Trash screens primarily protect culverts from becoming blocked by debris. Detritus is hard to extract once it has found its way into a culvert, and if it is allowed to build up, it can adversely affect flow. Trash screens also provide security, restricting public access to the culvert itself. Therefore, ensuring that trash screens are optimised to the needs of each culvert is essential.
As part of the service, ECS carried out thorough inspections of all the trash screen locations. With installations stretching from Chichester to the Isle of Wight, ECS employed its extensive on-site service teams to complete the work efficiently. Sites varied greatly, with trash screens in some cases near railways or on farmland. After inspections were complete, it was clear each would require an individual approach.
ECS operates an in-house design and fabrication capability to meet large projects such as this.
Each site has slightly different requirements, whether that was in the design of the trash screen or the supporting infrastructure. A number of locations require a newly designed trash screen and cranked handrails. In some cases, new access platforms were required to allow personnel to inspect and clear the screens. Fabrications were carried out in mild steel and then galvanised to Environment Agency specifications. All steelwork complied to CE Marking BS:EN1090-1 Execution Class 2 (EXC2) - well within ECS’ EXC4 certification.
With the fabrications work completed in house, ECS began to overhaul each site. Old trash screens are to be removed and replaced. Each and every new screen will feature a minimum 140 mm clearance underneath to allow smaller debris through, promoting water flow through the culvert. While many of the sites could be overhauled manually, in some challenging areas cranes are utilised to move loads into place. New railings are being installed, as well as new steps and access platforms where required. In certain areas, bunds will also built by ECS.
Mick Smith, project engineer at ECS, concludes: “Trash screens are a real area of expertise for our business. We have recently completed a similar overhaul in Nottingham, also for the Environment Agency, but this particular project was on a much larger scale.”