All images by Simon Kennedy
David Knight, from Flint & Neill Ltd., has been a practising structural engineer for eight years. Here he discusses the Greenwich Reach Swing Bridge project, which has been shortlisted in The Structural Awards 2015 “Pedestrian Bridges” category.
I’ve been involved in a number of interesting projects during my career, such as the 50,000 seat Philippine Arena in Manilla, the West Kowloon Terminus building in Hong Kong and the Mersey Gateway Bridge.
However, the Greenwich Reach Swing Bridge is the highlight of my career so far – it is the first completed project that I have led from start to finish, and I’m very proud of what we achieved: a project that is structurally daring, but also an efficient solution to the brief. It’s an elegant and understated example of what can be achieved through close collaboration between engineer and architect.
The main challenge was to build a bridge that would cross the river but allow taller vessels through. We weren't allowed to overhang the river at all when the bridge was open, and so piers, foundations and supports on both sides are located outside the main river channel. As the bridge swings open it loses the support of the opposite bank, so needs something to act as a counterbalance. We achieved this by creating a very lightweight main span, with a much deeper, short backspan containing a substantial counterweight made of thick steel plates.
It is fantastic to see the bridge completed and in use every day. We engaged with the public and local community during and after construction using Twitter, which allowed us to keep people up to date with the bridge’s progress and generate excitement. The local community all seem to be very pleased with the new crossing, and it is very rewarding to see it opening up the river front to more pedestrians and cyclists.
We at Flint & Neill have a number of other interesting bridge projects at the moment. Along with Studio Bednarski, we are just about to complete the Inderhavn Bridge in Copenhagen, a moving bridge across the harbour, known as the "Kissing Bridge". Indeed Copenhagen is a very exciting location for bridge engineers at the moment: Dissing + Weitling and Ramboll have just completed the "Cycle Snake" (Cykelslangen) bridge for cyclists, while Wilkinson Eyre and Buro Happold are designing a new opening bridge across the harbour.
Personally I have a number of favourite bridge designers, including Laurent Ney in Belgium, IPV Delft in the Netherlands and Fast + Epp in Canada. There is so much inspiration to be had worldwide! Historically I really like the work of Ove Arup (especially Kingsgate Bridge in Durham) and Jorg Schlaich. Further back, the work of the Roebling family on the Brooklyn Bridge is a very inspiring story.
There seems to be an increasing awareness that elegance and care in bridge design doesn't need to cost a lot more. At the same time, bridges can be terrible if too much effort is put into an architectural fancy. In my view, simplicity of form and a careful response to the site can have an immeasurable impact on the overall success of a bridge, making them the centre of a community or a part of the public realm, rather than just a connection.
Visit The Structural Awards 2015 website to find out about our other shortlisted entries, and to buy your tickets.