A project to install electric power on the Great Western Route Modernisation (GWRM) on the railway route between Swindon and Cardiff is now well underway.
The ABC Electrification team, comprising contractors Alstom, Babcock and Costain, was awarded two framework contracts in 2012 as part of the rail network’s National Electrification Programme. One was the London North West (South) contract between London and Crewe, the other West and Wales.
ABC is installing the overhead line equipment (OLE) between Swindon and Bristol Patchway. On the Bristol Patchway to Swansea section the team is responsible for OLE in open country, stations and tunnels, as well as alterations to a number of the bridges and viaducts to allow new rolling stock the necessary clearance with the structures.
GWRM programme director for the Welsh section Brian Fisher said that roughly 6,000 overhead line structures have still to be built over 350km of track, with 5,000 piles and 1,000 concrete foundations put in place. ABC together with a number of other contractors is carrying out over 60 major modifications to bridges and approximately 20 substructures.
“It’s a massive job,” said Fisher. “It’s the sheer scale that makes it challenging.”
He said that as one of the first stages of the job, a considerable amount of vegetation clearance alongside the lines is being undertaken, with this currently around 80% complete.
“The environmental challenges are quite difficult as we go through a lot of Sites of Special Scientific Interest (SSSI). Additionally, banging in piles is quite a noisy operation, so going through centres of population is quite tricky,” added Fisher.
“The focus is on the design and installation of the foundations and piles for the OLE at the moment. In terms of foundation installation we’re around 20% through and we’re about to commence the steelwork above ground.”
Fisher said that the project’s intention was to get construction completion by December 2017; at which point the wires would have been installed to allow commissioning to take place.
“All the work is done in railway possessions [when the line is closed to rail traffic] because you’re working on a live railway,” he said. “This means a lot of night and weekend working.”
Fisher explained that one particularly challenging section for the work crews was within the 7km long Severn Tunnel, where holes were being drilled in the tunnel lining and anchors installed for OLE.
“It’s not a particularly pleasant environment in which to work,” said Fisher. “There’s a lot of soot and it’s a 100-plus year-old damp tunnel.”