A key piece of the West Coast Main Line upgrade's final dash is nothing to do with electrification or 125mph running.
The £15M Glasgow and South West Route Clearance project will provide a link into and out of Scotland for diesel hauled Pendolino 390s when maintenance work shuts down the high speed line.
In engineering terms it is an intriguing scheme. The 116km Victorian rail line rolls from Gretna to Glasgow and is criss-crossed by low bridges. It is a busy route, particularly for freight from the Ayrshire coal fields. To create clearances for the Pendolinos and their pantographs five bridges must be reconstructed, and track lowered at 39 sites.
'The route will be clear for the Pendolinos by December, ' says Network Rail project manager Archie Tait. 'The bridge reconstructions will finish during 2006.' Network Rail called in Scott Wilson to survey the route to find out where work had to be done, and where regular inspection to ensure clearances are maintained would suffice. 'Anything under a 50mm clearance we needed to do something, ' says Tait.
'Between 50mm and 75mm, six monthly maintenance checks have been put in place; and up to 100mm we'll monitor the sites annually.' Clearances are being designed with the additional 400mm needed for any future line electrification.
For track lowering, Network Rail is opting for steel sleepers which, at 150mm, are half as deep as their concrete equivalents.
Network Rail has tackled some of the bridge replacements in partnership with local authorities to enable them to be upgraded to 40t weight limits. At Titfield Road in Glasgow Network Rail and Glasgow City Council are in a 50:50 joint venture to demolish and rebuild the 15m span bridge over the track. Project cost is around £6M.
The bridge was brought down in a 54 hour possession 'booked three years in advance', Tait says.