M103 Heavy Tank

Osprey has released a book on the subject of M103 Heavy Tank. The tank is equipped with 120mm gun and primarily served with the US Marine Corps. The design of the tank is based on the T43 design.


The T43 design represented the pinnacle of U.S. Army tank engineering of the late 1940s. The heavy tank proved fairly popular with its crews, who above all respected the powerful armament it carried. The outbreak of war in Korea brought a rush order in December 1950 which led to a complete production run of 300 vehicles. After 1951, the Marine Corps alone retained confidence in the heavy tank program, investing its scarce funds in the improvements necessary to bring about its fielding after a hurried production run in midst of the ‘tank crisis’ of the year 1950-51. The eventual retirement of the M103 in 1972, over 20 years after manufacture and after 14 years of operational service, demonstrated the soundness of its engineering. It may have been the unwanted ‘ugly duckling’ of the Army, which refrained from naming the M103 alone of all its postwar tanks. For the Marine Corps, it served the purpose defined for it in 1949 until the automotive and weapons technology of the United States could produce viable alternatives.

Source: Osprey Publishing

The chassis and design of the M103 tank is also used by subsequent tank family, in the M48 and M60 tanks.

The successive versions of the M103 shared many components with the M47 and M48 Patton tanks and the M60, which, with the exception of the M60 (a main battle tank) were all considered 90 mm gun (medium) tanks. Tracks, rollers and suspension elements were the same, with some modification to take into account the greater weight. The engine and transmission were never modified enough to give the extra power needed for the greater weight of the M103, and as a result, the tank was relatively underpowered and the drive systems were fragile. 

Source: Wikipedia

The M103 heavy tank, like other heavy tank, such as the Soviet built JS tank family and Germany Tiger II are underpowered. There was simply no engine capable of powering the heavy tanks of the era.

Designed for direct assault and support for medium tanks against Soviet armor. Had deficiencies in gun control.  Hugesize , weight, short range and poor reliability were problems. Phased out of service in the 1960s. Large turret has room for  4 men. Derived from T43. Entered service with U.S. Army. Never saw combat. Only 200 built. Underpowered.  M103A1 was used by the USMC. 

Source: Battle Tanks

While the choice of subject is uncommon. It does provide interesting insight into the evolution of tanks from World War 2 to the current Main Battle Tank.