Friday, July 26, 2013

The Spanish Train Tragedy 11

Well, if there isn't a concerted government effort to finger the train driver, it's beginning to smell as if there's one.

As I was reading El País at midday - front page headline: 'The Driver Braked too Late' - the waitress pronounced it was clearly the driver's fault. And when I said this wasn't at all proven yet, she responded: "But it's all over the TV".

Below its headline - which can, of course, be read neutrally - El Pais gave a balanced account of current knowledge across several pages. With the usual superb graphics of Spanish newspapers. They certainly quoted the Train Drivers' Union's insistence that the tragedy would never have happened if the advanced ERTMS system had been in place. This system takes over control from the driver and automatically slows or stops the train in dangerous circumstances.

The paper also clarified that the last 4.3km of the line to Santiago didn't have this system. As the train came off the rails 3km from Santiago, this means that 1.3km of track before it only had the older ASFA system. This only sends warnings to the driver if the train exceeds 200kph, meaning it could have come out of the tunnel 1.3km from the bend at 199kph and the driver would not have been warned. Likewise if, as he admitted, he'd been doing 190.

So, the questions remain:-
1. Why was the train doing 190kph when it emerged from the tunnel?
2. Why hadn't the 'foolproof' ERTMS system slowed or stopped the train before the switch to the, now implicated, ASFA system?
3. What information did the driver have about his speed at this point and why did he think 190 was a safe speed when he was familiar with the line and the bend?

There will be more questions than this, of course.

As to possible factors which had nothing to do with either the safety systems or the driver, one engineer has spoken of the possibility of rail displacement well before the bend, essentially meaning that things had started to go wrong well before the crash.

No one will be surprised to learn that, although the curvature of the bend is not considered dangerous per se, making it safer would have cost a great deal of money and caused a lot more (expensive) disruption to the people living near to the tracks.

The fear is that verdicts on this terrible accident will be a long time coming, politically driven and politically comfortable. As with the investigation of the Valencian metro crash of 6 years ago (no one found guilty of anything) and the Prestige oil disaster here in Galicia 10 years ago (trial(s) still in progress) no politician at any risk of being condemned for anything.

Right now, though, the priority is the wounded, and the response of the Spanish people has been highly commendable. At times like this, the word 'solidarity' can be used with only positive connotations.

4 comments:

Anonymous said...

Thank you Colin for your comments/observations/news briefings re. the train crash - Especially #11 where you ask some very sensible questions and say that "There will be more questions than this, of course."

Q1 Where was driver #2?
Q2 If he was in the rear engine, could he have slowed the train?
Q3 Were a driver to fall asleep, would he stay in his chair, or has it just one leg?
Q4 Were there not have been a deep ditch between the train and the wall, would there have been fewer casualties?
Q5 Are the train traffic controllers aware of the train's speed?
Q6 If so, could they have communicated with the driver(s)?

Colin said...

Thank-you for those. All very valid. I've just been told that the Adif president has blamed the driver. Astonishing, if true.

Perry said...

Colin,

The accident occurred in the transition section between ETCS Level 1, which is used on the 87km Ourense – Santiago high-speed line over which the train had travelled, and the standard Spanish Asfa system used on the conventional network. Santiago is one of dozens of ETCS-Asfa transition points on the Spanish network.

IRJ has learned from a senior source at Renfe that while ETCS is operable on the Ourense – Santiago high-speed line, class 730 sets of the type involved in the derailment operate exclusively on Asfa on this route despite the fact that they are equipped with ETCS. All other passenger trains operating on this line, including the fleet of class 121 Avant emus, operate on ETCS. The reasons for this have not yet been firmly established.

However, the final ETCS balise on the high-speed line, which is situated 4km from the crash site, would only inform the driver that he is exiting an ETCS section, that all automatic driving modes are disabled, and that manual driving mode is active. This means that if ETCS was in use the accident may still have occurred, and any train could in theory enter the 80km/h section at 200km/h. Drivers of Avant trains brake manually on the section where the accident occurred because the driver interface does not display a braking curve in the transition section between ETCS and Afsa.

The train passed Asfa distant signal E7 4km before the derailment, and E7 150m from the crash site.

Both Asfa and the more advanced Asfa Digital are automatic train protection (ATP) systems, but the latter provides the driver with information on braking curves while standard Asfa only triggers an emergency brake application if a signal has been passed at danger. It is unclear at this stage which version of Asfa is installed on the line.

The operation of both systems is linked to the interlockings but not to speed limits, which must be observed by the driver at all times.

This means that when a route is set on a main line with signals showing a green aspect, no command is triggered onboard the train to adjust the speed. The accident could only have been prevented by the Asfa signal before the curve where the derailment occurred if the following signal, positioned on the approach to Santiago station, was at danger.

The S-bend where the train derailed was intended only as a temporary link between the high-speed line and the conventional network and would have been eliminated by the extension of the high-speed line north towards A Coruña, although these plans have now been deferred.

A second driver was onboard the train, seated in coach 7. In Spain trains normally operate with only one driver in the cab except in the event of an Asfa failure.


http://www.railjournal.com/index.php/europe/etcs-not-operable-on-santiago-crash-train.html?channel=537

Colin said...

Very many thanks, Perry. I will re-read this in the morning. It's complex. But, above all, as you say, it's still baffling why the accident happening.

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