Investigators of the tragic Kaprun tunnel fire that killed 155 people on November 11 2000 have said they do not anticipate any conclusion or results before Spring 2001.
Currently both the technical and criminal investigations are being conducted by the prosecutors office led by Mag. Charlotte Rohan-Achmmer situated at the court of Salzburg, Austria. To date no information is available as to the duration of closure and little detail forthcoming on reconditioning works needed to the tunnel.
Dr Helfried Scharmüller of the Salzburg regional government told T&TI that due to the on-going nature of the investigation, questions could only be answered in a ‘restrictive manner’. Although he stressed, “We expect to find the cause of the burning disaster and to find out if and who is responsible for the burning.”
It is anticipated that the investigation results will become public upon completion. A press conference in Vienna has been planned following the investigations’ conclusion.
Only then will it become clear as to how the tragedy started. It is still not fully understood at which point the fire ignited. The discovery of molten material on the 601m long approach viaduct has added weight to the theory that the train was already on fire before even entering the tunnel, as reported by eye-witnesses.
Whether or not this is the case, it is certain that 600m into the 3.3km long single track tunnel the train, supposedly unburnable, stopped and burst into flames. Even the halting of the train remains a mystery as it is thought that neither the driver or the controller at the top of the tunnel applied the brakes. A crucial turning point in the incident appears to have been the decision of the Alpin Centre station controller, Manfred Aigner, to open the ventilation doors at the top of the tunnel, presumably in an attempt to extract smoke. This action effectively turned the tunnel, that angles at 43°, into a blast furnace as air was sucked up the tunnel through the bottom entrance resulting in a catastrophic chimney effect. Only 12 passengers managed to scramble to safety, being saved by their decision to turn back down the tunnel and not attempt to climb the remaining 2.7km to the station at the top. Reports by the survivors who made their way back down the tunnel say they saw the train suddenly became a giant fireball. The driver of the down train, stuck at the tunnel mid-point on the passing loop, was also killed as were three people at the top of the tunnel when they were overcome by lethal fumes that were fanned up to the station.
According to UK press reports investigators were focusing on eye-witness reports that the rear left-hand side wheel of the train jammed, sending sparks. These are thought to have ignited lubricant or hydraulic fluid on the track. Also under consideration is the possibility that something fell on to the train. The train stopped in an area that had needed rockbolting during construction of the tunnel in the in the 1970s. Although through generally good rock, an area some 600m into the excavation required 20, 2-3m long rockbolts to stabilise a local rock block system. During construction the contractor JV, ÖSTAG/Hochtief/Gewerkschaft/Thyssen Schachtbau struggled initially, using a 4.2m diameter DEMAG TBM. Difficulty with the 43 degree inclination and water influx was such that works were suspended for approximately 6 months. Once overcome, tunnelling progressed smoothly through reportedly good rock that required no lining.
What has become apparent is the extent of the damage to the rock in the immediate vicinity following the fire. Saltzburg Government geologist Gerald Valentin described to T&TI how temperatures in excess of 1000oC had resulted in a destabilisation of a partial length of the chalk mica schist rock. Over a 100m length approximately 600m in from the tunnel entrance the rock had been loosened in the shape of thin 2-3cm thick plates. Where the massive rock is jointed the heat seared to a depth of up to 500mm. Valentin supervised another geologist and a three man Austrian army team who were responsible for the initial stabilisation of the affected area. Initial works involved the clearing of nearly 3t of loose rock using bars and hammers.
Now that the tunnel has been stabilised, what remains of the train is expected to be removed within the next few weeks. It has been confiscated by the Salzburger Landesgericht (Ministry of the Interior) who form part of the investigation. The tunnel and trains are owned by the private enterprise Kapruner Gletscherbahen, who are also responsible for safety. The organisation has remained tight-lipped and was unavailable for comment.
Many criticisms have been levelled at the lack of safety precautions in the tunnel. The only means of escape is via a service tunnel situated 638m from the entrance, although this was only designed to be used by servicing staff and never intended as an escape route. There was no sprinkler system or emergency lighting provided although torches were available on the train. Survivors told how the lights went out when the train stopped leaving them in near complete darkness, with the only light coming from the tunnel entrance 600m below them. Only two fire extinguishers were situated at opposite ends of the train. Passengers on the train, that could carry some 1200 people an hour, had no indication of action to take in the event of a fire. An 800mm wide walkway would have been the only method of escape from a train that is a close fit to the tunnel internal diameter.
Fire-fighting facilities consisted of a volunteer force who had to be flown by helicopter to the top of the mountain to access the fire zone via the service tunnel. Fire-fighters were reluctant to enter via the bottom entrance fearing that the remains of the train could plummet on to them if the system’s 48mm diameter winch cable snapped. The transport ministry has said that due to the fact that the system is run by a private enterprise there is no legal requirement to hold fire drills. A spokesman for the Salzburg regional government told T&TI that no changes are envisaged to Austrian law following the fire until the investigations have been concluded. Safety checks had been carried out in September 2000 and found apparently no faults on the train. Manfred Mueller, head of the system’s technical operations admitted to UK press that little provision had been allowed for the fire event saying, “It wasn’t provided for, we were taken by surprise.”
The impact of the fire on other European tunnel systems has already been felt. The Confederation of Fire Protection Association for Europe is calling for a consistent system for escape procedures in tunnels throughout Europe. Constructors of the Botnia Rail line currently being built in northern Sweden have initiated plans for a system that will allow the driver to stop at a safe place after emergency breaking is applied. The route includes 16 tunnels. P.G. Björner, project manager for Banverket (The Swedish National Rail Administration) said: “We have already planned a number of safety measures but will now study the experience gained from the tunnel accident in Austria. Also measures already being taken are that evacuation routes be provided at distances of 600-800m, footpaths with handrails, emergency lighting and the study of system involving portable fans that would enable fumes to be blown away in the event of a fire. Björner also described the provision of rescue services saying,” We are working closely with the rescue services to minimise the risk of an accident happening and to reduce the consequences should anything occur despite all our precautions.”
A spokesman for the German geotechnical consultants company DMT, with a specialist department in tunnel safety, told T&TI, “the experts for tunnelling and safety in tunnels are waiting for the results of the investigations. We have to consider these in future and in all existing tunnel systems.” He concluded, “We hope that there are no rash or misleading conclusions pressed for by the public interests which lead to ineffective and unrealistic requirements for more safety in tunnels.”
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