Black Bridge

UK: A river bridge which has been subjected to 30 flood-related closures in the past decade has been raised by 1 m in a £3·6m six-week project undertaken by Network Rail and contractor AmcoGiffen.

It was decided to lift the 80 tonne bridge over the River Dulas on the Machynlleth to Shrewsbury line manually, rather than using hydraulics, to ensure there was no twisting or buckling of the structure. Eight 20 tonne chains were used, raising the bridge 10 mm for every 10 m of chain pulled.

Network Rail worked with Natural Resources Wales and ecological specialists to plan the work around fish spawning, and engineers were on site from May 15 to June 26 with the line reopening June 28.

‘With nine months from concept to completion, we knew from the outset that it was going to be challenging to deliver this scheme in such a short timescale’, said Andy Crowley, Operations Director for Wales & Western at AmcoGiffen. ‘We also understood the necessity behind the risk being taken. Collaboration was crucial from the start and when severe weather hit the early days of the project, we all worked together to recoup the lost time and maintain our schedule.’