Network Rail will commence a £3.5m upgrade of tunnels on Liverpool’s Merseyrail network on October 11.
Four Victorian-built tunnels on the Northern line will undergo waterproofing and strengthening, while across the Northern and Wirral lines power control systems will be modernised to make it easier to turn off the electrified rail for scheduled maintenance and emergency repairs.
For the HXS1 MT12a Central Tunnel an approximately 14m-long section will be repaired. The existing concrete will be hydro-blasted and then sprayed concrete applied to complete repairs to the tunnel walls.
In HXS1 St James 1, 2, and 3 tunnels, sections of 180m, 159m and 142m respectively will undergo waterproofing.
Network Rail’s contractor, Total Specialist Maintenance, will waterproof the tunnel lining by injecting a low-viscous, foaming resin based on polyurethane unlimited application time. It has a fast reaction when in contact with water and a high-volume increase within a few seconds to stop pressurised water.
A Network Rail spokesperson told T&TI that one of the key challenges was keeping both schemes in each tunnel running flawlessly simultaneously.
“The delivery team need to consider the significant amount of works and scaffolding inside St James Tunnels, while also ensuring that rail-road vehicle (RRV) movement is uninterrupted, as RRV access is required at all times for the works in Central Tunnel. Furthermore, there is a substantial amount of cabling, points, and signals that we need to protect in Central Tunnel where we will be hydro-blasting and spraying concrete,” the spokesperson said.
Network Rail Liverpool area director Paul Owen said the £3.5m investment would maintain four Victorian-built tunnels for 21st-century passengers.
The lines are scheduled to open again to passengers on November 7.
