickly. This book covers the development and use of this new weapon between 1939 and 1945. One type was successfully used in the invasion of France in May 1940. More were used on the Eastern Front against Soviet forces from 1941 until the end of the war in 1945.

Buy this book on Amazon!

Categories
WW2 German SPGs

10.5 cm leFH 16 auf Geschützwagen Mk.VI(e)

German Reich (1942)
SPG – 6 Built

The little SPG

With the fall of France in May 1940, after the German Blitzkrieg invasion, all British Army Expeditionary Force (BEF) tanks and vehicles had to be left behind as the soldiers escaped back to England via the beaches of Dunkirk. When the vehicles were abandoned the British troops tried to make them unusable so the German Army could not turn them against their previous owners.

The 10.5cm LeFH 16 auf Geschutzwagen Mk.VI(e) self-propelled artillery gun built on a Vickers Mk.VI light tank chassis
The 10.5cm LeFH 16 auf Geschutzwagen Mk.VI(e) self-propelled artillery gun built on a Vickers Mk.VI light tank chassis
Not all their efforts were successful. A number of the captured tanks were in a repairable condition. Parts were taken from different vehicles to make one vehicle serviceable. The German mechanics managed to repair a number of British Vickers Mk.VIb and Mk.VIc light tanks.
These were known as Beutepanzers (trophy tanks) and given the official designation of Leichter Panzerkampfwagen Mk.VIB 735(e) or Leichter Panzerkampfwagen Mk.VIC 736(e). They were used for combat, reconnaissance, internal police security and tank crew training. The letter ‘e’ in brackets referred to the country of origin of the captured tank, in this case, England.
The German army needed artillery that could keep up with the tanks of the Panzer Division. A decision was made to use some of the captured tanks, including the Vickers Mk.VI light tanks, as self-propelled artillery guns and mount a howitzer on the tank chassis.
Fighting compartment showing the commander's and gunner's positions on the left of the SPG
Fighting compartment showing the commander’s and gunner’s positions on the left of the SPG

Design and Production

A German engineer called Oberleutnant Becker, who had been attached to the tank producing factory of Alkett in Berlin, organized the mounting of six WW1 era 10.5cm le.F.H.16 howitzers on the top of captured Vickers Mk.VI tanks.
The gun crewmen were protected by an armored casement that surrounded the 10.5cm leFH 16 howitzer. Its armor thickness ranged from 11 to 22 mm (0.43-0.89 in). That was enough to protect the crew from small arms fire and shrapnel fragments from high explosive shells and mortar rounds.
This self-propelled gun was not designed to fight on the front line. It was an artillery self-propelled gun that would stay behind the main assault and fire high explosive HE shells over the heads of the troops and tanks at targets given to it as grid references on a map by forward observers.
It was not an anti-tank gun, though it did carry a few armor piercing AP rounds for self-defense at close quarters. A machine gun could be fitted to the front of the superstructure to the right of the gun. The crew had their own weapons that they could fire over the top of the fighting compartment if enemy troops got too close.
The fighting compartment was open topped, it did not have an armored roof. This kept the weight down and gave the commander all round vision. The crew would cover the top with a tarpaulin in bad weather and also in very hot weather, in order to provide shade.
To help deal with recoil from the gun when it was fired, the gun crew deployed a metal support frame attached to the rear of the vehicle. It was a square shaped metal frame that was strengthened by two cross bars and at the bottom had V-shaped ‘spades’ at the bottom that would dig into the earth.
The commander sat at the rear of the vehicle, on the left side, behind the gunner. He had access to a range finding periscope mounted to the side of the vehicle. The gunner’s gun sight poked out above the top of the forward gun shield and armor casement. The loader sat on the right side of the vehicle.
Prototype under going trials at Le Harfleur, France.
In June 1940, the prototype underwent firing trials at Le Harfleur, France. The gun crew protective armor casement had not been built around the gun at this stage – Photo: Dr Werner

The 10.5cm leFH 16 gun

The 10.5 cm leFH 16 gun was a German light howitzer used in World War I. It had a shorter range than the WW2 10.5 cm leFH 18 gun. Its maximum firing range was 9,225 m (10,089 yds). As it had the same caliber as the newer leFH 18, it could fire the same ammunition. Its muzzle velocity was 395 m/s (1,300 ft/s).
The 10.5 cm leFH 16 gun abbreviation leFH stands for the German words ‘leichte FeldHaubitze’ which, translated, means light field howitzer. It was not fitted with a ‘Mundungbremse’ muzzle brake.
The 10.5cm leichte Feld Haubitze 16 gun was not very useful in the direct-fire mode against enemy armored vehicles. It could only penetrate 52 mm (2 in) of armor plate at a very short range of 500 meters.
The high explosive shell was in two pieces. It was a ‘separate loading’ or two-part round. First, the high explosive HE projectile would be loaded and then the cartridge propellant case. Depending on the range of the target different sized bags of propellant were inserted into the cartridge. More bags were used for longer range targets.

Active Service

The six converted Vickers Mk.IV light tanks, now fitted with the long range 10.5cm leFH 16 artillery howitzer, were placed in the 15th battery of the Artillery Regiment, 227th Infantry Division. They were divided up into two platoons of three. The commanding officer was the same German Engineer Alfred Becker, now promoted to Captain, who had been involved in their construction.
The German documents refer to this unit as an assault battery. It was not used in that role. The armor on the front of these vehicles was not strong enough to take a direct hit from an enemy tank or anti-tank gun. These SPGs were used as artillery.
The 227th Infantry Division performed coastal defense and internal occupation security duties after the fall of France in Normandy, near the port of Le Havre, from July 1940 until late summer of 1941. The gun crews had time to train on their new vehicle before being posted to the Eastern Front and taking part in the heavy fighting in and around Leningrad (St Petersburg) Russia.
The 227th Infantry Division was transferred to the German Army Group North, arriving in the autumn. They relieved the 39th Motorised Corps who had been in position in the forests south of Ladoga.
At this part of the battle, the German commanders were expecting a Soviet counter attack to try and end the siege surrounding the city. The 10.5cm LeFH 16 auf Geschutzwagen Mk.VI(e) artillery SPGs of the 15th Battery took up defensive positions where they could fire on the routes it was believed the Red Army troops and tanks would take. They had time to zero in their guns, so as soon as the advancing Soviet forces were spotted by forward observers, they could cover the area in high explosive HE shells.
They were temporarily transferred to the nearby 254th Infantry Division and provided mobile artillery support when they took part in the 54th Army’s offensive of the 20th October 1941. The 10.5cm LeFH 16 auf GW Mk.VI(e) were used for numerous artillery fire missions between the 23rd and 24th October 1941, firing over 200 rounds. It appears that the 15th Battery was now divided into three platoons of two guns each.
The unit suffered its first casualties. Four men including Captain Becker were wounded when the SPGs were used for direct fire infantry support. This was a role not suitable for this artillery weapon due to the lack of heavy protective armor on these vehicles.
The two 10.5cm LeFH 16 auf Geschutzwagen Mk.VI(e) artillery SPGs of the 1st platoon were very active in late October. They were ordered to support the 11th Infantry Division as they attacked towards the villages of Volkhov and Pogostye. Soviet infantry surrounded the SPGs and the tank crews had to use their personal weapons and hand grenades to fight off the enemy troops.
On the 11th of November 1941, near the village of Khotovskaya Gorka, Soviet light tanks engaged the 1st Platoon Artillery SPGs. A German battle report confirmed the Soviet report that one of the vehicles was hit 16 times, but its armor was never penetrated. The tanks they confronted were Soviet T-40 light tanks of the 2nd Tank Brigade. Luckily for the German gun crews, the T-40 was only armed with machine guns.
Three men were killed on 15 November when the battery was ordered to act as assault guns whilst supporting an unsuccessful attack of the 223rd Infantry Division. One of the vehicles had to be left in no man’s land after being heavily damaged by a mine. It was recovered three days later.
The 15th Battery had fired over 1300 shells, which is just over 200 shells per gun crew, between November to mid-December 1941.
The 15th Battery conducted more artillery support fire missions during the winter and spring of 1942 as the 227th infantry Division continued to fight around the village of Pogostye.
Three of the six 10.5cm LeFH 16 auf Geschutzwagen Mk.VI(e) SPGs were knocked out on the 16th of February 1942, when KV-1 heavy tanks of the 124th tank battalion of the Soviet 54th Army attacked German units. The 10.5cm armor piercing ammunition given to the German gun crews failed to knock out the Red Army KV-1 tanks.
The three remaining vehicles provided close support as troops moved through forest roads near Pogostyle in March 1942. They used their HE shells to destroy a machine gun nest and fire on a Soviet infantry column they encountered in the woods.
One of the remaining three vehicles was reported not fit or active service and could not be repaired after the close quarters fighting during March. The 15th Battery now only had two vehicles. They were used to break through an enemy encirclement. One was knocked out by a Soviet anti-tank rifle.
The last remaining 10.5cm LeFH 16 auf GW Mk.VI(e) self-propelled gun was destroyed by a Red Army tank of the 98th Tank Brigade as it tried to provide protective covering fire for one of the German supply routes.

The post battle report evaluation

A German Army post-battle report dated November 1941 covered the role played by the 15th Batterie, Artillerie-Regiment 227 assault gun battery in the battle of Leningrad (St Petersburg) in October 1941 near the village of Mga south of the city.
The reporting officer was impressed with the high explosive shell performance of the 10.5cm LeFH 16 howitzer over the 7.5 cm HE shells. He judged it to be three times as powerful. It was found that the two-part ammunition used on the larger more modern guns, the 10.5cm LeFH 18, could be used up to canister charge 5. This helped in dealing with the logistics of ammunition supplies.
The overall evaluation of the 10.5cm LeFH 16 auf GW Mk.VI(e) in combat was positive as it was a good stable firing platform and it had good cross-country performance. Because of these findings, more self-propelled artillery guns were built although on different larger tank chassis.

Battery markings

On some photographs taken of 10.5cm LeFH 16 auf GW Mk.VI(e) on the Eastern Front there are numbers and letters on the side of the vehicle. The letters ‘Gp’ are an abbreviation for the word ‘Geschuetzpanzer’ which translated as gun tank or self-propelled gun. The number is the vehicle identification number given to the vehicle by the Regiment: Gp 4 would be gun tank number 4 in an artillery battery of 6 vehicles.

An article by Craig Moore

Gallery



Tanks Encyclopedia’s own illustrations of the 10.5cm LeFH 16 auf Geschutzwagen Mk.VI(e) by David Bocquelet.
There looks to be a machine gun mount at the front of the casement walls on the right of the main gun.
There looks to be a machine gun mount at the front of the casement walls on the right of the main gun.
227.Infanterie-Division 10.5cm LeFH 16 auf Geschutzwagen Mk.VI(e) self-propelled artillery gun
The driver would sit behind the loader on the right, at the back, when the gun was fired to assist with loading the gun.
The driver would sit behind the loader on the right at the back when the gun was fired to assist with loading the gun.
10.5cm LeFH 16 auf Geschutzwagen Mk.VI(e)
10.5cm LeFH 16 auf Geschutzwagen Mk.VI(e) SPG
Camouflaged 10.5cm LeFH 16 auf Geschutzwagen Mk.VI(e) SPG on the Eastern Front
Camouflaged 10.5cm LeFH 16 auf Geschutzwagen Mk.VI(e) SPG on the Eastern Front
A battery of three 10.5cm LeFH 16 auf Geschutzwagen Mk.VI(e) SPGs deployed for a fire mission. Notice the tracked ammunition carrier with a trailer in the background.
A battery of three 10.5cm LeFH 16 auf Geschutzwagen Mk.VI(e) SPGs deployed for a fire mission. Notice the tracked ammunition carrier with a trailer in the background.
10.5cm LeFH 16 auf Geschutzwagen Mk.VI(e) SPG in winter camouflage
10.5cm LeFH 16 auf Geschutzwagen Mk.VI(e) SPG in winter camouflage.
Two 10.5cm LeFH 16 auf Geschutzwagen Mk.VI(e) SPGs in a revers slope firing position to avoid detection from the Soviet troops
Two 10.5cm LeFH 16 auf Geschutzwagen Mk.VI(e) SPGs in a revers slope firing position to avoid detection from the Soviet troops.
10.5cm LeFH 16 auf Geschutzwagen Mk.VI(e)
Beutepanzer SPG conversion 10.5cm LeFH 16 auf Geschutzwagen Mk.VI(e)

Specifications

Dimensions (LxWxH) 4 m x 2.08 m x 2.26 m
(13ft 1in x 6ft 10in x 7ft 3in)
Total weight, battle ready 6.5 tons
Crew 4 (commander, driver, gunner, loaders)
Propulsion Meadows 6-cyclinder gasoline/petrol engine, 88 hp
Top road speed 35 mph (56 km/h)
Off road speed 25 mph (40 km/h)
Operational range (road) 125 miles (200 km)
Main Armament 10.5cm (4.13 in) leFH 16 Howitzer
Armor (chassis) Front 4 – 14 mm (0.16-0.55 in)
Total production 6

Sources

Beutepanzer unterm Balkenkreuz by Dr. Werner
Beute-Kraftfahrzeuge und panzer der deutschen Wehrmacht by Walter J. Spielberger
Warspot.ru by Vyachevlav Mosunov
Germans Tanks of ww2
Germans Tanks of ww2

German Self-Propelled Artillery Guns of the Second World War
German Self-Propelled Artillery Guns of the Second World War

By Craig Moore

One towed artillery gun required a team of six horses and nine men. WW2 German engineers came up with the idea of mounting an artillery gun on top of a tank chassis. This new technology reduced the amount of resources required to deploy one artillery gun. Artillery self-propelled guns only needed a four or five man crew. They could also be made ready to fire more quickly. This book covers the development and use of this new weapon between 1939 and 1945. One type was successfully used in the invasion of France in May 1940. More were used on the Eastern Front against Soviet forces from 1941 until the end of the war in 1945.

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Categories
WW2 German SPGs

10.5 cm leFH 16 (Sf.) auf Geschützwagen FCM 36(f)

German Reich (1942)
SPG – 12 Built

The German self-propelled howitzers

There were two main types of self-propelled guns in the German Army during WW2. One was fitted with an anti-tank gun and the other with an artillery howitzer, like the 10.5cm leFH 18 (Sf.) auf Geschützwagen FCM 36(f) self-propelled gun. The vehicle fitted with the artillery howitzer was called a ‘Geschuetzwagen’, which is literally translated as a ‘gun vehicle’. The letters ‘SF’ stand for ‘Selbstfahrlafette’ – self-propelled carriage. The letter (f) indicates that the chassis was of French origin.
Recently manufactured 10.5cm leFH 16 (Sf.) auf GW FCM 36(f)
Recently manufactured 10.5cm leFH 16 (Sf.) auf GW FCM 36(f) in factory fresh condition.
Improvised self-propelled artillery guns were developed to enable fast moving attacks to have artillery support that could keep up with the speed of advancing Panzer Divisions. They could use direct fire mode at targets they could see or, more commonly, use indirect fire at targets plotted on a map.
They were not designed to be in the front line or engage in combat with tanks. They were motorized artillery guns that could fire high explosive HE shells over the heads of friendly troops. Most targets would have been given to the crew as map grid references by forward observation officers or infantry units under attack.
Quite often, the gun crews could not see where their shells landed, as the target was so far away. They would have to rely on the forward observer to tell them if adjustments had to be made.
The open-topped back design of these self-propelled guns had a number of advantages. The elevated commanders position when standing in the crew compartment, behind the protective armored shield, meant that he had a good view on all sides. If there was the threat of enemy small arms fire, then the crew could use a twin lens range finder telescope that could peak over the top of the armored casement.
There was enough room for the crew to be transported towards the battlefield whilst protected from small arms fire and shell shrapnel. The vehicle had good mobility and could follow the infantry almost anywhere. The gun was quicker to get ready for action and fire on targets than towed artillery guns.
They were cheaper and faster to build than a new vehicle. They used the chassis of an obsolete captured French tank and an existing artillery howitzer.
Putting the 10.5cm leFH 18 howitzer on top of a captured French FCM 36 tank chassis was a more efficient use of manpower from the traditional form of German artillery battery transportation. Even in WW2, horse power was still widely used although tracked vehicles were also used when available.
Each field gun would require a six-horse team to pull the gun and limber. The ammunition, supplies and kit would be kept in the limber, which was a very large box on a pair of wheels with seats on the top. Three men would ride on the left hand horse of each pair to control them. The remaining six men of the gun crew would ride on top of the limber. Only a relative few were towed by the 3 ton halftracks.
10.5cm leFH 16 auf GW FCM 36(f) awaiting the gun shield to be fitted in the factory workshop run by Major Becker
10.5cm leFH 16 auf GW FCM 36(f) awaiting the gun shield to be fitted in the factory workshop run by Major Becker

The German FCM 36 artillery SPG

The total amount of 10.5cm leFH 16 (Sf) auf Geschützwagen FCM 36(f) built has not been confirmed. Some say only eight, whilst other sources say 12 or even 48. At present there is no documentary evidence to confirm the exact number. The reason why eight is the preferred number is because of a photograph taken inside the tank conversion factory workshop that shows six 10.5cm gun barrels on the floor waiting to be hoisted onto the new built SPG gun mounts and in the background there are two FCM 36 tank based artillery SPGs already fitted with their gun barrels.
There is good evidence that 12 were produced as German Army orders show eight being sent to an Artillery Battalion 31st October 1942 and later four more being sent to the same unit in early 1943.
There were a few disadvantages of an open topped vehicle. The crew was exposed to the elements and were also at risk of injury from enemy thrown hand grenades, mortars and shrapnel from air burst enemy shells. Rain covers were produced. They covered both the crew compartment and the gun. The canvas was attached to the upper protective armour using the small D shaped rings welded to the upper part of the structure.
Because the French FCM 36 tank chassis was small, there was limited space for the storage of ammunition. Only thirty six 10.5 cm HE two part shells could be carried. The propellant charges were kept on the left of the vehicle whilst the projectile shells were stored on the right.
A MG 34 machine gun was attached to top right side of the armor casement, on a swivel mount to the right of the main gun. 50 round drums of spare ammunition were stored underneath the mount. It fired 7.92 mm (0.31 in) bullets.
Only 100 French built FCM 36 tanks were completed by the time of the German invasion of France in May of 1940. In early 1939, the French Army 4e and 7e Tank Battalions were equipped with 50 tanks apiece. After the German invasion of Poland in September of 1939, the two battalions were consolidated under the banner of the 503e French Second Army reserve. The FCM 36 tanks saw active service when they attempted to counter the growing German presence at a bridgehead being set up along the Meuse River at Sedan
With the fall of France, it is believed that roughly 50 FCM 36 tanks remained in operational service. The Germans decided to use some of these French tanks to help strengthen their occupation forces around France. These captured tanks were known as Beutepanzers, trophy tanks. Thirty seven were used as tanks and give the German Army designation of Panzerkampfwagen FCM 737(f). The letter “f” indicate that the tank was of French origins. Ten FCM 36 tank chassis were used to mount 7.5cm PaK anti-tank guns. These tank destroyers were known as the Marder I.
It is not clear if Panzerkampfwagen FCM 737(f) tanks were withdrawn from internal security patrols and converted into self-propelled artillery and anti-tank guns or if the chassis came from knocked out or abandoned FCM 36 tanks that were recovered or captured on the battlefield .
10.5cm leFH 16 gun barrels awaiting hoisting into the new gun mounts on top of the modified FCM 36 tanks
Six 10.5cm leFH 16 gun barrels awaiting hoisting into the new gun mounts on top of the modified FCM 36 tanks. Two have already been fitted. This is why some sources say only eight 10.5cm le.F.H.16 auf GW FCM SPGs were built. Other documents state that 12 were built.

The 10.5cm gun

The 10.5 cm leFH 16 gun was a German light howitzer used in World War I. It had a shorter range than the WW2 10.5 cm leFH 18 gun. As the it had the same caliber as the newer leFH 18, it could fire the same ammunition. The abbreviation leFH stands for the German words ‘leichte FeldHaubitze’ which, translated, means light field howitzer. The number 16 refers to 1916, the year it was introduced into the Imperial German Army. They were produced by the German weapons manufacturer Krupp.
German 10.5cm LeFH 16 Howitzer preserved in a park, North Baltimore Street, Kirksville, MO, USA
German 10.5cm LeFH 16 Howitzer preserved in a park, North Baltimore Street, Kirksville, MO, USA
It was fitted with a ‘Mundungbremse’ muzzle brake to allow longer range charges to be fired and reduce the amount of recoil on the gun. This increased the operational life of the gun barrel.
The 105 mm high explosive HE shell weighed 14.81 kg (32.7 lb). The armor piercing shell weighed 14.25 kg (31.4 lb). It had a muzzle velocity of 395 m/s (1,300 ft/s) and a maximum firing range of 9,225 m (10,089 yd). With a good gun crew, it had a rate of fire between 4-5 rounds per minute.
The 10.5cm leichte Feld Haubitze 16 gun was not very useful in the direct-fire mode against enemy armored vehicles. It could only penetrate 52 mm (2 in) of armor plate at a very short range of 500 meters.
The high explosive shell was in two pieces. It was a ‘separate loading’ or two part round. First, the projectile would be loaded and then the cartridge propellant case.
Fully loaded 10.5cm leFH 16 auf Geschützwagen FCM 36(f) with high explosive shells and charge canisters. The machine gun was mounted to the right of the gun.
Fully loaded 10.5cm leFH 16 auf Geschützwagen FCM 36(f) with high explosive shells and charge canisters. The machine gun was mounted to the right of the gun.

Operational Deployment

Eight 10.5cm leFH 16 (Sf) auf GW FCM 36(f) artillery self-propelled guns were issued to the gepanzer Artillerie-Abteilung (Sfl.) z.b.V (Armored Artillery Battalion) on the Western Front through an order dated 31st October 1942 (K.St.N.430).
The letters z.b.V were the abbreviation for ‘zur besonderen Verwendung’. An English translation would be ‘for special deployment’ or ‘for special assignment’.
They were divided up between two self-propelled artillery batteries called 1.Batterie (Sfl.) and 2.Batterie (Sfl.). Four SPGs were in each battery. The abbreviation (Sfl.) roughly translates to gun carriage or self-propelled gun.
A further four were issued for deployment. They were put in the 3.Batterie (Sfl). This gives strength to the argument that twelve 10.5cm leFH 16 (Sf) auf GW FCM 36(f) were built.
On the side of the upper armor of one vehicle in one of the surviving photographs is the number 2 over a 6Gp. This means that this vehicle was the gun tank number 6 in the 2nd Battery. The 1st Battery would have SPGs numbered 1, 2, 3 and 4. The 2nd Battery would have SPGs numbered 5, 6, 7 and 8. The 3rd Battery would have SPGs numbered 9, 10, 11 and 12.
In March 1943 the unit was renamed. It was now called the Sturmgeschuetz-Abteilung 931 (931st Assault Gun Battalion). This unit’s long name is often abbreviated to Stu.Gesch.Abt. 931. This Battalion was also equipped with 7.5 cm Pak 40 auf FMC 36(f) anti-tank self-propelled guns and an anti-aircraft battery of 2cm Flak auf gep.Zgkw. P 107 vehicles for self-defence.
On 6th May 1943, Stu.Gesch.Abt. 931 was merged with Pz.Jg.Kp. 931 and renamed verst.Pz.Jg.Abt. and was now part of the Schnelle Division West. (Western fast response Division). The abbreviation ‘verst’ was for the word verstaerkte which means ‘reinforced’ (reinforced tank hunting battalion).
Pz.Jg.Kp. 931 was equipped with seven gep.Zgkw Somua MCG/MC 7.5 cm Pak 40 auf m SPW S307(f) anti-tank self-propelled guns. The abbrerviation  gep.Zgkw is short for Gepanzerte Zugkraftwagen (Armored Half-track)
A few weeks later, on June 27th 1943, the unit was renamed again. It was just called Sturmgeschuetz-Abteilung (Stu.Gesch.Abt.) but without a unit number. The Schnelle Division West was now called the 21.Panzer Division.
The rest of the men and equipment of the Pz.Jg.Kp. stayed part of the 21st Panzer Division, but they handed over their gep.Zgkw. Somua mit 7,5 cm Pak 40 halftracks and 2cm Flak auf gep.Zgkw. P 107 to one of the Division’s Panzer Grenadier Regiments.
On 15th July 1943 it was renamed again. This time it was called the Sturmgeschuetz-Abteilung 200 (200th Assault Gun Battalion) and was still part of 21.Panzer-Division.
In September 1943 the 4th battery was equipped with six 10.5cm leFH 18 (Sf.) auf Geschutzwagen 39H(f) artillery self-propelled guns. These had artillery guns that could fire high explosive shells over longer distances. The 4th Battery was also equipped with four 7.5cm Pak 40 (sf) auf GW 39H(f) anti-tank SPGs. To make the supply of spare parts and maintenance simple a decision was made in December 1943 that all the all FCM 36 tank chassis based SPGs were to be replaced with Hotchkiss tank chassis based SPGs.
German military units regularly sent reports to headquarters on how many soldiers and guns, tanks and SPGs were fit for action. In a battle strength report submitted by this unit dated 1st January 1944 there were no 10.5cm leFH 16 (Sf) auf GW FCM 36(f) listed.
It looks like they did not see action in Normandy fighting off the Allies invasion of France. At present it is not known what happened to them.

Identification

One of the easiest ways of telling the difference between a 10.5cm leFH 16 (Sf.) auf Geschutzwagen FCM 36H(f) self-propelled gun and a 7.5cm PaK 40 (Sf.) auf PzKpfw FCM 36(f) anti tank gun SPG is to look at the armored housing that surrounds the gun’s recoil recuperator mechanisms. A recuperator on an artillery gun is a device employing springs or pneumatic power to return a gun to the firing position after the recoil. On the 10.5cm leFH 16 it is long and is half the length of the gun. It is situated below the gun. The armored housing covering the 7.5cm Pak 40 gun’s recoil recuperator mechanisms is small and the gun barrel is thinner and much longer.
When looking at different German self-propelled guns the triangular road wheel armour covering between the tracks is very unique to the FCM 36 tank based SPGs and makes it easily identifiable.

An article by Craig Moore

10.5cm leFH 16 auf Geschützwagen FCM 36(f), having just come out of the tank conversion workshop.
10.5cm leFH 16 auf Geschützwagen FCM 36(f), having just come out of the tank conversion workshop.10.5cm leFH 16 auf Geschützwagen FCM 36(f), 21st Panzerdivision, Normandy, summer 1944.
10.5cm leFH 16 auf Geschützwagen FCM 36(f), 21st Panzerdivision, Normandy, summer 1944.

Gallery

10.5cm gun barrel being lifted by chain and rope hoist
10.5cm gun barrel being lifted by chain and rope hoist.
This 10.5cm LeFH 16 gun is being hoisted into position on its new self-propelled gun mount.
This 10.5cm LeFH 16 gun is being hoisted into position on its new self-propelled gun mount.
This 10.5cm leFH 16 auf Geschützwagen FCM 36(f) still needs its gun shield fitted before it can leave the tank conversion workshop.
This 10.5cm leFH 16 auf Geschützwagen FCM 36(f) still needs its gun shield fitted before it can leave the tank conversion workshop.
10.5cm leFH 16 auf Geschützwagen FCM 36(f) with camouflage livery in France
10.5cm leFH 16 auf Geschützwagen FCM 36(f) artillery self-propelled gun with camouflage livery in France
Gun crews of the 10.5cm leFH 16 auf Geschützwagen FCM 36(f) being inspected in France by senior officers.
Gun crews of the 10.5cm leFH 16 auf Geschützwagen FCM 36(f) being inspected in France by senior officers.
A member of the 10.5cm leFH 16 auf Geschützwagen FCM 36(f) gun crew posing for a photograph near his SPG.
A member of the 10.5cm leFH 16 auf Geschützwagen FCM 36(f) gun crew posing for a photograph near his SPG.
10.5cm leFH 16 auf GW FCM 36(f) SPG being transported by rail to the front line.
10.5cm leFH 16 auf GW FCM 36(f) SPG being transported by rail to the front line.

Last surviving FCM 36 tank

FCM 36 Char léger Modèle 1936 French WW2 light infantry tank at the Musée des Blindés, French Tank Museum, Saumur, France
The last preserved FCM 36 Char léger Modèle 1936 French WW2 light infantry tank at the Musée des Blindés, French Tank Museum, Saumur, France

Specifications

Dimensions (L x W x H) 4.60 (without gun 4.46) x 2.14 x 2.15 m
(15’1″ (14’7″) x 7′ x 7′)
Total weight, battle ready 12.2 tonnes
Crew 4 (commander, driver, gunner, loader)
Propulsion Berliet MDP V-4 diesel engine, 91 hp
Fuel capacity 260 liters
Top road speed 24 km/h (15 mph)
Operational range (road) 225 km (140 miles)
Main Armament 10.5 cm (4.13 in) leFH 16 howitzer with 37 rounds
Secondary Armament 7.92 mm (0.31 in) MG 34 machine gun
Hull Armor Front 25-40 mm (0.98-1.57 in)
Sides and Rear 20 mm (0.79 in)
Upper Armor Front 15 mm (0.59 in)
Sides 15 mm (0.59 in)
Rear 15 mm (0.59 in)
Total production 12

Sources

Encyclopedia of German Tanks of World War Two, Peter Chamberlain and Hilary Doyle, 1999
Panzer Tracts No.10 Artillerie Selbstfahrlafetten by Thanks L. Jentz
Profile AFV Weapons 55 German Self-Propelled Weapons by Peter Chamberlain and H.L.Doyle
Beute-Kraftfahrzeuge und panzer der deutschen Wehrmacht by Walter J. Spielberger
French Tanks of World War II by Steven J.Zaloga
French Infantry Tanks: part II by Major James Bingham
German Artillery at War 1939-45 vol.1 by Frank V.de Sisto.
Musée des Blindés, French Tank Museum, Saumur, France.
Special thanks to Marcus Hock
www.tank-hunter.com
Germans Tanks of ww2
Germans Tanks of ww2

German Self-Propelled Artillery Guns of the Second World War
German Self-Propelled Artillery Guns of the Second World War

By Craig Moore

One towed artillery gun required a team of six horses and nine men. WW2 German engineers came up with the idea of mounting an artillery gun on top of a tank chassis. This new technology reduced the amount of resources required to deploy one artillery gun. Artillery self-propelled guns only needed a four or five man crew. They could also be made ready to fire more quickly. This book covers the development and use of this new weapon between 1939 and 1945. One type was successfully used in the invasion of France in May 1940. More were used on the Eastern Front against Soviet forces from 1941 until the end of the war in 1945.

Buy this book on Amazon!

Categories
WW2 German SPGs

15 cm sIG 33 (Sf.) auf Fahrgestell Panzerkampfwagen II

German Reich (1940-1941)
SPG – 12 Built

One of Rommel’s Funnies

To move a towed 15 cm artillery piece, the Germans needed a team of six horses and three men to control and look after the horses. The five or six man additional crew rode on a wheeled limber behind the horses. Attached to the limber was the heavy 15 cm artillery field howitzer.
In 1941, Field Marshal Erwin Rommel needed heavy artillery to support his advancing armored divisions in North Africa. Horse drawn artillery was impractical in the heat of the desert. The logistics of supplying these animals with enough feed and water was a nightmare. He demanded a solution be found.
The gun barrel on this 15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) was fitted with a cover to stop dirt and sand getting inside
The gun barrel on this 15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) was fitted with a cover to stop dirt and sand getting inside. (photographer unknown)
The Panzer II tank had performed well in Poland in 1939, but it was out classed by some of the British and French tanks it encountered during the invasion of France in May 1940. This vehicle was considered obsolete by 1941 and was replaced by Panzer III tanks as soon as they came off the factory production line.
The German army now had a surplus of Panzer II tanks. The decision was taken to remove the tank’s turret and mount in its place a 15cm sIG 33 field howitzer with a gun shield to protect the crew. Rather than having to find a crew of 9 men and six horses to operate one artillery gun, the German army only needed to find four crewmen. It is sometimes called one of ‘Rommel’s Funnies’.
Driver's escape hatch on the 15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf)
Driver’s escape hatch on the 15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf). (photographer unknown)

The Name – Not a Sturmpanzer II or Bison II

The correct German Army designation for this self-propelled artillery gun is 15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) Sd.Kfz.121/122 or 15cm s.l.G.33 auf Fahrgestell Pz.Kpfw.ll (Sf.).
While undergoing trials, it was sometimes referred to as the 15cm s.I.G.33 B (this was to show it was an upgrade from the prototype SPG, the 15cm s.I.G.33 A, that used the original five wheeled Panzer II tank chassis and had not yet been lengthened).
After World War II, a scale model kit company produced one of the first retail kits of this vehicle. They called it the ‘Bison II’, believing it to be the natural progression for the earlier Bison 1 self-propelled 15cm Artillery Gun based on a Panzer I tank chassis’.
This was wrong. It was never called the Bison II during the war but, after the war, the name Bison II stuck. Museums, historical books and other scale model kit companies continue to call this mobile artillery weapon the Bison II.
Some authors, museums and scale model kit companies also wrongly call it the Sturmpanzer II. A ‘Sturmpanzer’ is a heavily armored assault tank. It’s crew is protected in a fully armored box, that is enclosed on all four sides and has an armored roof. The front armor of this vehicle is thick to enable it to get close to enemy strong points before firing it’s weapon.
This description bears no resemblance to the function and appearance of the German 15 cm s.I.G. 33 auf Fahrgestell Panzerkampfwagen II (Sf) SPG. This vehicle was not designed to advance towards heavily fortified gun emplacements and blow them up whilst under heavy fire. It is only thinly armored and the crew have very little protection.
This vehicle was designed to keep up with the advancing infantry and tanks, but remain behind them, out of harm’s way, and fire shells over their heads at enemy targets.
Notice the spare road wheels strapped to the top of the right track guard of this Bison II
Notice the spare road wheels strapped to the top of the right track guard on the 15cm s.l.G.33 auf Fahrgestell Pz.Kpfw.ll (Sf.) on the left. (photographer unknown)

Production and Development

Before the first 15 cm sIG 33 auf Fahrgestell Panzerkampfwagen I (Sf) (Bison I) had been tested in combat in May 1940, the German Army Waffenamt was already engaged in the development of an improved model based on the Panzer II Ausf.B tank chassis, rather than the Panzer I.
The prototype was successfully test fired at Kummersdorf on 13 June 1940. A 15cm s.I.G.33 B, without standard gun carriage wheels, had been fitted to a Panzer II tank chassis by Alkett, an engineering company near Berlin. As part of the trials, 120 rounds were fired.
15cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) prototype
This is a photograph of the 15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) prototype. Notice the curved gun shield and five, not six road wheels.
The Panzer II tank chassis absorbed the 15cm gun’s highest recoil force of 9 tons firing at all settings and at a rapid rate of fire of up to three rounds per minute. The tracks didn’t noticeably sink into the ground while firing on sandy soil.
Several months earlier, a similar trial had been conducted by Alkett. The standard field gun carriage wheels had been mounted on the Panzer tank chassis. This meant it had to be mounted too far to the rear.
The engine hatches at the rear of the vehicle were left in the open position when driving to keep the engine cool.
The engine hatches at the rear of the vehicle were left in the open position when driving to keep the engine cool. (photographer unknown)
Firing at the highest muzzle velocity of 240 meters/second at an elevation of about 15 degrees, the recoil force of 9 tons passed through the middle of the last road-wheels, resulting in the Pz.Kpfw.II tank chassis unacceptably tipping backward.
After this initial failure, the Alkett design team went back to the drawing board. They took the wheels off the gun carriage and devised new mounts. This meant that the 15 cm howitzer could be fitted considerably farther forward on the tank chassis, which made the vehicle significantly more stable when firing.
The Entwicklungsstueck (prototype development piece) was completed by Alkett in October 1940 using a normal length Pz.Kpfw.II chassis with five road-wheels. They only made one.
On 18th February 1941, General Halder commented in his diary: ‘Room inside the s.I.G. auf Pz.II is unacceptably small. New vehicles in four months. Mass production in one year. ‘
Alkett must have taken this criticism to heart because the Versuchsserie (trial series) of twelve 15cm s.l.G.33 auf Fahrgestell Pz.Kpfw.ll (Sf.) SPGs were produced with a lengthened and widened hull resulting in the addition of a sixth road wheel. Delivery was to start in August 1941. Overall length of the new vehicle was 5.48 m, width 2.60 m, and height 1.98 m (compared to the 4.81 m long by 2.28 m wide Panzer II Ausf.F light tank).
Additional space for the fighting compartment was also achieved by mounting the 150 metric horsepower Buessing-NAG L8V water-cooled gasoline petrol engine transversely across the rear. The gun had a 75-degree elevation, but only 10 rounds could be carried on-board.
15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) being loaded with supplies
15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) being loaded with supplies. (photographer unknown)

The 15cm sIG 33 gun

The Germany Army Infantry regiments could call on the support of a large 15 cm caliber towed artillery field howitzer called the 15cm schweres Infanterie Geschütz 33 (heavy infantry gun). They were designed by Rheinmetall in 1927 and were formally accepted introduced into the German military in 1933, hence the designation 33. This long name was shortened to 15 cm sIG 33 or 15 cm s.I.G. 33. About 4,600 were made between 1936 – 45.
This gun was not designed as an anti-tank gun. It was normally used to fire high explosive HE shells over the heads of advancing German troops at targets plotted on a map. This is called indirect fire. Occasionally it was called upon to fire at enemy positions it could see. This is called direct fire. The two part I Gr 33 HE shell was filled with 8.3 kg (18 lbs) of pressed TNT with smoke box and standard Zdlg. 36 exploder system. The total weight of the fused round was 38 kg (84 lbs).
Unlike anti-tank gun shells that came in one piece, artillery shells were loaded into the gun breach in two separate pieces. The high explosive HE shell was always loaded first and this was followed by the propellant cartridge.
The rimmed brass propellant cartridge case, with a c 12 n/A percussion primer was closed at the top by a cardboard closing cap and loaded after the HE shell had been rammed home into the gun. The gun crew had a range chart that told them what amount of explosive propellant to put into the empty brass cartridge case. More was added for longer range targets and less was used to hit targets closer to the gun.
The propellant consisted of six removable silk bags numbered 1 to 6 that contained Nitroglyzerin Blättchen Pulver (nitroglycerin flaked powder) or Diglykolnitrat Blättchen Pulver (diglycolnitrate flaked powder). For long distant targets all six bags would be put in the brass propellant cartridge case. For shorter distances fewer bags would be used.
The gun could also fire smoke rounds to cover the retreat or advance of an infantry or armored column. These shells were called 15-cm Igr. 38 Nebel and weighed 38.50 kg (85 lbs). These smoke shells were identified by the white letters ‘Nb’ on a field-gray projectile. The bursting charge consisted of picric acid, and the exploder system comprised of a detonator set in penthrite wax enclosed in an aluminium container. The shell produces a smoke cloud 50 meters (55 yards) thick.
It had an effective firing range of 4.7 km – 4,700 m (2.89 miles – 5,140 yd). When firing HE shells it had a muzzle velocity of 240 m/s (790 ft/s). A good gun crew could fire three rounds a minute. The shell fuze s.Igr.Z. 23 was a highly sensitive, nose-percussion fuze with an optional delay of .4 second. It operated on impact or graze. It fired two types of HE shells, the 15cm I.Gv.33 and the 15cm I.Gv.38. For all practical purposes they were identical.
The breach was a horizontal sliding block. The gun’s recoil was controlled by a hydropneumatic chamber. The gun was made by a number of different companies: Rheinmetall, AEG-Fabriken, Bohemisch and Waffenfabrik
The gun cradle was situated below the gun barrel. It was trough-shaped and is provided with guide ways, in which guides on the gun move as it recoiled and ran out. On either side at the front was a pad to receive the unabsorbed force of run-out. Between them was the expansion chamber which received the buffer fluid forced from the buffer by expansion as it became heated. Towards the rear were the two cradle arms to which the trunnions were fixed. Each trunnion was provided with a cranked compensator lever which compresses the compensator spring.
Abandoned 15cm s.l.G.33 auf Fahrgestell Pz.Kpfw.ll (Sf.) in North Africa 1941
Abandoned 15cm s.l.G.33 auf Fahrgestell Pz.Kpfw.ll (Sf.) in North Africa 1941. (photographer unknown)

North Africa

On 15th September 1941, the German Army Organisations-Abteilung ordered the creation of two new independent heavy self-propelled infantry gun companies: 707.schwere Infanteriegeschütze-Kompanien. and 708. schwere Infanteriegeschütze-Kompanien. These units were sometimes abbreviated to s.I.G.Kp. (mot. S).
Alkett completed seven 15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) in December 1941 and five in January 1942. Each company were issued with six of these new SPGs. The six vehicles in the 707 were assigned to the Schützen-Regiment 155 and the six vehicles in the 708 were assigned to the Schützen-Regiment 200. Both of these regiments were part of Rommel’s 90.leicht Afrika-Division and fought until the Axis surrender in Tunisia in May 1943. The 12 vehicles did get to Libya in time for Rommel’s assault on Tobruk, due to its postponement from November 1941 until June 1942.
On the 23 February 1942, the six vehicles belonging to 708 arrived in Tripoli. Three different ships were used, each carrying just two of the SPGs, just in case of a torpedo or bombing attack. The s.I.G.Kp.707 wasn’t transported to Libya until April 1942. Six different ships were used to transport the remaining six vehicles belonging to 707. The last vehicle was taken of the ship in Tripoli on 24 April 1941.
On 9 March, the 708 company commander reported at the division command post that they had arrived in Bengasi on 8 March, but they must remain there for two days to complete various engine repairs. Not enough spare parts had been shipped to North Africa. One of the units NCO’s flew back to Alkett in Berlin to arrange for replacement parts to be shipped out as soon as possible.
Mechanical problems were going to plague the deployment of these new self-propelled artillery guns in the desert. The engine had not been upgraded to take the additional weight and cope with the conditions encountered in Libya, Egypt and Tunisia. The Panzer II 155 horsepower engine was too weak for the vehicle weight of 16 ton.
The engine cooling system was inefficient for conditions in Africa. In accordance with the driver’s manual, the cooler flaps must be opened while driving. The large amount of dust thrown up by the tracks fell through the open grating and plugged up parts of the radiator reducing the available surface area and its ability to cool the radiator fluid. Engine temperatures became too hot.
A report dated 16 May 1942 stated that, ‘During the 70 km journey to SegnaIi-Sued it soon became apparent that the new 15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) of 708.schwere Infanteriegeschütze-Kompanien were unusable due to design faults. The same situation applied to the vehicles of 707. They were currently in Bengasi with two broken-down SPG’s without any resources to transport them to the front or repair them.’
The transmission and transfer boxes suffered from faults. After a very short running time, sometimes 15 minutes, the engines were so hot that they had to stop to cool them. The pressurized engine coolant reached 120 degrees Celsius after a short running time. Cracks appeared in the track and drive wheels due in part to poor material quality.
Panzer-Armee Afrika still listed eight 15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) as available, but not how many were operational on 23 October. All eight were reported as having been lost by 2 December 1942. The British reported capturing six of them abandoned during the withdrawal, all in a dismantled condition in a tank workshop.

Rain & Sun protection

The crew could fit two metal bands across the middle of the open top fighting compartment. They provided similar support as tent poles in a tent. A large canvas tarpaulin tied down at the back of the vehicle could be hauled over these bands and lashed down to the front of the vehicle to give the crew protection from the sun, as well as rain and sand storms.


The prototype 15cm s.I.G. 33 A only had five wheels and the normal length Panzer II tank chassis
The prototype 15cm s.I.G. 33 A only had five wheels and the normal length Panzer II tank chassis.The 15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) in grey livery
The 15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) in grey livery.
15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) ready for active service in North African 1941.
15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) ready for active service in North Africa, 1941.
15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) with tarpaulin frame erected and sun shade tarpaulin tied on
15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) with tarpaulin frame erected and sun shade tarpaulin tied on.

Gallery

15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) with wet weather tarpaulin frame in place
15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) with wet weather tarpaulin frame in place. (photographer unknown)
15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) with the tarpaulin pulled over the ridge frame to keep the crew in the shade
15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) with the tarpaulin pulled over the ridge frame to keep the crew in the shade – North Africa, 1941. (photographer unknown)
15cm s.l.G.33 auf Fahrgestell Pz.Kpfw.ll (Sf.) gun crew, driver and commander
15cm s.l.G.33 auf Fahrgestell Pz.Kpfw.ll (Sf.) gun crew, driver and commander – North Africa, 1941. (photographer unknown)
Notice the stick leaning on the vehicle. It was painted red and white and hammered into the earth behind the vehicle to help the gunner work out firing angles.
Notice the stick leaning on the vehicle. It was painted red and white and hammered into the earth behind the vehicle to help the gunner work out firing angles. (photographer unknown)
German 15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) parked in a North African street.
German 15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) parked in a North African street. (photographer unknown)
15cm s.I.G.33 B Sfl Waiting for the next target.
Waiting for the next target. (photographer unknown)
The driver's side vision hatch is open on this photograph of a 15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf)
The driver’s side vision hatch is open on this photograph of a 15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf). (photographer unknown)
Time for coffee out of sight of the enemy
Time for coffee out of sight of the enemy. (photographer unknown)
The rear engine hatch covers are in the up position. This was done to keep the engine cool
The rear engine hatch covers are in the up position. This was done to keep the engine cool. (photographer unknown)
The flap in the gun shield was opened to use the shorter periscope gun sight for direct fire targets. The taller gun sight was used for indirect fire targets
The flap in the gun shield was opened to use the shorter periscope gun sight for direct fire targets. The taller gun sight was used for indirect fire targets. (photographer unknown)
15cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf)
15cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) ready for a bombardment (photographer unknown)
15cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) in North Africa with a six man crew (driver hidden from view)
15cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) in North Africa with a six man crew? The driver hidden from view. (photographer unknown)

Why were only 12 built?

A German Army Waffenamt liaison officer assigned to Panzer-Armee Afrika filed a report dated 30th August 1942 about the use of the 15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) in North Africa:
‘From the ballistic and destructive effectiveness standpoint, the gun is judged to be outstanding but the Panzer II chassis too underpowered and liable to mechanical breakdown. The troops’ propose that a more suitable tank chassis should be used. I do not agree. The range of this gun cannot be increased. The expenditure is not justified. It would be better to use the 15 cm s.F.H.13 Sfl heavy field howitzer, which has the same caliber but a considerably longer range, on a better tank chassis.
Operationally it is too risky to employ such a valuable self-propelled gun as a fixed location defensive weapon. As soon as it opens fire the gun will be knocked out by concentrated artillery fire. In this situation, the should be replaced with a 12 cm Werfer (mortar) that, with its increased rate of fire, lower weight and easier transport on a truck, has almost the same destructive effectiveness.’
Lessons learned from this vehicle, the 15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II (Sf) Sd.Kfz.121/122 and earlier 15cm and 10.5cm self-propelled artillery guns resulted the design and development of the 10.5cm ‘Wespe’ self-propelled artillery infantry gun.

Specifications

Dimensions (L W H) 5.48 x 2.60 x 1.98 m (17’11” x 8’6″ x 6’6″)
Total weight, battle ready 12 tonnes
Armament 15cm s.I.G.33 L/11 howitzer, 10 rounds
Armor Front hull 30 mm (1.18 in)
Front gun shield 15 mm (0.59 in)
Side and rear 15 mm (0.59 in)
Crew 4 (driver, commander, gunner, loader)
Propulsion Buessing-NAG L8V water-cooled gasoline petrol engine
Max Road Speed 45 km/h (28 mph)
Range 170 km (110 miles)
Total production 12

Post WW2 Service

The British Army recovered six 15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II self-propelled artillery guns. They were left in Egypt. The Egyptians recovered one more. It is not known if any were repaired and used by the Egyptian Army against the Israeli Army in the 1948 war or what happened to them after that conflict. If you have any further information please contact us.
Recovered 15cm s.l.G.33 auf Fahrgestell Pz.Kpfw.ll (Sf.) in Egypt 1948
Recovered 15cm s.l.G.33 auf Fahrgestell Pz.Kpfw.ll (Sf.) in Egypt after WW2
A 15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II self-propelled artillery gun captured by Israeli forces in 1948
A 15 cm sIG 33 auf Fahrgestell Panzerkampfwagen II self-propelled artillery gun captured by Israeli forces in 1948

Sources

Ed Webster
German Infantry Weapons – US Military Intelligence Service, Special Series No. 14, May 25, 1943. U.S. War Department
Allied Expeditionary Force German Guns – Brief Notes and Range Tables for Allied Gunners – SHAEF/16527/2A/GCT July 1944
Chamberlain, Peter, and Hilary L. Doyle. Thomas L. Jentz (Technical Editor). Encyclopedia of German Tanks of World War
A Complete Illustrated Directory of German Battle Tanks, Armoured Cars, Self-propelled Guns, and Semi-tracked Vehicles, 1933–1945 – Arms and Armour Press
Trojca, Waldemar and Jaugitz, Markus. Sturmtiger and Sturmpanzer in Combat. Katowice, Poland: Model Hobby,
Sturmpanzer II Bison. Achtung Panzer!.
Info on Wikipedia
Germans Tanks of ww2
Germans Tanks of ww2

German Self-Propelled Artillery Guns of the Second World War
German Self-Propelled Artillery Guns of the Second World War

By Craig Moore

One towed artillery gun required a team of six horses and nine men. WW2 German engineers came up with the idea of mounting an artillery gun on top of a tank chassis. This new technology reduced the amount of resources required to deploy one artillery gun. Artillery self-propelled guns only needed a four or five man crew. They could also be made ready to fire more quickly. This book covers the development and use of this new weapon between 1939 and 1945. One type was successfully used in the invasion of France in May 1940. More were used on the Eastern Front against Soviet forces from 1941 until the end of the war in 1945.

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