The first lecture of 2022 was presented by Ricky Barsby (Business Change Lead) at LNER and Giles Clark from Network Rail. To view the lecture please log into the Member’s area.

As part of the £1.2billion East Coast Upgrade, Network Rail has increased capacity for passenger trains on the East Coast Main Line by building a new two-track railway line that dives under it at Werrington, north of Peterborough. The new line will remove constraints to the timetable caused by slower freight trains on the Great North Great Eastern (GNGE) route having to cross over the high-speed East Coast Main Line.

The new dive under provides an alternative route by enabling the new two track railway to run underneath the East Coast Main Line instead, separating it from any high speed passenger traffic.

From March 2020 work began to build the dive-under structure. The ‘curved box’ was built next to the East Coast Main Line in nine, interconnected sections. The structure is 155m long, 9.5m wide and 5.1m high, with 1m thick walls and soffit.

It weighs just over 11,000 tonnes, with is 1,000 tonnes heavier than the Eiffel Tower! The ‘curved box’ was pushed under the East Coast Main Line using large jacks to propel and steer it during January 2021.

During this nine-day partial closure of the East Coast Main Line in January 2021, the 11,000 tonne, 155-metre curved concrete box tunnel was pushed into place.

Whilst hydraulic jacks at the rear pushed the tunnel portal forwards at just 150cm per hour, excavators at the front broke away the guide tunnels to reveal the glide plates to guide and steer the tunnel into position.
This is the first time that a curved concrete box has been installed using this industry-leading engineering technique in the UK.

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.