When the curtain goes up on opening night of the new Royal Opera House in London’s Covent Garden on 4 December, the celebrity audience will be blissfully unaware of the work that has gone on behind the scenes.
Media attention surrounding the project has focused on its architecture and huge budget. But none of those sitting in the new auditorium will be aware of the ingenuity that has been required to meet the technical challenges thrown up by the building.
`Theatre is the art of illusion,’ says David Oldfield, works director for Hedley Hydraulics, which has installing a sophisticated £1m system for moving stage and scenery. `If something moves silently and then suddenly appears as if by magic, then you’ve created that illusion. The fact that you’ve been sweating over it for the last 18 months is irrelevant.’
The 3,000m2 stage floor is divided into 41 rectangular sections, each measuring 15m by 5m. Each section (known as a wagon) is supported by its own elevator, which can raise or lower it by 6m.
Not only that, but the wagons can be moved horizontally too, so that one section of floor (carrying a horse and a couple of spear carriers, for example) can be made to sink out of sight below the stage, while another piece (transporting a rocky cavern – or anything up to a weight limit of 30 tonnes) can slide into place from the wings.
Each wagon can be moved with pinpoint accuracy and precision timing, so several sections can be moved as if they were one piece. This is no mean feat when one wagon may be burdened with a 10-tonne structure and another may be carrying nothing more than a discarded blood-stained cloak.
Each wagon is driven by a system of cassettes, each incorporating a spring-loaded, hydraulically retractable drive unit with a 1.5kW electric motor. The motor drives a toothed belt, which engages with a similar belt on the edge of the wagon.
But a lot more than the scenery rides on the smooth running of this equipment. The £176m opera house development has been overshadowed by controversy since the announcement of a £58.5m grant from the National Lottery. Its opening will be closely scrutinised for anything that may be seen as a waste of public funds – from poor sightlines and acoustics, to clunky scenery changes.
Oldfield remains confident: `As far as we’re concerned it should work fine – it’s a good system. With the exception of the synchronisation, it’s not particularly demanding. It’s just large.’
The hydraulic floors are a step forward for the Opera House and far removed from the method used in the old building to move sets. `As far as I know they moved things using pallet trucks, cranes and brute force,’ says Oldfield.
The new machinery will enable the backstage crew to change whole productions quickly, an advantage when the protection of singers’ voices means running different productions on consecutive nights.
The equipment will also be cheaper to run. More automation means more rapid scene changes using less staff. In fact, the Royal Opera is understood to be moving to a single-shift system for stage hands, instead of the former three-shifts – a direct result of time savings made possible by the automated stage system.
The project involved the use of 220m of hose, 8,000m of piping and 9,000 litres of mineral oil. These figures give some idea of the scale of the work involved installing new staging for a theatre in which the distance from the front of the stage to the back of the auditorium is less than that from the front to the back of the stage. Although this gives the impression Oldfield had plenty of space in which to operate, the reality was different.
`The design of the flooring was very restrictive,’ he says. `We were basically operating in an area 800mm high throughout the floor area at stage level. Getting pipework, manifolds and hydraulic cylinders under the elevators proved to be quite a challenge.’