Concrete Repairs to Vital International Infrastructure
The Channel Tunnel, which took 8 years to build and cost £9,5bn was officially opened on the 6th May 1994 by HM Queen Elizabeth II and President Francois Mitterand. Now nearing 18 years old, the wear and tear is beginning to take it’s toll, and it is only with a lot of planned maintenance by a dedicated team of engineers that the water is kept at bay and the trains are kept running. In 2010, CRL was awarded the framework contract to carry out the civil maintenance of the tunnel.
With the trains running 24hrs a day, all ‘non-emergency’ work in the tunnels has to be carried out during engineering hours, generally between 01:00am & 05:00am on weekends. During the day both ‘running’ tunnels are in use, but on weekend nights the trains run through a single tunnel allowing the other one to be freed up for repairs & maintenance.
Due to the critical nature of the tunnel and the prior commitment by Eurotunnel for the use of the tunnels, programming is critical and the type of repair works and how they are to be carried out are planned, discussed and decided on 6 weeks beforehand. Regular meetings are held between the CRL and Eurotunnel staff to constantly evaluate the degree of preparedness required for the work ahead, and any uncertainty in any aspect of the works would see the works cancelled on that night.
Besides injecting large amounts of resin into the cracks in the tunnel linings to reduce the flow of water, CRL were also responsible for carrying out all the repairs to the concrete trackbed where years of high pressure cleaning has resulted in the top layer of any slightly sub-strength/sub-standard concrete being eroded away. There are signalling cables below the concrete surface, and the lack of depth once the top layer has been eroded away tends to cause problems with the systems wireless communications signal.
As part of CRL’s responsibilities, we are also required to have a certain number of our staff trained and certified as ‘Schoma’ drivers, and as CDC’s (Chef de Chantier). This enables us to be completely self-sufficient whilst carrying out the repairs and sealing/injection works during the possessions.