A concrete box weighing more than the Eiffel Tower has been pushed under a railway line to form a new tunnel, in a “UK first” for engineering.
The 11,000-tonne, 155m (510ft) structure was moved into place under the East Coast Main Line at Werrington, Peterborough, at 150cm (60in) per hour over nine days.
The tunnel, opening at the end of 2021, will separate freight and passenger trains on the London to Edinburgh route. It will lead to faster and more reliable services, said Network Rail.
The project is part of £1.2bn being spent to upgrade the line.