The M18 "Hellcat" self-propelled tank destroyer represented the most advanced development of the American technology in this specific branch of armored vehicles during the Second World War. It was born from the further development of an idea which had already led to the construction of the preceding M10, whose formula had demonstrated to be valid enough. In practice it was a model created from scratch with an especially conceived hull, initially armed with the same 76.2-millimeter cannon of the M10, and later with more powerful pieces, such as the 90-millimeter cannon and the 105-millimeter/22 howitzer. But these last models remained in the stage of prototype, whereas the M18 not only had a great success but was acquired after the war by numerous armies which used it for many years. In the early 1970s some M18 still operated within the armored forces of the Yugoslavian Army. But let us return to the beginning of the operational life of this tank destroyer. Above all it should be mentioned that the M18 was the fastest armored vehicle deployed during the Second World War. Its radial engine, a Continental of nine cylinders and 400 horsepower, enabled it for reaching the surprising speed of 72 kilometers/hour on road. Naturally, for obtaining this amazing result the entire constructional concept had to be radically changed. Just to make a comparison, it would not be like that of a heavy battleship, which is well protected but limited by the weight of its thick steel plates. It was rather like a cruiser, which is lightly armored but fast and very maneuverable, and above all is fitted with weapons which, used in conjunction with its outstanding mobility, could put in trouble any German armored element which was in use in that time. The hull of the tank destroyer, which was formed by plates welded to each other, in such a way that they formed multiple sloped surfaces which diverted the projectiles, had a maximum thickness of only 13 millimeters. In contrast, the 76-millimeter cannon installed in the rotary turret was capable of perforating an armor plate of 175 millimeters in thickness from a distance of little less than one kilometer. When the services which this vehicle could offer in the battlefield became evident (already in the beginning of 1944), it was decided to force its production for having the chance of experimenting with the weapon "in live". In this way, after only nine months the American war industry managed to build some more than 2500 of these tank destroyers, namely about 277 per month, all of which were used by the United States Army. From the operational standpoint, the "Hellcat" matched the expectations which had been put on them, managing to destroy a moderate number of German tanks while suffering a relatively low number of losses. It should be noted as well that while vehicles are easily "rolled" more time is required for training the personnel, and that the American tankers, unlike their German adversaries, were not used to fighting a fast-paced ambush warfare with armored vehicles.