A bigger splash

27 September 2011

A high-angle photograph reveals the flowing design details of the Aquatics Centre. Image: Hufton + Crow

The Zaha Hadid-designed Aquatics Centre is set to become one of the Olympic Park’s most impressive and frequented sites. Amanda Allen talks to Arup about its lighting design for the arena

Dates have been set, tickets have been bought and now, with less than a year to go to until the beginning of the London 2012 Olympic Games, work on the Aquatics Centre has been completed. Home to all swimming and diving events at the Games, the Aquatics Centre will also mark a gateway to the Olympic Park: more than two thirds of spectators are expected to enter via a bridge running across part of the venue’s site.

Designed by acclaimed international firm, Zaha Hadid Architects (ZHA), the Aquatics Centre houses 50m and 25m competition diving pools, a 50m warm-up pool and a dry warm-up area for divers. It was no easy task for Arup to offer a lighting design for all this that could also contend with water and high humidity and the requirements of high-definition television (HDTV) equipment. “Arup’s lighting team carried out the full design for all electric lighting […] The team also carried out daylight design for both legacy [public use of the Park after the Games] and Games needs, addressing specifically the athletes’, spectators’ and broadcasters’ requirements,” says Florence Lam, global practice leader for lighting design at Arup.

The design team worked closely with the architect on the scheme. Lam says: “The training pool is a remarkable example of integrated design: the lighting scheme consists of an array of bespoke light boxes designed with a light diffusing fabric, which not only provides a ‘natural’ sky ambience, but the fabric also has an acoustic function in reducing reverberation.”

Reflection

Working with water is always a complex task for lighting designers and in this instance Arup had the added pressure of lighting international competition pools where the greatest challenge was reflection. Giulio Antonutto, Arup associate and the project’s lighting designer, says: “Water movement and displacement due to activities in the pool had to be accounted for in the lighting calculations.”

The other key consideration, according to Antonutto, was vertical illumination, which is specific to TV broadcast needs: “Luminance is a key parameter for filming and Arup had to assess camera views in 3D with full, physically-accurate rendering. Studies were made to show the difference in vertical illuminance levels and shadow pattern on the field of play. In addition, an interactive game-engine-based application was developed to explore the pool environment under various lighting scenarios, checking out reflections of floodlights.”

For HDTV, control of luminance and brightness contrast across an image is required. “Variation of brightness is measured in ‘stops’ and variations have to be minimised,” says Antonutto. “Flicker is another critical element that needs to be right for broadcast. The current requirement for super slow-motion filming is 150 frames per second, and the lighting installation has to respond to state-of-the-art camera technology.”

Different strokes

Several iterations of the design were carried out to fine-tune the chosen solutions. Antonutto says: “Energy efficiency is the principle design criterion for legacy. An LED source was considered for the Games lighting, but dismissed, as the industry is not ready for such demanding output. The light sources used in the main hall were high-wattage discharge lamps, designed to be switched off whenever the daylight is sufficient.”

For legacy use, dimmable sources were used where possible, significantly reducing energy consumption at the centre. Antonutto says: “The legacy building will have fully-glazed façades. Our team worked closely with ZHA to design the envelope, ensuring that glare from daylight is minimised.”

Throughout the centre, the admission of daylight is filtered by large, temporary stands, covered by a translucent material with a transmission factor to suit the anticipated summer light levels in London for the duration of the Games.

Antonutto says: “Luminance distribution across the pool has been assessed to ensure there will be an optimal image for cameras, while providing a comfortable viewing environment for the spectators during the day. The design also ensures that there is no direct sunlight admitted to the venue. By night, the use of a translucent fabric for the stands creates a glowing lantern effect externally.”

Take a load off

The design of the Aquatics Centre was based on achieving an overall 15 per cent building-level carbon reduction, compared with the Part L 2006 target. Conservation of lighting energy, which accounts for 12 per cent of the building’s overall carbon emissions, plays an important part in achieving the target.

The overall lighting power of the Aquatics Centre is predicted to be 30 per cent more carbon-efficient than the notional building.

This improvement is achieved through the use of efficient lamp types throughout the structure, such as metal halide and high-frequency fluorescent lamps. It is also achieved by the use of a lighting control system that incorporates presence detection in many public areas, as well as daylight control in the main pool hall when it is set to legacy mode.