The usual process is WH356 is red as you approach, then changes to yellow with a number 4 junction indicator as you get nearer. When you cross the magnet, WH154 cycles through to green, then the signal protecting Bedford South, WH356 cycles through to green. It’s not normally still yellow before you contact the points. It was a break in ‘routine’.
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Report of collision Bedford (Elstow) - 19/06/26
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hexagon789
Veteran Member
That definitely remains a very high possibility - I'm perhaps just reading too much into choice of words.
This is the most likely explanation given the unwarranted acceleration while under caution, although a coincidental timely activation of the DSD cannot be ruled out.
Worth also mentioning the accident occurred in brilliant sunshine, which would have been coming from the driver's right hand side - the investigation will want to attempt to reproduce the lighting conditions on the day to see if the red signal could be adequately seen.
bramling
Veteran Member
It must presumably be fairly common for the signal to remain at yellow if being turned out following another train on the up fast, though? It will be interesting to see if RAIB are able to produce some daya on how often drivers, or even the driver involved, would have experienced each scenario.
What absolutely wouldn’t be common is for the next signal to remain at red, especially if the train passing on the up fast has just been seen to pass through at full speed.
Are we suggesting a contributing factor may be the driver has witnessed the 810 belt through Bedford at linespeed, and thought "I'm following that all the way to London (great, WH154 will clear to green on the fasts)"?
Once again, not prejudging the driver's actions or inactions, but attempting to understand the factors at play.
Signal Head
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Flashing yellows are a means of conveying additional information to the driver, ie 'you are receiving cautionary aspects because a diverging route is set at the next junction", rather than because a signal is at red.
They also remove the anticipation risk inherent in Approach Release from Red, which was the norm for signalling schemes commissioned before the mid to late 1970s.
This junction doesn't have flashing yellows.
Mile Post 13
Member
If a train signalled under the same arrangements as at Bedford South Jct would be travelling towards a red signal on a regular basis (of course "regular" would need to be defined) then there is the making of an argument that TPWS may be justified. However in this case WH154 would not usually be at Red in which case would installing TPWS produce a justifiable safety benefit ? I think not.
Locations where trains will regularly approach a Red aspect after passing a Y with a junction indicator are generally located at busy junctions or at station approaches where speeds will be low.
Bedford South Jct is a running junction which was originally designed to enable accelerating trains to gain line speed quickly and so does not fall into this category. As I think others have already alluded to, safety costs money and money is always in short supply, and will be even more going forward no doubt. The HASAWA and the Management Regs clearly accept that safety is risk based and only imposes control measures to meet ALARP or SAFAIRP principles.
Locations where trains will regularly approach a Red aspect after passing a Y with a junction indicator are generally located at busy junctions or at station approaches where speeds will be low.
Bedford South Jct is a running junction which was originally designed to enable accelerating trains to gain line speed quickly and so does not fall into this category. As I think others have already alluded to, safety costs money and money is always in short supply, and will be even more going forward no doubt. The HASAWA and the Management Regs clearly accept that safety is risk based and only imposes control measures to meet ALARP or SAFAIRP principles.
Surely an AWS brake application would have happened much earlier, as the Corby train was just about at the end of the section having passed the red?
bramling
Veteran Member
I wouldn’t go quite that far. I think it’s one of potentially many factors that could have been in play.
What I would say I think it’s unlikely that the driver has consciously thought “the train has just gone past, the line ahead will be clear”. But it could have had a subconscious impact on what happened next. But equally plenty of other possibilities.
I’d have been much less intrigued had it been a case of the driver reacting to the red at the last moment and braking hard but with insufficient room to stop. What seems to have occurred is much more unusual, and will no doubt probably have a more complex explanation.
What I was more alluding to is that having the yellow remain on at the junction signal would be quite normal, hence there can be a tendency to sort of normalise the situation and let the guard down, whereas in reality the opposite should happen. This seems to be a facet of human nature rather than anything negligent. Could well be something else though, a lot hinges on how the train was driven in the bit where it passed over the crossovers and when it reached the up fast line, there’s a lot we don’t yet know.
Mile Post 13
Member
I have experience of precisely that occurring some years ago.
That did not end in the 1970s. It remained the standard, early approach release from R to Y with a step up after the AWS magnet was only implemented for junctions 40mph and above. This was to enable the benefit from these speeds. Lower speed junctions always released from R either on the approach to or after the magnet. This arrangement was also always applied where a set of points was located greater than 200 yards ahead of a protecting signal. P468 signal on the Up Fast at Spital Jct, Peterborough being a good example
I am sure RAIB will be considering this, however as @Haywain says above, it doesn't explain what happened next.
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But as @baz962 and others have said this is that is not what was normal. Because of the two-stage release WH356 normally stepped up to YY and then G while it was still in view. Unless the UF was not in fact clear. This could of course have been explained by 1B76 occupying the next section.
But it can be normal. It is quite routine for WH356 to remain at Y if a train is routed to the UF right behind a passing service. That happens frequently. What doesnt happen often - if ever until now - is for that passing service (or indeed any service) to stop in the section ahead of WH154.
MarkWi72
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The recording data , with other evidence (Railcam?) will tell more about line speeds and driving before the collision , RAIB will be over this now its been acquired.
Signal Head
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I agree that MAR was, and is still, provided when other forms are not appropriate. Perhaps I should have said that MAR (Main Aspect Approach Released from Red) was the predominant, or even the only, form of junction control for those schemes.
In its original form it was an attempt to impose speed signalling on top of the route signalling, with graphs showing where the release point should be to regulate the speed for the junction. The release point was typically relatively close to the signal back then.
I remember SSP6 became rather notorious for regular revisions, some undoing changes which hadn't been in place for that long.
bramling
Veteran Member
What I was saying is that it would, I imagine, be quite common for the junction signal to remain at yellow due to a train just having passed on the up fast - just as the Nottingham train did. By the time a train has crossed over it is likely on the vast majority of occasions that the next signal would be displaying some kind of proceed aspect as the preceding train had progressed onwards.
This is something commonly experienced on the GN route out of King’s Cross, although less common since 2018. You would regularly get southbound Cambridge stopping trains held on the up slow line waiting for a slot on the up fast, at places like Welwyn Garden City, Marshmoor, Potters Bar, New Barnet or Alexandra Palace. It still happens at Hitchin mainly with up Fen Line trains. In these locations you would normally get fairly unrestricted acceleration once clear of the points, though of note is that in those days it was 317/321/365, which didn’t accelerate quite as much as more modern trains (especially 317/321). In my 40 years of using the GN route I’m struggling to think of a time when I’ve been on a train which has been “turned out” onto the up fast line and then had to come to a complete stand at the next signal. I’m sure it will have happened, but certainly very atypical.
bramling
Veteran Member
I suspect there will be another interim report fairly soon. There’s significant key issues to be resolved, not least the issue over what AWS indication the driver received, and how the train was driven in that crucial couple of minutes.
This should all be able to be resolved fairly soon. Then it all gets more complex and yes we’ll likely be oooking at a year or so
CalderRail
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RAIB are traditionally cautious to a fault with their investigations
43074
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The driver of 5Z14 will also be vital evidence as they would have seen both trains in the seconds before the collision occured.
Yes, they are very careful with their language. It's not their direct role but they also need to maintain faith and trust in the railway (among both passengers and staff) and this is why they will release only known facts.
Today's update is careful about what it does and does not say.
Yes I accept that hence the final sentence of my post, the aspect is readily explained by the recent passage of 1B76.
Yes, it doesn't happen often. I recall enquiring here about the similar 4 into 2 tracks situation at Digswell, how do the slow line drivers judge their approach to the restriction? And the answer was they look at the fast signals so they can predict when their slow signal will clear, with a good deal of precision.
CalderRail
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Does the rear cab still record the Forward Facing CCTV (actually Rearward Facing, but YKWIM)? It may even have seen the collision if so.
Markuk
Member
There was an issue earlier in the journey that caused a delay at Leicester wasn't there? Was this also an AWS system issue?
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Only true if the brakes on the 810 were not applied.
DynamicSpirit
Established Member
I'm puzzled by this. Before the stop at Bedford, there would have been 14 miles of clear running between Wellingborough and Bedford. Then a brief swap from fast running to dealing with the station-stop. So that would seem to me not so much like a change from intensive work to fast running, as a brief intensive work interval in the middle of a long fast running period. Would that really have the kind of psychological impact you're describing?
Kilopylae
Member
I don't read it that way. I took it to imply merely that the 810 stopped out of its usual course, i.e. in the middle of the line without the signaller or other trains having any prior reason to anticipate that it might stop. Not that its stop was unexpected to the driver.
bramling
Veteran Member
The stop wouldn’t be that intensive, especially as the station work would be being handled by the guard. But we don’t know the context, what else might have been going on, especially in terms of human factors. A train cab is an awful place to be for someone who has things on their mind, for example.
edwin_m
Veteran Member
Depending on spacing of the signals and points and the acceleration of the train, there's also the risk that the train might pass the overspeed sensor below the tripping speed but still accelerating, and TPWS only intervene when passing the red. TPWS OSSs are designed on the assumption the train is approaching at a constant speed.
What will also be of note would be at what point the signaller was aware that WH154 had been passed at danger and what - if any - action they took. I imagine we’re talking seconds, in which case there was nothing further they could do to intervene. Perhaps they were on with the driver of the 810 discussing the AWS issue.
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Signal Head
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They wouldn't know until the rear of the 360 cleared the overlap at WH154, since the next track circuit was already occupied by the 810, so wouldn't 'see' the 360 entering it as well.
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