Disappearing gun

A disappearing gun, a gun mounted on a disappearing carriage, is an obsolete type of artillery which enabled a gun to hide from direct fire and observation. The overwhelming majority of carriage designs enabled the gun to rotate backwards and down behind a parapet, or into a pit protected by a wall after it was fired; a small number were simply barbette mounts on a retractable platform. Either way, retraction lowered the gun from view and direct fire by the enemy while it was being reloaded. It also made reloading easier, since it lowered the breech to a level just above the loading platform, and shells could be rolled right up to the open breech for loading and ramming.