British main battle tank (MBT) in service from 1983 to 2001. Armed with a 120mm L11A5 rifled gun (retro-fitted with L30A1), 7.62mm L8A2 & 7.62mm L37A2 machine guns mounted on the turret roof. Equipment included virtually impregnable Chobham composite armour for protection against threats including kinetic energy penetrators and high-explosive anti-tank (HEAT) rounds. Other defensive measures included laser warning system and smoke grenade launchers. Challenger 1 performed very reliably in the Gulf War in 1991 and without loss. Mk 3 has passive armour plates and extra stowage bins for 120mm rounds.