A SECOND bore is to be added to the 12km Frejus road tunnel through the Alps between France and Italy, operators have confirmed.
Construction of the new tunnel, which will be used as an escape route, is in response to fears about the safety of single bore tunnels following the Mont Blanc tunnel fire in 1999 when 38 people died. It will carry no road traffic.
Design has begun for the project, which is expected to be completed by 2011.
The new bore will be approximately 4.8m in diameter said Alain Chabert, technical director for SFTRF which operates the French side of the tunnel. The Italian end is run by SITAF.
The E 280M ($298M) project is part of a plan to upgrade safety levels for the busy 10m diameter main tunnel. This carries between 3,500 and 4,000 heavy trucks daily.
Governments and operators have been increasingly concerned about fire and evacuation risks following the disasters at the Mont Blanc, Tauern, Kaprun and Gleinalm tunnels.
The Mont Blanc tunnel has since been upgraded to incorporate an escape route in the under road ventilation duct. This is not possible at Frejus as the ventilation duct is above the road The new Frejus tunnel could provide an escape route, but will also be used to gain access for construction of extra fire shelters in the wall of the main tunnel.
This will allow the tunnel to stay open during construction work.
At the moment, fire shelters are at 1,500m intervals. The new refuges will reduce spacings to 400m.