The scheduled mid-February re-opening of the Mont Blanc tunnel between France and Italy has been delayed by at least one month following the discovery of cracks on a section of old concrete some 4.5km into the tunnel. The cracks were found as French and Italian officials were completing an accident simulation with 200 volunteers as part of safety checks prior to the re-opening.
Emergency repairs to the cracks, that cover a surface of 5m x 6m, started on the 4th February during which a block of rock and concrete casing fell from the roof on to the road. Autoroutes et Tunnel du Mont-Blanc (ATMB), the company that operates the tunnel, rejected outright any suggestion that the collapse of the archway was caused by the possible use of sub-standard concrete. The problem seemed to be due to a displacement of the shallow layer of part of the existing lining, which may have been weakened by the vibrations from nearby safety improvement works undertaken in the last months. These works included excavating shelters and niches using drill-and-blast. Officials also believe they may have been caused by a slight seismic tremor that was detected in the region on 2nd February.
The tunnel has been closed since 24th March 1999, when a lorry caught fire which spread to nearby cars killing 39 people. This is the third postponement to re-opening the tunnel in two months, a situation that has caused tensions between Italy and France. Italian authorities and truckers have accused the French of dragging their heels by insisting on a multitude of safety checks. A staggered system is about to be used for heavy vehicles. Fourty-five minutes in one direction, twenty minutes to empty the tunnel and fourty-five minutes in the other direction.
