Automation of flood defences improves safety

Part of the project has concentrated on Stone Row Bridge that crosses over Skinningrove Beck in the centre of the village and was the scene of two devastating floods in 2000. It has involved the building of flood protection walls along the banks of the beck and the installation of flood doors as well as railings on the bridge that can be lowered to prevent the build up of debris.

The project also included improved communications links with the EA as well as telemetry equipment designed to give the village sufficient warning of increased water levels that could result in flooding. The increased warning time allows two local wardens sufficient time to lower the bridge railings and close the flood doors before warning local residents of the potential high water levels.

In a more recent review of the procedures involved during such events, it was concluded that there wasn’t always enough time to safely remove all the barriers before the doors needed to be shut. Originally there were ten sections of railings, five on each side, which had to be lowered manually before the flood doors could be closed. In some instances there was insufficient time to finish lowering all of the sections before the wardens had to leave the bridge and close the flood doors on account of the rising water level.

In order to improve the existing system, it was decided to automate the lowering of the barriers using linear actuators that would be controlled from a control station located adjacent to the flood doors. In this way the flood doors could be closed first, improving the integrity of the flood defence wall and allowing the barriers on the bridge to be lowered from a safe position.

ECS Engineering Services was awarded the contract for the mechanical aspect of the project as well as the installation and commissioning of the new bridge railing system. The new design uses connecting steel brackets to join the individual sections of railings together so that now there are two sections on each side of the bridge.

Each one of these will be raised and lowered using an electric actuator that is sealed so that it can continue to operate once the flood waters have receded. Working from designs supplied by the main contractor, ECS has provided the detailing for the steel designs and fabricated the brackets as well as installing and commissioning the control panel and the actuators.

Marc Jordan, Project Manager for ECS, comments: “The design of this system has been slightly constrained by the local electricity supply available at the site of the bridge. As a result, we have had to ensure that only one actuator is capable of operating at any one time, which has been achieved by including a series of interlocks in the control circuits.

“Once again the Site Services team has delivered, installed and commissioned the project on time and within budget. There is no doubt that this improvement to the original design will make a significant impact on the safety of the wardens who are being trained to operate the new system. This, in conjunction with other facets of the project, will help to reduce the risk of flooding to the village.”

In addition to this project the EA has completed further work with the replacement of three trash screens and a two mile stretch of the Beck being cleared of trees. Furthermore, it has also installed a lighting system to ensure that anyone operating the gates can work safely after dark as well as a flood warning signal that provides the local residents with advanced notice of high water levels.

The success of the improved flood defences has even reached as far as Japan with engineers visiting the village to learn from the scheme and its involvement of the local community.