Client: Nomenca Limited
Project Name: River Avon Weir, Remedial Works, Chippenham
Project Overview: The counterbalance that operated the Radial Gate on the River Avon Weir had been found to be corroded and in an unsafe condition. The Contract required Lifting Projects UK to supply fully competent personnel and the necessary equipment to ensure that the Radial Gate was made safe thus eliminating the potential risk of the counterbalance becoming detached from the radial gate, which would then create a blockage in the Weir. There were several restrictions on site, one being the actual access and egress which was very tight and the other being an arbitrary ceiling height of 7 metres had been imposed on the entire site due to the proximity of high voltage power lines in the working area. This was set by Lifting Projects UK, and Nomenca as a ‘blanket’ site rule for simplicity.
Our Approach The work to alleviate the situation was proposed and executed to our detailed method statement, which was approved by the client. The work included:
• Existing stop logs had been provided to replicate the function of the existing Weir and these were installed using a small telescopic crawler crane and located by divers.
• 2 x 15 tonnes SWL gantries were designed and fabricated by Steelwise (our in house fabrication facility) to operate the Weir manually. These were then installed using the crawler crane and operated by Lifting Projects UK personnel.
• Once the Weir had been raised, it was locked into final position using an existing mechanism.
• The gantries were then removed and the site handed back to the client on time and as the agreed programme.