The project also delivered improved automation and reliability which reduced maintenance costs. Located in Waltham Abbey, Essex, the Rammey Marsh sluice gates form part of the extensive flood prevention equipment on and around the River Lee. Originally built as part of a flood alleviation scheme, the three sluice gates form part of a network of sluices and weirs designed to maintain the water level in the flood relief channel and associated lakes, but also allow flood water to be discharged towards the Thames when necessary.
Originally built in the 1950s, the drive systems for the sluice gates, each of which had reached the end of its serviceable life and the EA set in place a project not only to replace them but also to improve the automated control system at the same time. The motors, gearboxes, brake assemblies and hand wheels all needed to be replaced with the new components connecting to the existing main shaft which held the wire ropes used to raise and lower the sluice doors.
ECS designed the new drive system to incorporate Rotork IQ35 actuators that were connected to 90°gearboxes. The new actuators have an IP68 rating to ensure optimum performance in this application and they are also fitted with additional 4-20 mA relay outputs that provide a signal for the current position of the sluice gate. This information can be transmitted back to the central control point to provide vital data on the status of the sluice structure.
The renovation project involved design and fabrication work to position the new drive mechanisms in exactly the right place for the connection to the main drive shaft above each sluice gate. In addition ECS created some additional access platforms and hand railing to ensure that EA engineers can safely operate the hand wheels without the need for temporary access equipment.
The original motor control centre (MCC) was retained but the ECS electrical engineers modified the control wiring of each sluice gate to accommodate the new position signals and the more modern actuator controls. As each drive system was completed it was tested and commissioned before work started on the next sluice gate. In this way the EA maintained operational control of two sluice gates at all times, which is sufficient for the day to day operation of the site.
Jamie Wesley, Commercial Manager, Water Control Division, explains: "This contract forms part of our on-going commitment to delivering projects for the EA across the UK. As a framework contractor for the EA, ECS is trusted to deliver the skills and expertise required to design, fabricate and install entire projects safely and on time. This project required a wide range of skills including fabrication, electrical control engineering and mechanical design work, all areas in which ECS has considerable experience.”