Safety In Railway Tunnels

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Railway Tunnel Safety

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  • Safety in railway tunnels and selection of tunnel concept ESReDA 23rd Seminar, November 18-19, 2002, Delft University, Netherlands Mr. Terje Andersen Det Norske Veritas (DNV), Veritasv. 1, N-1322 Hvik, Norway Mr. Brre J. Paaske Det Norske Veritas (DNV), Ingvald Ystgaardsvei 15, 7496 Trondheim, Norway Abstract: A number of serious tunnel accidents have put tunnel safety on the public agenda. Concerns have been directed towards the safety of both road and rail tunnels. The choice of tunnel concept for double tracked rail lines has been given much attention. Two alternative tunnel concepts are discussed in a safety perspective in this paper:

    1. Single bored tunnel, i.e two parallel tracks in the same tube with escape ways to open air through the tunnel portals or through intervening cross cuts.

    2. Parallel twin bored tunnels, i.e two parallel tubes with one track in each with intervening connections between the two tubes equipped with fire doors or smoke traps.

    The risk and safety arguments for various concepts are examined and pros and cons for each of the concepts are discussed. An investigation of known tunnel and metro fires is used to assess how the choice of tunnel concept may have influenced the outcome of the accidents. Further, typical results of CFD calculations of tunnel fires and risk analysis results are presented.

    1. Introduction and scope Several serious accidents in tunnels have recently years put safety in tunnels on the public agenda, both in Norway and in other countries. Concern has been directed towards both road and rail tunnels, and the scope is here limited to safety in rail tunnels. The choice of tunnel concept for double tracked rail lines has been given much attention. Two alternative tunnel concepts are discussed in a safety perspective: 1. Single bored tunnel, i.e. two parallel tracks in the same tube with escape ways to open air through

    the tunnel portals or through intervening cross cuts or specially designed escape ways. 2. Twin bored tunnels, i.e. two parallel tubes with one track in each with intervening connections

    between the two tubes equipped with fire doors or smoke traps. From a safety point of view it has in general been argued that twin tube tunnels are safer than single tube tunnels, and that new tunnels therefore should be built according to a parallel twin tube concept. Twin tube tunnels with frequent intervening connections have some obvious safety advantages, but also some disadvantages, which are not equally obvious. Each bore of two parallel tunnel tubes has in general a much smaller cross sectional area than a double tracked tunnel. The larger cross-sectional area is an obvious advantage of double track tunnels. If each parallel tube in a twin bored concept is built equally large as a double tracked tunnel, two parallel tubes will be advantageous in any aspects, except economy. Such concepts would be prohibitively expensive and may cause further environmental impacts due to depositing of removed material. Such concepts are not discussed in this paper.

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  • The presentation deals with following issues: - Discussion of advantages and disadvantages for different concepts

    Double track single bore tunnel: Large cross sectional area and long escape way Twin bore tunnels: Reduced cross sectional area and shorter escape way

    - Today's status for a selection of countries with examples of different solutions and risk analysis results

    - Description of tunnel accidents and how the choice of tunnel concept may have influenced the outcome of these accidents.

    2. Advantages and disadvantages of different concepts 2.1 Single bored tunnels without meeting track or block stations This is the traditional railway tunnel for less used lines with a single track. The tunnel is normally without sophisticated technical installations, except necessary technical installations for operating the trains. During normal traffic there will be one train only in the tunnel, and in general there will be no signals controlling traffic in the tunnel which may prevent the train from driving out of the tunnel. The ventilation direction is determined by the traffic direction, as long there is a train in motion in the tunnel. If a train, of any reason stops inside the tunnel, the air flow will quickly decrease because of the speed of the train and the ventilation direction may be turned, depending on the topography and temperature conditions inside and outside the tunnel. A fire may contribute to a change of ventilation direction. In Figure 4 is shown the smoke concentration results of a CFD calculation for a stopped train on fire in a single track tunnel after 4 min exposure of a 10 MW fire. No mechanical ventilation was applied only the general draft produced by the train movement prior to stopping. 2.2 Single bored tunnels with meeting track and/or block posts These tunnels are in principle the same as the tunnels described in 2.1, but with traffic controlling installations, like block posts and/or meeting track with signal installation making it possible to handle several trains simultaneously in the tunnel. Signals controlling the traffic will be present in such tunnels, and they may request trains to stop in the tunnel. A meeting track in the tunnel will also include switches which may be elements of increased risk to the traffic. In case of an accident, several trains will make the rescue work more complicated, but only one train will be present in each tunnel section (signal section). The ventilation direction in the tunnel may be unpredictable if there is possibility for several trains in different directions in the tunnel. When a train drives into the tunnel, the flow pattern may be changed rapidly. 2.3 Double track in single bored tunnel Both tracks are located in the same tube. For tunnels blasted in rock this normally gives the lowest investment costs. Many factors are contributing and among these are: - Less work faces during construction - Less total mass to remove - Less rock/ground surfaces to seal and secure.

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  • Figure 1: Sketch of double track in single bored tunnel concept This is the traditional tunnel concept for double tracked rail tunnels blasted in rock in most countries. In general the cross sectional area for common railways is large (80 115 m2 for new tunnels) with big air volumes under the tunnel roof. The cross sectional area is normally substantial less for metro tunnels. The tracks are normally equipped with one or more block stations to handle subsequent trains and in longer tunnels it is possible to build one or more connections between the tracks within the tunnel. Normally there will be more than one train in the tunnel and if an immediate evacuation from a train in the tunnel is necessary, it is important to regard any possible traffic on the other tracks. The natural ventilation direction in the tunnel is relatively unpredictable with several trains in different directions in the tunnel, but the tunnel has large air volumes which normally will give good smoke stratification during the first phases nearby the fire. In Figure 4 is shown the smoke concentration results of a CFD calculation for a stopped train on fire in a double track tunnel after 4 min exposure of a 10 MW fire. No mechanical ventilation was applied only the general draft produced by the train movement prior to stopping. 2.4 Twin bored tunnels In this concept there are two parallel tubes, one for each track, with possibility for intervening connections and escape ways between the tunnel tubes. This tunnel concept is especially suitable for very long (15 20 km) tunnels, without any possibility for cost effective escape ways to open air. In full profile bored tunnels, it may also be used in shorter tunnels because the cost picture is different for such tunnels, and there might be stability problems during construction while boring a full double track profile in soft soils. The twin bore tunnel concept may also be used in other tunnels were two separate tracks are required, but will normally not be a cost effective solution for tunnels which are made by traditional rock blasting techniques. The ventilation direction in the tunnel tube will be predictable and are given by the traffic direction, but may change when train stops or be influence from a fire. In longer tunnels one or more connections between the tracks may often be necessary. Such connections will break the separation between the tunnel bores unless expensive gate constructions are established. The cross sectional area in each bore in a double tube tunnel is substantially less than for a double track tunnel. Smoke and heat accumulation in the individual bores will be as for s single track tunnel as presented in Figure 4, and smoke accumulation will occur much more rapidly than in a double track tunnel, especially in head height for walking persons. This may be an element of great importance to evacuating passengers.

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  • Figure 2: Sketch of twin bored tunnel

    2.5 Double bored tunnel with service tunnel For long high traffic tunnels under mountain massifs/plateaus or sub-sea tunnels it may be difficult to ensure access to the tunnel for servicing, maintenance or emergency assistance. In such tunnels it can be relevant to evaluate a separate service tunnel along the whole distance or part of it. The Eurotunnel from France to Britain is of this type. A concept with service tunnel is often combined with separate traffic tunnels for each direction, but there are also examples where service tunnels are combined with a single bore double track traffic tunnel. The subsea part of the Seikan tunnel in Japan is of this type. A concept with service tunnel has obviously many advantages regarding safety and rescue and access for inspection, tests and maintenance of technical equipment. However, such service tunnels also represent a considerable cost element and are not risk free. 3. Existing status 3.1 Summary of regulations and practice in some countries In Table 1 below is made a brief summary of regulation and practice in some countries as well as recommendations from UIC (International Railway Union).

    Table 1: Regulations and practice with regard to tunnelling concepts in various countries

    Country: Regulations and practice:

    UIC UIC the International Railway Organisation is promoting standardisation within rail traffic. In 2001 UIC issued a draft for the document Safety in Railway Tunnels Recommendations for Safety Measures. /8/. The document identifies and evaluates various safety measures for railway tunnels. Twin bore tunnels is not generally recommended, but a measure to be evaluated for new tunnels under certain conditions.

    Germany New tunnels on high speed lines have generally been constructed as single bore double track tunnel. A new regulation calls for escape and rescue access for every km where the overburden is less than 60 m.

    France Tunnels on the new LGV Mediterranne, including the Marseille tunnel (7.8 km) are built as single bore double track tunnels. The LGV network in France in general has few tunnels. Plans for a new line from Lyon to Turin is based on parallel twin bore single track tunnels.

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  • UK The Channel Tunnel Rail Link from London to the Channel tunnel involves several full profile bored tunnels. The tunnel under the eastern part of London and the river Thames is constructed as parallel twin bore single track tunnels with cross connection every 750 m.

    For the shorter North Downs tunnel (3.2 km) a single bore double track concept was chosen.

    Italy Italy is the European country with the largest length of railway tunnels and has an extensive program for construction of new tunnels. In general they are built as single bore double track tunnels. Regulations

    Switzerland Selection of tunnel concept is based level of traffic, length, soil condition and economy. Single bore double track concepts are in general preferred on main lines for economic reasons. Exception is the cross-Alpine baseline Gotthard and Ltschberg tunnels which are built as parallel twin bore single track tunnels with frequent cross connections (i.e. each 375m) between the bores.

    Sweden Regulation of tunnel safety matters in Sweden belongs to the Building Authority and rail tunnels are dealt with as an ordinary building. The building (tunnel) should be equipped with exits or cross connections such that the maximum distance to an exit does not exceed 150 200 m. New tunnels under Hallandssen and the city of Malm are built as parallel twin bore single track tunnels

    Denmark Historically, does not have many rail or metro tunnels. The new subsea tunnels under the Great Belt and the resund are built as twin bore single track tunnels. The same is the case with the new Copenhagen Metro. For the bored tunnels (Storeblt and Copenhagen metro), the concept is not chosen entirely from safety reason as it has other benefits.

    Todays practice can be summed up as follows:

    - Different concepts may be used for new tunnels to ensure desired safety level

    - Double track tunnels is far the most used concept in short and medium long tunnels, sometimes in addition to requirements for maximum distance between escape ways to open air.

    - Twin bored tunnels (also with service tunnels) are mainly used in extremely long tunnels where it is difficult top make escape ways to open air with reasonable distances because of topographic conditions. Soil conditions and construction method may also benefit twin bored tunnels under certain conditions, especially for full profile bored tunnels in soft soil or submerged underwater tunnels.

    3.2 Risk analysis results; example and general conclusion In Figure 3 is shown some of the results of a risk analysis of various tunnel concepts for different length tunnels for a new railway line in Scandinavia. The absolute risk values should only be taken as indicative, but the following general conclusion can be drawn:

    Twin bore tunnel concept has very marginal safety benefits if any for tunnels up to 10 km For tunnels above 10 km the safety advantage increases with increasing tunnel length.

    4. Accident experience at rail and metro tunnels A study of known tunnel and metro accidents may be a contribution to evaluate the conditions connected to the accident and may also gives an indication on which initiatives that considerably could have reduced the consequences. Data from the accidents are mainly collected from references /1/-/7/. During the period from 1940 to 2001 we have totally identified 26 serious accidents in rail and metro tunnels and stations from different references. 14 of the accidents involved fires in passenger trains or

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  • passenger facilities at stations. A list of those fires with information on the event is presented in Table 2. The overview is not complete and there are no uniform criteria for selection of these accidents, except that they occurred in tunnels or in subsea spaces of metro systems. It is reasonable to believe that the most serious fires during this period are included. The author has not detailed knowledge about the actual metro system and tunnel concept for several of the oldest accidents. 4.1 Example of rail passenger vehicle fire incidents in tunnels The most serious accident occurred in the Armi tunnel, Italy, in 1944 were 400-500 people were killed because of carbon monoxide poisoning caused by the smoke from the 2 steam locomotives hauling the train and did not manage to drive through the tunnel. Finally, the train had to reverse but by this time, most of the passengers had died. From information on the event that happened during WW2 it seems that the passengers may have transported on open flat-cars. This incident is not a traditionally fire accident and is not likely to be relevant for tunnels of today, but the combustion intensity and smoke production in the two steam engines (6-15 MW thermal effect) may have been comparable with what can be expected in a relatively severe fire in a single passenger car in todays train or metro system.

    Among other serious accidents, it is worth to mention the fire in the Metro of Baku in 1995 (289 people killed) and the fire on the cableway to Kitzsteinhorn, Austria, in 2000 (155 people killed). Both tunnels had relatively small cross sectional area (Kitzsteinhorn 10 m2 and Baku Metro 28 m2). It is reasons to believe that the narrow cross sectional area of these tunnels have contributed significantly to the severity of the accidents because most of the people that died did not manage to get out of the train, or got out very late. In the Baku fire approximately 245 casualties were found in the train and only approximately 40 were found in the tunnel. In both incidents, there were problems with opening the doors, but rapid development of the fire and smoke accumulation also made a considerable contribution to the casualties. Larger cross sectional area may have given better time for evacuation before the heat and smoke concentration became unbearable. Improved escape ways from the tunnels would not have reduced the consequences significantly, but may have saved a few persons. Regarding the accident in the Baku Metro it should be mentioned that most of the people that were killed as a result from mechanical damages (i.e. they were trampled because of panic onboard the train). Another serious accident occurred in 1972 in the double tracked Hokuriku tunnel (13,9 km) when a fire started in a restaurant wagon in a night train. The train stopped halfway in the tunnel to disconnect the actual wagon, but was not able to drive further from this place. The train carried more than 700 passengers and 30 of these were killed. The tunnel was not sufficiently equipped regarding ventilation and lightning and this was heavily criticised after this accident. There are also examples of serious train fires in trains that have stopped inside a tunnel and were the passengers by themselves have rescued themselves out of the tunnel both in double tracked and twin bored tunnels. The accident on the BART-metro in San Francisco in 1979 shows that a twin bored tunnel concept with frequent intervening cross cuts is no warranty for safety in a case of fire and do not necessarily lead to sufficient working conditions for the rescue team. This tunnel had a service tunnel in addition to two single tracked tubes, but still one person from the rescue team was killed and several were injured in this fire. 5. Brief analysis of accidents Totally about 1400 people have been killed in the 26 identified accidents of which 1000 in the 14 listed fires and toxification accident (Armi). The remaining accidents have been collisions, tunnel collapses and station overcrowding. The large majority of the casualties (90%) were found onboard the train or within station areas. Just a small proportion of the victims were suffocated in the tunnel outside the train. Also in fire accident most of the people were killed inside the train. Therefore it seems equally important to ensure the possibility to evacuate the train as to ensure safe escape from the tunnel.

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  • In 4 of the 14 fire accidents the train stopped in the tunnel due to a technical failure that also started the fire, or the fire resulted in a technical failure that caused the train to stop. The Baku and the Kitzstein-horn accidents as well as other severe accidents were of this type. In 2 other fire accidents (Hirschen-graben & BART) the train were forced to stop in the tunnel due to application of the emergency brake. After application of the emergency brake the trains were not able to continue out of the tunnel and the train had to be evacuated inside the tunnel. These two stops in tunnel could potentially have been avoided if the emergency brake could have been overridden by the driver, or if passengers were instructed not to use emergency brakes in tunnels. For these 6 fire accidents with un-wanted stop, the train must have stopped quite arbitrarily along the tunnel. Hence, to ensure safe evacuation in these cases there must be possible to carry out rapid evacuation of the train at all locations in the tunnel, and the interval between two cross-connections to a second tube/escape way must be quite short or the tunnel have a large cross-sectional area. In 4 scenarios (Eurotunnel, Hamburg, Hokuriko and Simplon) the train was deliberately stopped in the tunnel or at an underground station to evacuate people, decouple carriages on fire, and/or fight the fire. Apart from the Hamburg U-bahn incident where the train remained at a station platform, the other events happened in relatively long tunnels (14 km or longer). In the Eurotunnel fire the train stopped next to an emergency exit but the concentration of smoke and fire gases following the train made it difficult to use the exit until a bubble of fresh air at overpressure was injected into the tunnel at fire through the emergency exit. In Simplon the carriage at fire was decoupled and the diesel powered train moved out of the tunnel with most of the passengers. In the Hokuriko accident the train were not able to move after the effort to decouple the carriage at fire, and 30 out of the 700 passengers lost their lives before the remaining passengers were saved by trains on the neighbouring track. The remaining 4 accidents include events with train on fire driving through the tunnel without stop (Salerno 1999), CO-toxification from steam locomotive not able to pass the tunnel (Armi 1944), metro station fire (Kings Cross 1987) and collision between trains with subsequent fire (Batignolles, 1921). In two of the events (Eurotunnel 1996, BART 1979) the passengers escaped into parallel tunnels. For the other accidents it is doubtful whether the tunnel concept allowed such actions. The tunnel fire accidents with the highest number of fatalities have all occurred in tunnels with narrow profiles with a single track bore, either on a single track line or as part of a double tube tunnel concept. 6. Conclusion To conclude the paper, the following statements can be made: A large cross sectional tunnel area is a substantial safety benefit that should not be neglected in

    choice of tunnel concept. To promote fire safety in tunnels, it is equally important to ensure the possibility to evacuate the

    train as it is to ensure safe escape from the tunnel. To promote fire safety in tunnels, the evacuation concept must also cover for trains which are not

    able to stop at a defined location (i.e at a crosscut or escape way) for evacuation. For long tunnels twin tubes with intervening cross connections should be thoroughly evaluated

    against single tube with large cross sectional area in the context of the above conclusions. A risk based cost benefit evaluation of these concepts, including assessments of mechanical

    ventilation systems should typically form the basis for selection of tunnel concept.

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  • 7. References /1/: Semmens, Peter, Railway disasters of the World /2/: Kichenside, Geoffrey Great Train Disasters The Worlds worst railway accidents /3/: Hall, Stanley Hidden Dangers Railway Safety in the Era of Privatisation /4/: First International Conference on Safety in Road and Rail Tunnels, Basel, Switzerland, 23rd 25th November 1992 /5/: Second International Conference on Safety in Road and Rail Tunnels, Granada, Spain, 3rd 6th April 1995. /6/: Third International Conference on Safety in Road and Rail Tunnels, Nice, France, 9th 11th March 1998. /7/: Department of Transport; Investigation into the Kings Cross Underground Fire, HMSO 1988. /8/: UIC (International Union of Railways). Safety in Railway Tunnels; Recommendations for Safety Measures. October 2001. Ernst Basler & Partners.

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    Figure 3: Risk results for various tunnel concepts for a new railway line in Scandinavia

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  • Figure 4: Smoke concentration after 4 min around a stopped train calculated by a CFD tool for a 10 MW fire in a single track tunnel. No mechanical ventilation.

    Figure 5: Smoke concentration after 7 min fire around a stopped train calculated by a CFD tool for a 10 MW fire in a double track tunnel. No mechanical ventilation.

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  • Table 2: Passenger railroad and Metro Tunnel Fires - excerpt from extensive list of 26 accidents (international)

    No Location: Date: Accident category:

    Tunnel length:

    Concept: Fatalities/Injured:

    Passengers (total):

    Comments/descriptions:

    1 Kitzsteinhorn, Austria

    2000, Nov. 11th

    Fire 3,4 km / 43o inclination

    Single bore tunnel for cable cars

    155 fatalities

    167 The cable car caught fire at the bottom of the tunnel immediately after departure, and came to a stop 0.6 km inside the 3.4 km long tunnel. The car light went out, and at first the doors were impossible to open. After a while they nevertheless managed to open some of the doors. The cross section of the tunnel is very narrow (diameter 3.6 m) and the space at the side of the cable car is very narrow. The steep inclination (43o) made the tunnel a chimney in it self. People coming out of the train and trying to escape upwards the tunnel, were caught by the smoke and warm flue gases and died inside the tunnel. Only 12 of the passengers survived the cable conveyor fire. They managed to escape the train at an early stage by a broken window and evacuated downwards in the tunnel. 3 of the fatalities had been staying in the station building at top of the tunnel.

    2 Salerno,Italy

    1999, May 23rd

    Deliberately started fire in train

    About 10 km

    ? 4 fatalities/ 9 injured

    1100 A fire was started in one car of a 13-car train carrying 1100 football supporters on their way back home from a match. The fire was most likely arson or the result of a smoke bomb. The incident took place in a long tunnel, but there are no indications that the train stopped in the tunnel. Thus the tunnel may not be of essential significance to the outcome of the incident. This was the second football supporter train fire in Italy during a 2 week period.

    3 Eurotunnel,UK/France

    1996, Nov 18th

    Fire 50 km Twin bore tunnel with service tunnel. Cross connections every 375 m

    0 / ? 28? One of the trucks on the train caught fire before the train entered the tunnel. The train was one of the Euroshuttle train for trucks with truck drivers in a separate car next to the locomotive. The train continued at its speed (~120 km/h) for about 10 minutes before it stopped beside an exit to the adjoining service tunnel. I was impossible to disconnect the burning part of the train, and the power from the voltage conducting wire disappeared relatively quickly. The fire was at that moment very strong (max 100 MW) and it rapidly spread to cars nearby. Thick smoke forwarded quickly in the train due to other trains running in the current tube. This made the evacuation more difficult. Persons in the staff car and the truck drivers managed to evacuate through the neighbouring door leading to the parallel service tunnel. Overpressure from the service tunnel door created a "fresh-air bubble" when opened. Locomotive staff was at a later stage rescued by a rescue party from the adjoining service tunnel. The fire caused huge structural damages to the tunnel.

    4 Baku Metro,Aserbadjan; between Uldus and Narimanov station.

    1995, Oct. 28th

    Fire due to electrical fault on train

    Metro, about 2,2 km between stations

    Twin bore tunnel. Possibly no con-nections between the tubes

    289 fatalities and 265 injured. About 245 killed in train, 40 in tunnel

    About 1100

    Each tunnel bore has a relatively narrow cross-section (H=5,6m W=5m). The tunnel is equipped with a controllable ventilation system. A fully loaded 5 car metro train stopped about 200 m after Uldus station due to sparkover/ electric arc in electrical equipment in the rear end of the fourth car. The fire rapidly spread to car 5. Because of problems with the opening of doors in car 4, the passengers were forced to evacuate through car 3. Many travellers, narrow tunnel cross-section and the door problems lead to slow evacuation, and the people panicked. The ventilation direction of the tunnel was changed during the event and much of the smoke was drawn in the same direction as many of the passengers escaped. 245 of the casualties were afterwards found inside the remains of the train, most of them either squeezed or stamped to death. 40 of the casualties were found in the tunnel. 95 % of the persons who managed to evacuate the train survived.

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    5 Hirschen-graben tunnel, Zurich, Switzerland

    1991, April 16th

    Fire 1,3 km Doubletracked (A=70 m2)

    0 / 0? 50 in train S9 90 in train S5

    A fire was observed in the second last car of a 6-car local train, S9, as it left Zurich Hbf and drove into the Hirschengrabentunnel. The train stopped almost halfway through the tunnel, as someone activated the emergency brake. The tunnel has double tracks, and was rapidly filled with smoke. The escape routes leading to the tunnel gateways were about 500-800m long. It took 2-3 minutes from the train stopped until evacuation was initiated. Before evacuation started the passengers were encouraged to stay in the train. Nearly at the same time train S9 stopped inside the tunnel, train S5 entered the tunnel in the opposite direction from Stadelhofen station. Train S5 was stopped before it reached the accident area. The train driver takes the other driver's room in use, and after 4 minutes starts to drive slowly back towards Stadelhofen. After 100m he stops the train to pick up evacuating passengers from train S9. After a while the voltage disappeared from the overhead contact line leaving the trains stranded in the tunnel. All of the passengers were requested to evacuate the train and to leave the tunnel on foot. The fire brigade and rescue personnel were present outside the tunnel gateway 10 minutes after the burning train had come to a stop. Their duty was first of all to advise and help the last of the evacuating persons. They were all able to walk, and nobody needed to be carried out. The last passenger came out of the tunnel about 20 minutes after the burning train had stopped.

    6 KingsCross T-bane, London, UK

    1987, Nov. 18th

    Fire in escalator

    Metro-system

    Station 31/? ? Kingss Cross is one of the most frequently used stations in London Transportation's tube network. The station is operated by 5 different lines in 4 different levels. I addition there is a distribution hall with ticket offices, placed below street level. From the distribution hall several escalators descend to the different platforms. The fire started in escalator 4, which serves Piccadilly Line's platforms. After about 15 minutes moderate fire, suddenly an flashover of the whole upper part of the escalator shaft and the distribution hall occurred. The length and great inclination of the escalator shaft contributed to intensify the fire. Trains that continued running for some time after the fire outbreak, rescued the passengers on the lower platforms.

    7 HamburgU-Bahn, Germany

    1980, Apr 8th

    Fire in train

    Metro-system

    ? 0/3 ? A fire broke out in a train car in the Hamburg U-bahn. A passenger at the Altona station gave alarm, and the train driver immediately tried to put out the fire with a fire extinguisher. The attempt failed, and alarm was given to the control room, which called the fire department. The fire department was quickly in place, but the platform was totally covered by smoke, so all work had to be performed with smoke proof breathing equipment. 3 firemen suffered from smoke injuries from the incident. No passengers were injured. The fire started in a seat, and the prevailing car was totally over ignited after about 9 minutes.

    8 BART; SanFrancisco, US

    1979, Jan. 17th

    Fire 5,9 kmBART-metro

    Twin bore tunnel with service tube.

    1/58 40 passengers + fire-crew + +

    A fire broke out in a circuit breaker in the 5th and 6th of 7 cars in all. The train was stopped by the emergency break and could not be restarted. An unsuccessful attempt to disconnect the burning cars delayed the evacuation and escape of the passengers with about 30 minutes. The tunnel was filled with smoke despite of induced draught outlet every 300m and activating of the ventilation system. The passengers were taken to the service tunnel and out in the open air through the other main tunnel. Smoke was drawn into the service tunnel and the other main tunnel. The fire caused 1 fatality and 58 serious or minor injuries, most of them caused by flue gases or poisonous gases from combustion of plastics. The death victim was a fireman who died due to flue gas poisoning. The tunnel system has intervening connections from the main tunnel to the service tunnel every 100 m.

    9 Hokurikutunnel,

    1972, Nov

    Fire 13,9km,

    Double tracked

    30 fatalities /

    > 700 A dining car in the late night train "Kitaguni" caught fire while the train was in the tunnel. The train driver tried to disconnect the burning car, but a power failure brought the train to a stop in

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    Japan 6th built 1962.

    tunnel manyinjured

    the tunnel in darkness. The passengers evacuated the train and tried to get away from the fire and to escape the tunnel. Trains on the other track picked up some of the passengers trying to escape by foot. Rescue trains were driven in from both sides and most of the passengers were rescued (30 were killed), but there were many injuries. After the accident, criticism was raised at inadequate illumination and ventilation.

    10 Vranduktunnel, Yugoslavia

    1971, Feb. 14th

    Fire 1,6 km Singletrack?

    34 fatalities

    Ca 200 A Diesel-electric locomotive in a train carrying 200 passengers caught fire in the Vranduk tunnel between Zeneca and Doboi in Bosnia. The train stopped ca. 300 m from the northern end of the tunnel. The locomotive staff attempted to put out the fire, but it spread to the cars. Some of the passengers that jumped from the train and tried to escape from the smoke filled and dark tunnel were unable to get out.

    11 Simplon-tunnel, Switzerland /Italy

    1969, Nov 8th

    Fire 19,8 km Twin bore 0/0 ? A fire started in a diesel-powered train immediately after the train had entered the tunnel, most likely in the machinery in the aft end of the train. The passengers were directed forward in the train. The train stopped at an emergency station with an emergency telephone. The burning car was disconnected from the rest of the train and the rest of the train with the passengers could drive out of the tunnel with only a 14-minute delay. 10 of the passengers however did not follow the instructions from the conductor, and under guidance from to railroad employees they proceeded to the tunnel gateway. The light conditions were poor and the passengers were also obstructed by smoke. A train driving carefully towards them from the opposite direction rescued these passengers. There were no injuries. The fire extinguishing started after one hour and lasted for about three hours. The tunnel was re-opened the following day.

    12 London, UKShepards Bush/ Holland Park

    1958, July 28th

    Sparkover electric-arc - fire

    Metro-system

    ? 1 fatality/51 injured

    ? A sparkover in the electro-technical equipment caused a powerful electric arc that resulted in a subsequent fire. Delayed evacuation of the train caused intense smoke exposure of the passengers during evacuation. 1 person died in hospital after the accident.

    13 Armitunnel, Italy

    1944, Mar. 2nd

    Carbon monoxide poisoning

    Ca 1-1,5 km

    Single track?

    426 fatalities/ 60 injures

    ? Two steam locomotives were hauling a train from Balvano to Potenza and the train experienced problems in a steep tunnel due to low quality coal. The train remained in the tunnel for a long time without getting through, and in the end had to back out of the tunnel. Most of the passengers in the train had suffocated of carbon monoxide poisoning by then. The incident took place during the allied invasion of Italy in World War II. One source indicates that the travellers were stowaways on a freight train, while others have indicated that it was a matter of evacuation of civilians, transportation of troops etc. From the description of the course of events, it seems possible or probable that open cars were used.

    14 Batignolles-tunnel, Paris, France

    1921, Oct. 5th

    Collision Fire

    Ca 1 km Double tracked

    >28 fatalities

    2 trains A local train heading for Versailles stopped in the Batignolles tunnel, which is situated right outside Gare St Lazaire in Paris. Due to a mistake the subsequent train received permission to drive into the tunnel. The train drove into the rear end of the first train. Some people died in the collision, but even more died as a result of a subsequent fire caused by discharging gases from the train's illumination system which caught fire. After this accident all gas illumination on trains in France was replaced with electrical illumination. There are reasons to believe that the number of fatalities could be higher than the official number of 28 fatalities.

    Abstract:Introduction and scopeAdvantages and disadvantages of different concepts2.1 Single bored tunnels without meeting track or block stations2.4 Twin bored tunnels2.5 Double bored tunnel with service tunnel

    Existing statusSummary of regulations and practice in some countries4. Accident experience at rail and metro tunnels4.1 Example of rail passenger vehicle fire incidents in tunnels

    5. Brief analysis of accidents6. Conclusion7. References