Type Heavy tank
In service 1957 - 1974
Number built 400
Variants M103A1, M103A2
Weight 58 tonnes (65 tons)
Length 6.99 m (22.7')
Width 3.76 m (12.22')
Height 3.23 m (10.49')
Crew 5 (commander, gunner, driver, 2 loaders)
Armor 180 mm (7.34")
Primary armament 120 mm gun M58, 34 rounds
Secondary armament 2×.30-cal (7.62 mm) M1919A4E1 (co-axial), 1×.50-cal (12.7 mm) M2 AA machine gun
12-cyl. air-cooled gasoline, Continental AV1790, 810 hp (604 kW)
Continental AVDS-1790-2; V12 cylinder, air cooled, twin turbocharged diesel, 750 hp (560 kW) M103A2
Power/weight M103: 12.4 hp/ton, M103A2: 11.5 hp/ton
Transmission General Motors CD-850-4A or -4B, 2 ranges forward, 1 reverse
Suspension torsion bar
Fuel capacity 710 litres (280 gallons)
Operational range M103: 130 km (80 mi), M103A2: 480km (295 mi)
Speed M103: 40 km/h (25 mph) , M103A2: 37 km/h (23 mph)
The M103 was the late offspring of the US heavy tank projects T30 and finally the T43 which led to the M46 and M47 tanks. It was designed to counter the soviet heavy tanks JSIII.
The inital T43 were of such poor performance that they were never declared ready for active service. The following T43E1 project finally entered service as the M103 heavy tank.
The M103 as it finally appeared bears a strong family resamblance to the M47/ M48 Patton tanks.
The basic hull layout with its boatshape and suspension layout is similar to the M48 hull, however it is wider and longer with thicker armour and an additional roadwheel and six return rollers on each side.
The original M103 powerplant was the same as that of the M47 and early M48 resulting in the 65to tank being heavyly underpowered and mechanically unreliable. The main weapon was the 120mm T123 gun located in the huge turret designed to cope with the massive recoil of the gun. The commander and gunner were both located in the bustle of the turret. The commanders .50cal could be aimed and fired buttoned down, from within the turret.
The USMC finally funded an upgrade program under the designation T43E2 to overcome the major problems. This included new controls and a ballistic computer. 72 of these M103A1 were leased by the US Army for service in a heavy tank battalion in Europe. The USMC received the M103A1 in 1958-59.
The final upgrade was the M103A1E1, later to become the M103A2. This finally eliminated the original underpowered gasoline engine replacing it with the state-of-the-art AVDS 1790 diesel engine, the same in use with the M48A3 and M60 tanks. The new engine required a complete reshaping of the engine compartment. The M103A2 can therefore be easily distinguished from its predecessors.
The M103A2 remained in USMC service as late as 1974.
The armour is made from welded rolled and cast homogeneous steel of varying thickness.
Hull front: 100 mm to 130 mm.(4" to 5.3")
Hull side: 76 mm.(3.1")
Hull top: 25 mm.(1")
Turret mantlet: 250 mm.(10.2")
Turret front: 180 mm.(3.26")
Turret side: 76 mm.(3.1")
Turret top: 38 mm.(1.55")
M103 1957. 400 built.
M103A1 1959. 219 converted or rebuilt. New sight (Steroscopic T52) and T33 ballistic computer. Removed one coaxial machine gun. New turret electric amplidyne system traverse. Turret basket.
M103A2 1964. 153 converted or rebuilt. New 750 hp (559 kW) diesel engine from the M60 Patton tank, increasing the road range to 480 km at the expense of a lower maximum speed of 37 km/h. New sight coincidence XM2A.