M551 Sheridan

"Can it float though?"

• The M551 "Sheridan" AR/AAV (Armored Reconnaissance/Airborne Assault Vehicle) was a light tank developed by the United States and named after General Philip Sheridan, of American Civil War fame. It was designed to be landed by parachute and to swim across rivers. It was armed with the technically advanced but troublesome M81/M81 Modified/M81E1 152 mm gun/launcher, which fired both conventional ammunition and the MGM-51 Shillelagh guided anti-tank missile.

• The M551 Sheridan entered service with the United States Army in 1967. At the urging of General Creighton Abrams, the U.S. Commander, Military Assistance Command Vietnam, at the time, the M551 was rushed into combat service to South Vietnam in January 1969. Later that year, M551s were deployed to units in Europe and South Korea. The Sheridan saw extensive combat in the Vietnam War from 1969 to 1973. However, problems with the platform became evident, particularly its poor survivability and reliability.

• The 152 mm M81 gun-launcher that came to be used in the Sheridan was developed by Ford-Aeronutronic under a contract awarded by the Army in 1959. The gun's primary purpose was to fire the Shillelagh missile, but it could also fire more conventional combustible case ammunition. Two factors contributed to the selection of such a large-caliber gun. The Army desired a gun that would be capable of penetrating 150 mm of armor at 60 degrees, more than the 76 mm guns of the M41 or T92 were capable of. Secondly, the Shillelagh missile housed complicated electronics in addition to its warhead. As a consequence of the pairing of a large caliber gun and relatively lightweight vehicle, only low-velocity rounds would be compatible with the gun.

• The Sheridan was powered by a large 300-hp (224 kW) Detroit Diesel 6V53T diesel engine, and a flat track (no support rollers). The XM551 thus had an excellent power-to-weight ratio and mobility, able to run at speeds up to 72 km/h (45 mph). However, the vehicle proved to be very noisy and early Sheridans were unreliable under combat conditions.

• Swimming capability was provided by a flotation screen. The front armor was overlain by folding "surfboard". This could be opened up into a sloping vertical surface in front of the driver, providing a bow of a boat hull, about level with the top of the turret. Fabric formed the rest of the water barrier, folding up from compartments lining the upper corner where the side met the top of the hull, and held up at the back with poles. The front of the "hull" was provided with a plastic window, but in practice it was found that water splashing onto it made it almost useless, and the driver instead usually had to take steering directions from the vehicle commander. The M2 Bradley adopted a similar solution, but dropped it with upgraded armor. The Sheridan could swim across a river that was about 46 m (50 yards) wide. Tanks in the Patton series (M46, M47, M48), as well as the M60 tank could not perform these operations; they would have to crawl along the river bottoms using snorkels. Not by design, it was found that the swimming hardware acted to reduce the effectiveness of RPG hits. Although it was rarely used in Vietnam, fording was frequently used during Reforger exercises in Europe.
  

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Variants:

M551 Sheridan (T-55 Variant)

Controls:

Yaw/Trim : Tank Control
Pitch/Roll : Turret Control

AG1: Switch Ammo (HEAT-HE)
AG2: Flotation Screen & Front Surfboard
(note: enable AG3 with turret facing forward before activating AG2)
AG3: Turret Traverse Lock
AG5: Driver's Hatch
AG6: Commander's Hatch
AG7: Loader's Hatch
AG8: Headlights

Armaments:

• 152mm M81E1
- 10x High Explosive Anti Tank
- 10x High Explosive
- 6x MGM-51B Shillelagh

• 12.7mm M2HB
- 600x bullets

•7.62mm M240
- 1600x bullets

lol