The nine-day operation marked a major milestone in the project to build a new tunnel at Werrington, north of Peterborough, which will enable slower moving freight trains to dive underneath the famous passenger route and use an adjacent line northwards.
Newly released time-lapse footage shows the 155-metre curved concrete box tunnel, which is heavier than the Eiffel Tower, being pushed into place at just 150cm per hour, using four hydraulic jacks.
This is the first time that a curved concrete box has been installed using this industry-leading engineering technique in the UK which avoided hundreds of hours of passenger disruption on this vital part of the East Coast Main Line and meant that services could continue running throughout.
Teams removed three of the tracks, lifted the overhead wires and dug out spoil from the site. Once the tunnel was eventually underneath, they then put everything back in place ready for regular services to resume.
Morgan Sindall has spent the last nine months building the tunnel alongside the line.
Paul Rutter, Route Director for Network Rail’s East Coast Route, said: “Our teams have completed this challenging piece of engineering in a creative way, which also allowed a reduced train service to continue for those who still had to travel.
“Over the nine days, we’ve made major progress on this vital project which will bring faster, more reliable journeys for passengers on the East Coast Main Line.
“I’m so proud that this project has shown itself to be one which is industry leading and that our teams have had the opportunity to use this new technique for the first time in the UK on one of the country’s most famous railway lines.”
The next stage of the project at Werrington involves work to install two new tracks inside the new tunnel and the associated signalling system, ready for it to come into use at the end of 2021.
The project is part of the £1.2billion East Coast Upgrade. Once complete, it will bring a more reliable railway with more choice for passengers, as well as faster journeys between London, the North of England and Scotland.