Arts: Tricks of the trade 17 - How to revolve a stage

TERRY DEVONALD Systems Engineering Manager, Royal National Theatre, and the mastermind behind Neverland on 'Peter Pan'

THE NATIONAL is a repertory theatre, so we can't put in these multi-million-pound sets they have in the West End, but we must consider the public's expectations. The public expects to see very smooth, slick scene-changes, particularly in seasonal spectaculars like Peter Pan. The only way we can possibly match the West End is with the ingenuity of the designer and by making use of our revolving stage.

The set-up in the Olivier is quite unique, in that the stage has three elements. Looking down from above, you have a revolving stage - or "drum" - which weighs about 140 tons. One semi-circle of it is an elevator stage which can go up and down in a vertical movement as well as around, and is interchangeable with another one underneath. Each elevator is capable of lifting five tons of scenery.

The other semi-circle is fixed so that it can swivel around, but not up and down. In Peter Pan we have sets on both the elevators, which we exchange four times during the performance. When the Darlings' nursery goes offstage, another elevator ascends with half of the island. We then do what we call a trade - we exchange the elevators underneath the stage. The crew fits up the other half of Neverland to form a complete revolving island.

The whole structure is balanced on 48 wheels right down in the basement, which is about 13 metres below stage level. It is revolved by electrical motors. And the whole thing can move at up to four miles an hour, electronically controlled by a team of engineers who sit in the basement during performances to keep an eye on things.

Much of the scenery is fixed to the stage, so it can't come to any harm. But we have had doors crunched by the elevator if they've been left open during a scene-change. We've been very lucky in having no serious accidents with stage operation. But there have been minor mishaps, with actors clambering on the moving structure and losing their balance.

The original concept was that it should be controlled by one person. We've started a programme of refurbishment where we are upgrading the hardware of all this equipment. Eventually, we're hoping to integrate it into one big computer. One operator will be able to synchronise all the elements of the scenery, which will make it smoother than ever.

! 'Peter Pan': Olivier, SE1 (0171 928 2252), to Apr.