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Post by dave1 on Jun 24, 2020 10:36:36 GMT
This must be the only forum that has nothing on this incident. I am hearing some disturbing things as to what happened.
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drico
Station Inspector
Thank you driver, off clips.
Posts: 202
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Post by drico on Jun 25, 2020 15:18:47 GMT
This must be the only forum that has nothing on this incident. I am hearing some disturbing things as to what happened. What’s disturbing about this incident ? |
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Post by dave1 on Jun 26, 2020 7:01:37 GMT
This must be the only forum that has nothing on this incident. I am hearing some disturbing things as to what happened. What’s disturbing about this incident ? If you know the area then you will understand what could have happened and as to the drivers actions very frightening in charge of a train doing what he did. |
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Post by Nortube on Jun 27, 2020 21:30:49 GMT
There are educated guesses on the Railforums forum as to what the reason could be:
I'm only going by what has been commented on Raulforums and I've not gone back and reread the posts to refresh my memory.
It would appear that a NB Met train to Chesham had the route set from NB platform (plat 1) at Chalfont and Latimer and a signal to proceed with the move. The move takes it over two crossovers - from the NB line onto the SB line, then north on the SB line for a short distance before crossing over to the single line to Chesham.
The SB Chiltern main line train was running on the SB line. It passed the signal protecting ths crossovers and SB platform (plat 2). The signal was presumably passed at danger, as it should not be green if the crossovers ahead were set for the Met move. The alternative scenario is that a signal system failure caused the signal to show a green aspect instead of a red. Because of all the safety interlocking that should prevent this happening, it is very unlikely that this was the case.
As far as I know, there has been no official statement as to the cause of the incident although many people are speculating.
One scenario is that the signal could have been passed at danger (SPAD) and the correct procedure wasn't followed afterwards, or wrong instructions were given to the driver.
Another scenario is that a signal system failure caused the signal to show a green aspect instead of a red. Because of all the safety interlocking that should prevent this happening, it is very unlikely that this was the case.
I'm not sure if the Met train had started to move yet. If it had, the Chiltern train could have run into the Met train as it was proceeding to the single line.
If the Met train was still in platform 1, the Chiltern train could still have hit it because the way the points were set, the Chiltern train would have been routed from the SB line into platform 1.
Luckilly the Chiltern train stopped just short of a collision.
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Post by dave1 on Jun 28, 2020 9:35:12 GMT
The Chiltern driver would have left Amersham on double yellow (JW2) the next signal (JW5) would have been a single yellow the next signal (JT6) would have been at danger protecting the junction.
The NB Met had the route from the NB platform set (JT80 Rte2) with 45 & 47 points reversed. The Chiltern train ended up almost in the NB platform having passed JT6 at danger carried on smashed through 45 points and over 47 points!!
The driver’s actions leave a lot to be desired as to why he failed to follow correct procedures. I am sure RAIB will try their best to find out all they can.
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drico
Station Inspector
Thank you driver, off clips.
Posts: 202
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Post by drico on Jun 28, 2020 12:19:32 GMT
Are Chiltern trains fitted with speed control after tripping SCAT ?
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Post by dave1 on Jun 28, 2020 14:12:59 GMT
Are Chiltern trains fitted with speed control after tripping SCAT ? No SCAT fitted and as I understand they don't speak with Met control over the radio it is their own ccontrol. |
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drico
Station Inspector
Thank you driver, off clips.
Posts: 202
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Post by drico on Jul 7, 2020 13:56:20 GMT
Railway Accident Investigation Branch RAIB now have an item on their website about this.
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Post by Nortube on Jul 8, 2020 9:55:33 GMT
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drico
Station Inspector
Thank you driver, off clips.
Posts: 202
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Post by drico on Jul 8, 2020 11:51:04 GMT
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Post by Nortube on Jul 8, 2020 12:48:44 GMT
The preliminary report doesn't state what speed the train was doing after restarting having been stopped at the signal at danger.
The set of points leading into the NB platform (the first points if departing north from is quite close to the platform and, judging by the photo, it appears that the front cab stopped on the NB track with the first car probably still on the crossover.
This could mean that the driver was: going slow and applied the brakes at the facing crossover leading off from the SB track or just before. Either they weren't observing the track properly to notice the points weren't set correctly and be able to stop in time.
or
the driver was going faster and running through the first / second trailing points made them think something was up and applied the brake
The details will eventually come out in the full report
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Post by dave1 on Jul 9, 2020 8:39:45 GMT
Considering the move the Chiltern driver did how come he went that far. Was he going too fast or was there some other reason but like you say the RAIB final report comes out.
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Post by Nortube on Jul 10, 2020 11:59:52 GMT
I don't know if LU or NR procedures apply when passing that particular signal at danger, but I assume that the maximum speed should be similar.
LU used to teach that after applying the rule at a signal the driver should "proceed at a slow walking pace" until the 2nd consecutive stop signal at clear or danger (I think the last part is the correct wording). It was later changed to something like 'proceed at such a speed that you can stop short of any obstruction'
I have never been happy with the change to 'Can stop short of an obstruction' as it always seemed too vague to me because that was, theoretically, giving drivers carte blanche to do whatever speed they wanted. I would always impress on trainees the sort of speed that they should be doing. Indeed, whenever possible, I would try to go through the actual procedure if held at an auto without waiting for the minimum one minute (usually an outer home). Getting their hands dirty (59 / 72 stock) usually meant that they retained the information better 
A driver is supposed to be looking out for reasons why the signal would have remained at danger. A cracked rail is unlikely to be seen; flooding, possibly, depending on how deep and how big an area; METAL obstruction, possibly depending on size; points incorrectly set, definitely; Train In Front, definitely! However, it does depend on the speed that the train is doing (and the visibility). A slow walking pace was usually deemed to be 3 - 5 mph. At that speed, a standard tube train can stop almost instantly and there should never be a collision with the train in front, whether round a bend in a tunnel or in thick fog.
Using the stop short of any obstruction advice, especially where there is good sighting ahead, it is very easy for a driver to think "it's OK, there's no train in front and there's plenty of sighting distance if I do see a train, so I'll speed up". In this scenario, other reasons for a signal remaining at danger, such as points not correctly set, may not be seen until it is too late to stop.
Even with Speed Control After Tripping, it's still possible to reach up to about 10mph when the driver should really be going slower in certain circumstances.
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