Is-2 is perhaps the most famous heavy tank of the great Patriotic war. They won the battlefields in the last year and a half of the war and have become a well-recognized symbol of anti-blitzkrieg. On a formidable reputation with is-2 can compete, perhaps, only his chief competitor-German " Tiger-I." Meanwhile, the path of Isov to victory was not strewn with roses…The birth of a heroThe creation of a new heavy tank began to think back in the spring of 1942. It was then that the battle for the first time went modernized German tanks Pz-4 and self-propelled guns StuG-III with reinforced armor and advanced tools. In addition, the Germans began to use heat shells, which produced real havoc in the ranks of Soviet tanks.The project of creating a new tank was supervised by Joseph Kotin. It was one of the most experienced designers of the USSR, received a huge experience of designing heavy tanks, in particular, he was the father of the family KV. "Klim Voroshilov" was not without flaws, ranging from low reliability to very heavy working conditions of the crew. The direct designer of the tank was Nikolai Shashmurin, whom Kotin knew perfectly well from work in the 30s at the Kirov plant in Leningrad.Originally it was about the car weighing 30 tons and a gun caliber of 85 mm. tank builders tried to create a universal machine that combines good mobility with survivability. The first sample received the designation KV-13. Testing the new machine failed completely: suspension proved to be unreliable. Completion of the KV-13 led to the emergence of prototypes with different weapons systems. On one of versions of teetered 76-mm gun, substitute for the, that was used on serial KV. However for heavy the tank the second than half war needed something more a powerful.In the autumn of 1942 in the hands of the designers got lined "tiger". And almost in working condition, even with technical documentation. No less important event was the meeting of the red army with the novelties of the German field fortification. These included, for example, mass-produced armored machine-gun nest type "Crab". The armored covers entirely of armored steel was utaplivaja in a specially dug pit, and then the outside had to hang around only loophole and roof.In short, it became clear that the troops needed a machine armed with a gun capable of hitting even a very well-protected target. The attacks captured "tigers" has led to the unequivocal conclusion: you need to increase the caliber. However, more powerful weapons inevitably led to an increase in size: the car was heard in breadth, the mass grew. The idea to create the perfect tank with high speed, armor protection and firepower was thrown and the victim fell mobility.Initially thought to be limited to the gun caliber of 85 mm. For a medium tank this gun was a good fit, but Kotin insisted on installing even more powerful weapons: at a typical distance of a tank battle average armor of the enemy 85-mm gun could be beat, but heavy anymore. As a result, Kotin and his team decided to experiment with a 122-mm gun.As a basic model, the 122-mm a-19 body gun was chosen. It was a powerful artillery system, and Permian plant number 172 has mastered them a long time and quite intensively produced. Autumn 1943 year was ready draft project, which impressed people's Commissar tank industry Vyacheslav Malyshev, and then and Stalin. Even more furor new model produced at the site, where he was shot trophy "Panther". With a one-mile distance of the projectile literally tore up the cat tower, breaking through it. However, the muzzle brake on the gun exploded. Fortunately, no one was killed, and the design of the brake had to be completely redesigned.The disadvantages of the new tank was. First, it is bad for the tank gun rate of fire (only 1.5–3 shots per minute) did not allow to throw the enemy projectiles at a high pace. Another serious problem of is-2 was small ammunition. Tankers often tried to put into the car shells over staff.However, much better than any medium tank survivability and, most importantly, a powerful weapon was enough. Is-2 went in a series of.