In a first for UK engineering, an 11,000-tonne curved concrete box has been successfully pushed under the East Coast main line at Werrington near Peterborough. The new tunnel will enable slower moving freight trains to dive underneath the passenger route and use an adjacent line northwards.
The 155-metre curved concrete box tunnel, which is heavier than the Eiffel Tower, was 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.
It took nine days, but using this cutting edge technique 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.