Show Dome

he £758 million Millennium Experience on London's Greenwich peninsula is one of the UK's largest-ever construction projects. At the centre of it all stands the Millennium Dome, the much-publicised Sir Richard Rogers-designed exhibition venue that is set to attract up to 12 million visitors.

The Dome has an 80 000 m² roof, with the space below able to fit in the Albert Hall 13 times over. How on earth do you design the lighting scheme for such a vast arena?

Step forward celebrated lighting architect Speirs and Major. Fresh from devising the lighting for the 150 000 m² Bluewater Retail Park, the practice is currently working alongside Richard Rogers Partnership project director Mike Davies, and engineers Peter Carew and Ken Carmichael of m&e consultant Buro Happold, to create a welcoming and vibrant environment inside the Dome.

To make things as simple as possible, the design team decided to work closely with manufacturers and split the project up into two distinct areas: ambient lighting to the perimeter and central areas of the Dome¹.

The ambient lighting design centres on illuminating the internal perimeter of the space. A large amount of indirect uplighting is being supplied to the Dome's canopy by Whitecroft Lighting's Sportsliter floodlights, boasting 1000 W Iwasaki metal halide lamps.

Individually rated at 1 kW, there is a bank of 48 single-ended lamps on top of each of the six 'core' buildings which sit equidistantly around the Dome's circumference. These buildings play host to hospitality suites, restaurants, toilets and rest areas for the visiting hordes.

"We weren't convinced that we would get very much light bouncing back onto the floor with this design," said Ken Carmichael, "as the roof is anything from 25 to 35 m off the ground above the exhibition areas." The design team needn't have worried. "Calculations showed that the glass fibre mesh on the roof would act like a mirror," added Carmichael. "We are now achieving something like 50 lux halfway between each core." An excellent result.

Basic perimeter edge uplighting is by way of a series of 340 stirrup-mounted Sill Lighting power projectors. Rated at 400 W, the fittings house 150 W Osram lamps.

"Outside of the six core areas, all of the light fittings had to be attached to the main structure in one way or another," said Ken Carmichael. In practice, this led to architects at the Richard Rogers Partnership having to devise huge, bespoke V-shaped bracketry which link the Sill fittings with the canopy roof. The bracketry was put together on site by electrical contractor N G Bailey.

The next element of the ambient lighting to be considered was that for the 12, 90 m-high open lattice steel masts which rest on 10 m-tall pyramidal bases around the perimeter. These vast struts, prefabricated in Bolton and Bristol, hold in position the tensioned steel cabling which supports the Dome's roof.

Special fittings were developed by Speirs and Major in conjunction with Richard Rogers' Mike Davies and Concord Lighting. These use four 150 W PAR 64 metal halide reflectors in a spun aluminium housing. "This is just one instance of where we have been able to inject some style into the job," stated Mark Major. "It's not purely an engineering solution."

Lighting the Dome is about style, it’s not just an engineering solution

Meantime, Sill Lighting's narrow and medium beam projector luminaires – boasting 250 W and 70 W single-ended Iwasaki metal halide lamps respectively – provide uplighting to the high and low level area of each mast.

Emergency lighting provision will be extremely important of course. Two rows of floor-buried red light emitting diodes are being installed around the raised promenade circulation route. In addition, 1000 W tungsten halogen PAR 64 downlighters have been attached to the gantry which runs between the central area and the edge of the Dome.

To make sure that the emergency lighting doesn't fail, client the New Millennium Experience Company (NMEC) turned to Liebert for power protection. Six of the company's 7200 ups units running at 30 kVA are linked to the emergency lighting systems. In addition, a 20 kVA AP400 ups has been installed to ensure continuous up-time for the computers monitoring the lighting systems.

Ambient lighting to the central area of the Dome really concerns the lighting for the main arena, which will seat several thousand people at showtime. Immediately above this area, bespoke theatre-style luminaires will provide the stage lighting, while a series of six lighting towers (akin to football stadium floodlights) will light the surrounding areas and stage periphery.

"The towers will provide light, but will also be lit themselves to make them more of an architectural feature," said Mark Major. Sill Lighting's beam projector floodlights, complete with 500 W tungsten halogen lamps from Philips Lighting, will be used here.

Outside the canopy, there are areas where the Dome's roof overhangs. "We didn't want to leave these areas unlit," said Mark Major, "so we added some direct-burial 70 W CDM lamps housed in Louis Poulsen fittings, to illuminate them." These light sources are supplemented by white uplighting from Sill Lighting's beam projectors.

All of these lighting systems are controlled by a specially-developed system devised by Dynalite's David Kerr. The company's 'intelligent distribution board' system combines the simplicity of a standard 12 or four-circuit electrical distribution board with the flexibility of a networked control system.

Three units are being used at the Dome. These include 12x10 A units with integral contactors for controlling the non-dim loads (eg the metal halide fixtures), 12x10 A angle dimmers and four 10 A high frequency ballast controllers. The latter provide 10 A switched outputs and 0-10 V outputs to set the intensity of fluorescent lighting loads.

The control units each have their own processor and memory, enabling them to store up to 96 different lighting scenes. Control is from local push-button control panels located in the core buildings, as well as master lcd touch-screen controllers. "There will be an interface with the show lighting controls once they are installed," stressed Mark Major. "If the show lighting teams want to turn all the architectural lighting off to create a particular effect, then they will be able to. For our part, we'll be able to programme-in all the pre-sets that will enable the Dome to function, right down to the lighting for security and cleaning."