Safety upgrade

The Vereina tunnel is 19.1 km long and is characterized by mixed traffic, with conventional passenger trains and transport of road vehicles on train carriages.

The Vereina tunnel connects since 1999 Klosters-Selfranga with Susch-Lavin, in Eastern Switzerland. The tunnel is used for person transport as well as for carrying road vehicles on train carriages and is operated by the Rhaetian Railways (Rhätische Bahn RhB).

The key characteristics of the tunnel are:

  • Single-track tunnel, 19.1 km long, with crossing sections at the portal and in the center
  • Narrow-gauge tunnel (1 m)
  • Operation with passenger trains and with special shuttle trains transporting road vehicles (cars, busses and lorries)
  • The existing tunnel infrastructure and operation sets unusual challenges for person safety in case of fire incidents
  • After over 15 years of operation, a general renovation of the safety concept was required, due to both normative changes and evolving safety requirements
  • This involved practically all safety-relevant sectors, ranging from the tunnel infrastructure (e.g. ventilation and emergency exits, in particular in the crossing areas), rolling stock and train management over to the intervention concepts in case of incident within the tunnel.

Project description

  • Ventilation design for the all tunnels
  • Ventilation sensors, power supply and ventilation-control system
  • Tender design, construction design and site supervision
  • Commissioning
  • Intrinsic limitations resulting from the existing infrastructure
  • Unusual challenges arising from mixed traffic, including normal passenger trains, conventional HGVs and lorries
  • All interventions to be carried out under traffic, with night closures
  • All new safety concepts should apply as much as possible for the whole line
  • Cost-effectiveness of all measures
  • Time scheduling of the investments, for achieving economic sustainability
  • Investigation of the potential consequences of vehicle fires on the shuttle trains
  • Analysis of existing safety concept and identification of potential for improvement
  • Investigation of possible additional mitigating measures, including new facilities for self-rescue
  • Development a new tunnel safety concept, taking into account infrastructure, operation and rescue
  • Investigation of consistent safety packages and development of a time schedule for matching the available financial resources
  • Detailed investigations on self-rescue facilities, ventilation and fire scenarios
  • Risk analysis