The Electricity Alliance benefits from Layher new bridge system
By Maria Hadlow27 August 2010
The Electricity Alliance has become the first UK organisation to use the new Allround Bridging Truss System from modular scaffolding manufacturer, Layher Ltd. The installation, adjacent to Drax power station, is providing temporary pedestrian access during maintenance work: it has met key application requirements and, Layher says it has cut installation time by an estimated 83% compared to conventional alternatives.
Dixon Scaffolding has been appointed by the Electricity Alliance East, a partnership between the National Grid and Balfour Beatty, to provide access above a live road used by all the goods vehicles entering Drax via the material handling gate-house. Managing director Lee Dixon said that the strong yet lightweight design of the Layher system has meant the 18.5 m single span has had an immediate beneficial impact on the installation procedure.
"We were given permission to close the road for six hours overnight but in reality we needed only four," he says. "This compares dramatically to a 'traditional' tube and fitting approach which, we anticipate, could have required continuous closure for some 24 hours. As a result, potential disruption to road traffic was kept to an absolute minimum."
The Layher Allround Bridging Truss System now connects the Drax site to a temporary car park located on the opposite side of the road. The work being undertaken by the Electricity Alliance - replacing elements of overhead line conductors - required an existing car park on the Drax site to be used for both access and plant storage.
"The decision was taken, therefore, to create a temporary car park area on the far side of the roadway which clearly needed to connect to the main complex - a requirement which has now been easily addressed using the Layher bridging system," said Mr Dixon.
The reduction in installation time was due to the modular design of the new system which uses the same rosette connection system as Layher's Allround scaffolding. Support towers, incorporating the Layher Stairtower system, were erected both sides of the carriageway to a height of 6.2 m with kentledge used at ground level where the location called for a cantilevered section over underground electricity cables.
"Because of the inherent strength of the Layher design the full span was assembled as a single unit at ground level and was then easily and rapidly craned into position to become operational almost immediately," said Mr Dixon. The facility, which uses standard Layher steel decks, provides a walkway width of 2.07 m accommodating peaks in foot traffic at key times of the day for both the power station staff and the Electricity Alliance workforce.