Eschede train disaster

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The destruction of the rear passenger cars.
The destruction of the rear passenger cars.

The Eschede train disaster was the world's deadliest high-speed train accident. It occurred on 3 June 1998, near the village of Eschede in the Celle district of Lower Saxony, Germany. The toll of 101 dead and 88 injured surpassed the 1971 Dahlerau train disaster as the deadliest accident in the history of the Federal Republic of Germany.

Contents

[edit] Chronology

InterCityExpress trainset 51 was travelling as ICE 884 "Wilhelm Conrad Röntgen" on the Munich to Hamburg route. After stopping in Hanover at 10:30 am, the train continued its journey northwards. Six kilometres south of Eschede, near Celle, the rim of a wheel on the third axle of the first car broke, peeled away from the wheel, and punctured the floor of the car, where it remained embedded.

What followed was a chain of events that unfolded within minutes yet took investigators months to piece together. The rim embedded in the rail car was seen by one of the passengers in his cabin. Instead of pulling the emergency brake, he went to inform a conductor. The conductor, who noticed vibrations in the train, was going to check on the problem when the train reached the site of the impending accident.

As the train passed over the first of two track switches, the embedded wheel rim slammed against the guide rail of the switch, pulling it from the railway ties. This steering rail also penetrated the floor of the car (an occurrence known in North American railroads as a "snakehead"), becoming embedded in the vehicle and lifting the axle carriage off the rails. At 10:59, one of the now-derailed wheels struck the points lever of the second switch, changing its setting. The rear axles of car number 3 were switched onto a parallel track, and the entire car was thereby thrown into and destroyed the piers supporting a 300-tonne roadway overpass.

Car number 4, likewise derailed by the violent deviation of car number 3 and still travelling at 200 km/h (125 mph), passed intact under the bridge and rolled onto the embankment immediately behind it. Three DB railway workers who had been working near the bridge were killed instantly when the derailed car crushed them. The breaking of the car couplings caused the automatic brakes to engage and the mostly undamaged first three cars came to a stop. The detached front power head came to a complete stop long after passing the Eschede train station, some three kilometers (two miles) down the track. As the second half of car number 5 passed under the bridge, the bridge collapsed and fell on the car, flattening it completely. With the track now completely obstructed by the collapsed bridge, the remaining cars jackknifed into the rubble in a zig-zag pattern: Cars 6 and 7, the service car, the restaurant car, the three first class cars numbered 10 to 12, and the rear control car all derailed and slammed into the pile. The resulting mess was likened to a partially collapsed folding ruler. An automobile was also found in the wreckage. It belonged to the three railway technicians and was probably parked on the bridge before the accident.

Powerhead 401 051 of the crashed train was hardly damaged. It is still in use (Munich, August 2007).
Powerhead 401 051 of the crashed train was hardly damaged. It is still in use (Munich, August 2007).

The crash made a sound that witnesses later described as "startling", "horribly loud", and "like a plane crash". Nearby residents, alerted by the sound, were the first to arrive at the scene. At 11:02, the local police declared an emergency; at 11:07, as the magnitude of the disaster quickly became apparent, this was elevated to "major emergency"; and at 12:30 the Celle district government declared a "catastrophic emergency" (civil state of emergency). More than 1000 rescue workers from regional emergency services, fire departments, rescue services, the police and army were dispatched. Some 37 emergency physicians, who happened to be attending a professional conference in nearby Hanover, also provided assistance in the early hours of the rescue effort, as did units of the British Army of the Rhine.

While the driver and many passengers in the front part of the train survived, there was little chance of survival for those in the rear carriages, which crashed into the concrete bridge pile at a speed of 200 km/h. Including the three railway workers who had been standing under the bridge, 101 people died. ICE 787 had passed under the bridge going in the opposite direction (on the Hamburg to Hanover route) only two minutes earlier.

[edit] Accident statistics

  • Total number of passengers: 287 (ICE-1 max. is 651)
  • dead: 101
  • severely injured: 88
  • unharmed: 106

[edit] Causative factors

[edit] Wheel design

The ICE 1 trains were equipped with single-cast wheels, known as "monoblock" wheels. Once in service it soon became apparent that this design could, as a result of metal fatigue and out-of-round conditions, lead to resonance and vibration at cruising speed. Passengers noticed this particularly in the restaurant car, where there were reports of loud vibrations in the dinnerware and of glasses "creeping" across tables.

Managers in the railway organisation had experienced these severe vibrations on a trip and exerted pressure to have the problem solved. In response engineers decided that to solve the problem, the suspension of ICE cars could be improved with the use of a rubber damping ring between a metal wheel rim and the wheel body. A similar design had been employed successfully in trams, though at significantly lower speeds. This new rim, dubbed a "wheel-tire" design, consisted of a wheel body surrounded by a 20 mm thick rubber damper and then a relatively thin metal wear rim. The new design was not tested at high speed before it was commissioned and brought into service, but proved successful at resolving the issue of vibration at cruising speeds.

No facilities then existed in Germany to physically test the failure limit of a wheel and so complete prototypes were never actually tested. The design and specification relied heavily on available materials data and theory. Very few laboratory and rail tests were carried out, and the few that were did not measure wheel behaviour under extended wear conditions or outside of cruising speeds. Nevertheless, over a period of years the wheels proved themselves apparently reliable and, until the accident, had not posed any major problems.

The Fraunhofer Institute was charged with the task of determining the cause of the accident. It was later revealed that the institute had told the DB management as early as 1992 about its concerns about possible metal wheel rim failure. In the months leading up to the accident, the Hanover transit authority reported that the metal wheel rims employed in its trains were failing far earlier than expected based on the failure limit estimates; it unilaterally decided to replace the wheels much earlier than was legally required by the specification. In doing so, it reported its findings in a warning to all other users of wheels built following similar designs, including the German Federal Railway.

It was soon apparent that dynamic, repetitive forces had not been accounted for in the statistical failure modelling done during the design phase, and the resulting design lacked an adequate margin of safety. The following factors, overlooked during design, were noted:

  1. The metal wheel rims are flattened into an ellipsoid as the wheel turns through each revolution (approximately 500,000 times during a typical day in service on an ICE train), with corresponding fatigue effects.
  2. In contrast to the monoblock wheel design, cracks can also form on the inside of the metal wheel rim.
  3. As the metal rim gets thinner due to wear, the dynamic forces are exaggerated and the microfine cracks become larger.
  4. Flat spots and ridges or swells in the rim surface dramatically increase the dynamic forces on the assembly and greatly accelerate wear.

As a consequence of the Eschede disaster, "wheel-tire" designs are no longer used in Germany.

[edit] Failure to stop train

Failing to stop the train permitted the wheel disintegration to result in a catastrophic chain of events. Had the train been stopped immediately it is unlikely that the subsequent events would have occurred.

Conventionally, railways apply a stop and examine policy when there is strange behaviour or noises from a train. However, this was not the case aboard the ICE. Valuable time was lost when a passenger tried to warn the train crew about a large piece of metal coming up through the floor, instead of pulling the emergency brake himself. The train manager refused to stop the train until he had investigated the problem himself, saying this was company policy. This decision was upheld in court, clearing the train manager of all charges.

[edit] Other factors

The design of the overbridge may have also contributed to the accident because it had two thin piers holding up the bridge on either side, instead of the spans going from solid abutments to solid abutments. The Granville train disaster of 1977 had a similar weakness in its bridge. The bridge built after the disaster is a cantilevered design and does not suffer this deficiency.

Another contributing factor is the use of welds in the carriage bodies that "unzipped" during the crash (see Modern Railways December 2004, p16).

[edit] Consequences

Memorial site next to the bridge, with the railway line in the background
Memorial site next to the bridge, with the railway line in the background

[edit] Legal

In August 2002, two Deutsche Bahn officials and one engineer were charged with manslaughter. The trial lasted for 53 days with expert witnesses from around the world blaming each other for wrong approaches and bad results. The case was dismissed in April 2003 on condition of a fee being paid.

[edit] Technical

Within weeks, all wheels of similar design were replaced with monoblock wheels. The entire German railway network was checked for similar arrangements of switches close to possible obstacles.

Rescue workers at the crash site experienced considerable difficulties in cutting their way through the train to gain access to the victims. Both the aluminium framework and the pressure-proof windows offered unexpected resistance to heavy rescue equipment. As a result, all trains were refitted with windows that have predetermined breaking points.

[edit] See also

[edit] External links

[edit] References

[edit] Numbered References

Coordinates: 52.7344° N 10.2202° E


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