Network Rail CEO reviews Bletchley flyover progress
NETWORK Rail CEO Andrew Haines paid a visit on February 10 to the work taking place at Bletchley to mark the first anniversary of the East West Rail Transport & Works Order being signed – and with it the process of demolition and rebuilding of the flyover for the East West Rail project.
With Mr Haines was route director Tim Shoveller, who were shown around the main worksite by Mark Cuznor, the overall EWR project director, and Bletchley area project director Jeff Booth.
Two years ago, it was announced the flyover would be refurbished and its deck raised, but the inquiry into the Italian Morandi bridge collapse in Genoa identified potential risk, so the plan was revised to replace spans 17 to 29 inclusive, over or alongside the West Coast Main Line (WCML).
The flyover was identified as the key component in the EWR project infrastructure while also potentially carrying the most risk in terms of disruption to the existing railway given the WCML’s proximity.
Former site
Preparatory work for a compound on the site of former Bletchley carriage sheds southwest of the station using 20,000 tons of material was undertaken. This was in order to accept spans 17 to 25 inclusive, to be directly lifted into this works compound and then crushed and removed from site.
Spans 20 to 25 required a 1250-ton counter-balanced crane to lift the 300-ton reinforced concrete spans above and across the WCML. This was carried out every Sunday morning in August and completed on September 20.
Supporting piers and crossbeams were then removed, requiring further delicate and accurate lifting from in between, with spans 26 to 31 removed beam by beam at the same time on the east side of the WCML.
An estimated 5,500 tons of concrete has been removed, crushed and reduced to fill, and used around the site for haul roads. The steel concrete reinforcements were recycled, as were redundant OLE stanchions and associated 25KV wires.
New entrance
Ballast from spans 34 to 37 was removed in November, enabling work to commence on two high level platforms and associated new eastern station entrance. This involved piling operations for reinforcements to support the platforms and buildings.
The last piece of the flyover to be removed, a small supporting pier section, took place in the early hours of January10. From May, as part of the rebuilding, more than 100 prefabricated beams will be craned into position across the WCML by two cranes, with the expectation that track on the rebuilt flyover will be laid in the autumn.
■ The 605-metre 37-span Bletchley flyover opened 60 years ago but never saw the use envisaged when planned in 1953 as a result of a British Railways freight study. This looked at how to direct crosscountry freight away from London by creating a circular route 50 miles north of London, crossing the West Coast Main Line (WCML) on a flyover. Its construction was confirmed in the 1955 British Railways Modernisation plan when Sir Brian Robertson, chairman of the British Transport Commission, outlined plans to create a marshalling yard at Swanbourne. In 1963 Dr Beeching acknowledged the importance of the 77-mile cross-country Varsity Line between Cambridge and
Oxford, but BR took a contrary view, with services finishing in 1967 and the Bletchley flyover mothballed in September 1993.