Engineers have successfully completed a challenging track renewal project through the narrow confines of Northchurch Tunnel, a Victorian-era structure on the West Coast Main Line, enhancing journeys for both passengers and freight.

The work, led by Network Rail and its contractors, began on New Year’s Eve and concluded on January 4. The project involved replacing 400 metres of railway line within the tunnel, located between Berkhamsted and Tring, a vital section of one of Europe's busiest mixed-use rail routes.


The Northchurch Tunnel system comprises three tunnels, with the fast lines sharing one and the slow lines each having their own. One of these, built in 1836, required track renewal, posing significant logistical challenges due to its tight space. Traditional construction methods were not viable, requiring a staged approach to remove old materials and install new components.

Key achievements of the project included:

• Installation of 672 new sleepers across 24 track panels.

• Removal of 1,860 tonnes of old spoil from the tunnel.

• Laying of 2,200 tonnes of new ballast (track foundation stone).

• Deployment of six engineering trains.

• Installation of 430 metres of steel rail.

• A total of 2,440 staff hours worked.

Due to the complexity of the upgrade, both slow lines were closed during the works, with trains operating on the fast lines instead.

The line reopened on Saturday, January 4, and full service resumed today, January 6.