River weir upgrade demonstrates Rotork’s extended scope capabilities

A recent UK Environment Agency river management scheme has demonstrated the ability of a Rotork Site Services extended scope contract to provide project management and organise all the mechanical, electrical and civil engineering work required to complete the project. A major benefit for the customer is the simplified contractual route that the extended scope contract enables by reducing the number of separate sub-contractor contracts.

For many years Buscot Weir on the River Thames had been equipped with electric motors that were used to adjust the position of two sluice gates in order to manage the river level and flow rate during fluctuating weather conditions. These motors, with the associated valve shafts and an electrical control panel in an adjacent building, had become obsolete and required replacement to safeguard the river banks from potential flooding in the future.

As well as replacing all the obsolete equipment, the Environment Agency wished to ensure that future inspection and maintenance could be carried out safely. To achieve this it would be necessary to construct a new access walkway platform along the length of the weir. Following the preliminary site survey of the existing installation, Rotork Site Services submitted a contract proposal to the principle contractor AMCO Engineering which encompassed project management services and the total supply of all the elements of the project – new valve actuation, valve adaptation, wiring and control panel, new walkway platform, removal of old equipment, installation of new and commissioning.

Upon acceptance of the proposal, Rotork engineers returned to site to carry out a detailed survey to enable the replacement equipment to be dimensioned, designed and fabricated and to organise all the other equipment needed for the installation work such as scaffolding and temporary access. In this case it included the provision of pontoons by a company that specialises in safeguarding working environments when the presence of water is a potential hazard.

Rotork’s design team was able to replace the two existing electric motors with a single IQ3 electric valve actuator to operate both sluice gates simultaneously, driving through a combination of new shafting and three Rotork gearboxes. The IQ3 actuator is certified as watertight and temporarily submersible to IP68, providing secure environmental protection for long term reliability in all anticipated ambient conditions. As the installation is adjacent to a public footpath, additional security is provided by the fitting of a vandal-proof cover over the actuator’s local control buttons to prevent any unauthorised operation or interference.

Rotork Site Services co-ordinated the manufacture and fabrication of all the new equipment and materials required for the upgrade. When this was completed, engineers from Rotork and the sub-contractors were back on site to remove the old equipment, install the new actuator and valve shafting with control panel, wiring, walkway platform and all associated ancillaries, completing the installation and commissioning within seven days.