German Reich (1938-1945)
Self-propelled Anti-Aircraft Gun – At Least 3 Converted
The Schulfarhzeug 1-5b. Serie/La.S. mit MG 34/42 Zwillingssockel 36 (Eng. training vehicle 1-5. Series of agricultural vehicles with MG 34/42 dual mount 36) was a Panzer I training variant that mounted anti-aircraft weapons. It was a field conversion that first appeared in 1938 and was last seen in Denmark in 1945. The vehicle lacked protection and was most likely only used for training soldiers in the anti-aircraft role.
History of the First Light Anti-Aircraft Vehicles
The concept of protecting troops from air attacks and air raids was not new to the Second World War. Already during the First World War, anti-aircraft vehicles, mostly trucks with machine guns or small guns, were introduced to deal with support planes. During the Interwar years, Germany was forbidden from building any tanks or AFVs due to the Versailles Treaty.
In 1930, the German Army gradually started to rearm and also began to develop and build more AFVs. After the Nazis took over Germany in 1933, the Treaty of Versaille was completely disregarded. With this general rearmament, the concept of self-propelled anti-aircraft vehicles was brought up again. It was introduced to many types of vehicles with different armaments. Alongside the Sd.Kfz.10/4 (a small half-tack with a 2 cm Flak gun), there was also the Kfz.4 Truppenluftschutzwagen (Eng. air defense vehicle) introduced in 1938. It was a 4-wheeled cross-country personal carrier featuring the Einheitsfahrgestell I (Eng. unitary chassis I) with a Zwillingslafette 36 (dual mount 36) and machine guns. The idea behind the Kfz.4 was to have a small reliable vehicle that could effectively defend itself and the troops against low-flying aircraft with its dual machine guns. However, these vehicles would be produced in smaller numbers, as the unitary chassis I was used for more important vehicles. However, the Kfz.4 was not only the unitary chassis I, but this designation was used to describe many different motor vehicles using the Zwillingslafette 36. It was also mounted on cars and horse drawn trailers and even in fixed positions.
Making Use of an Old Chassis
The Panzer I Ausf.A and B were introduced as the first real German serial-produced tank in 1935. Even though it was obsolete by 1939, it still saw service throughout the war. Next to the regular Panzer I which was intended for combat, a number of Panzer I chassis would be reused as training tanks. These Schulwagen (Eng. training vehicles) were open-top chassis without armament and superstructure. but maintained the engine deck. They also often had railings.
The Schulwagen saw service from 1934-1945 as training tanks. However, at some point, even the Schulwagen became obsolete. Therefore, many Schulwagen were converted into new roles. One of these conversions was the anti-aircraft role.
Production and Conversion
It is unknown how many Flakschulwagen Is were built, but photographic evidence suggests that at least 3 different vehicles were built. Based on photographic evidence, the first Flakschulwagen I appeared around 1938 during pre-war training. The vehicle used the Panzer I Ausf.B chassis, and, unlike the others, it used only a singular anti-aircraft MG 34 on a monopod mount placed in the crew compartment.
It is unknown when the second Flakschulwagen I was built, but photos show the vehicle in 1943 and in 1945. It had the dual mount anti-aircraft MG 34 and was based on the Panzer I Ausf.A chassis.
The third and final confirmed Flakschulwagen I was built after 1942 due to its dual mount MG 42, which was first introduced in 1942.
The vehicle was a field conversion and therefore never received a real designation. Furthermore, it is unknown how the troops referred to it. Therefore, a name can only be drawn from the combination of the parts. The chassis was the Panzer I training school tank referred to as Schulfahrzeug 1-5.Serie/La.S. and the gun, the Zwillingssockel 36. This designation would be: Schulfahrzeug 1-5b. Serie/La.S. mit MG 34/42 Zwillingssockel 36 (Eng. training tank 1-5b. Series/agricultural tractor with MG 34/42 Zwillingssockel 36). The article will use a more simplified version of the designation: Flakschulwagen I (Eng. anti-air training vehicle I).
This modification was based on both the Panzer I Ausf.A and B chassis. Both versions were in principle quite similar, the main difference being that the Ausf.B version was longer with a modified engine compartment (including a new engine) and had one more road wheel in the suspension.
The Panzer I hull, like nearly all German tank designs, could be divided into three sections: the front part where the transmission was placed, the central crew compartment, and the rear-positioned engine. The overall construction was made out of several armor plates welded together, with a firewall separating the engine compartment and the crew compartment.
The later Ausf.B’s hull design did not change much aside from the rear hull, which was extended to be able to fit the new suspension and larger engine. Furthermore, the extension allowed for additional space for cooling air and the tow coupling to be relocated to the rear. The rear armor cover was redesigned to fit the new engine. It was made higher at the rear for the air intake to cool the engine. The air was drawn through the radiator and blown out of a grill placed at the rear right-hand side of the engine deck. A new split hatch was placed above the engine for easy access. Lastly, the two exhaust pipes, which on the Ausf.A were located on the mudguards, were removed and a single muffler with extra armor protection was fixed to the rear side. The Flakschulwagen I’s hull design appears to be unchanged from the original Panzer I tank configuration.
The suspension on the Flakschulwagen I was unchanged. The Panzer I Ausf.A’s suspension consisted of one front sprocket wheel, three return rollers, one idler wheel, and four road wheels on each side. While the first/front road wheel was a single wheel, the second and third road wheels were paired in a leaf spring suspension. The fourth road wheel was also mounted on a suspension cradle connected to the idler wheel. The idler wheel was partially connected to the fourth road wheel and touched the ground, which would later turn out to be a significant problem, as the steering of the tank was severely impaired. In addition, the first wheel used a coil spring mount with an elastic shock absorber in order to prevent any outward bending
The suspension upgrade is probably the most visual change from the Ausf.A to Ausf.B and is often used to distinguish between them. The reason for these changes was to upgrade the overall mobility and mainly the steering. With the Ausf.A, the tank, whenever it was being steered, had to also move the idler wheels, which inhibited and slowed down the steering process. This would also increase the chance of the tank throwing a track. Furthermore, a new lengthened suspension would help with a more stable ride and more stability whilst firing.
On the Ausf.B, a fifth road wheel and a fourth return roller were added. The connection between the fourth road wheel and the idler wheel was cut and the fourth wheel was instead connected in a pair to the new fifth road wheel. The second and third were also connected in a pair, whilst the first one was independent. The idler wheel was raised and its crank arm was mounted in a housing. Track tension was done by rotating the idler wheel’s crank arm.
The engine on the Ausf.A was the Krupp M 305 four-cylinder giving out 60 hp @ 2,500 rpm. The maximum speed with this engine was 37 km/h. The later Ausf.B version received a completely new engine. This was necessary as the Krupp M 305 proved to be unreliable and prone to overheating. The new engine used was the water-cooled Maybach NL 38 Tr, able to supply 100 hp @ 3,000 rpm. The tank’s speed increased to 40 km/h. The fuel was located in two tanks, with one holding 82 liters and the other 62 liters, both on the right side, separated from the crew compartment.
With the removal of the upper superstructure and turret, a great deal of weight was removed from these modified vehicles. The weight of the Panzer I Ausf.A was 5.4 and the Ausf.B 5.8 tonnes. According to P. Chamberlain and H. Doyle (Encyclopedia of German Tanks of World War Two – Revised Edition), the weight of the Panzer I Ausf.B modified with the upper superstructure that was used for training was 4 tonnes. This reduction in weight of over a tonne would probably have affected the overall drive performance of these vehicles, possibly being slightly faster than the original tank configurations. Given the lack of information about the Flakschulwagen I’s overall drive performance, this could be considered as speculation at best.
The Flakschulwagen I vehicles were based on modified Panzer I chassis intended to be used as training vehicles. These were never provided with a superstructure, and instead, the crew was completely exposed to weather and to enemy fire. Given the role that these vehicles were to perform, this was not an issue. Metal bars were usually added on top of the hull to act as a safety measure to prevent one of the crew from accidentally falling off the vehicle.
The modified Panzer I Ausf.A and B armor was quite thin. The Panzer I’s front hull armor ranged from 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). The later Ausf.B did not receive any changes to the overall armor thickness.
The crew operating the main armament on the Flakschulwagen I was completely exposed, as no gun shield was ever used on the light machine gun mount.
This vehicle was armed with either two 7.92 mm MG 34 or MG 42 machine guns. Both were designed as a general purpose machine gun intended to fulfill several different roles, including acting as a light machine gun, heavy machine gun (placed in a fixed mount), secondary armament of armored vehicles, etc. They were excellent designs with a great rate of fire, 800 to 900 rounds per minute on the MG 34 and 1,200 on the MG 42. While these could be operated by one man, ideally, two men would be needed, with the second acting as an ammunition carrier. The MG 34 was introduced just prior to the Second World War, but proved to be rather expensive to build. As a replacement, the much cheaper MG 42 was developed and put into service after 1942. After that point, the MG 34 was only used as the secondary armament for tanks or other armored vehicles, while the MG 42 was issued to infantry formation.
When these two and some older machine gun designs were used in the anti-aircraft role, they were simply placed on a three-leg mount. There was a simple connector point that merged the machine gun to this mount. It had a 360° traverse, so that any aircraft that came into sight could be targeted. To be able to effectively engage flying targets, an especially designed sight was also used.
The use of this mount was quite common and was the basic line of anti-aircraft defense for many infantry units. Nonetheless, something with more firepower that could be used by infantry and other units was needed. Early in the war, the Germans introduced the Zwillingslafette 36. This was basically a simple pedestal mount with a 360° traverse armed with either two MG 34s or MG 42s. To the back, the gunner seat was located, while the mounting for the two machine guns was placed on the front. The two machine guns were positioned parallel to each other. In the middle of this mount, a machine gun sight specifically designed for engaging air targets was added. While this mount was usually placed inside various vehicles, it was also towed in trailers or even employed as a static emplacement. With its two 7.92 mm caliber machine guns, realistically, it could only do minor damage to enemy aircraft. That said, destroying an enemy aircraft was not always the goal of anti-aircraft units, as even forcing the enemy to stop an attack was considered a success. Despite German anti-aircraft units being supplied with larger caliber weapons, this mount would remain in service up to the end of the war. Both machine guns usually used a 75-round capacity drum magazine. The precise ammunition load of these modifications is unknown.
While the precise installation of the Zwillingslafette 36 inside the Flakschulwagen I is not clear given the lack of sources, it was probably simple in nature. The bottom of the mount was likely bolted down the Flakschulwagen I’s hull bottom. This way, it could be easily removed if the weapon mount was damaged or the vehicle needed to be modified for other purposes. The Zwillingslafette 36 appears to have had a full 360° traverse in this vehicle.
Interestingly, at least one Flakschulwagen I was armed with a single MG 34 machine gun or possibly even some older model. Due to the photograph’s poor quality, it is not clear if the mount was an improvisation or taken from other vehicles that were in the German service. The latter option seems to be more plausible, as the Germans used a single machine gun mount on a number of their reconnaissance vehicles, such as the a href=”https://tanks-encyclopedia.com/ww2/nazi_germany/sdkfz-221-222-223.php”>Sd.Kfz.221, for example.
It is unclear how large the crew of this modification was. Given the rather small size of the Panzer I, it would be limited to a few only. This likely included the driver, who would be positioned on the hull’s left side; the commander/gunner, who would operate the machine guns; and, lastly, possibly a loader, who would help to load the two machine guns or act as an extra spotter. Given the vehicle’s limited interior space, the remaining crew would have to stand on its side fenders in order to help with the ammunition supply.
Doctrine and Organization
How the Flakschulwagen Is were actually used is not known. There are two ongoing theories. One states that the Flakschulwagen Is were used as training vehicles for anti-aircraft instruction. This theory is supported by the first Flakschulwagen I with the single MG 34 used during pre-war training. Furthermore, the dual mount MG 34 was also stationed in Germany, providing further evidence. The second theory states that the Flakschulwagen Is were taken over from training battalions to real divisions and actually saw combat. This theory is supported by the dual mount MG 42 Flakschulwagen which was deployed in the Soviet Union in 1943. However, due to the limited protection for the crew, the first theory is more likely.
In what exact divisions the vehicles were organized is also not known. The regular training vehicles were part of training schools and later divisional training battalions. This would also be the part where the Flakschulwagen would be organized within. If the vehicles were to have been sent into combat, they would most likely have been organized similarly to the Kfz.4 air defense car, since these were the units that received the Zwillingssockel 36. The Kfz.4s were organized into 4 anti-aircraft sections with one vehicle each, within an anti-aircraft platoon within the HQ unit of the tank’s regiment.
The service life of the Flaschulwagen I is not recorded anywhere and can only be deduced by using photographic evidence.
The first Flakschulwagen I with the single MG 34 was used as a training vehicle. It is most likely that the vehicle did not see combat service and was presumably lost at some point throughout the war.
The second Flakschulwagen I most likely appeared around 1943 due to the dark yellow camouflage, which was introduced in said year. This vehicle can be seen used as a training vehicle in Germany and it later ended up in Denmark in 1945.
The third Flakschulwagen I also presumably appeared around 1943, due to its camouflage. In the photos, the vehicles can be seen dug in, possibly used in a stationary role as a defense position of an HQ unit. The vehicle was photographed in the Soviet Union, which would suggest the vehicle was part of an actual combat unit.
Other Flakpanzers Based on the Panzer I Chassis
During the early stages of the war, the Germans modified small quantities of Panzer I Ausf.A tanks as ammunition carriers. These lacked any kind of defensive weapons to protect themselves from either ground or air targets. For this reason, from March to May 1941, some 24 Panzer I Ausf.A were modified as self-propelled anti-aircraft vehicles.
In addition to the Flakpanzer I armed with the 2 cm Flak 38, a few were built with the triple 1.5 or 2 cm MG 151 Drilling. These (the precise numbers are unknown, it could have been only a single vehicle) were built by placing the new weapon mount inside the crew compartment, but without the upper superstructure. The existing photo shows it was built using a Panzer I Ausf.B chassis. Not much is known about this modification. As the MG 151 Drilling was employed in greater numbers at the war’s end, it is likely that this was a last-ditch effort to increase the Panzer I’s firepower by any means possible when there was nothing else available. There is also the possibility that this vehicle was also made using a Panzer I training vehicle.
The Flakschulwagen I was quite an unusual and generally poorly documented vehicle. It was created using the obsolete Panzer I chassis and armed with the two machine gun mount creating a vehicle that was likely used for crew training. The ever-increased reliance on anti-aircraft vehicles to provide protection against enemy aircraft would explain the need to create the Flakschulwagen I.
Using photo evidence, it seems at least one of them saw frontline combat to some extent. Its combat performance would be limited at best, as it had virtually no armor to protect the exposed crew and only possessed weak armament. Sadly, the fate of any of these vehicles is unknown.
|Dimensions (L-W-H)||4.61 x 2.13 x 1.12 m|
|Weight, battle-ready:||Around 3 tonnes|
|Crew||3 (driver, commander/gunner, loader)|
|Propulsion||Ausf.A: Krupp M 305 4-cylinder air-cooled, Ausf.B: Maybach NL 38 TL 6 cylinder water-cooled petrol|
|Speed||37 km/h (on roads) / 25 km/h (cross-country)|
|Range||140 km, cross-country: 93 km|
|Armament||Zwillingslafette 36, 2x 7.92 mm MG 34 and MG 42,|
|Armor:||Up to 13 mm|
|Trench crossing capability:||1.40 m|
|Ground clearance:||29.5 cm|
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