The Gallows first appeared on the 'Killer' Tour of 1971 and was created by Warner Bros. props department.. It was used during the performance of 'Killer' at the end of the show. As the band reenacted the end of the song, Alice was dragged up a scaffold and his head placed into a noose. A piano wire, laced through the hangman's rope was hooked onto a harness that Alice had been wearing throughout the show. To cheers of 'Hang Him, Hang Him', a handle was pulled, releasing the trapdoor beneath and letting Alice fall. The lights went out and a tape of thunder was played through the P.A. system to lighting effects.
The effect was also used on 1988's 'Raise Your Fist And Yell' Tour.
During a show at Wembley Arena on this tour the stunt went horribly wrong. The cable snapped and Alice fell to the stage hitting his chin on the edge of the trap door as he went, knocking him out cold. Luckily he was revived and as a true professional completed the show!