By rosebell
The work will begin on October 11 and includes structural repairs and waterproofing on tunnels serving the Northern line. Network Rail will also upgrade power control systems to make it easier to isolate electrified railway sections during planned maintenance and emergency repairs.
Central Tunnel Receives Structural Repairs
At HXS1 MT12a Central Tunnel, an approximately 14m-long section will undergo structural repairs. Existing concrete will be removed using hydro-blasting before new sprayed concrete is applied to repair and strengthen the tunnel walls.
The works must be coordinated with continued rail-road vehicle (RRV) access through the tunnel, as construction vehicles require uninterrupted access to support the programme.
St James Tunnels to Be Waterproofed
Waterproofing will be carried out across sections of three St James tunnels. Approximately 180m of HXS1 St James 1, 159m of St James 2 and 142m of St James 3 will be treated.
Network Rail’s contractor, Total Specialist Maintenance, will inject a low-viscosity polyurethane-based foaming resin into the tunnel lining. The resin reacts rapidly when it comes into contact with water and expands significantly within seconds, helping to seal pressurised water ingress.
Complex Works in Operational Railway Infrastructure
One of the main challenges is coordinating the two work programmes while protecting existing railway infrastructure and maintaining access.
Network Rail said the delivery team must manage extensive scaffolding inside the St James tunnels while maintaining uninterrupted RRV movement for the Central Tunnel works.
The Central Tunnel also contains significant quantities of cabling, points and signalling equipment that must be protected during hydro-blasting and sprayed-concrete operations.
Liverpool Tunnel Works to Finish in November
Network Rail Liverpool area director Paul Owen said the £3.5m investment would help maintain the four Victorian tunnels for passengers using the Merseyrail network.
The Northern and Wirral line works are scheduled for completion in time for passenger services to resume on November 7.
