Type Tank gun Manufacturer Royal Ordnance Factory Length 5.89 m (19.3 ft) | Place of origin United Kingdom Weight 1,282 kg (2,826 lb) Barrel length | |
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The Royal Ordnance L7 is the basic model of Britain's most successful tank gun. The L7 was a 105 mm L/52 rifled design by the Royal Ordnance Factories intended for use in armoured fighting vehicles, replacing the earlier 20-pounder (84 mm) tank gun mounted on the Centurion tank. The successful L7 gun was fitted on many armored vehicles that include the British Centurion (starting from the Mk. 5/2 variant), the German Leopard 1 and the US M1 Abrams (only the first variant).
Contents
The L7 was a popular weapon and continued in use even after it was superseded by the L11 series 120 mm rifled tank gun, for some Centurion tanks operating as Artillery Forward Observation and Armoured Vehicle, Royal Engineers (AVRE) vehicles. The L7, and adaptations of it, can be found today as standard or retrofitted equipment on a wide variety of tanks developed during the Cold War.
History
Work on what became the L7 began in the early 1950s under Armament Research and Development Establishment at Fort Halstead with the first gun trials in mid-1956. Later that year during the Hungarian Revolution of 1956, a Soviet T-54A medium tank was driven onto the grounds of the British embassy in Budapest by the Hungarians. After a brief examination of this tank's armour and 100 mm gun, British officials decided that the 20 pounder was apparently incapable of defeating it. Hence there was a need to adopt a 105 mm gun.
The L7 was specifically designed to fit into the turret mountings of the 20 pounder. This would enable the Centurions to be upgunned with minimum modifications; hence, the fleet could be upgraded in a shorter time and at a lower cost.
User trials of the weapon began in 1959. The first tank to be equipped with the L7 was a single uparmoured Centurion Mark 7 in 1959 which was to prove the viability of up-armouring and up-gunning the Centurion. From 1959 onwards existing Centurions were given upgrades with the L7 gun and armour and new builds incorporated the L7 at production. The gun was subsequently adopted by the German Leopard 1 (for which the L7A3 variant was developed) and the Japanese Type 74 (produced under licence by Japan Steel Works).
The U.S. M60 series and earliest versions of the M1 Abrams are armed with the M68 gun, which was designed to fire the same ammunition as the L7. The M68 is also featured on the early Israeli Merkava (also the M68). The Swedish Stridsvagn 103 turretless S-tank (armed with the Bofors L74 with an automatic loader) makes use of an indigenous gun design, which is compatible with rounds made for the L7. In addition, several countries have used the gun to improve the firepower of existing main battle tanks. Derivatives have even been mounted in Warsaw Pact-built T-54 and T-55 tanks in Israel, India, Egypt and Iraq, and Type 79 tanks in China.
Design
The breech uses a horizontally sliding breechblock for loading the fixed cartridge cases. The gun recoils approximately 29 cm (11.5 inch) (in most applications), automatically opening the breech and ejecting the empty cartridge case as the gun returns to battery from full recoil. The barrel of the L7 is fitted with a bore evacuator approximately halfway down its length. The extractor is eccentrically mounted, which is a key recognition feature.
Specification
Ammunition
Variants
The US M68 is also fitted to the M1128 Mobile Gun System (MGS) version of the Stryker 8x8 wheeled combat vehicle.