delayed by the engine problems and by other factors, such as the bombing of the SPA factory in Turin in September 1942; in the end, production began only in summer 1943. About a hundred P 40s were built by Ansaldo from then until the end of the war, although most were not entirely completed because of a lack of engines. Variants There were at least two planned variants of the P 40, developed from early 1943 when the Italian Army realized that the tank was inferior to other designs such as the German Panther. The first one was named P 43, a tank with a weight of some 30 tonnes, with armour plates some 50–80 mm thick and a main armament of either the 75/34 gun or a 105/23 gun. In September 1943 Fiat and Ansaldo began development of a new design which could be comparable to the Panther, and the result was the P 43 bis, with heavily sloped armour, a 450 HP engine and a 90/42 gun. These designs never passed the wooden mock-up stage. The other project was the Semovente 149/40, based on the P 40 hull. Only one of these vehicles was ever built. It was intended to be a highly mobile self-propelled gun, and its armament was the most powerful gun of the Royal Italian Army: a 149 mm / 40 calibre artillery piece with a range of over (slightly more than that of the US 155 mm M1 Long Tom). This gun was produced in very few numbers, and the Italian artillery remained equipped mainly with obsolete weapons for the duration of the war. Due to its mass, it was quite bulky to move, and so it was decided to build a self-propelled version, utilizing the most powerful of all Italian military vehicles. All space of the P 40 hull was dedicated to supporting the gun, so the ammunition and crew would have required additional vehicles to be moved. The gun would have been ready to fire in three minutes from coming to a stop, compared to the 17 minutes required by towed artillery. Work on the Semovente 149/40 started in 1942 and the prototype was tested in 1943, but the Italian Army was not very impressed. After the Armistice the vehicle was acquired by the Germans, and they were not impressed by it either. Finally American forces captured it during the invasion of