Bridges I have Loved - Allen Paul (Zoom)

President Irene Walker opened with an “ice-breaker” question about Burt Lancaster and was surprised by how many members got the clue on his early circus career.

After some club business, member Jim Douglas introduced his wife’s cousin Allen Paul to talk about “Bridges I have loved”. As a civil engineer working for world renowned bridge designer and builder Arup Group, Allen explained how Fife was the reason for his career, after spending holidays as a child, fascinated by history of Tay Bridge and love for Forth Railway Bridge. 

In his very excellent presentation, Allen provided a fascinating story of bridge design, bridges worked on in UK and overseas. Some bridges described were very large and significant such as Queensferry Crossing, others small in lovely locations such as Kylesku Bridge in Sutherland.

In describing each bridge, Allen outlined key design principles and challenges, illustrated with photographs, diagrams and videos. Also included in the talk were bridges planned but never built, sometimes for political reasons. In one case in Chile, an earthquake area risk.

Moving on to talk about the 3 Forth bridges, Allen’s talk title was clearly brought out, as he thinks we are so lucky to have 3 different but lovely bridges to enjoy in one superb location. The members were very interested in learning more about the cable corrosion problems of the Forth Road Bridge but reassured by the success of measures taken; such problems are not uncommon, apparently, with such bridge designs.

In talking about the Queensferry Bridge, Allen’s last project before retirement, the reasons for its unique design were explained and photographs shown of the surprisingly complex interior of the roadway box girders.

Finally, Allen related the fascinating story about the history of the London Millenium “so called wobbly” Bridge. It was only when the bridge opened and thousands of pedestrians walked on to the bridge, was the lateral sway of the bridge identified, creating pedestrian fear and “sea sick” feeling.

Allen explained clearly how this wobble was created by crowds of people walking side by side and in finding a solution, the only previously recorded similar problem was found in an obscure Japanese technical paper. Although the bridge had to be closed until solution found, and was clearly an embarrassment, it was never at any risk of falling down.

The solution found was very elegant in that did not change the aesthetics or use of the bridge, now very popular; particularly interesting was that in the research, a simple golf club bridge in Aberfeldy provided clues to the problem and its resolution. 

Members raised number of questions, showing the close interest in Allen’s talk, but also how brilliantly he had explained the complexities of bridge design and why he had so much loved his work. Jim Douglas provided vote of thanks for a memorable talk.