Spanish Rail Crash

[Miss Prism]

The track looks superelevated to me.

Here's the horrific derailment:
 

http://www.youtube.com/watch?v=gkQ71CI5s9w

 

[Adrian Wintle]

From that video, it looks like the it derailed right at the step-down to the coaches (at the trailing end of the generator car or the leading end of the first coach). A substantial part of the train did make heavy contact with the start of the retaining wall which is probably why the death toll is so high.

 

I would also agree that is superelevated track.

 

Adrian

 

Edited to incorporate the info about the set from 1216 025 below.

[kintbury jon]

Horrific.  The passengers didn't stand a chance, it's a miracle so many have survived.  My sympathy to all those affected. 

[The Nth Degree]

Shocking video. It looks like the power car stayed on the track until the first derailed passenger car pulled it off.

[Kris]

I'm amazed that the footage from that camera has come out given the nature of this accident.

[roundhouse]

The video is  also on Sky news

[NGT6 1315]

Shocking video. It looks like the power car stayed on the track until the first derailed passenger car pulled it off.

 

A terrible sight to behold indeed. Thinking of everyone affected by this disaster...

 

I understand the set was a class 730 unit, which is essentially a derivative of the class 130 variable gauge Talgo set with an additional pair of generator cars behind the fully electric power units. These generator cars enable the set to also work non-electrified lines at up to 180 kph.

 

The line would appear to be a stretch of what will become the far northwestern branch of the AVE high speed network into Galicia. At this time, I understand it is still at 1,668 mm gauge, but will be adapted to standard gauge once it's connected to the remainder of the AVE network.

[Tim H]

Although it's difficult to tell, it does look as if some the worst damage was towards the rear of the train, which is a parallel with Eschede disaster.

[The Stationmaster]

There is now video footage of the moment of derailment on YouTube (it was shown on the BBC 13h00 news, ITN decided no to show it).  The filming comes from an official RENFE camera according to BBC reports and shows that the initial derailment appears to be of the leading coach which in turns pulls the back end of the power car into derailment while the remainder of the train follows the derailed leading coach although - certainly at first - the rear power car looks to be stable despite the train in front of it derailing and running out of line.

 

The train does appear to be running fast but the video obviously offers nothing to compare its speed with the permitted speed so could be misleading in that respect.

 

Referring to earlier comments above the track does appear to be super elevated through the curve - but on a curve of that apparent radius such superelevation would in any case be relatively small to allow 80kph.

 

Edited to remove video link that has already been posted by Miss P

[plarailfan]

Very sad to see such a tragic accident unfold right in front of the camera. My sympathy to anyone affected by this disaster.

The camera was perfectly located to capture the scene, which was a most remarkable coincidence.

At least the accident investigators will be able to study the footage and perhaps some added engineering / safety features might be found, that can be designed into rail travel of the future.  

[martin_wynne]

The video seems to rule out any obstruction on the track. And if caused by a track fault, it was not sufficient to derail the leading vehicle, although the passage of that vehicle may have made it worse.

 

I'm not convinced about the excessive speed theory, which as usual seems to have been picked up by the media from those with no actual knowledge of anything. Compare the train speed with that of vehicles on the road bridge behind.

 

Martin.

[trisonic]

Interesting that the coaches seem to set up a "standing wave" as they passed the initial point of derailment (seemingly). I've noted that some Brits were on the train........

 

I agree with what Martin says above. Wasn't there a major train crash in Germany in recent years where a mechanical/structural failure underneath one of the leading cars that caused the derailment?

 

Best, Pete.

[NGT6 1315]

I'm not convinced about the excessive speed theory, which as usual seems to have been picked up by the media from those with no actual knowledge of anything. Compare the train speed with that of vehicles on the road bridge behind.

 

The claim that the train may have been going at an excessive speed appears to be attributed to Renfe sources, with the Spanish media also quoting a reported phone or radio call by the driver immediately after the accident. Of course, only thorough examination of the wreckage and scene will hopefully reveal the true causes.

[phil-b259]

 

The suggestion of excessive speed seams to have come from what one of the drivers had said immediately after it happened and although the media do exaggerate things I am skeptical they would have completely invented it.

 

Besides we are not talking about a 186mph TGV style line here in the sense that the bend has a 50mph speed limit. If the traffic going across the bridge is on a motorway it will be traveling at about 80mph while the train is sledges to have entered the bend at just over 100mph (though if the curve is rated at 50mph even 80mph might be enough to derail it).

[kintbury jon]

In this situation, with the coaches being articulated, is it more likely for the whole train to derail?  The coaches in the French accident appeared to separate themselves.  Is this a flaw with articulated trains? 

[NGT6 1315]

I agree with what Martin says above. Wasn't there a major train crash in Germany in recent years where a mechanical/structural failure underneath one of the leading cars that caused the derailment?

 

The ICE set which crashed at Eschede in 1998 was equipped with wheelsets with separate, rubber-dampened tyres. One of these tyres on the first coach failed, triggering a derailment on a crossover and sending the coaches into a road overpass.

[The Nth Degree]

I wonder if the derailment was caused by braking for the speed restriction. I say that because while the power car stays on the track, under heavy braking it would cause a huge pressure force on the following cars, and going round a sharp bend would divert that force outwards and therefore cause a derailment or failure - either by the wheels skipping over the track or by a possible bogie failure.

 

Pure conjecture, of course.

[NGT6 1315]

I figure that whatever may be proven to be the root cause of this disaster, the video does look to me like the weight of the generator car right behind the leading power unit played a significant role in pulling the coaches outward as it looks to be tipping over well before the leading power unit completely derails also.

 

Spanish Wikipedia article on the class 730 sets: http://es.wikipedia.org/wiki/Serie_730_de_Renfe

[Jim]

I would be very surprised if there wasn't some form of infrastructure based over-speed protection, as we have with an AWS "Morpeth Warnings" coupled with TPWS for PSRs.

 

Jim

[Pacific231G]

Interesting that the coaches seem to set up a "standing wave" as they passed the initial point of derailment (seemingly). I've noted that some Brits were on the train........

 

I agree with what Martin says above. Wasn't there a major train crash in Germany in recent years where a mechanical/structural failure underneath one of the leading cars that caused the derailment?

 

Best, Pete.

That was the Eschede disaster in 1998 that cost 101 lives. It was caused by the breakup at 200kph of the tyre of a composite wheel of a type that DB had adopted from tramways because the monobloc wheels they'd been using on their ICE trains produced a vibration that was uncomfortable for passengers. The ICE train derailed after the  damaged wheel, which was on the leading coach, hit a set of points. The damaged points switched the rear wheels of the third coach which then derailed. What made the death toll unusually high was that this third coach hit the support columns of a road overbridge which then collapsed onto the track. The bridge landed on the fifth coach and remaining coaches slammed into the wreckage and it was in these that most of the deaths occured. This bridge collapse was similar to the one in Granville NSW in 1977 following a derailment of a commuter train. That cost 83 lives and was Australia's worst train accident.

 

The tragedy of Eschede was that part of the broken tyre penetrated the carriage next to a passenger who, instead of pulling the emergency handle, went off to find the train manager. Had he pulled the emergency immediately it's likely the train would simply have come to a halt.

The investigation revealed serious management and engineering failures in DB and three officials were tried for manslaughter. The composite "resilient" wheels had apparently never been tested to their limits for high speed use and reports of fatigue problems from the Hanover tram company that also used this type of wheel and concerns raised by the Fraunhofer Institute were not acted on. 

[Jim]

Looking at that awful video, it is a testament to modern traction and stock.

Can you imaging if that was a 47 with ten Mk 1s on?

[NGT6 1315]

I would be very surprised if there wasn't some form of infrastructure based over-speed protection, as we have with an AWS "Morpeth Warnings" coupled with TPWS for PSRs.

 

Jim

 

I understand the stretch of line in question is equipped with the conventional ASFA automatic warning system rather than the LZB cab signalling system Renfe use for high speed running on the AVE network, which is also used in Germany. ASFA does allow for enforcing penalty brakes in certain situations, such as not acknowledging restricted signal aspects or SPADing, but according to what I can derive from those descriptions I have been reading does not appear to be designed for speed check points as such.

 

There are several different ASFA versions which are deployed as required on any given route, with the version used as a back-up level on AVE lines having greater block lengths and allowing for speeds in excess of 200 kph.

[Pacific231G]

In this situation, with the coaches being articulated, is it more likely for the whole train to derail?  The coaches in the French accident appeared to separate themselves.  Is this a flaw with articulated trains? 

I thought that trains with articulated or firmly connected carriages are generally considered safer as the carriaged tend to stay upright following derailments and are less likely to depart completely from the track . I've always understood this to be an advantage that British main line trains fitted with buckeye couplings and interlocking corridor connections had for many years over typical European trains using screw couplings.  In the Brétigny-sur-Orge accident only two of the deaths were actually to passengers on the train, the other four were to people on the platform.

 

It does concern me that if so much of HS2 is to be in tunnels or deep cuttings so as to minimise its impact on the countryside the consequences of any accident may tend to be more serious. Dedicated high speed lines do though seem to be the safest expression of the safest form of transport we have. 

[Miss Prism]

From a Google map, I estimate the radius of the curve that the train is entering to be approx 350m. A 200mm superelevation will provide 50mph (80kmph) optimisation on such a radius, but I doubt that degree of superelevation would be present, so we are probably looking at a 'cant deficiency' situation for that curve anyway. (Someone please check my sums!)

 

One of the drivers is reported to have made a phonecall shortly before the crash saying he was doing 190kmph (approx 120mph). The track before the curve (beyond the motorway/autoestrada bridge) is substantially straight. Looks to me as though the derailment is beginning before the curve is encountered, so I'm inclined to go along with Nth's idea of an emergency brake application causing (somehow) the leading passenger coach to lift and thereby (centripetally) wanting to carry straight on when the the train does encounter the curve.

[phil-b259]

I thought that trains with articulated or firmly connected carriages are generally considered safer as the carriaged tend to stay upright following derailments and are less likely to depart completely from the track . I've always understood this to be an advantage that British main line trains fitted with buckeye couplings and interlocking corridor connections had for many years over typical European trains using screw couplings.  In the Brétigny-sur-Orge accident only two of the deaths were actually to passengers on the train, the other four were to people on the platform.

 

It does concern me that if so much of HS2 is to be in tunnels or deep cuttings so as to minimise its impact on the countryside the consequences of any accident may tend to be more serious. Dedicated high speed lines do though seem to be the safest expression of the safest form of transport we have. 

 

If - and I grant you its a big if at this stage, the accident was down to excessive speed then actually HS2 will be safer than any of our conventional lines*. Why - because proper dedicated high speed signalling systems such as TVM430 as used on French TGV lines / HS1 will enforce a maximum speed regardless of what a driver does and it is simply imposable for a train to enter said restriction above the specified speed. Not that I expect the anti HS2lot or even the mainstream media to recognise this of course

 

*(mind you the situation here is much improved with the introduction of TPWS overspeed sensors for particularly significant speed restrictions)