Royal Ordnance L7 - History

History

Work on what became the L7 began in the "early 1950s" under Armament Research and Development Establishement at Fort Halstead with the first gun trials in mid-1956. 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 several other nations for their own MBTs, most notably the German Leopard 1 (for which the L7A3 variant was developed), the Japanese Type 74 (produced under license by Japan Steel Works), the Swedish Stridsvagn 103 (as the L74, with a longer barrel and automatic loader), India for its upgraded T-55A, the US M60 series and earliest versions of the M1 Abrams (with the M68), and the Israeli Merkava. 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, Egypt and Iraq, and Type 79 tanks in China.