T95 medium tank

The T95 was an American prototype medium tank developed from 1955 to 1959. These tanks used many advanced or unusual features, such as siliceous-cored armor, new transmissions, and OPTAR fire-control systems. The OPTAR incorporated an electro-optical rangefinder and was mounted on the right side of the turret, and was used in conjunction with the APFSDS-firing 90 mm T208 smoothbore gun, which had a rigid mount without a recoil system. In addition, although the tanks were designed with a torsion beam suspension, a hydropneumatic suspension was fitted, and one of the tanks was fitted with a Solar Saturn gas turbine for demonstration purposes. The siliceous cored armor consisted of fused silica, which has a mass efficiency of approximately three versus copper-lined shaped charges, embedded in cast steel armor for an overall mass efficiency of 1.4. The early APFSDS penetrators fired by the T208 had a low length-to-diameter ratio, this being limited by their brittle tungsten carbide construction, with a diameter of 37 mm, although they had a high muzzle velocity of 1,525 m/s (5,000 ft/s). The rangefinder, the T53 optical tracking, acquisition and ranging (OPTAR) system, emitted pulsed beams of intense but incoherent infrared light. These incoherent beams scattered easily, reducing effectiveness in mist and rain and causing multiple returns, requiring the gunner to identify the correct return after estimating the range by sight. This, combined with the large and vulnerable design of the transmitter and receiver assembly, led to the abandonment of the OPTAR system in 1957.