AI will make things safer in the future

[old martParticipant @oldmart]

After seeing the Lewes train derailment and the previous video taken of the line from an earlier train, it is obvious to me that if constant AI scanning had been available the kinks in the track would have stopped traffic immediately. I had no idea that cameras were used on trains. That video will make the accident investigation much more straightforward as the track was displaced during the derailment and would tend to hide the cause.

[egaParticipant @ega]

Am I right in supposing that the move to continuous welded track has contributed to the accident?

NB I don’t recall seeing any warnings against discussion but would understand if the question is deemed out of order.

[old martParticipant @oldmart]

The expansion joints in continuous rail have their limits, but I’m not sure how hot the line was at the time.

Apparently the temperature was 33C at the time, but the kink in the track shown in the video from the earlier train was within the same few feet with both tracks and there is very little chance of the expansion joints being in exactly the same place.

[Andy StopfordParticipant @andystopford50521]

There was a rail engineer on the radio the other day who explained that kind of distortion usually starts with the track bed moving or sinking, sometimes due to the soil underneath drying out.

[Nicholas FarrParticipant @nicholasfarr14254]

Hi ega, I’ve always understood that there are expansion joints every so often in continuous welded track, but maybe this hot weather has made the track expand too much, and closed the expansion joints completely, and lead to the buclking.

Regards Nick.

[old martParticipant @oldmart]

I saw one of those long expansion joints from a platform at Bristol Temple Meads station on the line that goes westbound, and it looked like it could cope with about a foot of movement.

It sounds rather more like it was as Andy’s post explained.

[egaParticipant @ega]

In my commuting days I often saw parked at Bromley South station an elaborate locomotive with projecting arms designed to maintain the track. I think its main function was to manipulate the ballast so that it kept the sleepers, etc in correct alignment, a job presumably otherwise done manually.

[John HaineParticipant @johnhaine32865]

Doesn’t need AI as generally understood, just some image processing and machine learning.

[old martParticipant @oldmart]

I have just noticed something wrong with the pictures of the derailment and the supposed picture taken by another train of the “same section” of track. They do not match. The view of the accident shows the third rail different from the earlier picture. It is not the same section of track at all. The plot thickens.

 

https://www.bbc.co.uk/news/articles/c4gx12v8z51o

[ega]

On ega Said:

In my commuting days I often saw parked at Bromley South station an elaborate locomotive with projecting arms designed to maintain the track. I think its main function was to manipulate the ballast so that it kept the sleepers, etc in correct alignment, a job presumably otherwise done manually.

I saw one of these in action on a Saturday night on the Hastings line in Tunbridge Wells.

It would stop and the arms were jammed down between the sleepers deep into the ballast. They then vibrated vigorously to fluff up the ballast – it made a lot of noise and the ground shook. The arms were then retracted and it moved forward to the next set of sleepers.

You could see through a window into the control room with two or three operators and loads of computer monitors and coloured lights.

It was quite a sight – and sound.

[Nigel Graham 2Participant @nigelgraham2]

It’s important to consider that although the air temperature may be 33º – as Old Mart quoted – the temperature of the rails will be a lot higher.

[Michael GilliganParticipant @michaelgilligan61133]

There has been talk of painting the rails white

MichaelG.

[old mart]

1. On old mart Said:

   I have just noticed something wrong with the pictures of the derailment and the supposed picture taken by another train of the “same section” of track. They do not match. The view of the accident shows the third rail different from the earlier picture. It is not the same section of track at all. The plot thickens.

    

   https://www.bbc.co.uk/news/articles/c4gx12v8z51o

   He’s right, the third rail is on the other side

[PeteParticipant @pete41194]

AI will will make things safer in the future? I think that could or might be highly debatable depending on where and how its being used. https://www.youtube.com/watch?v=kjTaPtYhAo8

[egaParticipant @ega]

Andy Stopford:

Thanks for your description of the ballast fluffer! I never saw it in action myself. It sounds as though the fluffing was performed under human control rather than any form of AI.

I wonder whether Brunel’s 7′ track suffered in this way.

[Bo’sunParticipant @bosun58570]

As I understand it, continuously welded track is restrained at a specific temperature and allowed to expand and contract within limits according to the steel’s expansion coefficient.  Maybe the recent high temperatures just pushed the expansion beyond the predicted value.  Could we soon be seeing more expansion joints and a return to a little “clackety clack”?

 

[egaParticipant @ega]

PS The name of the ballast fluffer machine’s manufacturer eventually came to me:

https://www.plasser.co.uk/en/machines-systems/tamping/track-tamping-machines/08-16-32-u

[ega]

On ega Said:

PS The name of the ballast fluffer machine’s manufacturer eventually came to me:

https://www.plasser.co.uk/en/machines-systems/tamping/track-tamping-machines/08-16-32-u

That’s the one!

re. The photo of the kinked track – that seems to be about 100m behind the train at a small bridge over a farm track. The Google satellite image isn’t good enough resolution to make out the third rail, but I guess it might swap sides for some reason between there and where the train came to rest.

[old martParticipant @oldmart]

You are correct, Andy, the kink in the track is where you think it is. I looked on Google earth and there is a feature which shows earlier satellite images, and some do show the third rail for both tracks on the other side. The third rail changes over just out of shot of the derailed carriages. I would guess the kink is about 50 yards south of the bridge.

[Andy StopfordParticipant @andystopford50521]

Well spotted Old Mart, I’d forgotten you can show older images – the one from 2014 shows the third rail quite clearly.

[Author]

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