Optical technologies at the heart of spectacular engineering celebration

11 Apr 2006

21st-century optical lighting technologies are throwing light onto a classic 19th-century engineering innovation

One of this year's most spectacular lighting displays - the relit Clifton Suspension Bridge in Bristol, UK - is based on an integrated array of thousands of LEDs, fluorescent tubes and lamps.

Clifton Suspension Bridge

The display was switched on for the first time on 8 April as part of the city's celebration of the 200th anniversary of the birth of pioneering engineer and bridge designer Isambard Kingdom Brunel.

Brunel left his mark on the city - which is also the home to the pioneering website optics.org - with his famous bridge, the Great Western Railway and the S.S. Great Britain, the world's first propeller-driven iron steamship.

The illuminations were designed by international architectural lighting specialists Pinniger & Partners. They consist of various types of lighting technologies and elements:

Detail of LED unit

Along the length of the chains, from which the 214m-long bridge is suspended, are more than 3,000 1W LEDs, arranged in groups of three, each set focused on a section of the chain and throwing into relief the giant nuts which connect the links;

Fluorescent tubes positioned beneath the handrail not only illuminate the walkway for pedestrians but also silhouette and emphasise the delicate design of the iron lattice running the length of the bridge;

Conventional lamps, concealed within the arches of the two 26m-high towers at each end of the bridge, and in the spaces around the top, reinforces the three-dimensional aspects of the design in ways which were impossible with the previous "on-or-off" system. The two sides of each tower are bathed in white light, carefully directed and focused to avoid the problems associated with the city's "urban glow".

The Clifton Suspension Bridge Trust commissioned Ex-Or, a lighting management company, to provide SceneSelect II, its scene-setting and dimming system. This controls all of the lighting elements to deliver the lightshow.

Using SceneSelect II, the "Bridgemaster" John Mitchell can summon up a variety of pre-programmed lit displays by using a touch screen control in the bridge control office.