Pont Simone de Beauvoir

My thanks go to Mary for finding this article in the Sunday Independent on Paris’ newest bridge, Le Pont Simone de Beauvoir:  http://www.sundayindependent.co.za/index.php?fArticleId=3340477

I am fond of this bridge – not a word I would ever use for a person but entirely appropriate for a graceful structure such as this.  Last February I lead a group of 80 students on a three day tour of Paris’ engineering sites.  This is no news to most readers of this blog as I suspect that most of you were on the trip.  For the benefit of those that weren’t, the weekend was packed with an ambitious itinerary of Paris’ engineering and architectural attractions.  For me, the highlight was this bridge.

 Reading this article, I am sad, although not unsurprised, to see that the structural engineers on this project – Paris based RFR (www.rfr.fr) – are not once mentioned.  I struggle to think of a construction project where architects have been involved and not engineers.  Even the models at the end of year show at the Architect’s Association (www.aaschool.ac.uk)  this year had to be checked over by a structural engineer to make sure they were safe. 

When it comes to bridge design, I believe there is an important part to be played by architects but that the design should be lead by the engineering.  When it comes to buildings, the engineering – the stuff what makes it stand up and not fall over when the wind blows – can be hidden away, like in the Ritz (London’s first steel-framed building) or on display for all to see like at the Pompidou centre.  With bridges however, there is no hiding the engineering.  The structural design is the language of the bridge from which all other things follow.  It’s very hard to hide it.

I am sure that your comments will help me clarify my stance on this matter so I shall leave it there for the moment.  There is more to say however on this bridge.  Firstly, its structure should really referred to as a lenticular truss.  Thinking of it as an arch bridge supported by a suspension bridge is helpful.  Anyone who had just read that article might think that the bridge’s width was purely architectural.  It should be noted however that such a long-spanned bridge is susceptable to fluttering in the wind.  The bridge’s width helps to stabilise it from these wind induced oscillations. 

 Secondly, the bridge was not technically built in Paris, but rather on the banks of the Rhine in Germany.  The enormous central span of the bridge was constructed at a German steel fabricator, and then loaded onto two enormous barges, floated up the Rhine, along the North Sea Coast down to Le Havre, under the Pont du Normandie (my favourite bridge http://www.carte-postale.com/honfleur/pontdenormandie.htm) and up the Seine to Paris where low tide had to be waited for to get the enormous section under Paris’ low arch bridges.  The whole journey can be seen on the website of the guy who lead the strucutal desgin on the project, Henry Bardsley (http://www.henry-bardsley.com/).

Though it has been open for a few months now, I have yet to make a crossing.  I am sure that when I do, readers of this blog will be the first to know.