EuroTunnel

Delivering concrete repairs and sealing works within the Channel Tunnel demands exceptional planning, discipline and technical competence. With trains operating continuously, all non-emergency activities must be undertaken during tightly controlled engineering hours, typically between 01:00 and 05:00 at weekends. During these periods, one running tunnel is taken out of service while traffic is diverted through the adjacent tunnel, creating a narrow operational window in which all works must be completed safely and efficiently.

Programming is therefore critical. CRL worked closely with Eurotunnel to plan each activity up to six weeks in advance, defining the scope, methodology and resources required for every possession. Regular coordination meetings were held to assess readiness and eliminate uncertainty. If any element of the planned works was not fully assured, the possession were cancelled, underlining the importance of preparedness and collaboration.

A key element of the works involved resin injection to cracks within the tunnel linings to control water ingress and protect the structural concrete. Significant volumes of resin were injected to reduce water flow and maintain a dry, serviceable environment. In parallel, CRL undertook concrete repairs to the trackbed, where repeated high-pressure cleaning over many years had eroded weaker surface layers. These repairs were particularly sensitive due to the presence of signalling cables beneath the concrete, where reduced cover can interfere with wireless communications.

To operate independently within possessions, CRL maintained a workforce trained and certified as Schoma drivers and Chefs de Chantier. This capability allowed full self-sufficiency during maintenance windows and ensured works were executed to programme, supporting the safe and reliable operation of this critical asset.