The Motor Pool
M-551A1 SHERIDAN TANK
SERVICE: Army
DESCRIPTION: A light tank with airdrop capability
FEATURES:
The M-551A1 Sheridan is a lightly armored, tracked, air droppable, direct fire tank used
in airdrop missions by the 82nd Airborne Division, Fort Bragg, N.C., and by the Opposing
Forces Regiment, National Training Center at Fort Irwin, Calif. It uses a Laser Range
Finder and Tank Thermal Sight.
BACKGROUND:
The Army received the Sheridan in 1967. In 1969, the 11th ACR received a small quantity of
Sheridans for use in the war in Vietnam. It has been out of production since 1970
and is only in service in limited numbers. The 82nd Airborne Division has 57, using them
instead of the M-1A1, which cannot be parachuted from an aircraft). 300 Sheridans are used
by the Opposing Forces Regiment at the National Training Center as "enemy" tanks
in combat training.
Armored Reconnaissance Airborne Assault Vehicle (Sheridan)
The M551 Sheridan was developed to provide the US Army with a light armored
reconnaissance vehicle with heavy firepower. The main armament consists of an 152mm M81
gun/missile launcher capable of firing conventional ammunition and the MGM-51 Shillelagh
antitank missile (20 conventional rounds and 8 missiles). Due to problems with the
gun-tube-launched antitank missile, the Sheridan was not fielded widely throughout the
Army. The gun would foul with caseless ammuniton, gun firing would interfere with missle
electronics, and the entire vehicle recoiled with unusual vigor when the gun was fired,
since the 152mm gun was too big for the light-weight chassis. The Shillelagh missles were
evidently never used in anger. In addition to the main gun/missile launcher, the M551 is
armed with a 7.62mm M240 machine gun and a 12.7mm M2 HB antiaircraft machine gun. A
Detroit Diesel 6V-53T 300hp turbo-charged V-6 diesel engine and an Allison TG-250-2A
poweshift transmission provide the Sheridan's power. Protection for the four-man crew is
provided by an aluminum hull and steel turret. Although light enough to be
airdrop-capable, the alumninum armour was thin enough to be pierced by heavy machine-gun
rounds, and the vehicle was particularly vulnerable to mines.
Initially produced in 1966, the M551 was fielded in 1968. 1,562 M551s were built
between 1966 and 1970. The Sheridan saw limited action in Vietnam, where many deficiencies
were revealed. The missle system was useless against an enemy that employed tanks, though
the Sheridan saw a lot of use towards the end of the war because of its mobility.
Sheridan-equiped units participated in Operation Just Cause in Panama (1989), and was
deployed to Saudi Arabia during Operation Desert Shield. As projectile technology
advanced, the Sheridan's potential declined and it was phased out of the US inventory
beginning in 1978. However, the M551 is still used by the 82nd Airborne Division. Some 330
"visually-modified" Sheridans represent threat tanks and armored vehicles at the
National Training Center in Fort Irwin, California.
Specifications
|
| Weight (pounds) |
17 tons |
| Length |
22'4" |
| Width |
13'6" |
| Height |
12'6" |
| Forward speed |
45 mph |
| Reverse speed |
10 mph |
| Engine |
Detroit Diesel 6V-53T 300-hp water cooled turbocharged 2-stroke V-6 diesel.
Allision TG-250-2A powershift cross drive transmission with 4 forward /1 reverse |
| Vertical obstacle climb |
49 in |
| Maximum width ditch |
108 in |
| Fording Depth |
48 in |
| Main Gun |
152mm cannon/Missile Launcher with 20 HEAT-T-MP rounds and 8 Shillelagh missile rounds |
| Coaxial machinegun |
M240 - 7.62mm |
| Commander's machinegun |
M2 - .50 cal |
| Sensors and Fire Control |
M129 gunner's telescope, magnification 8x 8° field of view (FOV), M44 gunner's IR
night sight magnification 9x6° FOV, IR SACLOS data link |
