Switch to Rotork restores reliability on River Thames weir

Rotork IQ3 electric actuators and MTW gearboxes have been installed on Hambleden Weir on the River Thames.
Rotork IQ3 non-intrusive intelligent electric actuators have been chosen for the operation of radial gates on an important river management weir on the River Thames.

Hambleden Weir plays a critical role in maintaining the level and flow in an area that is used extensively for recreational activities, including the stretch of river that hosts the world famous Henley Regatta. The reliable operation of the radial gates is a vital requirement for effective river management, especially with the varying weather conditions and increased risk of flooding experienced in recent times.

The Environment Agency had been encountering numerous reliability problems with the eleven electric actuators previously installed. Lock Keeper Simon Shepherdson explained: ‘Most of the problems resulted from inadequate environmental sealing, which allowed rainwater to get inside the actuators and damage electrical components. In practice this often meant that an actuator would work on some days and not others.’

The sealing problems were aggravated by the design of the actuators’ manual operating mechanism, which sometimes would not work against the heavy weight of large radial gates.

There had been many attempts to upgrade the actuators with spare parts, but they had met with little success. It was therefore decided that replacing them with doublesealed Rotork actuators would be the best solution.

Working for the Environment Agency, Integrated Water Services awarded the turnkey contract to Rotork Site Services. Rotork’s proposal encompassed all aspects of the task in an extended scope contract, enabling them to organise the total supply of the work together with project management services.

These responsibilities encompassed the removal of the existing actuators and gearboxes, fitting Rotork IQ3 actuators and MTW gearboxes, cabling and commissioning. New junction boxes were fitted adjacent to each actuator enabling existing cabling to be used wherever possible to avoid additional expense. Beginning in the autumn of 2014, the project has been completed on time and within budget.

The new actuators are Rotork’s latest IQ3 units, featuring non-intrusive setting and diagnostic data management and fitted with 4-20mA signal input and output capabilities to facilitate possible further automation upgrades in the future. IQ3 actuators also feature a robust direct-drive handwheel mechanism, capable of moving the heavy gates if manual operation is ever required.

Combined with non-intrusive setting and commissioning, the IQ3’s doublesealed IP68 watertight and temporarily submersible enclosure specification permanently protects internal electrics from the ambient environment, even during site wiring. The double-sealed design, whereby the terminal compartment is separately sealed from the rest of the actuator, has been a standard feature on Rotork electric actuators for over forty years and is proven to increase long term reliability, durability and availability in the harshest of climates.

Simon Shepherdson summed up the changeover to Rotork by saying ‘The upgrade has given me the peace of mind of knowing that I can now operate the weir with confidence, without the worry and uncertainty that I was previously experiencing.’

This project is one of an increasing number that have been awarded to Rotork Site Services for the upgrade and automation of river weirs owned by the Environment Agency or in private ownership.

Rotork UK
Tel: +44 (0)1225 733 200
Email: information@rotork.com
Web: www.rotork.com

Published in Valve User Magazine Issue 34


Autumn 2015 // Issue 34
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