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WW2 Italian SPG Prototypes

Autocannone da 90/53 su SPA Dovunque 41

Kingdom of Italy/Italian Social Republic (1942-1945)
Truck-Mounted Dual Use Artillery – 1 Prototype Built

The Autocannone da 90/53 su SPA ‘Dovunque’ 41 was an Italian anti-aircraft and anti-tank self-propelled truck-mounted gun designed in 1942 on the SPA Dovunque 41 6×6 heavy duty truck chassis. It was meant to succeed the previous Autocannone da 90/53 su Breda 52 in the ranks of the Italian Regio Esercito (English: Royal Army).

Although it was a promising project, the Armistice of 8th September 1943 caused the cancellation of the vehicle’s development, which was restarted in 1944 under the control of the new fascist-aligned Esercito Nazionale Repubblicano (English: National Republican Army). They used the single armored prototype produced by Officine Viberti.

The name Autocannone da 90/53 su SPA Dovunque 41 means truck-mounted 90 mm L/53 [cannon] on SPA Dovunque 41 [chassis].

The North African Context

During the first stages of the Second World War, the Regio Esercito was involved in a military campaign against the Commonwealth troops in the vast deserts of North Africa. This campaign began on 9th September 1940, when the Italian troops invaded Egypt from Libya, which was an Italian colony.

During these actions, it was clear for the Regio Esercito commanders in Africa that the Army needed long-range and well armed reconnaissance vehicles with great mobility. They also needed support vehicles that would be fast and armed with field guns capable of supporting the Italian assault infantry units. Good mobility would allow them to quickly move from one point to another on the battlefield to stop British assaults and support Italian counterattacks.

For this purpose, some light trucks, captured from the British troops in Cyrenaica during the first days of war, were used. These vehicles were Morris CS8, Ford F15, and Chevrolet, all with a payload capacity of 15 cwt (750 kg). They were captured in large quantities and were put back into service with the Italian coat of arms as supply trucks.

General Gastone Gambara, one of the Italian commanders in North Africa, ordered some workshops to take a number of these British lorries and modify them, mounting artillery pieces on their loading bay. This was how autocannoni came to be.

In Italian, the word autocannone (plural autocannoni) designated a truck of civilian or military production, of any type (light, medium, etc.), modified to permit the transportation of an artillery piece of any type (anti-tank, field gun, anti-aircraft, etc.) permanently fixed on the cargo bay.

An Autocannone da 65/17 su Morris CS8 in the African Desert. Although these vehicles were not without flaws, they proved to be really effective in the African Campaign. Source: pinterest.com

The first autocannone produced in significant numbers was the Autocannone da 65/17 su Morris CS8, of which 24 were assembled. This vehicle had an old Cannone da 65/17 Mod. 1908/13 mountain gun mounted on its cargo bay and was stretched by 50 cm. The gun carriage was modified removing the spade and the wheels and welding it on a Italian medium tank turret ring that permitted 360° traverse.

While the Morris CS8 was transformed into a support autocannone, the smaller Ford and Chevrolet were converted into anti-aircraft autocannoni, mounting a Cannone da 20/65 Mod. 1935 or Mod. 1939. They were used to defend the Batterie Autocannoni (English: Autocannoni Batteries) or Italian supply convoys from aircraft strikes.

Autocannoni da 75/27 su TL37 lined up, ready to enter action. This type of autocannone proved to be really cramped, but was still used with some success. Source: pinterest.com

In North Africa, other autocannoni were produced with support guns, anti-aircraft, and anti-tank guns on different types of trucks, mainly of Italian production.

Autocannoni da 90/53

The only autocannoni officially produced in significant numbers, 120 in total, during the war, were the Autocannone da 90/53 su Lancia 3Ro and Autocannone da 90/53 su Breda 52. The first was produced by Lancia Veicoli Industriali in Turin and the latter by Società Italiana Ernesto Breda per Costruzioni Meccaniche in the Sesto San Giovanni plant (near Milan). They were modified by the Ansaldo company in the Ansaldo-Fossati plant in Sestri Ponente (near Genoa) and perhaps also by the Officine Viberti company in Turin.

The Autocannone da 90/53 su Lancia 3Ro prototype parked outside the Ansaldo-Fossati Plant in Genoa, 6th February 1941. It has the Pirelli Tipo ‘Sigillo Verde’ tires, open cab, and lower gun shield. Source: Gli Autoveicoli da Combattimento dell’Esercito Italiano

The Autocannone da 90/53 was a private project of Ansaldo proposed to the Italian Ministry of War on 7th January 1941. On the blueprints sent by Ansaldo, the truck chassis chosen for the project was an Alfa Romeo heavy duty truck, but the Ispettorato Superiore dei Servizi Tecnici (English: Technical Services Inspectorate) requested on 12nd January 1941, less than a week after, to mount it on the Lancia 3Ro heavy-duty truck instead.

The Autocannone da 90/53 su Breda 52 prototype parked outside the Ansaldo-Fossati Plant in Genoa, 11th March 1941. It has the Pirelli Tipo ‘Artiglio’ tires, open cab, and no gun shield. Source: Gli Autoveicoli da Combattimento dell’Esercito Italiano

Despite the need to modify the project to reinforce the truck chassis, the prototype was ready on 6th February 1941, the firing tests were performed on 10th February 1941, and the first order from the Regio Esercito for the Autocannone da 90/53 su Lancia 3Ro was placed on 10th March 1941.

After some changes, on 18th September 1941, the Regio Esercito order was extended to 30 autocannoni on Lancia 3Ro and 50 on Breda 52 chassis, plus 64 Lancia 3Ro ammunition carriers, 16 command trucks, and 16 recovery trucks.

On 2nd December 1941, the order was finally changed to 30 autocannoni su Lancia 3Ro, by this date all delivered or ready to be delivered to the Regio Esercito, 90 autocannoni su Breda 52 (20 ready to be delivered), a total of 96 heavy duty trucks (Lancia 3Ro and Breda 51) converted to ammunition carriers, 24 recovery trucks, and just 12 command trucks. The last Autocannone da 90/53 su Breda 52 left the Ansaldo-Fossati plant in Genoa on 1st May 1943.

These 120 autocannoni, 96 ammunition carriers, 12 command trucks, and 24 recovery trucks were assigned to 12 Groups that used Roman numerals: DI, DII, DIII, DIV, DV, DVII, DVIII, DXI, DLVI, DLVII, XX, and XXI (501st, 502nd, 503rd, 504th, 505th, 507th, 508th, 511th, 556th, 557th, 20th, and 21st), each divided into two batteries with 4 autocannoni da 90/53 each (plus one in reserve for each battery), 4 ammunition carriers with 840 rounds in total, one command truck, two recovery trucks, 10 logistic light and heavy vehicles, and other various equipment. The total personnel complement was 4 officers, 7 NCOs, 105 crew and gunners, and 31 drivers.

The DI, DII, and DIV Groups were sent to North Africa, where they were all lost during the North African Campaign. The remaining groups were used in the defense of southern Italy until the 8th September 1943 armistice.

During service, some defects of the vehicles were found, such as the poor top speed, poor range, and poor off-road capabilities, mainly due to weight increase (11,500 kg for the 90/53 su Lancia 3Ro compared to 5,610 kg of the standard Lancia 3Ro cargo truck variant), but also because neither of the two trucks had all-wheel drive.

In order to withstand the stress of the recoil of the powerful main gun, the Lancia 3Ro and Breda 52 trucks received six manual jacks with three spades each. These needed to be hammered into the ground before opening fire.

Before being ready to open fire, the crew need to stop the vehicle, put the jacks into position, mount the jack pads, hammer three spades for each jack, and open the gun platform. This wasted time and physically strained crews and made it impossible to promptly open fire to counter an unforeseen threat, or likewise, did not allow leaving the firing position quickly in the event of a retreat or counter battery.

Another serious problem was the height of the vehicle’s silhouette. In fact, the designers had preferred to mount a trunnion that allowed the gun to engaged ground and flying targets, but the solution proved to be problematic. The trunnion was high to permit a good maximum gun elevation, but its height meant it was easier to spot the Autocannoni da 90/53 on the vast and flat North African deserts.

An Autocannone da 90/53 su Lancia 3Ro in firing position. Source: pinterest.com

The 12 mm thick gun shield, the only armored part of the vehicle, was adequate for protecting the gunner and crew from small-arms caliber bullets, artillery splinters, or shrapnel, but was too high and only offered protection to the crew on the frontal arc. This meant that the crew was vulnerable from air attacks and to all the types of threats on the ground. The absence of armor also made the vehicle vulnerable to air strikes and enemy infantry ambushes during a march.

Despite these problems, the Autocannoni da 90/53 provided excellent anti-tank performance thanks to the powerful 90 mm gun. During the Allied landing on the shores of Calabria during the first days of September 1943, some Autocannoni da 90/53 su Breda 52 were used in the indirect fire role against Allied vessels.

Another great quality of the autocannoni was the 30-round ready-to-use rack placed between the cab and the gun platform, which permitted the crew to maintain a high rate of fire for a certain period of time.

In response to the problems encountered on the autocannoni da 90/53, three different projects were started:

An armored autocannone on a heavily modified Breda 52 chassis that would become the Semovente Ruotato da 90/53 Breda 501. Ansaldo produced only two prototypes before the September 1943 armistice, when the project was abandoned.

The Semovente Ruotato da 90/53 Breda 501 during tests. Source: reddit.com

The Autocannone da 90/53 su Autocarro Semicingolato Breda da 8t, an armored and shorter vehicle, a project initiated by Breda in August 1942. Due to delays in the production of the Breda 61 half-track and the 8th September 1943 armistice, the project was canceled.

The modern reconstructions blueprint of the Autocannone da 90/53 su Semicingolato Breda 61. Source: Gli Autoveicoli da Combattimento dell’Esercito Italiano

A new 90/53 Autocannone on SPA Dovunque 41 6×6 heavy duty truck developed by Ansaldo. The Officine Viberti company in Turin was designing an armored version before the Armistice.

Design

The SPA Dovunque 41 Truck

The SPA Dovunque 41 heavy duty truck was one of the heaviest trucks of the Regio Esercito. One of its main characteristics was the all-wheel-drive configuration that permitted it to transport materials or tow heavy artillery pieces even on rough terrain.

The development started in 1941 by the Società Piemontese Automobili or SPA, a subsidiary of the famous FIAT. The first prototype was a Trattore Medio (English: Medium Tractor) SPA TM41 with seats for 7 soldiers plus the driver. It could tow the most heavy artillery pieces in the ranks of the Regio Esercito, but was usually assigned to the Cannoni da 90/53 Mod. 1939 batteries.

The SPA Trattore Medio 41 prototype during tests. Source: voenteh.com

After the tests, it was accepted into service on 24th March 1942 and the production began the same year. The prime mover variant was accompanied on the production line by the heavy-duty truck variant in early 1943.

The SPA Dovunque 41 heavy-duty truck. Note the absence of doubled wheels on the rear axles (the tires were Pirelli Tipo ‘Artiglio’) and the presence of a small storage compartment under the cargo bay. Source: wikipedia.com

The trucks were produced in small numbers before 8th September 1943. The production resumed after the Armistice for the German Army, which received 153 vehicles.

There were also plans to produce a lighter variant, called SPA Dovunque 42, which would have entered production in 1944, but because of the Armistice, the project was canceled. After the war, production resumed until 1948, when it was replaced on the production line by the powerful SPA Dovunque 50. The old version remained in service with the Italian Army in the recovery version until the 1970s.

A SPA TM 41 towing a Rimorchio 3 assi Viberti with an M3A3 Stuart after the war. These particular vehicles were sent to Somalia in 1951. In fact, Italy was chosen by UN forces to administer Somalia after the British rule ended, which became the Trust Territory of Somaliland under Italian Administration. Source: Gli Autoveicoli da Combattimento dell’Esercito Italiano

The SPA TM41 did not have a closed cab, with the driver seated on the right, the engine compartment in the center, and, on the left, the vehicle commander’s seat. Behind them was a 4-seat compartment and a third 2-seat compartment. The passenger compartment did not have a roof but could be covered by a waterproof tarpaulin.

Behind the crew compartment was a small cargo bay for the transportation of artillery rounds. On the rear was a tow hitch and a powerful hydraulic winch operated by the truck’s engine thanks to a Power Take-Off (PTO) system. When necessary, the driver stopped the vehicle, would shift out of gear on the gearbox, engage the handbrake and, via a manual override, connected the engine’s flywheel to a second driveshaft that operated the winch’s gearbox, which regulated the speed of the cable.

The SPA TM40 frame. The power take-off driven winch and its connection to the vehicle’s engine are clearly visible. Source: alamy.com

The heavy truck version had a fully closed steel-cabin with two seats. Behind it was the cargo bay with a payload capacity of 5 tonnes. The chassis weighed 6.5 tonnes, plus 2 tonnes of bodywork. The total ready weight of the vehicle was 14 tonnes, consisting of 500 kg of fuel, cooling liquid, oil, spare wheels, sapper tools, etc. The spare wheels were placed 360 mm over the ground and were left loose and free to rotate in order to help the vehicle overcome obstacles.

In order to improve the already great off-road capabilities of the truck, the two rear axles could be equipped with tracks that could be wrapped over the stock tires. This system was easy to mount on the tires, weighed little and took up little space and made it possible to overcome obstacles or very steep slopes.

A SPA Dovunque 41 equipped with tracks. The tires were Pirelli Tipo ‘Artiglio’. Source: pinterest.com

Engine and Suspension

The SPA Dovunque 41 was powered by a 4-stroke, water-cooled, direct ignition engine equipped with DLL 145 S6-M injectors and a PE 6B 80E L4/11 pump. It was a diesel with 6 cylinders, 9,365 cm³ capacity giving out 110 hp at 1,800 rpm. The transmission had 4 forward and 1 reverse gears and a reductor. The fuel tank capacity was 130 liters.

The oil tank held 20.5 liters, while the cooling water tank had a capacity of 52.5 liters. The electric system had two 12 volts 140 ampere Magneti Marelli batteries. The maximum speed on road was 49 km/h, while the range was 270 km. The clutch was a single dry plate with compressed air servo brakes.

The SPA Dovunque 41 was the first of the ‘Dovunque’ series with the all-wheel drive configuration and was the only heavy duty truck of the Regio Esercito without twin wheels on the two rear axles.

The front suspension consisted of transverse leaf springs coupled with hydraulic shock absorbers. The rear suspension consisted of double overlapping leaf springs.

The SPA Dovunque 41 suspension during the prototype tests. The tires were Pirelli Tipo ‘Raiflex’. Source: offroadvehicle.ru

The tires dimensions were 11.25 x 24” (28.5 cm x 60.96 cm), the same as the armored cars and camionette of the Regio Esercito. Like the armored cars and camionette, it could use a wide variety of tires, such as the Tipo ‘Libia’ and Tipo ‘Sigillo Verde’ for sandy soils, Tipo ‘Artiglio’ and Tipo ‘Artiglio a Sezione Maggiorata’ for continental terrain and Russian steppes, and Tipo ‘Raiflex’ for continental grounds, all developed and produced by the Pirelli company in Milan.

A SPA Dovunque 41 captured by partisans and used during a partisan parade days after the war, probably in Turin on 6th May 1945. The heavy duty truck was equipped with Pirelli Tipo ‘Sigillo Verde’ tires and towed a Rimorchio Unificato Viberti da 15t. On the sides of the truck were painted slogans, such as “W Stalin” and CLN or Comitato di Liberazione Nazionale (English: National Liberation Committee). Source: pinterest.com

Armament

The main armament of the Autocannone da 90/53 su SPA Dovunque 41 was the Cannone da 90/53 Modello 1939. This was an anti-aircraft 90 mm L/53 gun developed from the Ansaldo-OTO da 90/50 Modello 1939 gun which had been developed exclusively for the anti-aircraft and illuminating role on the Italian Regia Marina (English: Royal Navy) warships. To give an example, the Littorio-class battleships had twelve 90/50 guns in as many independent turrets.

Like the German 8.8 cm FlaK 36 gun, it was also used as an anti-tank gun in the first phases of the war, proving equally adequate in that role. A total of 519 guns were used in North Africa and on the Italian mainland, 121 of them mounted on autocannoni.

The development of this gun started in 1938, when the Italian Army made a request for an anti-aircraft gun that could hit enemy heavy bombers at an altitude of over 10,000 meters. In that period, Ansaldo was developing the Ansaldo-OTO da 90/50 (OTO is ‘Odero Terni Orlando’) for the Regia Marina and decided to create a ground version of the same cannon to speed up development.

The first four cannons were ready on 30th January 1940. In April that same year, they were tested at the Nettuno Shooting Area, where they proved essentially identical to the 90/50 gun tested some months before. The gun was immediately put into production by Ansaldo.

The gun weighed 8,950 kg in the Modello 1939 towable version (6,240 kg the gun, not including the field mount) and had an elevation of -2° to +85° and a traverse of 360°. The rate of fire was 19 rounds per minute, the maximum firing range was 17,400 m against ground targets, and 11,300 m against flying targets.

On board of the Autocannoni da 90/53 su Lancia 3Ro and Autocannoni da 90/53 su Breda 52, the gun trunnion had an electromechanical system which, after entering the altitude at which the enemy aircraft was flying, automatically adjusted the fuse of the 90 mm round. The altitude of the enemy aircraft was measured by a Centrale di Tiro Borletti – Galileo – San Giorgio or Centrale di Tiro Mod. 1940 ‘Gamma’ stereoscopic rangefinders. It is therefore plausible that the Autocannone da 90/53 su SPA Dovunque 41 also had such a system on board.

The fuze-adjuster electromechanical system on a Autocannone da 90/53 su Lancia 3Ro with a 90 mm round positioned in it. In this image, the open platform, some bushes used by the crew to camouflage this behemoth, the Moschetto Carcano Mod. 91/38 Cavalleria rifle carried by the crew to defend themselves from enemy attacks and, bottom right, 12 of the 18 spades with their flat heads are visible. The photo was probably taken while positioning the autocannone in the firing position. Source: pinterest.com

Ammunition

The Cannone da 90/53 Mod. 1939 fired different types of rounds in 90 x 679 mmR, the same as its naval version.

Ammunition for the Cannone da 90/53 Modello 1939
Type Mass (kg) Quantity of TNT (g) Muzzle velocity (m/s) Fuze Penetration of RHA at 90° (mm)
Name 100 m 500 m 1000 m
Cartoccio Granata Esplosiva* HE – AA 10.1 1,000 850 Mod. 36 // // //
Cartoccio Granata Esplosiva* HE – AA 10.1 1,000 850 Mod. 36R // // //
Cartoccio Granata Esplosiva* HE – AA 10.1 1,000 850 Mod. 41 // // //
Cartoccio Granata Esplosiva* HE – AA 10.1 1,000 850 IO40 // // //
Cartoccio Granata Esplosiva* HE – AA 10.1 1,000 850 R40 // // //
Cartoccio Granata Perforante APCBC 12.1 520 758 Mod. 09 130 121 110
Cartoccio Granata Perforante APCBC 11.1 180 773 Mod. 09 156 146 123
Granata Effetto Pronto HEAT ** ** ** Internal Mod. 41 ~ 110 ~ 110 ~ 110
Granata Effetto Pronto Speciale HEAT ** ** ** IPEM ~ 110 ~ 110 ~ 110
Notes * The same round but with anti-aircraft or percussion fuze.
** Prototypes ready for testing only in mid-1943. According to some sources, they were similar to the German 88 mm Hl.Gr 39.

As with the other autocannoni da 90/53 batteries, the Autocannoni da 90/53 su SPA Dovunque 41 batteries would have had the majority of the ammunition carried in other vehicles.

The Autocannone da 90/53 su SPA Dovunque 41

The chassis of the Lancia 3Ro was not sturdy enough to withstand the recoil of the 90 mm gun, while the Breda 52 chassis had some problems while driving off-road, so the new SPA Dovunque 41 was chosen for the role.

The crew would be the same as on other autocannoni da 90/53, consisting of eight soldiers: driver, vehicle commander, gunner, three gun crew, and two ‘specialists’ (that probably were not only used to pass the rounds to the loader but they, for example, adjust the fuze of the rounds and check with the rangefinder the distance of the target), the last six of whom were in another vehicle in the battery.

The new autocannoni would differ from the others by having a new variable height trunnion. During a march and in the anti-tank role, the trunnion would be lowered to keep the vehicle’s shape as low as possible, but allowing limited elevation. In fact, the cab did not obstruct the line of fire because the rigid roof and sides were substituted by removable water-proof tarpaulins and the windshield, that could be lowered downwards, was divided in two parts to permit to the gun barrel to be placed between the driver and vehicle commander’s seats during a march.

The Autocannone da 90/53 su SPA Dovunque 41 mock-up. Source: Italian Tanks and Combat Vehicles of World War II

In the anti-aircraft role, the gun trunnion would have been raised to its maximum position, allowing the complete +85° elevation, exactly as on the Autocannone da 90/53 su Autocarro Semicingolato Breda da 8t or on the Semovente ruotato da 90/53 Breda 501.

Behind the cabin were what looked like two shields with the same height as the cabin’s sides. If they were truly protective shields, when opened, they protected the lower portion of the front arch of the entire platform from enemy small-arms bullets. These shields did not interfere with the line of fire of the main gun.

Between these shields was probably an ammunition rack, as on the other autocannoni da 90/53, most likely with the usual 30 ready-to-use 90 mm rounds.

There were four new type hydraulic jacks, probably operated by the same PTO system that worked the winch in the SPA TM41 prime mover version.

The power take-off system’s driveshaft was probably connected to an oil pump that put into operation the hydraulic circuit that controlled the elevation and depression of the jacks.

This meant that the autocannone was not on the SPA Dovunque 41 chassis, but on its prime mover variant, the SPA TM41. The heavy-duty truck was not equipped with the power take-off driven winch.

The SPA Trattore Medio 41, probably a prototype or one of the first produced vehicle chassis with the open cab. Between the rear wheel axles is the hydraulic winch. Source: pinterest.com

The side spare wheels were removed from behind the cab to make room for the frontal lifting jacks. Only one spare wheel was carried at the rear of the vehicle, under the gun platform.

Another order for Autocannoni da 90/53 was scheduled for 19th July 1943. This would consist of 96 on the Breda 52 chassis to replace the losses of other autocannoni in North Africa and 60 on the SPA Dovunque 41 chassis. Those 60 autocannoni would be enough to equip six different Autocannoni da 90/53 Batteries.

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The original SPA Dovunque 41 truck and the Autocannone da 90/53 su SPA Dovunque 41 modern reconstructions blueprints. Sources: pinterest.com and Gli Autoveicoli da Combattimento dell’Esercito Italiano, modified by the author

Armor

The Regio Esercito Autocannone da 90/53 su SPA Dovunque 41 project was mostly unarmored, but the gun had a 12 mm thick gun shield to protect the crew on the platform. The gun shield would be lower and angled to better deflect small-caliber rounds.

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The original Officine Viberti blueprints of the Autocannone da 90/53 su SPA Dovunque 41 Blindato. Source: Gli Autoveicoli da Combattimento dell’Esercito Italiano

The Technical Department of the Officine Viberti in Turin, a company specialized in bodyworks for Lancia and FIAT trucks and in the production (jointly with SPA) of armored cars and Camionette, began working on 30th June 1943 on the development of an armored body for the Autocannone on SPA Dovunque 41 chassis. This would then receive the designation of Autocannone da 90/53 su SPA Dovunque 41 Blindato (English: Armored) or Autocannone da 90/53 su SPA Dovunque 41 Semiblindato (English: Semi-Armored).

This variant would be identical to the unarmored one, but with an armored superstructure protecting only the driver and the vehicle’s commander. This structure would have been composed of angled riveted armored plates, probably of a thickness from 6 mm to 8.5 mm, maybe more on the frontal arc. The cab was divided in two compartments, the driver’s one on the right, and the vehicle commander’s one on the left.

In the center, the space left free would house the 90 mm cannon barrel and its travel lock. The two armored compartments would have their own armored doors, divided in two different parts, with the upper ones with a loophole. There was one frontal armored hatch for each compartment, opening downwards to increase visibility while driving. The frontal headlights were armored.

The vehicle is sometimes mentioned as semi-armored because the frontal vertical hood and the radiator grille remained unarmored, probably to keep the weight of the vehicle low.

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Frontal view of the vehicle. On the right image, in red, is the unarmored vertical hood of the vehicle. Source: Gli Autoveicoli da Combattimento dell’Esercito Italiano modified by the author

The design of the armored cab of the Autocannone da 90/53 su SPA Dovunque 41 Semiblindato was completed by the Technical Office of Officine Viberti on 3rd September 1943, five days before the Armistice that led to the cancellation of the order of the 60 autocannoni su SPA Dovunque 41 by the Royal Army.

Because of the height of the armored cab when shooting forwards, the gun trunnion would have been lifted over the roof of the cabin in anti-tank role, but it could also maintain the trunnion at the minimum height if the gun was aimed to the sides or rear.

A modern reconstructions blueprint of the vehicle lifted on the hydraulic jacks. The gun trunnion is in the lower position. Source: Gli Autoveicoli da Combattimento dell’Esercito Italiano modified by the author

Service

With the signing of the Armistice with the Allied forces on 3rd September 1943, which entered into force on 8th September 1943, the Regio Esercito turned its guns against the German Army, its former ally.

The Germans, expecting such a move, launched Fall Achse (English: Operation Axis), prepared by the Oberkommando der Wehrmacht after late May 1943. From 8th to 19th September 1943, about 20,000 Italian soldiers were killed and the German Army captured over one million soldiers and thousands of guns and armored fighting vehicles.

Some of the Italian soldiers loyal to Benito Mussolini and the Germans surrendered to them and continued to fight against the Allied troops with their Axis allies, while other captured soldiers decided to fight with the Germans.

On 23rd September 1943, Mussolini founded the Repubblica Sociale Italiana or RSI (English: Italian Social Republic) on the Italian territories under German control. The new army of the RSI, the Esercito Nazionale Repubblicano (English: National Republican Army), was equipped with few armored fighting vehicles, since the Germans had taken control of the Italian war industry.

One of the largest units of the Esercito Nazionale Repubblicano was the Xª Flottiglia MAS, with around 20,000 soldiers in its ranks divided between sailors and naval infantry. For most of the remaining two years of war, these fought as normal infantry units.

FIAT 666 medium truck equipped with a Breda 37 on a tripod in an anti-aircraft configuration behind the cab and a Breda 37 on a standard tripod on the rear, Battaglione ‘Barbarigo’ of the 1° Reggimento Fanteria di Marina ‘Scir’, Xª Flottiglia MAS. Source: zimmerit.com

One of the artillery units of the Xª Flottiglia MAS was the Gruppo Artiglieria da Campagna ‘Colleoni’ (English: Field Artillery Group), created in March 1944 at La Spezia, near Genoa. It was composed of 3 batteries with Obici da 75/13 and 100/17.

In July 1944, it was sent to Piemonte, in the Ivrea region, to fight the partisan units and to maintain efficiently the alpine roads that ran from Italy to France. Thus, in the event of an Allied landing in Liguria, German and Fascist units in Piemonte could retreat further north.

In that period, Lieutenant Malvezzi, an officer of the Gruppo Artiglieria da Campagna ‘Colleoni’, contacted Officine Viberti of Turin. Given the need for armored vehicles to be assigned to the unit to fight the partisans, Viberti probably proposed to Malvezzi to produce the Autocannone da 90/53 su SPA Dovunque 41 Blindato. The absence of information and pictures do not clarify the situation but probably the Xª MAS‘s officer helped with the development, giving suggestions or providing part of the raw materials to the Officine Viberti technicians.

Nothing is known about the vehicle, except that it was delivered to the Gruppo di Artiglieria da Campagna ‘Colleoni’ in Autumn 1944, just in time, as the Xª Flottiglia MAS was transferred to Veneto in October 1944.

From October to December 1944, the ‘Colleoni’ was employed in anti-partisan operations and then was active against the Slovenian partisans’ IX Korpus, where it was deployed in Gorizia and the Battle of Tarnova in January 1945.

The artillery unit was then sent to the Senio Front and the Autocannone was probably taken with them. In March 1945, the unit was sent to the southern front to fight against the Allies that were advancing.

The only Autocannone da 90/53 su SPA Dovunque 41 Blindato was probably lost during the fight on the Senio front or against the Allied troops some weeks later.

There are no photos of this vehicle, neither in the Officine Viberti plant nor in the hands of the Xª MAS. Some sources hypothesize that this vehicle could have been camouflaged with the standard Kaki Sahariano, the standard khaki camouflage, but it is also possible that the vehicle could be camouflaged in the three-tone Continentale camouflage typical of Italian vehicles used on the mainland, composed of Kaki Sahariano background with reddish-brown and dark green spots.

Two Carro Armato Medio M15/42 medium tanks. The upper one has Kaki Sahariano camouflage and the lower one the Continentale camouflage. Source: pinterest.com and inmontecchio.com with author’s collage

Conclusion

The Autocannone da 90/53 su SPA Dovunque 41 would have been an interesting vehicle if put into service for its characteristics. This is due to its special development with experiences from similar vehicles.

Unfortunately, the Italian Armistice of 8th September 1943 canceled the orders for this vehicle, and nothing is known about the only vehicle allegedly produced in 1944. The Gruppo di Artiglieria da Campagna ‘Colleoni’ of the Xª Flottiglia MAS used a single vehicle against Yugoslav partisans.

Autocannone da 90/53 su SPA Dovunque 41 proposed to the Italian Regio Esercito before the Armistice. Never produced.
Autocannone da 90/53 su SPA Dovinque 41 Blindato produced by Officine Viberti and used by Gruppo Artiglieria da Campagna ‘Colleoni’ of the Repubblica Sociale Italiana. Both illustrations by Pavel ‘Carpaticus’ Alexe funded by our Patreon Campaign.

Specifications

Size (L-W-H) 6.905 x 2.480 x ~2.8 m
Total weight, battle ready ~ 14 tonnes
Crew 8 soldiers (driver, commander gunner, 3 gun crew, and 2 specialists)
Propulsion 6-cylinders, 9,365 cm³ diesel engine, 110 hp
Speed ~ 40 km/h
Range ~ 200 km
Armament Cannone da 90/53 Modello 1939
Armor not specified
Total production one prototype

Sources

Gli Autoveicoli da Combattimento dell’Esercito Italiano, Volume Secondo, Tomo II – Nicola Pignato and Filippo Cappellano
Semicingolati, Motoveicoli e Veicoli Speciali del Regio Esercito Italiano 1919-1943 – Giulio Benussi
Italian Tanks and Combat Vehicles of World War II – Ralph A. Riccio
associazionedecimaflottigliamas.it

Categories
WW2 Italian SPG Prototypes

Autocannone da 90/53 su Autocarro Semicingolato Breda 61

Kingdom of Italy (1943)
Half-Track Mounted Dual Use Artillery – Paper Project

The Autocannone da 90/53 su Autocarro Semicingolato Breda 61 was an Italian anti-aircraft and anti-tank self-propelled gun designed in 1943 based on the Breda 61 half-track chassis for the needs of the Italian Regio Esercito (English: Royal Army).

Although it was a promising project, the delays with the production of the Breda 61 caused the delay of the half-tracked Autocannone. The project was canceled after the Italian Armistice that was signed on 8th September 1943.

Autocannone da 90/53 su Autocarro Semicingolato Breda 61 in Italian literally means Truck(-mounted) 90 mm L/53 cannon on Breda 61 half-track hull.

Lack of mobile artillery and the need for the ‘Autocannoni’

Already during the early stages of the Second World War, the Regio Esercito’s High Command received complaints about the absence of a mobile support gun to help the Italian troops during assaults to the enemy positions.

During the fighting in the vast deserts of North Africa, an armed vehicle with great mobility could reach the battlefront quickly to counter the enemy attacks and then move to another point of the battlefront to counterattack or for other defensive duties was needed.

Despite the need for such vehicles, development in Italy was very slow and the soldiers in Africa were forced to create such vehicles themselves in military and civil workshops. This is where Autocannoni (singular Autocannone) originated from.

In Italian, the word Autocannone means a truck (in this case, a half-track) of civil or military production, of any type (light, medium etc) modified to permit the transportation on its cargo bay of a permanently fixed artillery piece of any type (anti-tank, field gun, anti-aircraft, etc).

Autocannone da 65/17 su Morris CS8 of the 1° Batteria Autocannoni, 136° Reggimento d’Artiglieria Celere of the 136ª Divisione Corazzata ‘Giovani Fascisti’ in Tunisia, 1943. Source: reddit.com

The first autocannone produced in significant numbers (24 converted) were the Autocannone da 65/17 su Morris CS8. The old Cannone da 65/17 Mod. 1908/13 mountain gun, hard to tow on the soft desert terrains, was mounted on a 360° rotating support made from turret rings recovered from destroyed Italian tanks. It was then fixed on the loading bay of the British Morris CS 8 4×2 light utility truck, captured in significant numbers in the first days of war, slightly modified by the Autofficine del 12° Autoraggruppamento AS (English: Workshops of the 12th Motorized Group, AS standing for Africa Settentrionale – North Africa) located in the Village of Giovanni Berta, near the city of El Gubba, North-east Libya.

This workshop and the FIAT ones of Tripoli were responsible for the conversion of the trucks into autocannoni. By 1942, autocannoni with howitzers, anti-aircraft autocannons, naval guns, and standard field artillery pieces were produced.

An Autocannone da 100/17 su Lancia 3Ro, one of the dozens of autocannoni produced by the workshops in North Africa. Source: waralbum.ru

Autocannoni da 90/53

The only officially produced autocannoni were the ones armed with the powerful 90 mm Cannone da 90/53 Mod. 1939 based on the Lancia 3Ro and Breda 52 heavy duty trucks. These trucks were produced by Lancia Veicoli Speciali in Turin and by Società Italiana Ernesto Breda per Costruzioni Meccaniche in the Sesto San Giovanni plant (near Milan). They were modified by the Ansaldo-Fossati Plant in Genoa and perhaps also by the Officine Viberti plant in Turin.

These autocannoni were developed for anti-aircraft and anti-tank purposes and 120 were converted, 30 on the Lancia 3Ro chassis, and 90 on the Breda 52 chassis.

The Autocannone da 90/53 su Lancia 3Ro prototype parked outside the Ansaldo-Fossati Plant in Genoa, 6th February 1941. Source: Gli Autoveicoli da Combattimento dell’Esercito Italiano

These vehicles were assigned to 12 Groups with 2 batteries each, used in North Africa and Southern Italy. Some units were also used in the anti-naval role, shooting in indirect fire against Allied vessels that tried to disembark on the Calabria coasts on 3rd September 1943.

The Autocannone da 90/53 su Breda 52, ready to be delivered to the units, at the Ansaldo-Fossati Plant in Genoa. Source: pinterest.com

These vehicles had some problems caused by the heaviness of the gun and the recoil stress. In order to deal with these, the chassis was reinforced and manual jacks were adopted to lift the vehicles off the ground.

The increase in weight of the vehicle decreased the already moderate speed of these heavy trucks and the manual jacks forced the crew to exert a high physical effort and increased the times to get ready to fire and to leave the fire position, especially in dangerous situations.

Another problem was the height of the vehicle. This was not a factory defect, but a choice of the designers that proved to be problematic. The trunnion was high to permit a great elevation to allow the autocannoni da 90/53 to engage flying targets and ground targets. Its height made it easier to spot by enemy troops on the vast and flat desert terrain.

The 12 mm thick armored shield could protect the crew from small arms, shrapnel, or splinters. However, it protected the crew only on the frontal arc. This meant that the crew was vulnerable from air attacks and all the crew on the ground were vulnerable to all threats.

Despite these problems, the Autocannoni da 90/53 provided excellent anti-tank performance thanks to the powerful 90 mm gun. Another great quality of the autocannoni was the 20-rounds ready-to-use rack placed between the cab and the gun platform, which permitted the crew to maintain a high rate of fire for a certain period of time.

In response to the problems encountered on the autocannoni da 90/53, three different projects were started:

An armored autocannone on a Breda 52 chassis, which would become the Semovente Ruotato da 90/53 Breda 501. Ansaldo produced only two prototypes before the September 1943 Armistice, after which the project was abandoned.

Semovente Ruotato da 90/53 Breda 501. Source: pinterest.com

A new 90/53 Autocannone on SPA Dovunque 41 6×6 heavy duty truck was proposed in two different configurations. The first one, would be essentially a 90/53 su Breda 52 copy, while the second one, called Autocannone da 90/53 su SPA Dovunque 41 Blindato (English: Armored) had a lower armored cab and a new gun shield. Only a prototype was completed after the Armistice and assigned during the Fall of 1944 to the Reggimento ‘Colleoni’ of the Xª MAS.

A mock-up of the Autocannone da 90/53 su SPA Dovunque 41 with pneumatic jacks and a new gun shield. Source: Gli Autoveicoli da Combattimento dell’Esercito Italiano

An Autocannone da 90/53 su Autocarro Semicingolato Breda da 8t started by Breda in August 1942.

Design

The Breda 61

Before the Second World War, the Italian Army and the Italian industry were not interested in half-tracked vehicles, apart from some interwar projects, such as the Semicingolato Corni (1923). The Italians preferred heavy-duty trucks or medium trucks with all-wheel drive. With the start of the conflict, during the French Campaign, Italian officers were impressed by the mobility of the German half-tracked vehicles, such as the Sd.Kfz. 7 heavy-duty half-track.

The Italian Army High Command put out some requests for the creation of half-tracks in 1941, and the first developments were presented in the same year by the Centro Studi ed Esperienze della Motorizzazione (English: Vehicle Study and Experience Center) in Rome.

These were the Bianchi Mediolanum medium trucks modified with tracks and Alfa Romeo 800RE (‘R.E.’ stands for Regio Esercito) heavy duty truck.

The Alfa Romeo 800 CSEM semicingolato. Source: wikipedia.org

These two vehicles, which were tested by Italian Army specialists, were standard medium trucks with modifications to the rear axles. They did not give the desired results in off-road tests and towing tests and were abandoned.

The Autocarro semicingolato Breda 61 during field tests. Source: lombardiabeniculturali.it

In 1941, the Regio Esercito High Command asked for an Sd.Kfz. 7 from the German Army. The German Army responded positively and, during the same year, a German half-track was tested at the Centro Studi della Motorizzazione (English: Centre for Motorisation Studies) in Rome, impressing the Italian officers with its towing capabilities and robustness.

Almost immediately, the possibility of producing the half-track under license was requested, but some bureaucratic problems slowed the release of documents and the permission for producing the suspension and tracks came from the German manufacturer Krauss-Maffei only in 1942. The production of the Italian copy of the Sd. Kfz. 7, called Autocarro Semicingolato (English: Half-tracked Truck) Breda 61 (also known as the ‘Breda 8t’ for its weight) and a smaller version produced by FIAT and called FIAT 727 or Maffei-FIAT 727 started very slowly.

The Breda 61 prototype was ready in July 1943 and was sent to the Centro Tecnico della Motorizzazione (English: Vehicle Technical Center) in Rome, where it was accepted into service as a heavy artillery tractor as the Autocarro Semicingolato Breda 61 da 8t (English: Breda 61 Half-track weight 8 tons).

Before 8th September 1943, a total of 36 Breda 61 out of 500 ordered were delivered to the Regio Esercito. These went to equip the anti-aircraft artillery regiment of the 136ª Divisione corazzata ‘Centauro II’ (English: 136th Armored Division) to tow the Cannone da 88/55 (Italian name for the 8.8 cm FlaK 37).

An Autocarro Semicingolato Breda 61 of the 136ª Divisione corazzata ‘Centauro II’ towing a Cannone da 88/55 or FlaK 36 before the Armistice. Source: digilander.libero.it

After the Armistice, the Germans captured some of the vehicles produced and, in January 1944, ordered the Società Italiana Ernesto Breda per Costruzioni Meccaniche to produce another 300 Breda 61s. Until 1944, the Breda Plant in Brescia produced a total of 199 vehicles, for a total of 235 heavy half-tracks produced.

The German Army added them to its nationally produced medium half-tracks in the heavy artillery towing and recovery duties in Northern Italy, the Balkans, and France.

A Luftwaffe column in Northern Italy. From the right, an Autocarretta SPA CL39, two SPA-Viberti AS43 armed with FlaK 38s, an Autocarro Semicingolato Breda 61 towing a Flak 36, a FIAT 665NM Scudato and a truckload of soldiers. Source: Le Camionette del Regio Esercito

Engine and suspensions

The engine of the Breda 61 was a Breda Tipo 14, 6-cylinder, 6,191 cm³ unit delivering 140 hp at 2,600 rpm. It was probably a license copy of the Maybach HL62 TUK, which had similar characteristics and powered the Sd. Kfz. 7. The gearbox was of Italian origin and had 4 gears plus reverse (4 + 1) with a reductor. The book ‘Italian Tanks and Combat Vehicles of World War II’, written by Ralph Riccio, claims that the engine was a 6-cylinder, 7,412 cm³ unit delivering 130 hp at 2,400 rpm, but there is no proof in support of this thesis.

The maximum road speed was 50 km/h and the range with the 203-liter tank was 250 km on road and 160 km off-road.

Thanks to its powerful engine, this 9,750 kg vehicle could transport 1,800 kg in its cargo bay and a payload of 8,000 kg towed. This meant that the Breda 61 could tow essentially any of the heavy artillery pieces used by the Regio Esercito, such as the Obice da 149/40 Mod. 1935 and Obice 210/22 mod. 35.

The Autocarro Semicingolato Breda 61 chassis. Source: lombardiabeniculturali.it

The front wheels were 9.75 x 20”, the same as those of the Lancia Ro, Lancia Ro-Ro, and Lancia 3Ro heavy duty trucks. The steering wheel was mounted on the right side instead of the left side, one of the few differences from the German Sd. Kfz. 7.

The suspension was in the form of transverse torsion bars for the front tires and standard torsion bars for the tracks.

There were seven overlapping and interleaved road wheels, based on the German ‘Schachtellaufwerk’ design common with other vehicles.

Due to the increase in weight, the vehicle would have a decreased top speed on the road to about 40 km/h and its range on the road would have decreased to less than 200 km.

A Breda 61 captured by the Italian partisans of the Brigata Partigiana ‘Italia’ in the last days of war in Italy. Above the radiator was written ‘Patrioti’ (English: Patriots) and on the fenders ‘Valeggio’, the name of the city where the partisans were located and where the half-track was captured. Source: wikipedia.com

Armament

The Cannone da 90/53 Modello 1939 was an anti-aircraft 90 mm L/53 gun developed from the Ansaldo-OTO da 90/50 Modello 1939 gun which had been developed for the anti-aircraft role on the warships of the Regia Marina (English: Royal Italian Navy).

Like the German 8.8 cm FlaK gun, the Italian gun was also used as an anti-tank gun in the first phases of the war, proving equally adequate in that role. About 500 guns were used in North Africa and on the Italian mainland, sometimes even as field artillery guns in indirect fire roles.

The development of this gun started in 1938, when the Italian Army made a request for an anti-aircraft gun that could hit enemy bombers flying at altitudes of over 10,000 meters. During that period, Ansaldo was developing the Ansaldo-OTO da 90/50 (OTO is ‘Odero-Terni-Orlando’) for the Regia Marina and decided to create a ground version of the same cannon to speed up the development.

The first four cannons were ready on 30th January 1940. In April of the same year, they were tested at the Nettuno Shooting Area, where they proved essentially identical to the 90/50 gun tested some months before. The gun was immediately put in production by the Ansaldo.

The gun weighed 8,950 kg for the Modello 1939 towed version (6,240 kg for the gun only, not including the field mount). It had an elevation of -2° to +85° and a traverse of 360°. The rate of fire was 19 rounds per minute, while the maximum firing range was 17,400 m against ground targets, and 11,300 m against flying targets.

On the Self Propelled version, there was also a Breda Mod. 1938 machine-gun, a shortened version of the infantry Breda Mod. 1937 chambered for the 8 x 59 mm RB Breda rounds for tank use. It was mounted on an anti-aircraft support on the cabin and used to defend the vehicle from airstrikes and infantry attacks. The machine gun had a theoretical rate of fire of 600 rpm and a practical rate of fire of 350 rpm and was fed by 24-round curved top-mounted magazines.

Ammunition

The Cannone da 90/53 Mod. 1939 fired different types of 90 x 679 mmR rounds, the same as for the naval version.

Ammunition for the Cannone da 90/53 Modello 1939
Type Mass (kg) Quantity of TNT (g) Muzzle velocity (m/s) Fuze Penetration of RHA at 90° (mm)
Name 100 m 500 m 1000 m
Cartoccio Granata Esplosiva* HE – AA 10.1 1,000 850 Mod. 36 // // //
Cartoccio Granata Esplosiva* HE – AA 10.1 1,000 850 Mod. 36R // // //
Cartoccio Granata Esplosiva* HE – AA 10.1 1,000 850 Mod. 41 // // //
Cartoccio Granata Esplosiva* HE – AA 10.1 1,000 850 IO40 // // //
Cartoccio Granata Esplosiva* HE – AA 10.1 1,000 850 R40 // // //
Cartoccio Granata Perforante APCBC 12.1 520 758 Mod. 09 130 121 110
Cartoccio Granata Perforante APCBC 11.1 180 773 Mod. 09 156 146 123
Granata Effetto Pronto HEAT ** ** ** Internal Mod. 41 ~ 110 ~ 110 ~ 110
Granata Effetto Pronto Speciale HEAT ** ** ** IPEM ~ 110 ~ 110 ~ 110
Notes * The same round but with anti-aircraft or percussion fuze.
** Prototypes ready for testing only in mid-1943. According to some sources, they were similar to the German 88 mm Hl.Gr 39.

There is little information about the half-tracked SPG version and none about the number of rounds transported on the Autocannone da 90/53 su Semicingolato Breda 61. The blueprints show some boxes on the rear of the vehicle, which were probably used as ammunition racks for some rounds or as spare equipment boxes.

It is plausible that, as for the other autocannoni, the majority of the ammunition would have been transported in other vehicles. As an example, the batteries of Autocannoni da 90/53 had in their organic strength, apart from the 4 autocannoni and 13 logistic vehicles and other material, one more heavy truck for each autocannone which carried 210 90 mm rounds, for a total of 920 rounds for each battery.

An Autocannone da 90/53 su Lancia 3Ro disabled by its crew in Egypt 1942. The British Soldier is holding a 90 mm High-Explosive round and there is another one on the platform. Source: pinterest.com

The Autocannone da 90/53 su Autocarro Semicingolato Breda da 8t

On the half-tracked self-propelled gun, the chassis would be unchanged, but the rest of the vehicle would be modified.

The engine compartment would receive armor plates of unknown thickness, probably around 6 to 8.5 mm, as on similar Italian vehicles. In front, it would have sloped armored grilles to permit air intake to the radiator.

In order to allow the vehicle to maintain a low profile, the gun would have received a variable height trunnion. For anti-tank use and traveling, it would have been in a lower position and would have allowed a limited elevation. In the case of anti-aircraft fire, the trunnion would have been raised, allowing a higher elevation, exactly as on the Breda 501.

The original blueprint of the Autocannone da 90/53 su Semicingolato Breda 61, found in the Breda Archives in Milan. Source: Gli Autoveicoli da Combattimento dell’Esercito Italiano

The cab was divided into two armored compartments, one for the vehicle commander and one for the driver. This permitted the 4.73 meters-long barrel to be locked between the two compartments during traveling.

Each compartment would have had a large viewport protected by a hinged armored window on the front to permit the two crew members to drive and check the battlefield. An armored door with another viewhole was on the side.

The gun crew operated on the rear platform with foldable sides. This gave more space to operate the gun during operations.

Blueprint of the Autocannone da 90/53 su Semicingolato Breda 61 ready to shoot at flying targets, with raised trunnion and gun platform sides folded. Source: Gli Autoveicoli da Combattimento dell’Esercito Italiano modified by the Author

The gun was placed at the center of this platform on a variable trunnion. It would have received a frontal shield, probably 12 mm thick, to protect the crew from splinters and light weapons.

Thanks to the tracks and the sturdiness of its chassis, this autocannone could withstand the recoil stress of the 90 mm gun without needing jacks to raise it from the ground. This would have decreased the time needed for the crew to prepare the vehicle to open fire or to leave.

The Autocannone da 90/53 su Semicingolato Breda 61 with the gun pointing to the right side, with lowered trunnion in an anti-tank role. In the first photo, the shield is not present. The sides of the gun platform are folded down. Source: Gli Autoveicoli da Combattimento dell’Esercito Italiano modified by the Author

The armor would probably be made of armor sheets with variable thickness, from 6 mm on the sides up to 8.5 mm and maybe more on the frontal arc, in order to protect against enemy small arms fire, artillery shrapnel and splinters and high-caliber machine gun bursts from ground attack aircraft.

The gun shield would probably have been composed of 12 mm ​​thick armor sheets. The blueprint shows that the shield was angled to better deflect small-caliber rounds.

The crew was probably composed, as on the other autocannoni da 90/53, of 8 soldiers: driver, vehicle/gun commander, a gunner, three loaders and two specialists.

The driver and vehicle commander sat in the armored cab during travel, while the rest of the crew would probably sit on the gun platform, where some foldable seats were probably placed or traveled on one of the logistic vehicles assigned to the autocannone battery. During firing, crew members from the battery’s logistic vehicles would assist the gun servants, by speeding up reloading and increasing the rate of fire.

If the course of the war had not prevented its development, the Autocannone da 90/53 su Semicingolato Breda 61 would have probably entered service in late 1943 or early 1944, too late to change the fate of the conflict, and most likely in very small numbers. Nevertheless, the vehicle would have undoubtedly provided Italian units with an adequate mobile anti-aircraft and anti-tank defense, very useful, especially in the desperate situation in which the Royal Army was forced on the Italian peninsula.

Autocannone da 90/53 su Semicingolato da 8t ready to shoot to ground targets, with raised trunnion and gun platform sides folded. The machine gun has been removed by the author. Source: Gli Autoveicoli da Combattimento dell’Esercito Italiano modified by the Author

Conclusion

Even if was never produced, it is plausible to assume that the Autocannone da 90/53 su Semicingolato Breda da 8t would have answered the needs of the Italian Regio Esercito. It had the same firepower characteristics as the already existing autocannoni da 90/53, but with good off-road mobility, faster to deploy and withdraw, and more protection.

Unfortunately, the Armistice of 8th September 1943 put an end to this promising project. Like many other Italian vehicles, it remained only on a sheet of paper abandoned in an archive for the rest of its existence.

Autocannone da 90/53 su Autocarro Semicingolato da 8t. Illustrations by the Glorious Pavel Carpaticus funded by our Patreon Campaign.

Autocannone da 90/53 su Autocarro Semicingolato da 8t Specification

Dimensions 6.9 x 2.45 x ~2.5 m
Total weight, battle ready not specified
Crew 8 soldiers (driver, commander gunner, 3 servants and 2 specialists)
Propulsion Breda T14 130 hp, 6-cylinders, 6,191 cm³
Range ~170 km
Maximum speed ~40 km/h
Main Armament Cannone da 90/53 Mod. 1939 and a Breda Mod. 38 machine gun
Armor not specified
Total production Only paper project

Sources

Gli Autoveicoli da Combattimento dell’Esercito Italiano, Volume Secondo, Tomo II – Nicola Pignato and Filippo Cappellano
Semicingolati, Motoveicoli e Veicoli Speciali del Regio Esercito Italiano 1919-1943 – Giulio Benussi
Italian Tanks and Combat Vehicles of World War II – Ralph A. Riccio

Categories
WW2 Italian SPG Prototypes

Semovente M43 da 149/40

Kingdom of Italy (1942-1943)
Self-Propelled Gun – 1 Prototype Built

Prior to and during the Second World War, the Italian industry generally lacked the capacity to fulfill all the military demands placed upon it. This was probably most obvious in regards to producing and developing more modern armored vehicles. Italian armored formations mostly consisted of obsolete light tanks, which were no match for the Allied armor. Even in regards to the medium tanks they produced, these were severely lacking. On the other hand, Italians introduced a number of vehicles that proved to be useful, although their number was small. These were the so-called Semoventi (Eng. self-propelled vehicles), which proved to be quite effective, but with some issues. They were armed with 47 mm, 75 mm, 90 mm, or 105 mm guns. In the later stages of the war, one installation of an even larger weapon was tested in the form of the highly mysterious and poorly documented Semovente M43 da 149/40.

The Semovente M43 da 149/40. Source: comandosupremo.com

History

When it entered the war on the German side in 1940, the Italian Army was mostly equipped with the CV series of small fast tanks. While cheap, these were only lightly armed and protected and were virtually obsolete even before the war started. The development of more powerful vehicles, such as the M-series of medium tanks, was underway but the small production capabilities and some bad decisions (like limiting the overall strength of the engine) ultimately led to rather a slow production and introduction. These tanks were armed with a 47 mm gun, which may have been effective in the earlier stages of the war, but struggled to do anything against newer Allied tank designs.

The Italians turned to their German allies for help, and after observing the StuG III, they came up with the idea of developing a similar vehicle utilizing components that were already in production. This would lead to the creation of a series of vehicles that, armed with a 75 mm gun, offered the Italians a means to fight back more effectively. The early and later improved versions were used as anti-tank vehicles. These could also act, if need be, as mobile self-propelled artillery.

While the 75 mm gun could fulfill this role, something with more firepower was preferable. It is for this reason that the Italian Army began showing interest in the development of a more dedicated design of self-propelled artillery armed with much larger caliber guns.

Unfortunately, due to a general lack of information about this vehicle in the sources, determining its precise developing history is quite difficult. Based on limited available information, it appears that the firm responsible for developing this vehicle was Ansaldo. When it was built and on which chassis it was based is somewhat confusing in the sources.

According to C. Bishop (The Encyclopedia of Weapons of World War II), work on such a vehicle was initiated by Ansaldo in late 1942. Ansaldo engineers used a heavily modified M15/42 chassis and placed the Cannone 149/40 Modello 1935 on it. When a fully working prototype was completed in late 1942, it was given to the Army for testing.

Author P. Battistelli (Italian Medium Tanks 1939-45) mentions that it was based on the improved P26/40 chassis. According to this source, the Semovente M43 da 149/40 was actually developed and completed by August 1943.

Authors C. Falessi and B. Pafi (Veicoli da combattimento dell’esercito Italiano Dal 1939 Al 1945) give a more detailed account. According to them, the Semovente M43 da 149/40 was not even a project requested by the Italian Army, but instead a private venture from Ansaldo. Ansaldo engineers, who had designed the large Cannone 149/40, were interested in increasing its mobility. Like all towed guns, it needed some time to be properly set up before it could effectively engage enemy positions. Mounting this gun onto a fully tracked chassis would resolve the mobility issue greatly. So, during 1943, Ansaldo engineers set out to develop such a vehicle. The prototype was completed by August 1943 and appears to have been presented to the Army.

The completed prototype at Ansaldo. Source: Ansaldo Archives

Sources, such as Gli autoveicoli da combattimento dell’esercito italiano, volume secondo (1940-1945) by Pignato and Cappellano., mention that Ansaldo started the whole project at the end of 1941, when a wooden mock-up was completed. The actual work on the first prototype began in April 1942. Due to many delays, the prototype took some time before it was finally completed in August of 1943.

Probably the first wooden mock-up of the Semovente M43 da 149/40, dating back to November 1941. Source: 2020.fondazioneansaldo.it

Design

The Hull

The Semovente M43 da 149/40 hull was divided into a few sections. In the front part were the transmission and two crew members. The engine was positioned in the center of the vehicle. To the rear was the gun mount.

Which precise chassis was used for the construction of the Semovente M43 da 149/40 is not clear. Sources mention that it could have been either that of an M15/42 or the larger P26/40. The hull front and the upper glacis do not resemble any of the M-series (even the chassis used for the later Semoventi). The M15/42 front hull had a rounded shape. The P26/40 hull has some similarities, but its design was also different. A more plausible solution is that the Anslado engineers simply took the best components from both chassis and combined them into a single-vehicle with some modifications. Authors C. Falessi and B. Pafi (Veicoli da combattimento dell’esercito Italiano Dal 1939 Al 1945) claim that, while the chassis of the Semovente M43 da 149/40 was new, it incorporated a steering gear unit taken from the M15/42, together with a strengthened suspension copied from the P26/40. The upper glacis on the Semovente M43 da 149/40 had two small hatches used as access points to the transmission and brakes for repairs and maintenance.

Close-up view of the front hulls of the Semovente M43 da 149/40, M15/42, P 40, and the Semovente M42. While the latter two are somewhat similar, they were still different from the Semovente M43 da 149/40 front hull shape. Sources: tvd.im/land-systemshttps:, forum.warthunder., beutepanzer.ru/Beutepanzer
Front view of the Semovente M43 da 149/40. Note the two smaller maintenance hatches placed on the upper glacis. Source: Ansaldo Archives

Suspension

The suspension used was the Italian standard semi-elliptical leaf spring type. On each side, there were four bogies with eight doubled rubber road wheels, paired onto two suspension units. This suspension type was obsolete by the early 1940s and did not allow the vehicle to reach a high top speed. The drive sprockets were at the front and the idlers, with modified track tension adjusters, were at the back, with three rubber return rollers on each side. Interestingly, the front-drive sprockets had an unusual design not seen on other Italian armored vehicles. The tracks had a width of 400 mm.

The Semovente M43 da 149/40 suspension was the standard Italian type used on all mediums and later developed heavy tanks. While it did the job, it was far from perfect. Note that the front sprockets had a completely new design in comparison to the one used on previous vehicles. Source: tvd.im/land-systems/2946-semovente-da-149-40

Engine

The Semovente M43 da 149/40 was powered by an unspecified 250 hp SPA petrol engine. With a weight of 23.5 to 24 tonnes, the maximum speed was around 35 km/h. This engine somewhat complicates the matter of determining which chassis was used. The M15/42 used a SPA 190 hp engine, while the P 40 was powered by a 330 hp SPA engine. Neither of them matches the known data. Ansaldo engineers had plans to equip the first small production series with a similar engine, which was to be slightly lighter and smaller in size, but nothing came of this. Some sources also mention a completely different power plant, an eight-cylinder V-shaped 185 hp @ 2,400 rpm engine. The use of the engine from the experimental Sahariano tank was also proposed, but nothing came of it.

The engine was placed in the central part of the hull. It was fully enclosed, with two exhaust pipes placed on each side. Ventilation grills were placed to the rear, close to the gun installation. On top of the engine compartment were several smaller hatches.

Superstructure

The superstructure of the Semovente M43 da 149/40 consisted of a simple box-shaped and fully enclosed crew compartment. As was the standard for Italian designs, this was constructed using a metal frame on which armored plates were mounted, connected with bolts. On top of this compartment, two hatches were placed, one for each crew member. In addition, on top, a simple round-shaped travel lock was located. To the front were two protective observation ports without any slits. These too were of a standard Italian design, which was commonly used on other armored vehicles. No side ports nor slits were used on this vehicle.

To enter their positions, the front crew had two hatches placed on top of the fighting compartment. Source: beutepanzer.ru/Beutepanzer
Two protected observation ports (the left port has number 262 painted on it) without any slits were placed in front of the crew compartment. Source: Pinterest
Such protective observation ports were also common on Italian vehicles, like this Semovente. Source: http://beutepanzer.ru

Armor Protection

As it was intended to use the Semovente M43 da 149/40 for long-range support, the vehicle was only lightly protected. The front armor was, depending on the source, 25 to 30 mm thick. The side armor was 14 mm thick, while the top armor was 6 mm. No armor protection was provided for the gun operating crew.

Armament

This vehicle was armed with the long Cannone 149/40 gun. Its official name was Cannone Ansaldo da 149/40 Mod. 1935 (Eng. Ansaldo Cannon 149 mm L/40 Model 1935). The development of this gun was initiated in 1929, when the Regio Esercito (Eng. Italian Royal Army) asked OTO, Ansaldo, and Arsenale Regio Esercito di Napoli, or AREN (Eng. Royal Army Arsenal in Naples), to develop a new 149 mm artillery gun to replace some aging artillery pieces which dated to before the First World War. It was requested to have a firing range of 20 km with a maximum weight of some 11 tonnes. In order to ease transport, it had to be dividable into two parts. In addition, it had to be assembled in half an hour. While OTO did not participate in this competition, both Ansaldo and AREN proposed their projects.

Ultimately, the Ansaldo project was chosen over its competitor. After some testing in 1934, the gun was officially adopted in July of 1935. In total, some 180 guns of this type would be produced (this number may have been lower as 63 to 64). These were used on various fronts, including in the Soviet Union and North Africa, and were deemed good designs. The Germans managed to capture some guns after 8th September 1943, renaming them to 15 cm K 408(i). After the war, the surviving guns were kept in reserve by the new Esercito Italiano (Eng. Italian Army) until 1969.

The Cannone 149/40 had a 6,360 mm long barrel and could fire a 46 kg round (with a muzzle velocity of 800 m/s) at ranges up to 23,700 m. It could fire a standard high-explosive, armor-piercing, and training round. The rate of fire was only one round per minute. Elevation was 0° to 45°, while the gun traverse was 57° (or 60° depending on the source).

The Ansaldo Cannon 149 mm L/40 Model 1935. Source: www.italie1935-45.com

This gun had modern twin-split trail legs. Additionally, in order to further absorb the recoil, the trail spades had metal bars that could be hammered into the ground. Both of these would be used on the self-propelled vehicle. Given the rather large size of the original trail legs, shorter ones were instead placed to the rear of the vehicle. When on the move, these would be raised from the ground and then folded down toward the vehicle. The spades would be placed on each of these two trail legs when the vehicle was prepared for firing. On the move, these would be removed and placed on each side of the gun for transport. In order to fully prepare the vehicle for action, the crew needed around 3 minutes. In contrast, the towed version of the same gun needed 17 minutes to be ready for action.

Elevation of the Semovente M43 da 149/40 gun was the same as on the towed version, but the traverse was slightly reduced, at 53°. The ammunition load allegedly consisted of only six rounds, which seems unlikely due to the lack of storage space for them.  Additional spare rounds were carried by an auxiliary ammunition supply vehicle. No secondary armament besides the crew’s personal weapons was to be carried.

Rear view of the Semovente M43 da 149/40. The two shortened trail legs and the left spade are clearly visible here. In addition, note the rear positioned engine ventilation grilles. Source: Wiki
The Semovente M43 da 149/40 gun was placed at zero elevation. Source: www.militaryimages.net
Elevation of the Semovente M43 da 149/40 gun was the same as on the towed version, but the traverse was slightly less, at 53°. Source: Ansaldo Archives

Crew

Like most information regarding this obscure vehicle, the number of men needed to effectively operate it is unknown. Often, sources mention that the vehicle only had two crew members, but this is likely referring only to those that were stationed inside the vehicle. This would include the driver, and likely the commander, but it could also be anyone from the crew. The remaining crew would be transported in an auxiliary vehicle. Ideally, in order to keep up with the Semovente M43 da 149/40, a fully tracked vehicle would be used in this role.

Given the general lack of such vehicles in Italian service, a more plausible solution would be to use simple trucks. The crew would most likely consist of a driver, commander, gunner, and possibly up to two (if not more) loaders. In the original towed version the 149/40 gun needed 10 crew members to be fully operational. The crew operating the gun were completely exposed, but given the firing range of more than 23 km, this should not have been a major issue most of the time.

The Fate of the Project

The Semovente M43 da 149/40 was used by the Italian Army for testing and evaluation. It is not clear if the Italian Army officials were satisfied with this vehicle. Nevertheless, Ansaldo made preparations for the production of a small series of some 20 vehicles, which were scheduled to be completed by the end of 1943. Unfortunately for them, in September of that year, Italy surrendered to the Allies and any further work on this project was terminated.

Following its former ally’s capitulation, the Germans took over what was left of the Italian industry and weapons. This included the sole-built Semovente M43 da 149/40 prototype. In German service, it was renamed to gepanzerte Selbstfahrlafette M 43 854(i). Its precise usage by the Germans from this point is not clear. Some sources suggest that this vehicle may have been used to defend the German Gothic Line against the Allies in Italy.

What happened next to it is also not clear. According to the American archives from the Museum of the Aberdeen Proving Grounds, the prototype was captured near Rome by the advancing American forces. In 1944, it was transported to America for evaluation. There is another version of the story, for which there is photographic evidence. The prototype was transported to Germany for examination. What the Germans thought of this design is unknown, but appears to have not influenced the development of German self-propelled artillery in any way. The prototype would eventually be captured by the Allies, possibly somewhere in France, during 1944-45, after which it would be shipped to America for examination and evaluation. Luckily, the prototype survived to this day. While initially located at the Military Museum Aberdeen Proving Grounds, it was later moved to the U.S. Army Field Artillery Museum at Fort Sill, Oklahoma. Unfortunately, at some point during the 1970s, its tracks were removed and ultimately lost.

A number of German vehicles together with the Semovente M43 da 149/40 prototype, were captured by the advancing Allies. This photo was taken in a military depot near Paris in 1944. Source:beutepanzer.ru/Beutepanzer
The Surviving Semovente M43 da 149/40. Source: comandosupremo.com

Conclusion

The Semovente M43 da 149/40, while not unique, was quite an interesting vehicle from Italy. It was designed and built with the intention of providing mobility to heavier guns. Alas, due to the deteriorating Italian industrial situation, lack of resources, and urgent need for tanks and self-propelled vehicles, there was simply no place for the new Semovente M43 da 149/40. In addition, taking into account that it was actually developed just prior to the Italian capitulation, there was simply no time for its introduction to service. Other nations also developed somewhat similar projects, like the American 155 mm armed M12 GMC, which saw some service during the war. Unfortunately, due to a general lack of information about the Semovente M43 da 149/40, a precise conclusion about its overall performance cannot be made.

The author would especially like to thank Art and Roshindow for providing valuable sources.

Semovente M43 da 149/40

Semovente M43 da 149/40 specifications

Dimensions (L-W-H) 6.6 -6.5 x 3 x 2 m
Total weight, 23.5 to 24 tonnes
Crew 2 (Driver and possibly the Commander)
Propulsion SPA petrol engine 250 hp
Speed 35 km/h
Armament Cannone 149/40
Armor 6 to 25 mm

 

Sources

Categories
WW2 Italian SPG Prototypes

Semovente M15/42 Antiaereo

Kingdom Of Italy (1943)
Self-Propelled Anti-Aircraft Gun – 1 or 2 Prototypes Built

During the Second World War, the Regio Esercito (Italian Royal Army) lacked an anti-aircraft vehicle that could protect its armored formations from enemy air attack. Sometime in 1942-43, the Italian Royal Army began development of an anti-aircraft vehicle based on the new M15/42 tank chassis. As its development began too late, only one or two prototypes would be built. Sadly, due to insufficient sources being available, very little is known about this vehicle.

The Semovente M15/42 Antiaereo. Note that the sides of the turret are missing. Source: www.worldwarphotos.info

Development

During the fighting in North Africa, the Italian ground armored forces were often subject to Allied fighter and fighter-bomber attacks. The Italian Royal Air Force (Regia Aeronautica) lacked modern fighter designs and was thus unable to provide sufficient aerial protection. One solution was to mount anti-aircraft guns on a mobile chassis. There were some attempts to mount 20 mm anti-aircraft guns on available trucks. These proved to be insufficient due to many factors like poor mobility, weak firepower, and no armor protection for the men or vehicle.

One of the first attempts to use a truck chassis (the SPA Dovunque 35) for the role of a mobile anti-aircraft vehicle. Such vehicles were usually armed with a Breda 20 mm gun. Source: Pinteres

Due to the ineffectiveness of these truck-based vehicles, the Royal Army moved on to the idea of using a tank chassis for this role. With only limited time and resources, it was decided against developing a brand new chassis and to instead use the available tank production capacities. As the M15/42 was entering production during 1942, it was decided to use it for this modification. During early 1943, one prototype was completed and presented to the Royal Army. The only visible change in contrast to the original M15/42 was the introduction of a new polygonal turret equipped with four 20 mm Scotti cannons. According to D.Nešić, (Naoružanje Drugog Svetskog Rata-Italija), this vehicle was built using the command version of the M15/42, which lacked the hull machine guns and had an extra radio set.

M15/42 tank

Due to the increasing obsolescence of the M13 Series (including the M14/41) and the slow development of the heavy tank program, the Italians were forced to introduce the M15/42 medium tank as a stopgap solution. The M15/42 was mostly based on the M14/41 tank, but with a number of improvements. Most noticeable was the introduction of a new 190 hp FIAT-SPA 15TB (‘B’ stands for Benzina – Petrol) engine and a new transmission. With the installation of the new engine, the tank hull was lengthened compared to the M13 Series tanks by some 15 cm. The standard 8 mm Breda anti-aircraft machine gun was removed and the access hatch door was repositioned to the right side. The removal of the anti-aircraft machine gun on the turret may appear odd given Allied air superiority of the time and the threat it posed, but a single 8 mm Breda machine gun was almost completely ineffective in the anti-aircraft role and was seen as a waste of resources and weight. Most noticeable for the M15/42 was the installation of a new 4.7 cm main gun with a longer barrel, producing a more effective anti-tank gun, albeit still inadequate by this point in the war. The armor protection on the tank was also slightly increased, but this too was still inadequate to keep up with newer and better Allied tanks.

The most modern Italian tank available in 1942 was the M15/42. Source: www.worldwarphotos.info

The Royal Army placed an order for some 280 M15/42s in October 1942. However, due to attempts to produce more Semovente self-propelled vehicles, the order for 280 was reduced to 220 tanks. These were built by June 1943 and an additional 28 tanks would be built under German command after the September Armistice was signed with the Allies. The M15/42 had introduced some improvements, but these tanks were generally outdated by the time they were put into service. Nevertheless, they would remain in service up to the end of the war, mostly with their new Germans owners (known as PzKpfw M15/42 738(i)), although some would also serve with Italian Fascist troops of the Italian Social Republic (RSI – Republicca Sociale Italiana).

Just like the earlier M13 Series tanks, a command tank variant (carro centro radio/ radio tank) of the M15/42 was developed. On these vehicles, the turret was removed and some were rearmed with 13 mm heavy machine guns instead of the two 8 mm machine guns and extra radio equipment was added. By the time of the September Armistice, some 45 M15/42 CC vehicles were built. An additional 40 vehicles were built after September 1943 under German control. There were also a few different Semoventi vehicles based on the M15/42 built.

The command version based on the M15/42 (like all Italian command tanks) lacked the turret and had the two radio antennas on the rear of the casemate. Source: pinterest

Designation

Various sources give many different names for this vehicle, including: Semovente (self-propelled) M15/42 Antiaereo (anti-aircraft), Carro Armato Medio Antiaereo (anti-aircraft medium tank), M15/42 Antiaereo or Contraereo (M15/42 anti-aircraft), M15/42 “Quadruplo” (M15/42 Quad), Semovente Antiaereo M42 (self-propelled anti-aircraft gun M42), Semovente da 20/70 quadruplo, among others.

In Italian service

Not much is known of this vehicle’s development history. What is known is that the first prototype was completed sometime in early 1943. It was presented to the Italian Army at the Centro Studi della Motorizzazione (Study Center of Motorization). If the Army showed any interest in it is unfortunately not known. In March 1943, the prototype was stationed in Cecchignola (Rome) and given to the VIII Reggimento Autieri (8th Driver Regiment), possibly to be used for evaluation.

Illustration of the M15/42 Antiaereo. Source: pinterest

Some sources (mostly on the internet) suggest that this vehicle was shipped to Tunisia for field combat tests and that it would remain there until the Axis surrender in May 1943. This seems highly unlikely, mainly due to the lack of evidence and photographs of it in the theater. If it was captured, its unusual construction would have certainly sparked some interest among the Allies and they would have certainly taken photographs or mentioned it in their documents. The more realistic fate of the M15 anti-aircraft vehicle (or vehicles) was that, after the Italian capitulation in September 1943, it was seized by the German forces.

Technical characteristics

Being an obscure vehicle and rarely mentioned in sources in more detail, the precise technical characteristics are hard to come by. What is known with certainty is that it was based on a slightly modified M15/42 tank or the command version of the same vehicle. Most parts of the tank, including the suspension and hull, were unchanged. The only visible change to the hull was the removal of the two machine guns which were replaced with an armored cover. If the armor thickness was changed there is no information about it, but it seems likely that it remained the same in order to save development time.

The most obvious change was the introduction of a new turret equipped with four 2 cm Scotti cannons. The new turret had a polygonal shape and was made using a frame on which (unusual for the Italians) armor plates were welded.

The two obvious changes to the M15/42 tank were the introduction of a new turret and the removal of the two hull positioned machine guns. Source: https://forum.warthunder.com/index.php?/topic/390776-semovente-contraerei-2070-quadruplo-m1542-aaa/

For the main weapon, four Cannone-Mitragliera da 20/70 autocannons (generally known as Scotti, after their designer, Alfredo Scotti) were chosen. This type of gun was intended to be cheaper and easier to build compared to the Breda Cannone-Mitragliera da 20/65 modello 35. But, despite its simplicity, a higher rate of fire, and being lighter, its performance was not much better than its counterpart. In all, some 300 were built either as static emplacements or with a twin-wheel carriage. The Germans also managed to capture a number of these guns, where they were known as 2-cm Scotti(i). The Scotti had a 250 rpm rate of fire with a maximum range of 2,100-3,500 m (depending on the source). It had a barrel length of 1,540 mm and the muzzle velocity was 830 m/s. Elevation was -10° to +85°, with a rotation of 360°.

The Scotti during the African campaign. While it could be fed by using a drum magazine, it was usually fed by a 12 round strip. Source: Wiki

The Scotti anti-aircraft guns that survived the war would be used by the new Italian Army for some years on. These would mostly be used to equip navy ships. An unknown number of quadruple-gun systems would also be built after the war, with some even supplied to Israel in the late forties.

One Scotti quad system is preserved in the Santa Barbara barracks of Sabaudia. Source: warthunder.com

Prior to their installation into the new turret, the four Scotti cannons had to be modified and a specially designed mount had to be developed. The most obvious change to the cannons was the feed mechanism. This type of cannon had two feed options, by a clip or by drum magazine. Both of these were unusable due to the cramped space of the turret, and for this reason, a new type of fed system had to be adopted. The manufacturer of this cannon, Isotta Fraschini, developed a new ammunition supply system that consisted of a metal belt feed with disintegrating mesh which allegedly also increased the rate of fire up to 600 rpm per gun. The elevation of the new turret installation was -5° to + 90° with a full traverse of 360°. How the main armament was mounted inside the turret is, due to a lack of information, unknown. The armor thickness is also unknown, but would most likely have been very light, in order to provide protection at least from small-caliber weapons while keeping weight down.

Interestingly, in some photographs, the front part of the new turret is lacking armor plating. The reason why is not known. It could potentially be that it was not yet completed or due to some problems with the main weapon mount that required more working space.

The M15/42 Antiaereo’s four cannons placed at a high elevation. Thanks to its good elevation, it could cover a wide arc of fire, Source: Pinteres
Interior illustration of the M15/42 Antiaereo turret and main weapon. Source: warthunder.com

According to the few sources available, the crew consisted of three crew members. While they are not listed, an educated guess can be made. At least one crew member had to be the driver. The second crew member would be the commander who was probably also the gunner and his position would likely be behind the main gun installation. The last crew member was probably a radio operator (if a radio was ever to be used on this vehicle) or a loader.

The mobility of the M15/42 Antiaereo was probably similar to that of the original tank configuration. The new turret and weapons would have probably been similar to the weight of the previous turret and gun, giving a total weight in the vicinity of 15.5 tonnes. The speed and the operational range were probably also similar. Some of the dimensions, such as the length of 5.06 m and width of 2.28 m, were almost assuredly the same but the vehicle may have been somewhat higher than 2.4 m.

How many were built

The precise number of built vehicles is unfortunately not known. What is known with certainty is that at least one prototype was built and tested. According to the few available photos, there is a possibility that at least one more vehicle was built. This vehicle has German markings, camouflage paint, and lacks the frontal turret armor. Of course, there is the possibility that this was simply the first vehicle just slightly modified by the Germans. Author D. Nešić (Naoružanje Drugog Svetskog Rata-Italija) quotes that a few were built but does not mention how many precisely.

In German hands

The Germans managed to capture the M15/42 Antiaereo prototype during their occupation of Rome. Interestingly, in one photo, this vehicle is lacking some front turret armor plates, despite having pictures of it with them. This may be additional proof that at least another vehicle was built beside the one prototype.

What the Germans did with it is not completely clear. According to a few sources, it appears that the prototype was transported back to Germany for evaluation. It also allegedly saw service against the Soviet Forces in 1945 in the Teupitz area (Germany). At that time, it was supposedly attached to the 5th SS-Freiwilligen-Gebirgskorps (Mountain Armored Corps).

The prototype in the barracks of the VIII° Reggimento Autieri, at Cecchignola (Rome) which was seized by the Germans. The vehicle has camouflage paint on it, but it is not clear who applied it. Also, note the German Balkenkreuz on the turret side. Source: beutepanzer.com

The Germans did use large quantities of Italian captured weapons and thus had available spare parts and ammunition, making it plausible that this information has some merit. By 1945, the Germans were trying desperately to stop the Soviet offensive, and in their desperation they used any available weapons that they had on hand, perhaps including the M15/42 Antiaereo prototype. Of course, on the other hand, due to insufficient sources, the information about its use by the Germans could easily be incorrect or even fake.

After seizing a number of Italian production factories, the Germans produced small numbers of some Italian equipment, mostly self-propelled Semovente vehicles. Why the Germans did not bother producing more Antiaereo, even as they were themselves in great need of such a vehicle, is unknown.

Influence

It is relatively common to find claims that, after the M15/42 Antiaereo, was seized by the Germans, it influenced their development of anti-aircraft tanks like the Flakpanzer IV (2cm Flak 38 Vierling) ‘Wirbelwind’. Does this assumption have any merit? First, it must be taken into account the fact that this vehicle was completed in the first months of 1943 and captured by the Germans later that year, after the Italian capitulation. This meant that it would have been shipped out to Germany after September 1943.

The issue is that the German had already begun (in early 1943) to develop their own anti-aircraft tank based on the Panzer IV. This vehicle had a completely different design, simply installing the 2 cm Flakvierling anti-aircraft system on a Panzer IV chassis, protected by large metal plates that could be folded down during combat situations. As the 2 cm caliber was deemed weak by the Germans, it would be later replaced with the 3.7 cm gun and put into production as Flakpanzer IV (3.7cm Flak 43) “Möbelwagen”. Also, even earlier in the war, the Germans had tested the anti-aircraft tank concept on the Panzer I and later Panzer 38(t) chassis.

While not the first Flakpanzer, this Flakpanzer IV armed with four 2 cm cannons was the first serious attempt made by the Germans to develop an anti-aircraft vehicle based on a tank chassis. This vehicle (and the later Möbelwagen) was obviously not inspired by the Italian vehicle. Source: Panzernet

Conclusion

The Semovente M15/42 Antiaereo was certainly an interesting vehicle that was developed for the Italian army. It also represents a modern concept of an anti-aircraft vehicle based on the tank chassis. The installation of its main weapon in a fully enclosed turret had important benefits, as it would provide sufficient protection for the crew. In practice, this was not easy to achieve and often came at the cost of reduced visibility, and not many anti-aircraft vehicles were built during the war that used an enclosed turret.

The Semovente M15/42 Antiaereo, showing the new turret placed on the body of an M15/42. It would have been a potent SPAAG for its time, but very cramped. Illustration by Andrei Octo10 Kirushkin

Semovente M15/42 Antiaereo

Dimensions 5.06 x 2.28 x 2.4 m
Total weight, battle ready ~15 tonnes
Crew 3 (Commander/Gunner,Loader and Driver)
Propulsion 190 hp FIAT-SPA 15TB
Speed 38 km/h road, 20 km/h off-road
Operational ranger 200 km road, 130 km off-road
Armament 4x20mm Scotti-Isotta Fraschini M41 20/70 cannons
Armor 6-50 mm
Total production 1 to 2 prototypes
For information about abbreviations check the Lexical Index

Source:

D. Nešić, (2008), Naoružanje Drugog Svetskog Rata-Italija, Beograd

F. Cappellano and P. P. Battistelli (2012) Italian Medium Tanks 1939-45, New Vanguard

D. Doyle (2005). German military Vehicles, Krause Publications.

Pafi, Falessi e Fiore Corazzati Italiani Storia dei mezzi corazzati

N. Pignato, F. Cappellano. Gli Autoveicoli da combattimento dell’Esercito Italiano Volume secondo

L. Ceva and A. Curami (1989) La meccanizzazione dell’esercito italiano dalle origini al 1943, Volume 2″ from Stato maggiore dell’Esercito, Ufficio storico,

V. Meleca, Semovente M 15/42 “Contraereo”.

N. Pignato, (2004) Italian Armored vehicles of World War Two, Squadron Signal publication.

A. Lüdeke (2007) Waffentechnik im Zweiten Weltkrieg, Parragon books

C. Bishop (1998) The Encyclopedia of Weapons of World War II, Barnes Book.

R. Riccio and N. Pignato (2010) Italian Truck-mounted Artillery in Action. Squadron Signal publication

N.Pignato (1978) Le armi della fanteria italiana nella seconda guerra mondiale, RIVALBA,

Categories
WW2 Italian SPG Prototypes

Semovente Moto-Guzzi

Kingdom of Italy (1921)
Self-Propelled Gun – 1 Built

Mountainous northern Italy was treacherous tank country. Any war fought there on that terrain would be difficult. As well suited to defense as mountains were, any force which could deploy armor there, especially if they could also deploy some mobile artillery, would have a significant advantage. Combine this need with the late 1920’s assessment that the doctrine for new warfare should be highly mobile tactically making full use of light tanks combined with strategic mobility and Italy had a clear requirement for a vehicle able to achieve both goals.

Early work had involved testing the British Carden Loyd Mark VI light tank as well as the Mark V* light tank. Both had some advantages such as their small size and mobility but also some disadvantages in terms of the arrangement of automotive components.

Carden Loyd Mark V* fitted with Schwarzlose machine gun. Source: Ceva and Curami

The Carden-Loyd Mark VI entered service with Italy fitted with a single machine gun as the CV29. The Mark V* was not assigned an official Italian service number but served as an inspiration for Ansaldo’s design for a 65 mm gun armed vehicle.

The Entry of Moto-Guzzi

The Italian firm Società Anonima Moto Guzzi, better known as just ‘Moto Guzzi’, is world famous for motorcycles and is Italy’s oldest motorcycle producer, having started in 1921. They even developed a completely enclosed armored motorcycle mounting a heavy machine gun. Of far more military use though they also worked on a fully tracked vehicle design. This design was a significant departure from anything seen before. It had two versions. The first was just a tractor which served as a test bed and the second was based on the same vehicle, but mounting a gun.

Semovente Moto-Guzzi 65/17. Source: Pignato

Structure

The basic structure of both vehicles was the same as the chassis were the same consisting of two independent track units mounted on arms and driven by an engine in the front. The driver and another crew member would sit at the back to command, drive and service the gun. The cabin seen in the test bed is a roll cage for protection from rolling over and it is unknown whether it was intended to be a permanent feature on either vehicle. Certainly, some sort of protection for the crew would have been required for the Semovente (a self propelled gun for infantry support) should it have been built.

Suspension

The suspension was very unusual and consisted of two tracks completely independent of each other consisting of four wheels on a supporting bar, along with an idler and drive sprocket all suspended on three rotatable arms. As one track moves down, these arms rotated, ensuring that the body of the vehicle remains horizontal and the tracks move at different heights. The arrangement was unlike anything before in Italy and had the significant advantage of allowing movement across the side of a steep slope. The drawing from Moto-Guzzi suggests a side slope of approximately 45 degrees. Drive appears to be provided via the front sprocket as per the prototype vehicle. However, the exact arrangements of the fastenings for the wheels is likely to have differed on the envisaged production vehicle from the test bed.

The drawing of the Semovente shows four road wheels and the test bed also has four wheels but each wheel is paired so as to leave a gap down the centre for the track guide. A large external supporting bar ran from the front sprocket to the rear idler wheel on which were mounted small track support wheels.

Engine

Moto-Guzzi made a lot of motorcycles for the Italian Army and had a lot of experience in small high powered engines but it is not known what engine was used in the design. The cylindrical object at the front of the test bed is unknown but appears to be either the exhaust or possibly a fuel tank, which would have to have been completely rearranged on a production vehicle to permit the gun to be used.

The Moto-Guzzi designed vehicle chassis, during mountain trials, showed off its incredible ability to remain upright even when traversing a steep side slope. This flexibility is shown in the modified image from the outline drawing. Source: Ceva and Curami, and Pignato (modified) respectively
1: The Moto-Guzzi vehicle showing its ability to climb very steep slopes even in snowy alpine conditions. 2: The Moto-Guzzi traversing a steep side slope in snowy conditions. The ability of the tracks to move vertically keeps the body horizontal. 3: The Moto-Guzzi tractor during trials. Note the large logo on the cab. Source for all: Pignato
Enlarged view of the logo on the side of image 3. Source: Pignato

Armament

The Moto Guzzi, as a tractor, would (amongst other duties) be used for towing light guns. As a semovente, it would mount the 65mm Model 1913 mountain gun. This gun was made by the Royal Arsenal in Naples and was 17 calibers long. It was an ideal gun for use in the mountains as it could be broken down easily into 5 loads for transport. It fired the 65mm x 172R rounds just under 5kg in weight and ammunition for the gun was mainly high explosive, but a specific shrapnel shell was also available. Later, an armour piercing (AP) and also a hollow charge shell were available for it.

65mm L/17 Model 1913 Mountain gun. Source: Italian Ministry of Defence

Conclusion

The Semovente Moto-Guzzi was a very advanced design for the time. A design ideally suited to the rigours and demands of mountain warfare and carrying a weapon specifically designed for the job. It was not to be, however. The Moto-Guzzi design, either for work as a tractor or as a semovente, was discontinued by 1930. The Italians would have to look elsewhere for a suitable gun carrier to meet their unusual requirements.



Illustration of the Semovente Moto-Guzzi produced by Andrei Kirushkin, funded by our Patreon Campaign.

Specifications

Crew 2
Armament 65mm L/17 Model 1913 mountain gun

Sources

Italie1939-45.com
Italian Artillery of WWII, Ralph Riccio
Iron Arm: The Mechanization of Mussolini’s Army, 1920-1940, John Sweet
Gli Autoveicoli da Combattimento Dell’Esercito Italiano V.2, Pignato and Cappellano
Italian Armoured Vehicles of World War Two, Nicola Pignato
La Meccanizzazione dell’Esercito Italiano, Ceva and Curami
motoguzzi.com


Categories
WW2 Italian SPG Prototypes WW2 Spanish Prototypes

Fiat CV33/35 Breda

Nationalist Spain/Kingdom of Italy (1937-1938)
Light Tank/Tank Destroyer – 1 Built

When the Spanish Civil War broke out in July 1936, neither side was equipped to fight a modern war, so they sought allies to deliver up-to-date materiel, including tanks and planes. The situation of the Nationalists was especially desperate. At this point, they were a group of generals who had organized a coup and who had lost any central command. Their main army, led by General Franco, was stranded in North Africa with little hope of being able to reach the mainland.
Thanks to personal connections, Mussolini and Hitler came to Franco’s aid and airlifted the Spanish regulars across the Strait of Gibraltar.
Mussolini’s motivations to intervene and help Franco were probably not out of kindness or to support a fellow fascist, but a show of strength and power and to give the impression that any crisis within the Mediterranean region was to be solved by Italy.
All in all, Italian aid in Spain included 50,000 ‘volunteer’ troops, 758 planes, 155 tanks of the Carro Veloce L3/33 (CV33) and L3/35 (CV35) variants (including flame-thrower versions) and 8 Lancia IZ armored cars as part of the Corpo Truppe Volontarie (CTV). Their most notable action in the war was their defeat at the Battle of Guadalajara to a force largely made up of Italian members of the International Brigades. However, they were instrumental in the capture of Málaga and Santander.

The Need for a Bigger Gun

It was clear from the very first tank engagement around Seseña in 1936 that the Nationalists had no tank capable of facing the armament supplied by the USSR for the Republic. At Seseña, a company of T-26’s caused havoc among the poorly armed and armored Italian CV33’s. Even tactics involving overwhelming them with numbers did not succeed, and the 45mm gun on the T-26 and the BA-6 made it impossible to engage at a close enough range for the 8mm machine-guns of the CV33/35’s (Spanish designation for both the L3/33 and L3/35) or the 7.92 mm MG13 machine-guns of the Panzer I to do any harm.
To this end, an effort was made to improve the firepower of the existing machines by equipping the CV33/35 with a 20mm gun which would have enough penetration at a reasonable distance to confront anything in the Republican inventory. It is not clear whether the idea originated with the Italians or with the Spanish or both. It is also not clear where the conversion took place. A blueprint of the conversion is written in Spanish and Spanish accounts put the work as having been carried out under the direction of Lieutenant Colonel Ayuela. Italian records state that the conversion was carried out by technicians from the Italian CVT, sometime “between the end of 1937 and beginning of 1938”. In addition, the Italian Captain Oreste Fortuna, the commander of the 1st Tank Company ‘Navalcarnero’, noted in his journal that the main armament of the CV35 should be replaced with the 20mm Breda gun or with a Brixia Model 35 45mm mortar
Two guns were considered – the German Flak 30 (which would later be the basis for the main armament of some Panzer II variants) which had a significant recoil, and the gas-operated Italian Breda M-35. Both guns had ammunition that weighed 147 grams and could penetrate 40mm of armor at 250m and a 90º angle. The latter gun was selected mainly because of its gas-operated reload and its fewer moving parts which would ease the modification and would allow the larger gun to fit inside the already cramped interior of the CV33/35.
The vehicle chosen for the conversion was one of the CVT and that, after the conversion and the tests, the vehicle was returned to the Italians who put it through more trials. This explains the two photos showing the vehicle with Italian markings and with Italian soldiers in the background. While it is not implausible to think that the two sides cooperated on the matter, neither side acknowledges any help from the other in designing the vehicle.

The Transformation

Work on equipping the CV33/35 with the Breda gun commenced at the beginning of the summer of 37. By mid-August, the blueprints had been completed and a tank and gun were requested from the CTV which were supplied almost immediately. The tank is referred to in Spanish-language literature as a ‘C.V. 35 IIº tipo’, which can be assumed to be an L3/35 (CV35). The vehicle’s identification number was 2694. The modification would mean that the two parallel Fiat 35 machine-guns on the left frontal firing position were to be substituted by the individual 20mm Breda. Apart from that, no other substantial modification was to take place or was recorded.
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1:5 original blueprints of the modifications to fit the 20mm Breda gun – Molina Franco & Manrique García, p. 30.
Whilst there is a lack of any empirical evidence, it can be assumed that the transformations of said vehicle would have been done in the Fábrica de Armas of Seville, which had been under Nationalist control from the very start of the war due to the actions of General Queipo de Llano. This assumption is based on the fact that captured T-26’s were sent to this city in Andalucía for repairs and the Panzer I ‘Breda’ modifications carried out during approximately the same time period were also done there. Prior to the capture of Bilbao in June 1937, Seville had been the main industrial hub for Franco’s side. The work was carried out by Spanish technicians, and according to Italian sources, supported by Italian artillery and technical service officers.
Even before the modification was completed on August 10th, a request to the Italian delegation for a further 40 tanks and guns for transformation were made by order of the HQ of Generalissimo Franco. However, this order would not fully materialize; though it seems that some of the requested Breda guns were sent at that or a later time. Even so, Spanish tank historians Lucas Molina Franco and Jose Mª Manrique García, agree that this request for more tanks with the prototype yet to be finished was a bit hasty.


Illustration of the Fiat CV33/35 ‘Breda’, produced by Alexe Pavel, funded by our Patreon Campaign.

The Lesser of Two Evils

The reason why the order did not materialize and that this modification was never mass produced or used on the field of battle was that an alternative was found. Halfway through the transformation, General Joaquín García Pallasar, an artillery officer and close friend of Franco, sent a report to Franco’s HQ recommending that the same modifications should be carried out on the German-supplied Panzer I. The request to the Italian delegations was consequently put on hold until the modification on the Panzer I had been done so it could be evaluated and compared to the Italian tank.
On the 2nd of September, General Pallasar notified Lieutenant Colonel Barroso of the Estado Mayor del Generalissimo that the modifications on the CV35 had been carried out and that it was ready to be shown to Franco if he had any interest. Franco was indeed interested and the vehicle was transported to his seat of government in Burgos.
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One of two known pictures of the CV35 just after its transformation was complete alongside what are presumably factory workers – Molina Franco & Manrique García, p. 46.
Later that month, the vehicle was taken to Bilbao, where it was enlisted and trialed against the Breda gun modification carried out on the Panzer I, during which the German vehicle proved to be slightly superior. One of the main advantages was that the Panzer I had a turret, whereas the Italian tank did not. It is perhaps important to remember that the Italian tanks did not have much of a reputation in Spain and were given the nicknames ‘lata de sardinas’ (sardine tin) because of their small cramped space and poor armor or ‘topolino’, the Italian name for Mickey Mouse.

Further Testing

Even before the trials took place and probably in the knowledge that the Panzer I conversion would prove more satisfactory, the Italians requested the prototype to be given back on the September 1st with a second order for the return of spare Breda 20mm guns on the December 9th. Once it was given back, presumably in late September or October, the tank was assigned to the Reggruppmaneto Carristi where it was subject to more trials. The conclusions were not positive and three main flaws were found: 1. the increase in the gun’s size within the hull made it uncomfortable for the commander/gunner; 2. the left side visibility of the driver was limited by the increased length of the gun; and 3. There was an imbalance in the vehicle with the left side now weighing 200kg more than the right.
With this in mind, the Italians did not adopt this conversion and the final fate of this prototype is unknown.
After being trialed, it followed operations first at Rudilla (Teruel) on the 9th of March 1938, and later at Tortosa (Tarragona) on the 19th of April in the aftermath of the bloody battle of Teruel and the build-up to the Aragón Offensive.
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The other known photo of this modification, presumably taken at the same time as the other. This photo shows Italian troops in the background, denoting that Italy had some role in the modification. Photo: SOURCE.

Legacy

Despite the failure of this tank, it is a fair assessment to say it influenced the development of other tanks. The aforementioned Panzer I ‘Breda’ was a direct successor of this tank and 4 were converted and saw action, though this project faced problems of its own.
Furthermore, Italian Army records of the period talk about another modification with the 20mm Breda, this time mounted on top of a CV33/35 in an improvised ‘rotary top similar to the Panzer I’. This may well be referring to the CCI tipo 1937, which was heavily based upon the CV33/35 and was equipped with that same gun.
Direct correlation with the WWII-era CV35 20mm gun conversion undertaken by the Italians in North Africa is harder to prove and seem highly unlikely. This field conversion consisted of equipping the Solothurn 20 mm Anti-Tank rifle to enable it to counter the lightest Allied vehicles. Initially, the gun was mounted at the top but it was moved into the hull. Unlike the Breda gun, the Solothurn rifle was heavy and had a considerable recoil.

Interesting note on markings

The photos of the CV35 ‘Breda’ show some interesting markings on the side of the hull. These are two white empty parallelograms which do not match up to any of the common markings of these tanks in the Spanish Civil War. However, this is because they are Italian tactical markings that correspond to the 2nd vehicle of the 2nd platoon, 2nd Squadron.

Links, Resources & Further Reading

Artemio Mortera Pérez, Los Medios Blindados de la Guerra Civil Española Teatro de Operaciones de Aragón, Cataluña Y Levante 36/39 Parte I (Valladolid: Alcañiz Fresno’s editores, 2011)
Lucas Molina Franco and José M Manrique García, Blindados Italianos en el Ejército de Franco (1936-1939)(Valladolid: Galland Books, 2009)
Italian Army records of July/August 1938
forum.warthunder.com
blitzkrieg1939-45.foroactivo.com

Fiat CV33/35 ‘Breda’ specifications

Dimensions 3.17 x 1.4 x 1.3 m (10.4×4.59×4.27 ft)
Crew 2 (driver, gunner)
Propulsion Fiat SPA CV1 6 cyl, 38 hp
Top speed 40 km/h (25 mph)
Range (road) 125 km (78 miles)
Armament 20 mm Breda M-35 gun
Armor From 5 to 10 mm (0.2 to 0.39 in)
Categories
WW2 Italian SPG Prototypes

Semovente M6

Kingdom of Italy (1939)
Self-Propelled Gun – Wooden Mockup Built

Italy had a shortage of armor, guns and of just about everything they needed to wage a modern war against a modern, well equipped, and well-disciplined opponent. As World War Two beckoned in Europe, the Italians, under the leadership of Benito Mussolini, were far behind in their modernisations with the majority of funding going to the Navy rather than the Army or Air Force. The result was that the Army, despite having requirements for tanks and support guns, was not getting what it needed, namely armor in quantity.
One particular shortfall in planning was the lack of a gun of an adequate calibre to fire high explosive and smoke shells to support the infantry during their attacks.
The small CV3 series of tanks could provide machine gun fire support but even the tanks which were available in 1939 with a proper cannon, such as the Fiat 3000, were horribly out of date, slow, and poorly protected, and with just a 47mm gun which lacked the firepower needed to smash an enemy defensive structure. What was needed was a larger caliber gun.

Wooden mockup of the Semovente M6. Source: Pignato

Ansaldo’s Venture

The M6 (later L6) was a private venture by Ansaldo and Fiat which built forth on the success of the CV3 (L3) light tank. A working prototype of the vehicle was ready by 1936 albeit with a small cannon instead of the later 20mm commonly associated with it. The CV3 had been a successful design, small, rugged and adaptable, it was ideally suited to many of the needs of the military but it lacked a turret mounted gun to function effectively as a tank. The M6 was a logical step up, with improved suspension and a 360-degree arc of fire, it was superior in every way to the CV3 while still being transportable easily by truck due to its small size. The development of the M6’s improved suspension allowed it to take more weight and be better off road than the CV3 series of vehicles which made it an ideal platform for a larger gun.

Mockup of the M6 medium tank with the 47mm L/32 cannon mounted behind a gun shield on top. Source: Ceva and Curami

Selection of a Cannon

If you need to fire a high explosive shell with enough explosive to make a difference, then the 47mm gun in widespread use was simply not sufficient. The CV3 mounting a 47mm gun, for this reason, was clearly not sufficient for the infantry support role and was abandoned. The next common gun, a step up, would be 65mm. Several years before-hand, the attempt to put a 65mm gun on a small vehicle – work done by the firm of Moto-Guzzi, had also failed. The 65mm gun had been used on the enormous Fiat 2000 but that was a generation earlier and redundant, and to add to the issue, the 65mm L/17 was already effectively obsolete. It had been relegated to infantry use in the 1920’s and replaced in the mountain gun role by a 70mm gun.
It is important to note that the 47mm gun option was not abandoned for the M6 (L6) hull. At the same time as this 75mm plan was developed, a scheme was produced with the 47mm L/32 cannon mounted on top of the casemate of an L6 hull in place of the turret. Although that idea was abandoned, that design morphed into the Semovente L6/40 with the 47mm gun mounted in the front of the vehicle instead.
By 1935, the venerable 65mm had been replaced in the infantry support role by the 47mm so it was a poor choice for any future support gun, or ‘Semovente’ as it is known in Italy. The obvious choice, therefore, was a 75mm calibre. Italy already had a huge stockpile of 75mm field guns and on the 26th October 1939 General Pariani (Chief of the General Staff) listed a series of decisions on tank development programs. The M6 featured heavily within those plans including a study to modify an M6 hull to transform it into a carrier for a 75 mm gun. He noted that it must also have an anti-aircraft machine gun fitted. The choice of the M6 for this project was logical if for no other reason than that there was nothing else available. At this time, the only medium-sized vehicle in production (just) was the M11/39. Those hulls were urgently needed for the Medium tank program so none were going to be available for a Semovente.
The commonplace CV3 hull was in plentiful supply but was too small. The work on putting a 65mm on a machine that size had already shown that. The best option therefore was the new projected 6 or 7 tonne medium tank which was just entering production itself. This new vehicle was ideal, small and light enough to be easily transported on the back of trucks but large and rugged enough to deal with the weight of the gun, ammunition and the necessary crew to serve it.
The decision by Pariani confirmed the 75mm gun as the choice for infantry support and the M6 was the vehicle to carry it. He had other plans for the M6 including as a platform for an anti-aircraft vehicle but concerned about air defence was requesting all new vehicles to come with some protection from the air.
It was not until a letter from a delegation of industry to General Pariani on the 30th of October 1939 though that a final decision as to which 75mm gun was going to be used. The gun selected was a 75mm L/18 and, as an aside, it was also mentioned that the 20mm cannon selected for the ‘tank’ version of the M6 was also suitable for use in an anti-aircraft role as well as an anti-tank role.

The vehicle which was to serve as the hull for the Semovente M6. This is the production L6/40 light tank. Source: Public Domain

Front view of the Semovente M6


Illustration on the Semovente M6 by Yuvnashva Sharma, funded by our Patreon campaign.

Modifications

The M6 was reclassified as a light tank L6 in 1940 (as the new M13/40 design was available for the medium tank role) and was a very mobile vehicle with the transmission at the front. A large hatch openable for the inspection and maintenance of the transmission and brakes was retained on the glacis as was the whole rear of the hull, allowing access to the engine and suspension components. The difference between the two came in the body of the vehicle at roughly track level. In place of the M6’s squarish body and vertical driver’s plate with a small turret on top (for a 20mm cannon or 37mm gun) was a large open-topped, open-backed rotating turret with the large 75mm gun mounted prominently in the center, although it is not known exactly how far this turret could rotate. A large order for 583 examples of the L6 was placed in March 1940 and this seems to have killed off the Semovente M6 project. Ansaldo and Fiat had won a large order and production would focus on that vehicle for the time being. A new Semovente on the hull of the L6 would appear shortly afterward but, for the time, the turreted M6 idea was over.

From approximately the same angle the modifications to the M6 are apparent.

Automotive

Like the M6 (L6/40) from which it was made, the Semovente M6 used two pairs of bogies on each side of the hull attached to torsion bars. The track was supported on the return run by two small rollers. Drive was from the front and the rear wheel was in contact with the ground. Power came from the same SPA model 18 68-70hp petrol engine as on the early L6 light tank although the L6 had not yet been formally standardized. This engine allowed the L6 to reach 25km/h off road and up to 42 km/h on road.

Semovente M6 with 75mm gun turret turned to the left showing a single crew position (driver) through the front of the turret presumably where a large hatch would go in a production version.

Crew

The previous Semovente version based on the CV3 had two crew, and the L6 light tank on which the Semovente M6 was based also had two crew members. It is therefore highly likely that this vehicle continued the trend. The Semovente da 47/32, also based on the L6, which later was approved, operated the much smaller 47mm gun, had a crew of three and was very cramped. This adds to the evidence that there was very little room inside the Semovente M6, especially considering the size of the 75mm shells it would have to carry.

Semovente M6 mockup showing the elevation of the 75mm gun in the turret.

Armament

The only gun known to have been planned for this vehicle is of 75mm calibre. A caliber which Italy had in no short supply. The gun selected was the Anslado 75mm L/18 gun, as this was already in production at the time by the makers of the designers of the vehicle. The gun would see use in later Semovente too. The 75mm L/18 was a howitzer standardized in 1934 and was actually just under 21 calibers long (20.75) despite being an ‘L/18’ thanks to an older Italian convention regarding how to measure the length of a barrel. It could fire a 6.4 kilogram shell out to nearly 10 km. Although the elevation and depression figures for this gun are not known when fitted to the M6 it did have a range of elevation from -10 to +45 when mounted normally as a field gun and the available photograph of it elevated would indicate 45 degrees was still probable. Various ammunition was available weighing between 4.5kg up to just over 8kg depending on ammunition type. Available ammunition for the 75mm gun at the time included several models of High Explosive shell, Armor Piercing (AP), Armour Piercing High Explosive, and the Effetto Pronto (EP) shaped charge round.

Conclusion

The Semovente M6 was a very good attempt by Italy pre-World War Two to field a large calibre gun onto a tracked chassis to support the infantry in the attack. It is not clear why this project was not adopted as the L6/40 was produced in large numbers, but the most likely explanations are that by this time the Carro Medio hull was already coming into production for the M11/39 and later the M13 series. This chassis was bigger, stronger and more adaptable so would be a better choice for a large-caliber Semovente than the L6. Within just a few months after the termination of this turretted M6 project, a new Semovente mounting the 47mm gun using the same L6 chassis began.

Semovente M6 specifications

Weight 7 tonnes
Propulsion likely SPA model 18 68- 70 hp petrol
Speed est. 25km/h off road / 42km/h on road
Armament 75mm L/18 and 8mm anti-aircraft machine gun
Armor est. 6 to 30mm
Production Mockup only

Sources

Curami, L., Ceva, A. (1994). La Meccanizzazione dal Regio Esercito. Arte Della Stampa
Pignato, N., Cappellano, F. (2002) Gli autoveicoli da combattimento dell’Esercito Italiano. Stato Maggiore dell’Esercito

Categories
WW2 Italian SPG Prototypes

Semovente B1 Bis

Kingdom of Italy (1941)
Assault Gun – At Least 2 Captured

The French Char B1 Bis is probably one of the most recognizable tanks ever made. An impressive union of a hull-mounted 75mm gun, thick armor, and a 47mm gun in the turret made this tank a formidable enemy in 1940. Despite its less than handsome appearance, this was a technologically advanced tank and was the product of a huge amount of time and money invested in its development. In 1940, it was the most powerful tank fielded by any army during the battle for France.
Despite its many advantages though, the Char B was unable to prevent the collapse of France. When the country was occupied, huge stocks of war material in factories plus those captured in the field, came into the hands of the Germans and her allies. While the Germans made good use of a lot of captured tanks, a large amount was also supplied or permitted to be taken by her allies and the Kingdom of Italy was no exception to this.

Colonel Keller (the Italian Inspector General of Tanks) had already reported on the advantages of the Char B (referred to as the ‘Carro B’) back in 1935. In 1940, after the fall of France, the Italians, occupying parts of the south of France, took the opportunity to seize some of these tanks when they could get their hands on them. The Italian author Nicola Pignato states that some twenty B1 Bis’, in various stages of preparation and construction, along with a single 36-tonne B1 Ter prototype were recovered from the FCM factory, of which an unknown number were to be destined for Italy. An official report, however, from 1943 related that just 2 turretless B1 tanks were taken directly from the factory along with an additional 4 which had their turrets, and the single experimental 36-ton vehicle along with a quantity of engines, parts, and armor plate.

The French author Pascal Danjou states that the Italians got hold of only 8 Char B1 Bis tanks though, six made by FCM (Compagnie des Forges et Chantiers de la Méditerranée) and two made by FAMH (Compagnie des Forges et Aciéries de la Marine et d’Homécourt). These vehicles had been rapidly pushed by the French into action in June 1940, half of which had no turrets (which would make 4 tanks although which turretless vehicles of those 8 came from which factory is not clear) and none of these vehicles were captured but were instead hidden by workers in a cave. Their hiding place was later revealed by an Italian worker to the Commission d’Armistice Italienne pour la France, the CAIF (Italian Commission for Disarmament in France), who then seized them in October 1940 for Italy. Whatever account of how these vehicles or even exactly how many came into the possession of Italians is correct, the Italians got hold of some Char B1 Bis tanks of their own.
The exact number shipped to Italy cannot be determined as not all of them received official army registration numbers, but at least two vehicles did receive registration numbers R.E. 508 and R.E. 750 on 30th April 1941.

Turretless B1 Bis with an armored plate covering turret ring undergoing trials in Italy 1941. Source: Pignato

Role

It is debatable as to what function the Italian Army wanted to use these tanks. The Italian author Nicola Pignato classifies the Italian use as one of a ‘Semovente’, literally a self-propelled gun; one used to both indirectly shell enemy forces and also provide direct fire against the enemy. Lacking a turret, this is the most likely consideration for its use, as the poor mobility and relatively low velocity of the French hull gun did not lend themselves to the role of a tank destroyer.

Evaluations

In 1940, the heaviest Italian tank in service was barely half the weight of the 32-tonne B1 Bis. Even without the turret, the Char B1 Bis weighed about 28 tonnes and was still a significantly larger vehicle than the Italians had used since the Fiat 2000. The tank was also not as easy to operate as other similar vehicles and the design called for well-trained crews proficient in the use of the machine.
The sheer size of the vehicle though was the biggest problem. The standard means of moving tanks was on the back of a truck or small trailer, neither of which would be possible for this tank meaning it could only be moved long distances by rail. Even then, it wasn’t going to be an easy task.
Two of the B1 Bis chassis were subjected to trials in November 1941 against anti-tank obstacles. The hulls, lacking turrets, had the hole in the roof of the hull covered with a rudimentary 60mm thick armor plate. Photographic evidence from France shows a captured turretless Char B1 Bis in German hands with an identical circular plate over the missing turret suggesting that this modification was done in France and not in Italy.

Captured French B1 Bis. Sent into action with the turret replaced by a circular cover as seen on the example in Italy. Source: Les chars B
Against all the obstacles tried, the only one which the tanks could not get past was an anti-tank ditch with a 45-degree escarpment. Experiments were terminated on the 24th of May 1943, a ridiculously long testing time for a production-quality vehicle simply being repurposed. The time involved though does suggest that the concept of using the vehicles in the Semovente role had long since expired and they were more suited to experimental work relating to the design of obstacles than anything else.

Illustration of the Semovente B1 Bis by David Bocquelet
Illustration of the Semovente B1 Bis by Tank Encyclopedia’s own David Bocquelet

Armament

There is no information to suggest any gun other than the French 75mm hull gun was ever considered but the Italians did have large numbers of antiquated field guns of various calibres which could have fulfilled the role if required. Even so, the French 75mm hull gun was still a potent weapon against tanks or enemy defences and in the turreted vehicle the French would carry up to 74 rounds of armor-piercing or high explosive shells. It is reasonable to assume that, without a turret, at least that amount or slightly more could be carried had this vehicle entered service with Italy.

Turretless B1 Bis undergoing trials in Italy in 1941. Source: Pignato

Conclusion

Despite some initial interest in using the B1 Bis turretless for the role of an assault gun, it was simply not adopted. Italy had already got its own Semovente program using the hull of the M series tanks to carry a short-barrelled 75mm gun for exactly the same type of fire support the B1 Bis offered. This had the same firepower but in a much smaller, lighter, simpler vehicle, one which could be built in large numbers and shared parts with their other tanks meant that the B1 Bis was not needed. With the program of trials terminated and any remaining combat value remaining in the vehicles now gone in 1943, records state that they were instead sent for testing out as ammunition carriers, as firing range targets and presumably some parts scrapped or salvaged.
The Italian author Nicola Pignato recounts that, on 4th June 1943, the situation was lamented that the 20 B1 Bis and single B1 Ter (36 tonne prototype) tanks seized by the Italian military in Marseilles in 1940 could have provided a much needed heavy armored unit for the Italian Army even if by the end of 1942 the tanks had been technically outdated. Despite the advantages their armor and firepower could have brought, the problems and presumably the poor war situation led to the project’s end. No trace of the tanks is known to remain in Italy today.

Char B1 Bis specifications

Dimensions (l-w-h) 6.37 x 2.46 x 2.79 m (20.8 x 8.07 x 9.15 ft)
Total weight, battle ready 28 tonnes (56,000 lbs)
Crew 4 (driver, main gunner, sec. gunner, commander)
Propulsion Renault 6-cyl inline, 16.5 l, 272 bhp
Speed (road/off road) 28/21 km/h (17/13 mph)
Range (road/off road)-fuel 200 km (120 mi)-400 l
Armament Unknown
Maximum armor 60 mm (2.36 in)

Links, Resources & Further Reading

Gli Autoveicoli da Combattimento Dell’Esercito Italiano, Pignato and Cappellano
La Meccanizzazione dell’Esercito Italiano, Ceva and Curami
Axis history forum
Les Chars B, Pascal Danjou