Fiat M11 / 39 The Fiat - Ansaldo M11 / 39 was an Italian medium tank used from 1939 through the early period of World War II . Although designated a medium tank by the Italian Army , in weight and firepower it was closer to contemporary light tank s . The official Italian designation was Carro Armato ( " armored tank " ) M 11 / 39 . The designation M11 / 39 is understood as follows : " M " for " Medio " ( Italian : " medium " ) , followed by the weight in tons ( 11 ) and the year of adoption ( 1939 ) . Development . The M11 / 39 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 armour . The M11 / 39 ' s career was cut short due to several weaknesses of its design . The most important was the placement of the main 37 mm armament in the hull . The 37 mm gun was in a fixed position with traverse restricted to 15° to port or starboard . The only other armament was the dual 8 mm machine guns in a rotating turret . While the machine guns were served by only one man , the turret was cramped and manually operated . The concept was to use the main gun against heavy targets and defend the tank against all - round threats with the turret armament . The layout was similar to the American Grant / Lee tanks , still to come in 1939 . The original intent was to place the 37 / 40 mm armament in the turret , but there was insufficient space . A redesign of the M11 / 39 , in order to mount the main gun in the turret , was commenced , finally resulting in the development of the M13 / 40 . In the meantime an order for 100 M11s was placed . In addition to the poor gun positioning , the M11 / 39 had other shortcomings : its endurance and performance were both poor , it was relatively slow , its mechanical reliability was very poor , and its 30 mm maximum riveted steel armour , 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 . All M11 / 39s were designed to carry a radio , but none of the production vehicles were so fitted . The M11 / 39 hull design , with modifications , was used in the development of the more successful Fiat M13 / 40 . Combat . The majority ( about 72 of the 100 total ) of the M11 / 39s were used in combat in the North African Campaign , but a number were also sent to Italian East Africa . Compared to the L3 / 33 and L3 / 35 tankettes otherwise available to the Italian forces , the M11s were a vast improvement . The M11 / 39 proved somewhat successful in early encounters with British light tanks like the Mk VI . The 37 mm gun of the M11 acted as a deterrent against attacks by these relatively fast but thin - skinned vehicles armed only with machine - guns . However , the M11 / 39 was outclassed by heavier British cruiser and infantry tanks such as the A9 , A10 , A13 , and Matilda . North Africa . In September 1940 , M11s participated in the Italian invasion of Egypt . In December 1940 , M11s also operated defensively in the opening stages of the British counter - offensive , Operation Compass . When Operation Compass was launched , many of the M11 / 39s were damaged , broken , or immobilized inside some of the static Italian positions . The British used Matilda tanks to over - run many of the Italian positions and the M11s could do little against the heavy armour of the Matildas . From 10 April 1941 , during the siege of Tobruk , a few captured M11s were employed by the 6th Australian Division Cavalry Regiment over some months . They painted large white kangaroo symbols on the tanks to clearly identify them . The Australians used the captured M11s , together with several M13s , until they ran out of diesel fuel . The tanks were then destroyed to prevent re - use by advancing Axis forces in the spring of 1941 . East Africa . In June 1940 , about twenty - four M11 / 39s were rushed to Italian East Africa . They were used in the East African Campaign . In East Africa , the M11s fought as the only medium tank available to the Italians . In August 1940 , many of the M11s participated in the successful Italian invasion of British Somaliland . By January 1941 , M11s were used on the defensive in Eritrea when the British launched their counter - offensive there . Unfortunately for the Italians , the British had a small number of Matilda tanks available to them during the Battle of Keren and this negated any value that the M11s may have added . By the end of May 1941 , the Italian forces were defeated on the East African fronts where M11s were deployed . By November , organized Italian resistance in East Africa was over . There is no indication that captured M11s were re - used by the captors in East Africa .