16 January 2009

Bridge criticism 1: Of heads, and parapets

Late last year, I attended a talk by architect Cezary Bednarski, which ran through his experiences in the bridge design competition arena. I've covered some of the issues raised previously, but there's one that I wanted to return to.

A topic that arose repeatedly related to the various occasions when Bednarski had lost a competition and lost it to a design which in his view was a very poor choice. He offered as examples the notorious Krakow footbridge (pictured left, click any image for a larger version), Glasgow, and a competition for temporary bridges in Rome. Other examples of bizarre competition winners include Cambridgeshire Landmark East and River Wear. These mostly offer examples of exotic, ambitious designs where their very structural feasibility should have been in doubt from the start.

There has been ample criticism both of a competition process which frequently delivers designs beyond the budgetary constraints of a project's promoter (e.g. Stratford-upon-Avon, pictured right), or which will saddle them with expensive maintenance costs for years to come (e.g. Trinity Footbridge). But where precisely does the fault lie? With the competition clients, organisers, jurors or the entrants? I actually think at least some of the fault lies elsewhere.

Several of these competition designs were criticised in the press after the winner was announced. However, in most cases serious criticism only appeared after the project had failed (e.g. when the Glasgow bridge scheme, pictured left, went massively over budget). Is there perhaps a failure of the bridge design community as a whole to speak up about designs which are likely to be unusually challenging or high risk?

For several of the competitions mentioned above, there was no specialist landmark bridge engineer involved on the jury, and it is possible that whoever did judge them had no realistic way of benchmarking the likely costs and risks of the designs put in front of them. In many cases, the shortlisted entries are not made public, so there is no possibility for anyone else to assist by making informed comment.

If there's an appropriately knowledgeable and empowered bridge specialist involved in the judging, then in theory the absence of wider input should not matter. But I still wonder whether competitions would benefit generally from greater transparency, and the opportunity for a promoter to receive wider comment on the merits of the entries. One of the aims of this blog is to see whether a space exists for constructive public criticism of the merits of bridge designs.

Of course, that's where the problems begin. The heads, and parapets, of this post's title, and the unwillingness of bridge designers to stick the former above the latter.

Criticism of others' designs is far more common in the architectural field, indeed it's something that's positively encouraged from an early stage through the use of the architectural crit as part of an architect's education. There are very few analogues in structural engineering, although I'll address some that do exist in a future post.

Engineers are traditionally reluctant to publicly criticise the work of their peers. There are several reasons: simple politeness, commercial pressures, legal constraints, etc. All three of these can be found at work here on the Happy Pontist whenever comment is made on the merits of a particular bridge design. Legally, there is the risk of committing libel if criticism goes too far. Commercially, the critic can upset someone who may otherwise be a future client or commercial partner.

In a follow-up post, I'll look in more detail at one: ethics. Could it actually be unethical to criticise designs? That might seem ridiculous, but the engineering institutions promote precisely that view.


Anonymous said...

HP why was the Krakow design a well known example,
was it lack of ability to stand up? or was it because it was almost identical to the Bridge of Hope at Liverpool Cathedral.

The Happy Pontist said...

The Krakow design was one of those rare bridges that did receive public criticism for its ludicrous structurla design (via comments in New Civil Engineer magazine) - essentially it has a hinge at the middle so it could not possibly stand up. The Bridge of Hope (see http://www.hakes.co.uk/flash.html) is different, because it has a supporting column at the hinge point.