Stage machinery
Stage machinery, also known as stage mechanics, comprises the mechanical devices used to create special effects in theatrical productions, including scene changes, lowering actors through the stage floor and enabling actors to 'fly' over the stage.
Alexandra Palace Theatre, London and the Gaiety Theatre, Isle of Man are two theatres which have retained stage machinery of all types under the stage.
Scene Changing
The wings of a theatre stage had to be at least half the width of the stage each side of the proscenium arch and the fly system for flying scenery had to be twice the height of the stage.Drum and Shaft
This consisted of a shaft around which was built one or more circular drums which had a much larger diameter than the shaft. A rope wound round the drum was pulled in order to rotate the shaft and if there was more than one drum on the shaft, several pieces of scenery could be moved at the same time to raise the scenery wings and backdrops.Slote/Sloat
This was a pair of vertical runners used to raise or lower a long profile of low scenery such as a groundrow, pieces of scenery made of canvas stretched over wood and used to represent items such as water or flowers, through a narrow slot in the stage floor.Column Wave
The column wave, developed by the Italian architect Nicola Sabbatini, was a 16th-century stage machine used to provide the appearance waves on the sea.Bridge
This was a heavy wooden platform with counterweights which were used to raise and lower either heavy pieces of scenery or a group of actors, from below the stage to stage level.Scruto
Scruto consisted of narrow strips of wood attached side by side on canvas material forming a continuous sheet which could be rolled. The scruto could be mounted vertically and rolled up or down to change the scenery or horizontally in the stage floor to form a trap cover.Traps
Anapiesma was the ancient Greek version of the stage trap we know today. It was a concealed opening under the stage floor, where actors and props would be hidden before they appeared on stage. The joists of the stage floor were cut and the opening was concealed in different ways, depending on the type of trap. In the 19th century many different kinds of traps were used. All except the Corsican trap were located downstage near the proscenium arch.The trap room is the large space below the stage where actors prepared to make their entrance and where the winches, drums and other machinery needed to operate traps and scenery were kept. It was referred to as "hell".
Newspaper advertisements looked for trap performers and newspaper notices for shows might advertise how high a performer flew out of a trap.
Grave Trap
This trap was positioned centrally and was named after its use in Shakespeare's Hamlet. It measured about 6 by 3 feet and consisted of a platform below the stage which could be raised or lowered.Star Trap
These were counterweighted traps which could be used to allow actors playing supernatural beings, such as ghosts in melodrama and demons and fairies in pantomime, to appear suddenly.The hole through which the actor appeared consisted of triangular flaps, hinged with leather, which opened upwards, resembling a star. The actor stood on a small platform below the trap and counterweights of up to 200 kg, attached to the platform, were raised by stage hands using ropes, at which point the platform moved up rapidly and the actor 'flew' through the trap. The trap closed immediately with no visible opening, giving the illusion that the actor had appeared through the solid stage floor. The star traps were hazardous. The first pantomime at Alexandra Palace Theatre, 'The Yellow Dwarf' had to be delayed when an actor twisted his spine and sprained muscles in his back in preparation for the role. Despite this, they were still used in the first half of the 20th century until banned by the actors' union Equity.