A green infrastructure approach repositions the role of nature in the city from optional amenity and attractive scenery to a prized and essential supplier of ecosystem services and a platform for more vibrant communities. Thus we come face to face with a new breed of high-performance landscapes that combine ecological realities and urban infrastructural needs, forming a dynamic network of interdependent systems that animates a city. The idea was to link up Singapore’s hill parks by turning Southern Ridges into a nine-kilometer recreational and leisure destination, a chain of green, open spaces spanning Mount Faber Park, Telok Blangah Hill Park and Kent Ridge Park. Started in 2006 and completed in 2008, the 274-m long Henderson Waves was one of the two bridges built under the Southern Ridges Project, commissioned by the Urban Redevelopment Authority of Singapore and designed by RSP Architects Planners & Engineers Pte Ltd and IJP Corporation Ltd, UK. The architectural firm’s larger design objective is that “the project will perform well as a social infrastructure serving the community and encourage human interactivity and, as a result, enhance meaningful values to the esthetic and natural environment and to those living in nearby estates”.
Henderson Waves is an excellent example of multifunctionality, the integration and interaction of different functions or activities on the same piece of land for efficiency and sustainability, which makes sense in land-scarce Singapore. It has proven to be a source of valuable community benefits, from recreation and providing shade and shelter to connecting separate existing spaces, demonstrating the importance of the natural environment in decisions about land use planning. Offering panoramic views of the city, harbor and Southern Islands, it is a good bird-watching point and especially popular with joggers, couples, families with children and photographers. It has become a landmark with which residents identify, as they have developed a relationship with the bridge. They have found a space to call their own where they can conduct activities that lead to improved health and wellbeing – relaxing on the timber seats hidden in the ribbed alcoves, enjoying the greenery, strolling on the deck, taking in the evening ambient LED lighting and crossing between Mount Faber Park and Telok Blangah Hill Park.
The highest pedestrian bridge in Singapore, at 36m above Henderson Road, Henderson Waves is just one of the nation’s projects to improve connectivity between natural areas, showcasing distinctive artistic wave-like architecture comprising a succession of undulating curved ribs, which act as alcoves providing shelter. Its flowing organic form of seven wave spans, undulating crests and troughs was shaped by the abstraction of the Southern Ridges’ natural landforms and the desire to create a space for spontaneous social interaction, showing how design can improve the environment and the community. Based on a highly accurate mathematical model, its form is a reflection of the structure. RSP explains that the bridge is a folded three-dimensional surface created with one simple mathematical equation, which determines the form of the bridge and inflects it in all three dimensions to the extent that the surface bridge bends, undulates and ascends based on the equation. In the process, it also deforms to provide adequate egress, sloping, shelter and scenic viewing to the south and with minimum structural column footprints to the existing rich biodiversity landscape. Every line of the mathematical surface becomes either a solid frame engineered in steel or a sloping timber board to tread or sit on and enjoy the moment.
Henderson Waves was designed to blend into the surrounding landscape and to connect existing pathways and parks for natural and continuous access from both hills. The bridge was built with an underlying ecological message, as RSP believes in socially-responsive and sustainable designs that create positive impacts on both people and the environment. The modular surface decking and curved balustrades and backrests, connected on the supporting steel spans and wave structures, are made of slats of indigenous yellow balau all-weather timber, sourced from certified sustainable timber farms in East Malaysia and crafted using the latest precision technology to reduce material wastage. The complex, doubly-curved portions of approximately 1,500sqm of yellow balau timber deck sitting on top of the steel structure form a tapestry of 5,000 modular boards, each varying by a single degree every 10m and many tapered to measure. Naturally weathered structural concrete pylons were limited to minimize ecological impact, with maximum bridge intermediate spans within the tree conservation area.
RSP believes that Henderson Waves could serve as an international model as Southern Ridges was one of five outstanding developments selected as winners of the 2010 Urban Land Institute’s Global Awards for Excellence competition, recognized as the land use industry’s most prestigious recognition program. The jury commended Southern Ridges for creating “a rare contiguous recreational space in densely populated Singapore”, having demonstrated strong urban design quality, innovation and contribution to a workable, livable and sustainable model of development. It called it “a pinnacle in models for design and quality”, adding that it is a “first-rate example of how to connect open space in order to create continuity between other opportunities for redevelopment”.
