With a rock overburden of up to 2,300 metres, Gotthard Base Tunnel, which has been opened for scheduled train services in December 2016, is not only the world’s longest, but also the world’s deepest railway tunnel ever constructed.
The temperatures within the tunnel rise quite high: During operation the rock temperature is expected to be 45 °C and the air will heat up accordingly. Since 40 °C is the permitted maximum for trouble-free rail traffic, temperature must be regulated by an appropriate ventilation system. TLT-Turbo’s heavy-duty fans, developed specifically for this purpose, do not only provide the tunnel with fresh air during normal operation, maintenance, service and repair work, but also ensure smoke extraction in case of fire and a separate ventilation of escape ways. The project’s high level of complexity, in addition to a technical solution mastering those special demands, also required extensive preliminary planning and a well-designed concept for logistics and assembly.
The fans are used not only for air exchange, but also for ventilation during maintenance, service and repair work in the tunnel. The current plan is to block one of the tunnel tubes for one night per week to carry out maintenance work at the system components of that tube. Such preventive action is to ensure high availability of the plant. During maintenance there are a lot of people in the tunnel who need fresh air supply. “The ability of the fans to approach a very large number of different operating points in no time at all, was an essential award criterion. Within this category TLT’s fans are among the best in the world. Further reading