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).
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.
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.
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.
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.
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.
An Autocannone da 90/53 su Autocarro Semicingolato Breda da 8t started by Breda in August 1942.
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.
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.
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).
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.
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 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.
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.
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.
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 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.
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 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.
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 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|
|Maximum speed||~40 km/h|
|Main Armament||Cannone da 90/53 Mod. 1939 and a Breda Mod. 38 machine gun|
|Total production||Only paper project|
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