Configurations of the drum revolve

'Droom' One elevator has a large structure built on it complete with roof. The interior of the structure provides settings for interior scenes when the elevator is fully raised. The roof provides an open acting area when the elevator is lowered.

Behind-the-Scenes Elevators are swapped over, or simply used to bring up scenery stored below behind a flown flat, gauze or cloth so that the audience has no idea that the drum has been used.

Quick-change One elevator is used as a storage area and the other comes down to meet it so that props, scenery and actors can be transferred across before it rises rapidly back to stage level.

Revolve One elevator is fixed at stage level and the drum is turned to produce a revolve. This may or may not be used with the rim revolve.

Scenic Automation One or both elevators are used indirectly to create motion, for example, via push-rods, to operate raking or tilting panels above the stage. The elevators may be used to provide motion for much smaller effects within sets, for example raising podiums.


http://www.nationaltheatre.org.uk/8052/the-drum-revolve/how-the-drum-works.html