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In 1809, Bristol was transformed by the opening of its floating harbour, which installed lock gates on a tidal stretch of the River Avon to allow visiting ships to remain afloat all the time.
Almost 200 years later, in 2006, the lock gates were found to be at serious risk of failure. This could cause the harbour to drain and lead to the collapse of the floating harbour walls and to subsidence of nearby buildings.
Securing this historic harbour was a major engineering challenge and required a careful marriage between existing Victorian infrastructure and modern methods. The work included replacing the existing timber lock gates, and installing new hydraulic operating mechanisms for the gates and the swing bridge. Manufacturing and installing the new equipment depended on sub-millimetre accuracy – a real challenge in this environment.
The impact on the community and environment were major considerations: the bridge remained open to traffic during the works; the two 80-tonne timber lock gates were recycled, and existing pits and trenches were re-used for new equipment.
"Bristol’s floating harbour is secure following this essential contract."