The Semovente da 75/18 (75/18 Self-Propelled [Gun]) was an Italian-built SPG used during the Second World War. It was one of the best tank destroyers employed by the Regio Esercito (Italian Royal Army), being one of the few able to destroy American-built M3 Lee/Grant and M4 Sherman medium tanks.
At the beginning of the Second World War, the high command of the Italian Royal Army (Regio Esercito) realized that their armored vehicles were inadequate against those of the other nations. Observing the successful German Sturmgeschütz III, it was decided to develop a similar vehicle.
Its development started in 1940 and the first prototype came to life in February 1941. The first vehicles operated in North Africa in January 1942. Based initially on the hull of the M13/40 tank, further improvements led to the adoption of the hulls of the medium tanks M14/41 and M15/42.
It was essentially a tank with the turret replaced by a casemate, housing a 75/18 Mod. 1934/1935 howitzer (a caliber of 75 mm – 2.92" – and a length of 18 calibers, that is 1350 mm – 53.15") on a half-ball mounting that allowed a large traverse of the gun. This weapon could fire High Explosive, Armor Piercing and hollow-charge High Explosive Anti-Tank (called in Italian Effetto Pronto, EP, that is "Quick Effect") shells. With the latters, it could pierce the front armor of enemy M3 and M4 medium tanks. The secondary armament was a Breda Mod. 30 6.5 mm (0.255 in.) machine gun, mounted on the casemate roof.
The armor was made of bolted steel plates, with a thickness varying from 15 mm (0.59") to 30 mm (1.18"). It had a diesel engine, for the M40-based version, with a maximum power output of 125 hp; the maximum speed was 32 km/h (20 mph) with an autonomy of 200 km (120 miles). Its mass was 13 t. The crew consisted in three members (driver, loader and commander, who acted also as gunner and radio operator).
It was overall a good vehicle: it had efficient mechanics and good driving performances, effective armament and a low silhouette that made it difficult to be spotted; the crew protection was nonetheless inadequate.
The Semovente was initially conceived as support artillery for the infantry, and only secondarily in anti-tank role. Its effectiveness against enemy vehicles led the Italian command to use them to support, with increasingly greater numbers, the tank companies.
It saw service with the Regio Esercito in North Africa, Sicily and Southern Italy from 1942 to 1943, fighting from El Alamein to the defence of Rome against the Germans on 9th September 1943. Afterwards the Wehrmacht used it in all Italian fronts from 1943 to 1945. After the war, it saw service in the Italian Army until the 1950s.