John Collins
Associate, Roughan & O’DonovanJohn is a chartered civil engineer and leads Roughan & O’Donovan’s (ROD) UK bridges team as an Associate. He has over 15 years’ professional experience as a designer, predominantly working with existing rail and highway bridges. This includes development of a specialism with suspension bridges including the Humber Bridge and Forth Road Bridge. He was a co-author of the CIRIA guide Hidden defects in bridges and has authored multiple technical and conference papers. In 2016 he was named an RAEng Engineers Trust Young Engineer of the Year.
My Speaker Sessions
Wednesday 08 March 2023
Humber Bridge rocker bearing replacement
When opened in 1981 the Humber Bridge was the world’s longest span suspension bridge, with a main span of 1410m. The bridge is owned and operated by the Humber Bridge Board (HBB).
The bridge was designed with bespoke A-frame rocker bearings to support the deck at the towers and anchorages, whilst allowing large movements under traffic, temperature and wind loading.
During a special post-storm inspection in February 2020, the A-Frames at the south tower were found to have significant new defects.
HBB appointed a team of specialists to perform a series of inspections, structural health monitoring, testing including a load trial and steelwork repairs. Information generated at this stage informed the design of replacement steelwork and bearings. The allowed installation of almost all replacement steelwork in advance of load transfer while traffic continued to use the bridge. Load transfer to the new steelwork was achieved by HBB as contractor supported by a local supply chain at both towers in less than 4 hours. This involved jacking load into the new steelwork, then cutting through the old rocker bearings to take them out of service, and finally bolting anti-uplift steelwork in place.
