The process of upkeeping tunnel lining needs an overhaul for Network Rail’s extensive network of tunnels, according to a statement from the rail infrastructure firm.
The majority of its 335km of tunnels were constructed in the Victorian era, and these structures, which are lined with bricks, can be difficult to upkeep and re-line. Not only is it costly, but time-consuming too.
For Network Rail, this poses a big problem. Tunnel re-lining which is time and labour intensive is ‘no longer sustainable’ for the firm, given the backlog of repairs which need to be completed. It is also looking for a method for tunnel re-lining which minimises downtime for tunnels in operation and reduces necessary access to tracks as the volume of trains in operation grows.
Other projects, including enhancements which look to improve gauge and electrification within tunnels, are also putting the pressure on re-lining efforts.
According to the Construction Enquirer, Network Rail has set out some goals that they want their Innovative Low Disruption Tunnel Renewals project to achieve, with the help of innovative civil engineering firms.
These goals include ideas on how tunnel re-lining can be enacted without the need for long blockades and innovation on how rail traffic could pass through both one and two track tunnels while works take place.
Other priorities include the adaptation of current machinery for new re-lining concepts as well as looking at modern construction materials such as shotcrete and segmental for innovation in this sector.