Optimisation of tapered stress joints for offshore catenary risers

The Anderton Boat Lift is located on the banks of the River Weaver at Northwich in Cheshire. The lift links the River Weaver Navigation with the Trent and Mersey Canal (T & M), which is 15m higher and runs very close at this location (Fig 1). In 1875 the original hydraulically-driven iron structure was built to speed up the transhipment of goods between the river and canal. In 1908 the lift was converted into an electrically driven mechanical operation by adding a new steel structure over the original lift. The lift continued to operate in this way until its closure in 1983 on safety grounds due to deterioration of the structural elements. This paper describes the recent restoration of the boat lift by British Waterways, back to the original hydraulic method of operation whilst retaining the 1908 structure as a static monument. Jamie Gray, BEng Project Engineer, British Waterways North West Region Tim Brownrigg, BSc, CEng, MICE Senior Project Engineer, British Waterways North West Region.