P26/40 tank

The development work began in 1940, on Benito Mussolini's specific orders. Initial requirements were for a 20 tonne (the maximum load allowed by pontoon bridges) tank with a 47 mm gun, three machine-guns and a crew of five, but this was quickly superseded by another 25 tonne design, to be named P26. The development work proceeded quickly except for the engine; the Italian military staff, the Stato Maggiore, wanted a diesel power-plant, while the builders favoured a petrol engine. However, in Italy at the time there were no engines (diesel or petrol) available capable of developing the required, and the Italian tank industry (i.e. the duopoly Fiat-Ansaldo) did not turn to easily available aircraft engines for its tanks as contemporary US and British tank manufacturers had done. The design and development of a new engine was very slow; a petrol engine (Fiat 262) was eventually tested as an interim solution, even though it was not adopted. The gun designation "75/34" referred to a 75 mm bore diameter gun with a length equal to 34 calibres. However, the weight increase (which was now 26 tonnes) and the difficulties in finding a suitable engine further hampered the start of mass production; in the end, it was decided that the prototype and the early production samples were to be equipped with a 330 HP SPA 8V diesel engine, later to be replaced by a 420 HP petrol engine. A few were used in combat, under the German designation of Panzerkampfwagen P40 737(i), for example at Anzio; some, without engines, were used as static strongpoints. == Combat history ==

Only 21 P40s were finished by September 1943 and during the armistice it served in the defence of Rome. The Germans ordered production to continue after the armistice and appropriated completed tanks to the Southern Tank Training Battalion, 10th and 15th Police Panzer Companies, and the 24th Waffen Mountain Division of the SS Karstjäger. == Design ==

The turret was operated by two crew members and this was a significant drawback as it put excessive workload on the tank's commander. At that time, most new tanks were designed with three-man turrets. It also lacked a commander's cupola. For secondary armament, the P40 had a co-axial machine-gun and another which could be used in the anti-aircraft role, eschewing the traditional dual mount in the hull; the standard ammunition load was also lower, only around 600 rounds, compared to 3,000 of the "M" series. The mechanical systems were a development of the "M" series, in particular the leaf spring suspension which was reliable, but in rough terrain would not allow speeds similar to the more modern Christie suspension or torsion bar suspension. Nevertheless, the power-to-weight ratio represented a significant improvement in mobility over its predecessors. The armour, quite resistant by Italian standards, was sloped and 60 mm thick at the turret front and mantlet (by comparison the M13/40 had 42 mm), but it was still riveted at a time when most tanks were constructed by welding. in support of the widely used medium ("M") tanks on the battlefields. In weight, armour and armament it was similar to the medium tanks of the Wehrmacht or other contemporary armies, its armament and protection being roughly the same as the early production American M4 Sherman tank. It was the final evolution of Italian tank designs, that began with the Vickers-based tankettes (such as the CV29 and L3/35) and developed into models such as the M11/39 medium tank, a much heavier construction whose internal design shared many characteristics of the earlier tankettes. ==Production==

Some 1,200 tanks were ordered (but the total was later reduced to 500 when development work on the heavier P 43 began), but the start of production was 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 and twenty 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. 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 Germany and sent it to the Aberdeen Proving Ground for testing. ==Surviving vehicles==

Two P26/40s still exist, one preserved at the Museo della Motorizzazione in Rome and another is currently on display near the army barracks near Lecce. ==See also==