[SystemSafety] Spanish train crash

Dick Selwood dick at ntcom.co.uk
Mon Jul 29 13:47:25 CEST 2013


1) It is alleged that the driver driver posted a facebook image of his 
doing 200 kph - an timetabled speed on the high-speed section of the 
line. One source - which I cannot now find - says that he had a 
reputation for being a slow-coach and was proving that he could go 
faster. It seems to be in the interest of the authorities to blame a 
human rather than look closely at the questions of control systems and 
track-geometry.

In fact all the reporting seems to be concentrated on finding a single 
person to blame than look at the underlying issues of having a very 
short transition from from 200kph plus to 80 kph line speed. A RENFE 
spokesman is reported to have said -"He should have started braking 4 km 
away."  A few seconds lack of concentration and the driver is going to 
have to move from heavy braking to emergency braking  just to get round 
that bend.


2) The video of the crash is now on several youtube sites now.  It is 
disturbing if you think about what is happening inside the carriages, 
otherwise it is like watching a model train crash.







On 27/07/2013 08:37, Peter Bernard Ladkin wrote:
> Folks,
>
> Chick Perrow just sent me the following link to an interview with him 
> about the accident:
> http://www.thespainreport.com/2013942/perrow-striking-evidence-for-operator-error/ 
>
>
> I haven't checked it out (I don't belong to Facebook) but it suggests 
> that the train driver has a Facebook page on which he has talked about 
> behavior which might have some relevance to explaining why the train 
> was overspeeding.
>
> What is puzzling me is the overall geometry and control on and around 
> that section of track.
>
> Jens Braband sent me a link to an explanation (in German) of ASFA on 
> Wikipedia http://de.wikipedia.org/wiki/ASFA I imagine people can 
> suitably transform for the page in their preferred language. It's a 
> form of (in British) ATP, designed by Westinghouse Air Brake Systems 
> (those of the freight braking recently discussed in the wake of the 
> Lac-Megantic accident) in 1972 to a RENFE specification.
>
> ASFA consists of occasional "balises" (electronic milestones) that 
> work on induction and signal-frequency communication with up to 8 
> "resonant frequencies". The trainside actions consist of driver 
> warnings, speed surveillance (here, the German word "Überwachung" is 
> ambiguous between surveillance and some amount of control), and 
> emergency automatic braking. It is "point-based" (that is, interaction 
> occurs purely at the balise locations) rather than "linear" (continual 
> control/sensing, as with ERTMS).
>
> People have said that the accident location is in or near the 
> "transition zone" between ERTMS and ASFA. The HS line was finished and 
> has been in operation since late 2011. The pictures show an obviously 
> new section of track (for example, the sleepers and gravel are still 
> all light-colored), so I imagine that this piece of track follows the 
> older track trace into Santiago, but has been rebuilt.
>
> But still - I wonder about a 80kph curve - surely you'd design a 
> transverse gradient into the track (German "Querneigung" - I don't 
> know what it's called in English and picked the best-looking word from 
> LEO, but it's for roads, not railtrack) in order to enable faster 
> train transition and reduce maintenance. What would the reason be here 
> for not going so? Maybe simply because it is close to a station at 
> which most or all trains would stop, or because this stretch is also 
> used by local stopping trains travelling more slowly, which would make 
> a transverse gradient here uncomfortable for their passengers?
>
> I also wonder about the general design of a track which is 
> "transitioning" from high-speed track with ERTMS control. If you are 
> designing-in an 80kph curve and you have high-speed continuous-control 
> transitioning to low speed and ATP, wouldn't you put a balise and 
> automatic emergency brake activation at a suitable point before the 
> curve? After all, it was 2011 and everyone in rail knows about 
> Waterfall (New South Wales; the driver is supposed to have had heart 
> failure and the "dead man's pedal" didn't work).
>
> Bernd told me the CCTV video of the accident happening was available 
> through the Guardian (reliable, worthy British newspaper). I haven't 
> had the discipline to look at it yet.
>
>
> PBL
>
> Prof. Peter Bernard Ladkin, Faculty of Technology, University of 
> Bielefeld, 33594 Bielefeld, Germany
> Tel+msg +49 (0)521 880 7319 www.rvs.uni-bielefeld.de
>
>
>
>
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