For the first time, this was a three-man crew design. The armour was 30mm thick, and the engine was a 105 bhp V6 diesel, sufficient to a 32 km/h max speed and 200 km range. It was an 11-ton model, hence its denomination. The M11/39, which saw service in Africa and Italy (1939-1944), was developed as a "breakthrough tank" ("Carro di Rottura"). The design of the M11/39 was influenced by the British Vickers 6-Ton. This influence is reflected particularly in the track and suspension design. One innovative aspect of the design was the placement of the final reduction gears inside the front-mounted drive sprockets, eliminating the need for enlarged final drive housings in the bow armor. However, it was relatively slow, its mechanical reliability was very poor, and its 30 mm maximum riveted steel armor, designed to withstand only 20 mm fire, was vulnerable to British 2-pounder guns at any range at which the M11/39s main gun was useful. The Carro Armato M13/40 was the Italian tank designed to replace the Fiat L3, the Fiat L6/40 and the Fiat M11/39 in the Italian Army at the start of World War II. The M13/40, weighing 13-14 tons, was fitted with a 47 mm gun, having armor-piercing capabilities, in the turret and a four-men crew. After a single prototype, series production began in late 1940. The late production (by 1941) had a 42 mm armour, similar to the next model, the almost identical M14/41. It was the main tank the Italians used throughout the war. The design was influenced by the British Vickers 6-Ton and was based on the modified chassis of the earlier M11/39, whose production was cut short in order to get the M13/40 into production. The M14/41 was a four-person medium tank that served from 1941 and was first employed in the North African Campaign. The M14/41 was a slightly improved version of the M13/40 with a more powerful diesel engine. It was produced in limited numbers as it was considered already obsolete by the time of its introduction. The M14/41 used the same chassis as the M13/40 but with a redesigned hull with better armor, and was manufactured in 1941 and 1942. Nearly 800 were produced by the time production ended.