28 May 2010

Lessons from history - the steel box girder story

Every year since 1989, the IStructE Study Group on the History of Structural Engineering has arranged an annual lecture, now titled the James Sutherland History Lecture in honour of the study group's founder.

Past lectures have been given by such notable figures as Ted Ruddock, Michel Virlogeux, Roland Paxton and Frank Newby, and many of the lectures have been published in the IStructE's magazine.

This year's lecture, in February, was by Ian Firth and covered the "steel box girder story".

All but the youngest bridge engineers will (or should) be familiar with the series of box girder bridge failures at the beginning of the 1970s, at Milford Haven, West Gate, Koblenz, etc. The subsequent investigations (by the Merrison Commitee and others) led to both a much greater understanding of the behaviour of plated steel structures, as well as new rules (such as the Interim Design and Workmanship Rules, see a very relevant paper by Bridle and Sims [PDF]) covering such issues as the need for checking of complex structures, involvement of designers in construction, and proper analysis of temporary conditions during construction.

My reason for posting is simply that the lecture is now available as an online webinar (with both video and slides), and although I've not had time to watch it all yet, what I have watched is excellent. This very important slice of bridge engineering history is covered in commendably thorough detail, but perhaps of more significance is the way it suggests that current procurement practices are forgetting the lessons learned from the 1970s (for example, on some schemes I have seen construction supervisors appointed who have had no involvement in the design, or understanding of it).

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