M56 Scorpion

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M56 Scorpion
M56 at AAF Tank Museum.JPG
M56 Scorpion preserved at the American Armored Foundation Tank Museum in Danville, Virginia.
Type Self-propelled gun
Place of originUnited States
Service history
Used bySee Operators
Wars Vietnam War
Western Sahara War
Production history
Manufacturer Cadillac Motor Car Division of General Motors
Produced1953–1959
No. built325
Specifications
Mass7.1 tonnes (16,000 lb)
Length4.55 metres (14 ft 11 in) (excluding gun)
5.84 metres (19 ft 2 in) (overall)
Width2.57 metres (8 ft 5 in)
Height2.05 metres (6 ft 9 in) over gun shield
Crew4 (commander, gunner, loader and driver)

Armor unarmored except for blast shield
Main
armament
90 mm M54 Gun
29 rounds
Engine Continental AOI-403-5 gasoline engine
200 brake horsepower (150 kW)
TransmissionAllison CD-150-4, 2 ranges forward, 1 reverse
SuspensionTorsion tube over bar at wheels 1 and 4, torsion bar at wheels 2 and 3
Ground clearance0.32 m (1 ft 1 in)
Fuel capacity210 litres (46 imp gal; 55 US gal)
Operational
range
230 kilometres (140 mi)
Maximum speed 45 kilometres per hour (28 mph)

The M56 "Scorpion" self-propelled gun is an American unarmored, airmobile self-propelled tank destroyer, which was armed with a 90 mm M54 gun with a simple blast shield, and an unprotected crew compartment.

Contents

History

The M56 was manufactured from 1953 to 1959 by the Cadillac Motor Car Division of General Motors for use by US airborne forces, though the vehicle was eventually used by the Spanish Navy Marines, Morocco and South Korea. With a crew of four (commander, gunner, loader and driver), the M56 weighed 6.4 tonnes (14,000 lb) empty and 7.7 tonnes (17,000 lb) combat-loaded. It had infrared driving lights but no NBC protection and was not amphibious.

The M56 was a fully tracked vehicle with rubber-tired run-flat road wheels and front drive sprocket wheels. It was powered by a Continental AOI-403-5 gasoline engine developing 200 brake horsepower (150 kW) at 3,000 rpm, allowing a maximum road speed of 28 miles per hour (45 km/h) and a maximum range of 140 miles (230 km). Twenty-nine rounds of main gun ammunition were carried, and only the small 5 mm thick blast shield was armored.

In service

M56 Scorpion of 16th Armor, US 173rd Airborne Brigade firing at Viet Cong during Operation Toledo 17 June 1966 M56 SPAT during Operation Toledo 17 Jun 66.png
M56 Scorpion of 16th Armor, US 173rd Airborne Brigade firing at Viet Cong during Operation Toledo 17 June 1966

The M56 saw combat service with U.S. forces in the Vietnam War. It was deployed with the 173rd Airborne Brigade, which was the only Airborne Brigade deployed with the M56, where it was used mainly in direct fire-support. [1] Its function as an air-mobile, self-propelled, anti-tank vehicle was eventually replaced in Vietnam by the troubled but effective M551 Sheridan which had a fully armored turret. The USMC used the M50 Ontos, which had an armored cabin and was armed with recoilless rifles, in a similar role (the running gear of the first Ontos prototype was the same as on the M56, but it was replaced for the production variant).

As for foreign operators, Morocco was the only export customer which used M56 Scorpions in combat. M56 Scorpions were deployed against Polisario rebels during the Western Sahara War. A number of examples were made available to South Korea but not used.[ citation needed ]

Operators

Map of former M56 operators in red M56 operators.png
Map of former M56 operators in red

Former operators

An APC based on the Scorpion APC based on the M56 Scorpion.jpg
An APC based on the Scorpion


Survivors

Diorama of destroyed M56 at the AAF Tank Museum. Note the prominent rubber tires on the road wheels. M56 Diorama of Destroyed M56 at AAF Tank Museum.jpg
Diorama of destroyed M56 at the AAF Tank Museum. Note the prominent rubber tires on the road wheels.
The outdoor display of M56 Scorpion 1740950 at VFW Post 2524, Culpeper, VA. M56 Culpeper.jpg
The outdoor display of M56 Scorpion 1740950 at VFW Post 2524, Culpeper, VA.

United States

South Korea

New Zealand

See also

Footnotes

Bibliography

Further reading