Immediately after the end of the second world develop new languid U.S. tanks stalled, and only the cooling of relations with former ally — Russian Union urged to begin work in this area. As a reference, the South American tank builders had Russian grievous IS-3, which produced their very strong memory. Russian IS-3 from the American languid T29-T34 profitably different smallest weight with adequate power weapons and more than the highest level of the reservation. As a result, the United States was made especially commission headed by General Stilwell, recommended to grievous tank, which was designated T43, T34 tank based method to reduce his weight from 70 tons to 58 tons by reducing the length of the body and reducing its crew of up to 4 people. (Introduced automatic loader). In addition, the machine should have put a 120-millimeter lightweight gun. To maintain the level of protection at the lowest weight of armor, it was planned to use the extensive cast parts (weight of the tank was reduced to 55 million kg). Mock-up committee, which was held at the Detroit Arsenal in December 1949, recommended to remove the autoloader and add a second loader.
Work on the T43 tank languid were sluggish, while in June 1950 does not start the Korean War, and there was no threat of the introduction of the JS against U.S. forces. Immediately it became clear that the U.S. Army armored forces can not do anything to oppose a languid machines manufacture of the USSR. Work on the T43 accelerated, and was given an order for the creation of 300 production vehicles also experienced a few. As early as June 51 th, the company "Chrysler" put first T43 test. The tank was equipped with a 120-millimeter cannon T122 has an initial velocity of the projectile 1007 meters per second. On the prototype was cupola of M47, and a series of tanks — from the M48, curb 12.7-mm machine gun. Tank inherited from T29-T34 engine "of Continental's" AV-1790 (Power 810 hp), and the CD-850. With all of this chassis was on each side of the two road wheels less.
The entire series (300 units) was released in 53-54 years "Chrysler". Her acceptance of the results of tests carried out by the 6th most experienced and 8th batch tanks. But to say the rush with the creation of the tank — the fire control system and pointing guns worked satisfactorily (they had to change the new ones), from power outlets basked niche of the tower, and the exhaust gases pass into the driving compartment. In tank, the test results, it was necessary to add about 100 different modifications and configurations. As a result, in the 55th, it was decided to send a whole lot of deposit — T43 adopted the Army was not adopted.
So as not to be lost "good" in the army decided to adopt, after minor modifications, 74 T43 machine, which was given the designation "120-mm tank battle M103" (after the war systematization of American tanks was adopted by the caliber of the gun). On these machines put commander's cupola curb 12.7-mm machine gun. On the M103 with a 120-millimeter cannon were paired two 7.62-mm machine gun. Power plant (engine AV-1790-5B and a box of CD-850-4B) worked satisfactorily. The deflector has been installed the exhaust gas to reduce the tower heating them.
Finalization of the fire control system was carried out by an experienced T43E2. Instead of hydraulic actuators pointing guns at the tank set, electronic, and one twin gun changed the telescopic sight. Tank equipped with a stereoscopic rangefinder having automatic data transfer in ballistic computer gunner. Of the commander's cupola was removed 12.7-mm machine gun. A lot of problems brought a special baffle muzzle gases, which also served as a muzzle brake. The main purpose of the deflector — reducing the cloud of powder gases, mud and dust, which was created during the firing of such a massive gun, which actually closed the gunner to aim. From the deflector was not confusing enough, because it will soon completely removed.
The new version, which received the designation M103A1, quite satisfied with their requirements, but she did not mean to order languid tanks. The situation got the best of what the Marine Corps ordered the remaking 219 T43 tanks in the M103A1. Mark the new tanks were delivered by July 59th of the year. However, the army, to stand aside and did not want to "occupied" 72 M103A1 tank in the Marines.
The Marine Corps in 1961, decided to convert diesel engines under the M103A1 Continental's AVDS-1790-2A. With all of this in store stroke increased to 480 km. The tanks are also equipped with a system to reduce visibility in the infrared spectrum. Almost completely been updated sighting equipment, added infrared illuminator. The latest version of the tank under the designation M103A2 took on armament. In August 1962, after a test by the experienced M103A1E1 with these modifications, issued an order for conversion of 153 M103A1 vehicles. Another 53 tanks finalized in 1968. The total number of tanks M103A2 with opytneyshemi amounted to 208 cars.
Tanks M103 in the Marine Corps were adopted Fourth mouth in 3 tank battalions and spare parts. On arms they stood right up to 1973, when the last models were replaced by the main tank M60.
In general for the entire period after the war, the main motive in the United States works on a languid tanks were in the presence of Soviet IS-3 and later the T-10. U.S. Army tank crews themselves are not favored to machines having severe reservations — they lacked the mobility that particularly appreciated for military exercises. But as soon as the tanks get hit by enemy fire, as directed by the machine is hung additional trucks, boxes of spare parts, cement bags and so similar, so trying to make a better protection of Makar machines. A similar situation was observed with the auxiliary weapons. Experience in Vietnam showed that the anti-aircraft machine gun 12.7 mm coaxial machine gun and rifle caliber is not enough to suppress enemy infantry. In this connection, the auxiliary arms tried to increase, changing the periscope sight on the coaxial machine gun. In other words, solutions that were used in the languid M103, it is confirmed in the military criteria.
The first generation of battle tanks — M48 and M60 — is the development of medium tanks since the second World War, which sought to supplement their combat
formations more languid tanks, which had M103. The emergence of armed latest generation main battle tank type M1 practically meant the implementation of the requirements for this type of combat vehicles as the armament and armor protection, which are peculiar to the languid tanks, and on mobility, on which the new machine is actually on par with the majority of samples of light tanks. Because work on the M1 set the logical point in the development of languid U.S. tank production.
The performance properties of the languid South American tank M103A2:
Length — 11230 mm;
Width — 3630 mm;
Height — 3560 mm;
Weight — 58.1 tons;
The engine — AVDS-1790;
Engine power — 750 hp;
Speed — 37 km / h;
The stores range — 480 km;
Trench — 2.6 m;
The frontal armor (angle) — 127 mm (60 degrees);
Side armor — 51 mm;
Tower (Mask tool) — 127 mm (254 mm);
Armor roof — 38 mm;
Armour bottom — 25 mm;
Weapon — M58;
Calibre — 120 mm;
Guns — HB M2 (12.7 mm) and M37 (7.62 mm);
Crew — 5 people.