Emergency works help to ensure River Mole water levels

A mobile crane installing the stop logs to the tilting gate

Mackley has completed works to improve the long-term reliability of an important sluice on the River Mole in Esher.

At the beginning of March, Mackley received an urgent request from the Environment Agency to attend Viaduct Sluice to recover the tilting gate which had become stuck in a 40% open position.

This was resulting in the upstream river levels dropping significantly to an unacceptably low condition.

Mackley, along with Hunton Engineering and Loxton Installations, quickly responded and were able to manually raise the gate into its fully closed position using the EA field team’s hand held electric power winder.

It was apparent that the actuator (motor) had a mechanical fault and also that the remote panel in the control room was not working as it should.

Mackley were then instructed to carry out work to the tilting gate to bring it back into reliable operation, which included removing the actuator and sending it off to Rotork for an upgraded clutch mechanism to be fitted.

Stop logs (temporary dams) were installed either side of the tilting gate so that it could be fully lowered to relieve the load on the actuator without affecting the penning level upstream.

The Mackley Hiab removing the stop logs

Sealift Diving assisted with the installation of the stop logs and proved their value to the operation when a diver removed a number of ceramic insulators that were lodged in the channel which would have prevented the installation of the upstream stop logs.

With the stop logs in place and the gate lowered, the actuator was removed and sent off to Rotork. The lead in time for the upgraded clutch would be several months.

Making good use of the stop logs being installed whilst the actuator was off site, the EA instructed further works to bring the sluice back into more reliable operation in readiness for the winter.

Hunton Engineering replaced the wire ropes, reconditioned the eel pass and carried out numerous maintenance tasks to improve general reliability. Loxton Installations carried out works in the control room, replacing old control panels to return them to an operational standard.

On 9 October the final testing and commissioning of the upgraded actuator and the new control panels were completed, the stop logs were removed and the sluice has successfully been put back into operation. For the first time in many years the displays in the control room are now working as they should.


12 November 2020

Posted in News.