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Cette scène d’apocalypse

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At least eleven people were killed when an Alstom TGV Duplex derailed and caught fire on Saturday 14 November during a non-passenger high-speed test run on phase two of LGV Est near Eckwersheim (Bas Rhin), about 20 km from Strasbourg. The line was scheduled to open in April 2016.

At the time of writing, the cause of the accident is unknown.

L'Alsace tweet about the TGV derailment 14 November 2015

[‘Children were aboard doomed TGV test ride, French rail says‘, Laurent Geslin, AFP, 15 Nov]

Officially, 49 technicians and railwaymen were assigned to conduct a test run Saturday of the next-generation of the TGV, France’s flagship high-speed train, which was due to go into service next spring.

The accident near Strasbourg killed 11 and injured 37, of whom 12 remain in critical condition, according to local deputy prosecutor Alexandre Chevrier.

[…] Investigators were unable to say how many children were aboard. Asked about their assertion Saturday that five people were missing, Chevrier said they were still trying to piece together “how many passengers may have boarded and how.”

[…] A senior official in the Alsace region on Saturday blamed “excessive speed” for the disaster.

Aerial view of the Eckwersheim TGV accident (France 3 tv)

The TGV struck the bridge over the Marne-au-Rhin canal and some carriages ended up in the water (France 3 tv)

[Onze morts à Eckwersheim, premiers éléments d’enquête, L’Alsace, 15 Nov 2015]

Selon un premier scénario d’accident dévoilé ce dimanche soir par le parquet de Strasbourg, la motrice a «percuté» le pont [du canal de la Marne-au-Rhin] et «le train a ensuite déraillé avant de basculer sur le tallus de la ligne ferroviaire».

Un porte-parole de la SNCF a confirmé ce premier scénario, précisant que dans le choc de l’accident, le train s’était séparé en deux. «Le TGV a quitté la voie au niveau du pont et a percuté des rambardes de protection. Une partie des voitures est tombée dans le canal et l’autre dans un champ», a-t-il indiqué.

In Alstom’s TGV Duplex and AGV designs, passenger carriages are carried on articulated bogies, which, according to the company, “minimises the risk of a derailment becoming a very serious accident”.

But at Eckwersheim, there was a complete break-up of the trainset. One might argue that in many circumstances, the “semi-rigid link between cars” of articulated bogies could result in reduced, rather than improved, safety. And with or without articulation, the quantum of kinetic energy in very high speed operation is bound to result in reduced accident survivability.

Britain’s HS2 trains would operate at higher speeds than those of LGV Est, so projectile debris from an accident would be even more energetic. HS2 is a deeply flawed vanity project, and there is no reason why GB trains need to operate at speeds greater than 250 km/h.

Eckwersheim TGV wreckage (Photo: L'Alsace/Jean-Marc Loos)

Written by beleben

November 16, 2015 at 10:04 am

Posted in High speed rail, HS2

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  1. The HS2 alignments discount using the high speed alignments already built for GC/GW joint line as the 1 mile radius (minimum) curves are too tight, It will be interesting to assess the crash site (the curve looks comparable with GC and the GW main line enhancements built and planned in the early 1900’s)

    The other detail is that the end loading limits are based on a presumed square on crash with the historic hazards of telescoping and riding over (inherent in the early designed of carriages with separate underframes and bodies) now dealt with, but in this impact there will have been a tangential force at each connection which translated into transverse and longitudinal forces on the carriages, with relatively low resistance to articulation in the horizontal plane, and a rapidly progressing decrease in resistance to centrifugal forces as the connections between carriages rotated from the square-on alignment.

    Could this mean that for safe operations the design of closely coupled articulated high speed train sets, a sacrificial crumple zone between carriages which both absorbs some crash energy and locks the hinged connection as a rigid element, needs to be designed in, The evidence that this is likely to be essential is seen in the crashes at Great Heck, Ufton Nervet, and Grayrigg where the carriages separated and/or hinged round on each other rather than locking in to a rigid ‘tube’, although arguably this may have to disbenefit of creating a single unit with substantially greater mass taking the impact on one end rather than breaking into discrete units making separate impacts.

    By way of comparison has any report been produced on the Spanish Talgo crash? Notable here was how the passively tilting Talgo section of the train broke away from the leading and trailing non tilting non Talgo carriages and travelled as a unit, tangentially to the track after the break-away. The clearly seen ‘flick’ as the Talgo section breaks off from both front and rear sections, on the curve, leaving the carriage(s) bridging between this and the non tilting section(s) flailing around, and ramming into the retaining wall pulling the leading carriages off the track. One hypothesis is that at the higher speed the passive tilt went beyond the limit allowed for in the design of the connection to the non-tilting section and split the coupling, derailing the string of carriages – Watch the video and see what you think.

    One detail which would be very likely is that as a test train the video recording and instrumentation may well be substantially more detailed than for a typical service train incident.

    Dave H (@BCCletts)

    November 16, 2015 at 1:22 pm

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