Double Helix Bridge – Innovative Engineering In Singopore
Singapore’s Helix Bridge is a key landmark of the Marina Bay precinct and its design inspired by the geometric arrangement of DNA, a symbol of continuity and renewal, with a walkway encircled by opposing double helix structures of stainless steel.
At 280 metres long, the curved double-helix bridge is part of a 3.5 kilometer long waterfront promenade and provides pedestrians a direct connection between Marina Centre, the waterfront area and Marina Bay Sands integrated resort. Next to the Helix is a new six lane vehicular bridge that has a simple, elegant design forming the backdrop to the Helix bridge.
Engineered to support more than 10,000 people at any one time, Arup designed the bridge’s two delicate helix structures to act together as a tubular truss. It is the first time in the world this double-helix structural solution has been applied to a bridge.
The Helix is created from two separate spiraling steel members held together by a series of delicate connecting rods to form a rigid tubular structure – like two springs wrapped around each other in the opposite direction, one inside the other. The bridge uses five times less steel than a conventional box girder bridge, and the frame supports the pedestrian deck, shade canopies and light fixtures without the need for a secondary structure. The end result is a visually appealing structure that is highly functional while using minimal resources.
While the structure was designed to be a landmark by day, it is the lighting that steals the show at night time, making it a visual spectacle seen from any location around the bay.
Arup’s lighting designers emphasised the DNA-inspired design through a series of dynamic multi-coloured LED lights installed on the helix structures. The outward-facing luminaires accentuate the sweeping structural curves, with another discreet array of lights illuminating the internal canopy of glass and steel mesh to create a dynamic membrane of light. The inner helix uses white light to illuminate a path for pedestrians. The latest LED technology was chosen for longevity, recyclability and for the flexibility of being able to offer more than 16 million dynamic colours.
When triggered via an intelligent control system, the dynamic lighting sequences accentuate the members, revealing the long sweeping strands as they intertwine along the bridge’s length. The lighting is programmed so that a variety of colours and dynamic sequence effects can be implemented for different events and festivals. Careful placement of luminaires ensures that energy requirements are kept to a minimum – and there is not a single luminaire on the entire bridge that consumes more than twelve watts of power.