Massive pre-built tunnel is first for UK rail

Network Rail is making the final preparations for the installation of an 11,000-tonne pre-constructed concrete tunnel on the East Coast Main Line.

tunnel
(Credit: Network rail)

Built on-site over the past nine months, the 155m concrete box will be slid under existing rail infrastructure at Werrington, north of Peterborough, where the East Coast Main Line is crossed by a slow-moving east-west freight route. The tunnel will take slower freight trains off the fast route, speeding up services and improving reliability. Work will take place over nine days between 16 and 24 January, avoiding more than a month of passenger disruption if traditional tunnelling methods had been used.

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“This is a massive engineering challenge, but it will avoid hundreds of hours of closure on one of the most important lines in the country,” said Paul Rutter, route director for Network Rail’s East Coast Line.

“This is industry leading work that really puts the needs of passengers first in how we approach improvement work. In the past, Network Rail might have approached this problem by thinking about the easiest way to do the engineering. Instead, I’m proud to say we have come up with a creative and innovative solution that will deliver massive benefits while keeping disruption to a minimum.”

tunnel
(Credit: Network Rail Air Operations)

The tunnel, which weighs more than the Eiffel Tower, will be inched into position using massive jacks that will push it at just 1.5m per hour along pre-installed guiding supports. While the line will be kept open during the work, it will mean a very limited number of services will run south of Grantham throughout the operation. Passengers who must travel are asked to plan ahead and think about whether journeys are necessary while the installation is underway.

“Passengers should only travel south of Grantham during these nine days if they have to,” said a spokesperson on behalf of the line’s train operators. “We strongly advise people to check before they travel and allow plenty of time as journeys will take longer.”