In December 2014 the Environment Agency awarded BAM Nuttall and its JV partner, Mott Macdonald, a 24 month long, £18m quay wall raising and refurbishment contract to improve flood defences in the east coast port of Great Yarmouth. This project would safeguard 2000 homes and business.
The project required installation of 24m long steel sheet piles and 60m long ground anchors and new concrete capping. This first phase was completed to great acclaim but was inevitably costly. The EA who had another 2500m of quay wall flood defences, over the next five years to address, needed a more cost-effective solution. Recognising that at another Great Yarmouth site, Bryant’s Wharf, accelerated low water corrosion was the primary cause of quay wall deterioration, BAM Nuttall suggested a more economical solution than full pile and ground anchor replacement.
The solution was BAM Nuttall’s tried and tested Limpet Dam technology which would allow the corroded area at the low water line of each pile to be accessed and repaired by engineers who could work continually in the dry, at all states of the tide, even when the workface was below the water line. Being much safer and economical than the full pile and ground anchors, limpet dams allow good quality patch repairs to be carried out without the risk and expense of divers and with minimal disruption to the socio-economic operations of the river users and port stakeholders. The EA sanctioned a trial of the limpet dam at Bryant’s Wharf which began in November 2016 and has proved to be very successful. Funding for the remaining 2500m of quay wall repairs is now being sought but as a result of the limpet dam trial much less funding is now needed than originally anticipated.
The animation which was produced by BAM Nuttall in house and the drone footage of works at Yarmouth were produced to help the EA gather support from local stakeholders for the future use of the limpet dam to solve Great Yarmouth’s critical flood defence requirements.
Click the links below to view both videos.