A team comprising architect Niall McLaughlin, engineer Price & Myers and light artist Martin Richman has won a competition to design the Temple Quay 2 pedestrian and cycle bridge in Bristol. The team beat three other shortlisted groups (see opposite) to produce a solution for an area that has been masterplanned by Urbed with a mixture of commercial and residential properties.
By using the balustrade as part of the stress-skin structure of the stainless steel bridge, the winning team has produced a particularly slender design, described by the judges as 'sophisticated, elegant and clearly thought out'. The shape of the balustrade changes constantly from the edge to the middle, becoming higher and thinner as it twists.
The bridge also becomes narrower towards the centre where, as the skewing balustrade becomes thinner and starts to slope in, it will be easy to lean over and look at the water below.Light, both natural and artificial, plays a crucial part in the design. The curved surfaces should provide fascinating reflections. In addition, perforations will be laser-cut in the stainless steel, giving views through to LED lights within the bridge which will make the whole structure glow at night and will also reveal the hidden ribs of the internal structure.
This structure is a portal frame, with the haunches and legs of the portals hidden behind the quay walls on both sides of the river in reinforced-concrete chambers.
A damping system consisting of a neoprene layer clamped between the decking and the stressed-skin structure below should absorb vibrations from people walking on the deck and soak up energy from the moving structure.
The project develops ideas realised by the same architect and engineer on the bandstand at the De La Warr Pavilion in Bexhill, Sussex, where again a stressed skin covering to an underlying structure allowed the development of complex curved shapes. A parametric 3D computer model was used to develop the form of the bridge, allowing the creation of surfaces with curvature in only one direction.A rapidprototype model also played a key role in development.
The client for the bridge is Castlemore Securities, with the South West of England Regional Development Agency. The winning scheme, estimated at £900,000, is above the original budget of £750,000, but the client has welcomed the fact that this is a lowmaintenance option. It is encouraging that it has rejected an alternative of constructing the bridge in painted mild steel on the grounds that, with repainting necessary every 10 years, increased maintenance costs would offset the lower capital cost.