This machine remained in service with the Soviet Army until the beginning of the 60-s. The EC-3, which was planned to replace it, had significant design flaws that hampered the operation of the tank in the army. The heavy tank EC-4 also proved to be difficult to operate and maintain. At the same time, the EC-2 completely suited the army as a technically reliable and simple combat vehicle. Therefore, in 1954, a major modernization of the EC-2 tank was carried out in order to prolong its service life.
The aft turret machine gun was seized, the gun ammunition was increased to 35 shots, a gun hoisting mechanism with a delivery link was introduced. The glass block (triplex) of the driver was replaced by a prism periscope, and in addition, a TVN-2 or BVN night vision device was installed. The В-2-10 engine was replaced with В-54К-ИС with the oil pumping system, the NYKS-1 nozzle heater and the VTI-2 air cleaner with a dust suction from the hopper. A gearbox with an oil pump and an oil cooling system was installed, and its rigid attachment to the rear support was introduced. Reinforced bearing units support rollers and guide wheels, changed the packing seals. The number of batteries increased from two to four. Installed radio station P-113 and tank intercom P-120 post-war design. The tanks upgraded in this way were designated the EC-2M. They were in service with heavy tank-self-propelled regiments and were finally replaced in the army with T-10 tanks.
In addition to the Red Army, the EC-2 tanks were in service with the Polish Army. The 71 combat vehicle was handed over to form the 4 and 5 regiments of heavy tanks. During the fighting in Pomerania, the 4 regiment of heavy tanks destroyed the enemy’s 31 tank, losing its own 14. Both regiments took part in the battle for Berlin. It was planned to form two more such regiments - 6 and 7, but did not have time to do this - the war ended. By the end of the hostilities in the Polish Army, 26 EC-2 remained (21 had the machine returned to the Red Army, and the rest were lost in the battles). After the war, the remaining tanks were incorporated into the Polish 7 heavy tank regiment.
In the postwar period, the EC-2 entered service and the Czechoslovak army. At the start of the 1950, a small number of EC-2 was transferred to China. In Korea, Chinese volunteers used them against the Americans. According to US intelligence, Chinese troops in Korea had four separate tank regiments, each of which consisted of four T-34-85 companies and one EC-2 company (5 tanks each).
During the Indochina war, French troops clashed with the EC-2, which China handed over to Vietnam. One tank "Panther", owned by the French, was delivered to Vietnam to conduct experiments to counter the EC-2 tank. Cuba received two IC-2M regiments in the early 1960-s. After 30 years at least 15 "Ises" were used there as coastal defenses as firing points.
Around the same time, the EC-2 received and the DPRK. On the basis of the tank EC-2 were created heavy self-propelled artillery installations (ACS) MIS-152 and MIS-122. Prior to the cessation of mass production in the third quarter of 1945, 4635 self-propelled guns of both types were manufactured. Thus, the total production of heavy artillery ships exceeded the number of manufactured heavy tanks EC-2. The ISU-152 and ISU-122 self-propelled artillery mounts were in service with the Soviet Army until the end of the 60s. At the same time, ISU-152 was upgraded twice.
The first upgrade was made in 1956 year. Then, on the roof of the cabin, a commander's tower was installed with a TPKU device and seven inspection units of the TNP. The ammunition of the ML-20 howitzer cannon increased to 30 shots, which required a change in the location of the internal equipment of the fighting compartment and additional ammunition packs. Instead of the sight CT-10 installed an improved telescopic sight PS-10. All machines mounted anti-aircraft machine gun DShKM with 300 ammunition ammunition. At the ACS, a B-54K engine was installed with an ejection cooling system with an 520 horsepower. The capacity of the fuel tanks increased to 1280 l. The lubrication system was improved, the design of radiators was changed. In connection with the ejection cooling system of the engine changed the mount of the external fuel tanks. Installed radio stations 10-РТ and ТПУ-47.
The mass of self-propelled guns increased to 47,2 t, but the dynamic characteristics remained the same. Power reserve increased to 360 km. Modernized thus ACS received the designation ISU-152K.
The second version of the modernization had the designation ISU-152M. Installed on the machine units of the tank EC-2M, anti-aircraft gun DShKM with 250 ammunition ammunition and night vision devices.
During the overhaul, some ISU-122 Self-propelled guns underwent some changes. For example, since 1958, full-time radio stations and TPU have been replaced by Granat radio stations and P-120 TPU.
In addition to the Soviet Army, the ISU-152 and the ISU-122 were in service with the Polish Army. As part of the 13 and 25 regiments of self-propelled artillery, they took part in the final battles of 1945. In the post-war years, the Czechoslovak People's Army also received the ISU-152.
At the start of the 60, one regiment armed with ISU-152 was part of the Egyptian army. 7 November 1957 for the first time on the Red Square in Moscow for the first time passed self-propelled rocket complexes. Among them were launchers of the first versions of tactical unguided missiles (according to the then classification - missiles - NURS) of the “Filin” type, created on the basis of the heavy tank EC-2. However, they did not last long in service, as a light tank was a more suitable base for a relatively lightweight missile.
The 8-218 self-propelled starter unit (803 object) for the 8K11 operational-tactical missile system (according to NATO classification - SS-1b Scud A) based on EC-2 was created in 1956-m. A year later, it began mass production, just released 56 starters. Each crew consisted of 5 people. A machine weighing 40 t developed the speed of 41 km / h. Power reserve was 300 km. At the end of the 50s, the 8K14 (SS-1c Scud B) complex with a heavier missile was adopted. The 2P19 machine was also used as the starting unit on the basis of the EC-2 tank, very similar to the previous one. The new complex began to arrive in the army in 1961 year. From 1965, the launch unit 9P117 of the 8K14 complex is based on the Uragan four-axle vehicle MAZ-543. At the beginning of the 60s, the 8K14 rocket complexes with launchers based on the EC-2 tank entered the armament of the armies of Poland, Czechoslovakia, the GDR, Romania, Hungary and Bulgaria as part of the modernization program of the armed forces of the Warsaw Pact member countries.
The large mass of IS heavy tanks and ISU self-propelled guns aroused the need for an appropriate evacuation tractor. In this case, they acted the same way as with a KB tank — linear tanks with towers removed were used as towers. A number of these machines have been used already in the 1945 year. With a weight of 35, the tractor had a pulling force on the hook of the 28 vehicle, but did not have a traction winch. At the beginning of the 50-ies the car was modernized - the opening under the tower in the roof of the hull was closed with a lid on which the commander's turret from the EC-2 was installed. In the 60-ies, after the decommissioning of the EC-2M, some more machines were thus altered.
Another type of repair-evacuation tractor was created on the basis of MIS-122, after MIS-50 was adopted as a standard ACS at the end of 152. The ISU-T tractor was a conventional self-propelled gun with a dismantled gun and brewed embrasure. At the beginning of the 60-s, two more tractor units arrived at the same base - BTT-1 and BTT-1T. The body of the machine BTT-1 has undergone changes, mainly in the frontal part. Two box-shaped dampers for pushing tanks with a log were welded to the lower front plate. The roof of the cabin was also modified, to which a beam with struts was welded to increase rigidity. In the engine room, located in the middle of the hull, placed a winch (traction force 25 ts, working cable length 200 m) with a power take-off mechanism from the engine. The winch was controlled by a driver from the engine room, in which for this purpose there was a second seat and two control levers. At the stern of the machine, there was a coulter for laying into the ground. On the tractor mounted collapsible boom crane 3 t with a manual drive. On the roof of the power compartment there was a cargo platform, designed to carry up to 3 tons of cargo. The towing device of the tractor was equipped with suspension with two-sided shock absorption and a rigid coupling. A B-54-EAST engine was installed on the machine, its feature was a crankshaft, borrowed from the B-12-5 engine. For driving at night, the driver had a BVN night device. The weight of the tractor was 46 tons. The crew consisted of two people. On the BTT-1T tractor, instead of the traction winch, a service or upgraded set of rigging equipment, designed for 15 tf traction force, was laid.
In addition to the Soviet Army, BTT-1 tractors were in service and abroad, particularly in Egypt. Several such machines were captured by Israel in the 1967 and 1973 years.