Water & Wastewater Treatment

www.wwtonline.co.uk | WWT | MARCH 2016 | 19 Project focus Flood defence Winds of change in tidal gate replacement Project focus ● Replacement required of 1930s tidal gate on River Trent ● 26-tonne sluice gate needed crane li with restricted local access ● Work carried out by ECS Engineering under Environment Agency framework agreement By Jamie Wesley, Commercial Manager, ECS Engineering Services H aving been in service for over 75 years, the tidal gate at West Stockwith in Nottinghamshire has been replaced as part of a continual improvement programme being carried out by the Environment Agency (EA). The project, which took just over three months to complete, was awarded to ECS Engineering Services as part of its framework agreement with the EA. The West Stockwith sluice gate forms part of the tidal River Trent flood defence scheme and was originally installed in 1938. It operates automatically at every high tide to prevent the River Trent flowing into the lower River Idle, which prevents local flooding, reduces the silt build- up in the River Idle and stops salt water contamination. The sluice gate works in partnership with the nearby pumping station located just upstream on the River Idle; between them they can act as a large lock to allow narrow boats to navigate up the river. ECS, as the appointed main contractor, was responsible for the complete refurbishment contract including the gate removal, installation and commissioning. ECS has completed several projects previously at this site that have involved the refurbishment of the counter-balance and of the winding gear located above the sluice gate. The timing of the project was planned for a time of year when flooding was least likely to occur so that the brief period between the removal of the old gate and the installation of the new gate would not pose any flood risk to the local area. One of the major logistical issues was getting a crane on site that was large enough to liŠ the 26 tonne sluice gate, especially with restricted local access. The answer came from a local crane hire company that managed to position a 120 tonne mobile crane on site and then rig it with 76 tonnes of ballast to give the crane a rated capacity of 220 tonnes. With the calculations done, all that was needed was a calm day to allow the old gate to be removed. With all the electrical services removed, the top platform of the sluice gate, which contains the liŠing winches and the control gear, was removed to allow access to the sluice gate itself. The liŠing operation required almost perfect weather conditions due to the weight of the sluice gate and its tendency to act like The completed sluice gate is precisely fitted ECS oversees installation of the newly refurbished sluice gate

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