Four finalists have been announced in London's Nine Elms / Pimlico pedestrian and cycle bridge design competition. They were chosen from a field of 74 entries.
The finalists are:
Buro Happold Limited with Marks Barfield Architects, J and L Gibbons Landscape Architects, Gardiner and Theobald
Bystrup Architecture Design and Engineering with Robin Snell and Partners, Sven Ole Hansen ApS, Aarsleff and ÅF Lighting
Ove Arup and Partners Ltd with AL_A, Gross Max, Equals Consulting and Movement Strategies
Ove Arup and Partners Ltd with Hopkins Architects and Grant Associates
It is, of course, grossly unfair to judge the outcome of the contest based solely on these four rendered images. The jury allocated only 30% of their marks to these images, with the remaining 70% being for images as yet unreleased and the accompanying written submissions. However, a few comments may be in order.
What unites the designs is that they are in general structurally feasible (a characteristic not shared by all the entries), relatively modest and undemonstrative, and yet also at the same time tall. Indeed, some of the finalists are far taller than seems reasonable. The Arup / Hopkins design appears to have masts roughly twice the normal height for a suspension bridge, the Bystrup / Snell masts are also a little on the pointy side, while the Happold / Marks Barfield bridge is really striving to dominate its surroundings.
The Happold design is a development of the work they did for the client at pre-contest stage, although with a few unusual features. The image appears to show only single cables emanating from the tower top, then splitting to pick up the deck via a cable net arrangement. This is a pretty diabolical structural arrangement, which would be a nightmare both to build and maintain. The entire load from the bridge's main span must pass through two cable attachments, creating single points of failure which cannot easily be replaced if damaged. The mast is also split into two stems, although whether this two-fingered salute is aimed at the Nimbies on the Pimlico bank, or at the nearby US Embassy, it is difficult to tell.
The Arup / Hopkins bridge minimises physical impact on the riverbanks by locating the necessary serpentine cycle ramps above the river, and hence vulnerable to impact from stray boats in time of flood. Pedestrians appear to share the main span with cyclists, but to pass down via staircases which, like the masts, penetrate vulval openings in the ramps in what seems to me a very awkward arrangement.
Bystrup's entry is shrouded in mist but clearly features a quite improbable cable-stayed arrangement, where the back-stay cable are so steep as to be almost ineffective at restraining the tower. It's possible the weight of the supported ramps provides sufficient balance, but it looks horribly wrong in the image provided.
The Arup / AL_A design is my favourite of the four finalists. The skewed arch arrangement echoes several other similar bridges (the Clyde Arc, Hulme Arch, Gogarburn Bridge, Newport Street Bridge, and River Taff Central Link Bridge) but would become easily the largest of this type in the UK. Given how massive the Clyde Arch is (with a 96m span), this gives some feel of quite how enormous the Nine Elms Pimlico structure would be. This is not a straightforward bridge to build over a busy river, so it will be interesting to see how the designers addressed the "constructability" challenge set as part of the competition's first stage.
Overall, it is pleasing to see that the jury has not been swayed by either celebrity or by irrelevant flash, but I am far from convinced that these four were the best designs available, they instead have a strong scent of mediocrity. However, the promoter was clear that they were not choosing a design at this stage (indeed, the press release very pointedly labels each image as merely an "initial design idea"), but choosing a team. As a result, it will be very interesting to see how the designs evolve through the remainder of the competition and beyond.
The finalists go through to Stage 2 of the competition, described as a "competitive dialogue". Each team will be paid £12,000 to develop and further detail their design proposals, and to participate in a series of workshops and review meetings with both the Technical Panel and Jury Panel. I find this separation into two panels to be quite bizarre: it implies that the jury has insufficient technical expertise to properly evaluate the proposals, while relegating that evaluation to subordinate status. Why not just ensure the jury includes sufficient technical expertise within its ranks?
As well as being evaluated on their designs, the four finalists are also required to submit formal financial tenders for the design commission. As in the recently announced Bath Quays footbridge contest, the final evaluation of the competition will blend both the quality and commercial aspects, although the way in which this will be done remains opaque at present.
Right now, it's difficult to judge whether this project will ever actually make it to site, with Westminster Council, the authority for the north bank of the River Thames, actively opposing it. The project promoter, Wandsworth Council does at least now have four designs all of which should in principle fit within their £40m budget, so one of the normal issues with architectural bridge competitions has been successfully negotiated.