Keadby Drawbridge is unique in the UK as the only rail drawbridge, with the deck retracting to allow boats to use the Keadby Canal. Originally a swing bridge, it was converted to a drawbridge in 1925 by Sir William Arrol, but the deck and much of the equipment was replaced in 2003. Despite the deck replacement, the bridge continued to suffer from problems over excessive movement of the track at the north abutment and difficulty maintaining track condition on a strategically vital freight route. Inspection revealed that the north abutment was in extremely poor condition below the water line as a result of the numerous heavy axles crossing a gap in the rails.
HBPW have engineers who have extensive experience in working on rail moving structures, despite their scarcity. They built on previous investigation work and using their knowledge designed a replacement for the north abutment to give far more robust support that could cope with the hammering effect from passing trains. Working with their trusted supply chain, HBPW designed replacements for the timber waybeams supporting the track with a steel beam system, similar to that successfully employed on two nearby swing bridges.
The work was undertaken during a nine day blockade, with HBPW also providing design support for extensive temporary works. Despite being one of the most complex bridges on the network, the works were completed and the track was handed back on time. Following the repairs the performance of the track system was dramatically improved with reported faults reducing to almost zero – a situation almost unheard of at this bridge. The scheme demonstrates HBPW’s ability to undertake technically complex multi-disciplinary projects.
