Incredible teamwork prevailed at the successful installation and raising of the two bascule leaves of Herring Bridge, a significant achievement of the Great Yarmouth Third River Crossing project. To monitor and provide engineering support during construction, H&H’s movable bridge engineers were on site with design partners Roughan & O’Donovan, joint venture contractors BAM Nuttal and Farrans Construction, client Norfolk County Council, as well as Victor Buyck Steel Construction and Qualter, Hall & Co Limited.
Construction staging and coordination between the design team and contractor included detailed calculations of the bascule leaves weight and weight distribution for each stage of this highly choreographed installation. Each 770-tonne bascule leaf was carefully lifted and placed by a 1,800-tonne floating crane. Verification measurements of the bascule span trunnion assemblies were performed to confirm alignment prior to rotation to the upright position.
H&H Principal, James Phillips, notes, “Achieving success in the installation and raising of the bascule leaves in a 72-hour window is only possible through detailed planning, coordination, and on-site supervision. Relationships formed during design were fully realised in the field. This supports our goal of delivering a movable bridge that will operate as seamlessly and reliably as the design-build team has worked together throughout.”
This new movable bridge will support two carriageways, two footpaths and provide a 50-metre navigational clearance along the River Yare, improving journey times, reliability and easing traffic congestion. In the upcoming weeks, mechanical and electrical systems will be integrated seamlessly with the mechanized bridge’s structure.