T42 medium tank

T42
T42 at Aberdeen Proving Ground, 1951
Type	Medium tank
Place of origin	United States
Production history
Designed	1948-1953
Variants	T69, T87
Specifications
Weight	Combat loaded: 74,500 lb (33.8 t) Unstowed: 68,080 lb (30.88 t)
Length	Gun forward: 314.7 in (7.99 m) Gun in Travel Position: 273.4 in (6.94 m) Without Gun: 232.1 in (5.90 m)
Width	Over fenders: 140.8 in (3.58 m)
Height	Over AA MG: 126.3 in (3.21 m)
Crew	4: Commander, Gunner Driver, Loader
Armor	Upper glacis: 102 mm (4.0 in) at 60° = 204 mm (8.0 in) LoS
Main armament	T42: 90mm Gun T119 T69: 90mm Gun T178
Secondary armament	Flexible AA mount: .50 cal HB M2 Coaxial: .50 cal HB M2E1
Engine	Continental AOS-895-3 500 gross hp 370 net hp
Power/weight	T42: 13.4 gross hp/ton T69: 13.2 gross hp/ton
Suspension	Torsion bars
Operational range	70 mi (110 km)
Speed	32 mph (51 km/h)

The 90mm GUN TANK T42 was a medium tank powered by the AOS-895-3, a 6-cylinder, Air cooled, Opposed cylinder, Supercharged engine displacing 895.9 cubic inches. It was intended to fulfill OTCM 32529's, dated December 2, 1948, call for a tank weighing 36 tons and equivalently armed as the M46 while having superior armour. With an engine producing only 500 hp, concern about the T42's performance was expressed. Testing, with a T40 loaded to the weight of T42 and powered by the AOS-895 through a CD-500 transmission, revealed it to be only equivalent in performance to the late model M4A3, which was below the design estimates.