Monday, 11 September 2023

Italian Cruiser Tank

Italian tank building developed along a fairly usual trajectory. Once a direction was identified, the Italian military tried to stay on course. Under their close guidance, Ansaldo developed a series of combat vehicles: first a tankette, then a light tank, a medium one, and a breakthrough tank. In almost all cases, success was based on a foreign idea, primarily the British one. At first the Italians further developed the idea of the Carden-Loyd Mk.VI tankette and then the Vickers Mk.E support tank. 

Captured Cruiser Tank Mk.IVA at trials in Nettuno. This tank was the inspiration for a "colonial" tank.

Combat in North Africa revealed a series of deficiencies, including insufficient characteristics of Italian medium tanks. One of the biggest issues was their low mobility. The increase in engine power was not an accident. British vehicles were studied in parallel. A Cruiser Tank Mk.IVA was among those examined. This was not the most successful tank, but it was fast. A captured tank was tested at Nettuno in May of 1941. The idea of creating an Italian cruiser tank came about around the same tank. This tank was later called Carro M Celere Sahariano.

Model of a turret platform and turret of the Carro Medio Coloniale, June 1941.

Judging by correspondence, Italian commanders began to think about a high speed medium tank in December of 1940. They admired the mobility of the Cruiser Tank Mk.IV. Of course, the tank was not very successful in terms of protection and reliability, but it still caught the attention of the enemy. This was the tank chosen for imitation, and not the Matilda. The British were also far from giving up on the Cruiser concept, as the Crusader, the successor to the Cruiser Tank Mk.VI, saw battle by the end of 1941. However, it's also hard to call the Crusader a success since it was overloaded and not any more reliable.

The initial look of the Carro Medio Celere 1942. This blueprint gave rise to the myth that the final design used a Christie spring suspension.

The Italians weren't about to copy the Cruiser Tank Mk.IV. They were more interested in the overall concept and individual components. The new tank was first called Carro Medio Coloniale, which hinted at its intended use. The first requirements for the tank were formed on May 24th, 1941. Its mass was estimated at 18 tons. It would be powered by a new hungrier and more powerful gasoline engine. The new tank would have a lower silhouette than the Carro Armato M 13-40. The chassis of the latter was used to carry a full sized model of the new tank. This model demonstrated the layout of the fighting compartment as well as the new 47 mm L/40 gun.

Soon after, the tank gained a torsion bar suspension.

In August of 1941 the tank was renamed Ansaldo-Fossati Carro Medio Celere 1942. A 1:10 scale model was also built. This model and preliminary drafts created confusion about the final product. At this point, the tank weighed 13,100 tons and had a 250 hp engine that gave it a speed of up to 55 kph. The crew consisted of 4 men, 2 of which sat in the turret. This project remained on paper and further iterations of the design used it as a foundation.

The first and only prototype of the Carro M Celere Sahariano built in March of 1942.

This project had little to do with the Carro M Celere Sahariano that appeared later. The Italians quickly turned on the Christie suspension. It was too complex and took up too much room. And why would they need it, as they already had torsion bars? The first prototypes of Italian armoured vehicles with a torsion bar suspension appeared in the second half of the 1930s. The Italian torsion bar suspension was paired with two road wheels per bogey, with the torsion bar acting like a big volute spring. This was an unintuitive but compact and functional design.

The tank had a very low silhouette.

This suspension was used instead of Christie springs on the Carro M Celere Sahariano. The mass of the tank also grew. It reached 15 tons by the end of 1941 and kept growing. Little was left of the original tank aside from the overall concept: a fast and low fighting vehicle that could fight in the conditions of North Africa. Italian engineers considered speed as their primary objective, which is why the tank turned out even faster than originally required.

The tank's tracks were based on the tracks of the T-34 tank.

There were high hopes for the Carro M Celere Sahariano, so high that the development of the Carro Armato M 15-42 was stopped. It wasn't as fast, but could be put into production much faster. The M 15-42 had the same new L/40 gun, thicker armour, and a more powerful gasoline engine. The "colonial" tank was still more interesting, which is why it retained a higher priority. This turned out to be a mistake. The first experimental Carro M Celere Sahariano was finished in March of 1942, whereas the Carro Armato M 15-42 prototype was delivered back in 1941. The Italian military lost precious time.

The tank had a progressive design, but it was about a year too late.

It's hard to call the Carro M Celere Sahariano a bad tank. The 16-ton vehicle accelerated to 60 kph (some sources say 71 kph) and was very low (2 meters to the turret roof). In addition to the progressive suspension, it was also partially assembled with welding (for instance the sides of the turret platform were welded) and had sloped armour. The problem was that this sloped armour was only 30 mm thick. The 47 mm gun was too weak, even at 40 calibers. By the summer of 1942 it was clear that it was too late to put the tank into production.

Work on the Carro M Celere Sahariano was stopped in the summer of 1942.

The Italians decided not to continue working on the Carro M Celere Sahariano in July of 1942. The Carro Armato M 15-42 was hurriedly put into production instead. It was also outdated, but fine until the Carro Armato P 40 was being worked on.

The prototype of the "colonial tank" survived until 1944, at which point its trail ends. According to existing information, the design was later used as a reference during heavy tank development. In conclusion, let us say that as an independent design the Carro M Celere Sahariano was a success for Italian tank building. The problem was that it should have been built a year sooner. By the spring of 1942, it had nearly no chances to see production.

1 comment:

  1. The springs used in the L3/38 and Sahariano are "torsion springs," not "torsion 'bar' springs." Although these two springs are sometimes not clearly distinguished, they actually have completely different shapes. This suspension is basically the same as a clothespin.
    On the one hand, Sahariano's choice is certainly interesting, since they already had a true torsion bar on their L6 light tank. Apparently they wanted something that wasn't a torsion bar or a Christie.