14 July 2011

Footbridge 2011

I spent most of last week in Wrocław, Poland, for the Footbridge 2011 conference. It was a wonderful opportunity to meet old friends and make new ones, and made particularly enjoyable by the generous hospitality of our Polish hosts. The 2011 Footbridge Awards were presented at Wrocław's Town Hall, parts of which dating back to the 13th or 14th century. The gala dinner at the Centennial Hall was also hugely enjoyable, although sadly this didn't take place within the Hall's main building, a spectacular reinforced concrete dome spanning 65m (pictured, courtesy m.by).

The conference featured 162 papers from 38 countries, and I was pleasantly surprised at the generally high quality both of the papers and accompanying presentations. There were seven keynote lectures, of which the first three set the agenda for many of the informal discussions that took place throughout the week.

The first of these was Benchmarking cost and value of landmark footbridges, by Brian Duguid. This took the conference's official theme ("Attractive structures at reasonable costs"), and tackled the question of reasonableness in two ways. First, by presenting a survey of about forty recent landmark bridges which suggested an average cost of about €8k per square metre, or €38k per linear metre. More intriguingly, it asked us to consider what value a landmark pedestrian bridge provides to its local community, and whether we could actually calculate it. I suspect that's a tall order, although perhaps worth pursuing in the current climate (which, at least in the UK, has seen landmark footbridge construction hugely diminished). The presentation nearly managed to make cost estimating sound interesting, which is a tough challenge.

This was followed by Cezary Bednarski's The 'Chained' Bridge: Attractive structures at reasonable cost?, which pursued the theme of "reasonableness" from a very different angle. This talk's contention was that designers have an obligation to avoid waste, and that bridge architects tend to produce designs which are both wasteful and irrational when not restrained by chains, particularly the chains imposed by the requirements of sound structural engineering. A number of examples were given, including a footbridge proposed for Krakow which I have covered here previously (pictured below).

Bednarski's outrage both at its structural impudence and its visual impact on a nearby castle was a rare and welcome case of a head being raised above the parapet, although it proved controversial, with one Polish engineer boldly stating his view that the engineer's job was to help realise the architect's vision, a suggestion which didn't even meet with the approval of many of the architects present. The Poles are clearly treating the Krakow bridge as a serious proposal, with the magazine Mosty ("Bridges") devoting six pages of a recent issue to an explanation of the engineering plans, including various technical and construction sequence diagrams (these make clear, incidentally, that it is a twin-cantilever bridge, not an arch).

Jan Biliszczuk and Wojciech Barcik's keynote presented Footbridges in Poland - the history and present state. This made for interesting viewing following on from open criticism of the Krakow bridge (as well as another landmark footbridge Krakow, already completed). Large parts of the presentation suggested that Poland has yet to catch up with the aesthetic sensibilities that most contemporary footbridge designers aspire to.

The Luk Erosa footbridge, pictured, is one of a number of Polish bridges where bold colour seems to be used to divert attention from an unnecessarily gimmicky structural form and, in many cases, an over-reliance on circular steel tubes. Those tubes are everywhere, the styleless stock-in-trade of dozens of footbridges. The colour at Luk Erosa is pretty inoffensive compared to some of the other examples which were presented. I heard one attendee asking whether it was all an exuberant over-reaction to freedom from communism, but there are other countries in Eastern Europe which don't seem to share this affliction.

In fairness, I heard a lot of criticism of Polish designs, but I saw several footbridges which were sensitive and attractive in appearance. In Wrocław itself, there is a simple glulam timber bridge over the town's old moat (pictured above), which sadly I didn't get a chance to visit, and at Sromowce Nizne, there is a 90m span glulam timber cable-stayed design which is both technically adept and charming (pictured below). [Incidentally, following that last link leads to a collection of the papers from Footbridge 2008, and many other conference proceedings in rather blatant breach of copyright].

There were several other papers that I would like to discuss here, although I am currently snowed under with work, so don't expect anything very quickly. I also visited quite a few bridges in Wrocław, and will post photos and commentary on those, again when time permits.

The next Footbridge conference will be in 2014, and it will have a tough job living up to the hospitality, organisation, and delightful setting which Wrocław provided.

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