Report of collision Bedford (Elstow) - 19/06/26

[Watershed]

Sorry if it's been mentioned already but 9 seconds of braking and the speed only dropped by 27mph? I don't know the 360s but does that suggest he didn't have it in emergency?

The trains I drive would drop more than that in brake step 2 ..

It equates to 3mph per second which is slightly above the 12%g figure required for emergency braking on mainline trains.

 

[John R]

I would welcome insight with the investigation as to the impact of luggage space or lack their of in modern trains on safety following several reports that many injuries were caused by luggage and 'furniture' and if it is felt this may have had an impact.

Until the trend of installing "airline seating" took off, luggage space was typically found on the floor between two sets of adjacent seats facing in opposite directions. Nowadays a lot more heavy luggage gets placed on the overhead racks, often in preference to the racks at the end as people are concerned about security. I can hazard a guess which option is safer in the event of a collision like we have just seen.

== Doublepost prevention - post automatically merged: 24 Jun 2026 ==

With regard to these units specifically, the refurb they have started to receive increases the amount of floor level luggage rack space significantly.

Presumably because of their role in serving Luton Airport?

 

[Nottingham59]

The location of the two trains after the collision is just past WH152. With the best will in the world a 49mph collision isn't going to allow a class 360 to shunt a much heavier class 810 as much as 700m along the track.

Even in an energy dissipating collision, momentum is still conserved. If the 5-car 810 weighed twice as much as the 4-car 360, then the combined consist will have been moving at one third of 49mph immediately after the collision, i.e. around 16mph. With several bogies derailed and the brakes fully applied on both units, I'd expect it would stop well within 700m

 

[Vince C]

Assuming the signal was green, then any fault with the AWS trackside would have been ‘right side’, and would not require the driver to stop immediately.

The report says that the AWS fault caused the Nottingham train's brakes to be applied, so it was not driver action that stopped the train.

 

[43074]

Assuming the signal was green, then any fault with the AWS trackside would have been ‘right side’, and would not require the driver to stop immediately.

Although the report from RAIB notes the 810 came to a stop "unexpectedly", which implies the driver of the 810 did not initiate the brake application

RAIB’s preliminary examination has found that train 1B67 was standing next to WH152 signal when the accident occurred. The train had come to a stop unexpectedly because a fault had developed with the Automatic Warning System (AWS) equipment fitted to it, which caused the brakes to apply.

 

[king_walnut]

It equates to 3mph per second which is slightly above the 12%g figure required for emergency braking on mainline trains.

Seems pretty bad for a 4 car EMU though?

 

[Dieseldriver]

Sorry if it's been mentioned already but 9 seconds of braking and the speed only dropped by 27mph? I don't know the 360s but does that suggest he didn't have it in emergency?

The trains I drive would drop more than that in brake step 2 ..

Actually to be honest with you, I personally feel that nine seconds for a drop from 76mph to 49mph actually seems impressive

 

[scotraildriver]

Although the report from RAIB notes the 810 came to a stop "unexpectedly", which implies the driver of the 810 did not initiate the brake application

It may simply be a case of "slow to cancel" on the 810. If you're running at high speed under greens and suddenly get an unexpected AWS horn (right side failure) it can take a couple of seconds to process what's happening and certainly on our Hitachi units you need to be pretty quick to cancel it before the brakes aoply. For some reason Hitachi units have a shorter time to cancel it than older stock. (At least on our class 385s)

 

[sharpener]

With several bogies derailed and the brakes fully applied on both units, I'd expect it would stop well within 700m

Somewhere (?upthread, not in report) it mentions the consist was pushed 3 carriage lengths along the track so more like 75m than 700. They are said to be replacing 600m of track which is over twice the length of both trains plus that skid distance (if correct).

Actually to be honest with you, I personally feel that nine seconds for a drop from 76mph to 49mph actually seems impressive

And very useful. As the impact energy is proportional to the square of the speed this drop will have halved the energy that had to be dissipated and made a substantial reduction in the damage/injuries.

 

[tumbledown]

Even in an energy dissipating collision, momentum is still conserved.

That only applies to an isolated system. The braking forces here alter that (momentum is transferred to the Earth).

 

[dk1]

It may simply be a case of "slow to cancel". If you're running at high speed under greens and suddenly get an unexpected AWS horn it can take a couple of seconds to process what's happening and certainly on our Hitachi units you need to be pretty quick to cancel it before the brakes aoply. For some reason Hitachi units have a shorter time to cancel it than older stock. (At least on our class 385s)

My first impression was late to cancel on 1B67.

 

[Bryson]

Assuming the signal was green, then any fault with the AWS trackside would have been ‘right side’, and would not require the driver to stop immediately.

Unless the startle effect of getting a horn warning but with a green visible signal meant that the driver didn't acknowledge the warning in time, resulting in the automatic brake application.

 

[matchmaker]

The lunatics are having a great time on Facebook. Apparently the driver is being made a scapegoat...even when more than one person pointed out that RAIB have only published a finding that the 360 passed a red signal and didn't give a reason because they don't know yet, the rants continued! A mention that the driver isn't being blamed because RAIB don't apportion blame produces much frothing at the mouth. The power of social media.

 

[bramling]

Absolutely. But we both know it won't stop the usual "case closed" attitude from many on here and the press when they read that initial briefing.

This is a good reason why discussion should be encouraged not suppressed. I’ve been sick of reading the smart-arse “oh who needs RAIB when we have a bunch of armchair investigators” type comments - not here, but very present on other platforms especially Facebook.

The message that should be going out is that the root causes will be extremely complex, there is going to be a lot to unpick from here, even if the immediate cause is very simple.

Informed discussion is much better than rubbish circulating around which goes uncorrected if people are denied the opportunity to inject facts.

It was always likely that this was going to turn out to be a SPAD, simply on balance of probability because wrong-side failures of the signalling infrastructure are so incredibly rare, and when one considers how unusual it would have been for the 810 to stop where it did. Hence a lot of the frenzy now being seen on Facebook and elsewhere could have been avoided by some factual balanced discussion.

 

[Annetts key]

This is why factors like signal sighting will form part of the investigation

I think a SPAD was pretty much what we all expected.

The question remains, and hopefully the investigation determines, why he didn’t see or react to the red signal.

Signal sighting is always a factor when a train passes a signal at red or overspeeds over points. However, the far more significant point here is not simply the sighting distance of WH154 which was red (protecting the stopped train ahead) but why the driver did not react to the previous signal (WH356) showing a signal yellow.

He means the approach control to the crossover - there may well be some learnings about approach control and the potential dual implication of a single yellow clearing onto a fast line which introduces a layer of risk.

Many drivers experience a junction signal (that has approach control / approach release) showing a single yellow due to there being a train ahead of them. It happens quite often at some junctions near some stations.

The fundamental principle of the way the signalling system works is that drivers should obey the aspect displayed by a signal, no matter what they are used to or think is happening.

I think we need to wait for the RAIB full report before discussing how the driver reacted or failed to react in this accident though.

The issues with approach control / approach release are real, but from my point of view, the only network wide solution is ETCS/ERTMS fitment.

I do think potentially the AWS fault is a bit of a red herring. As you say there are train bourne faults and track bourne ones and it could be something as simple as the Nottingham driver didn’t cancel their AWS in time and it applied the brake (who knows)

But even if it was track bourne the Corby train would’ve passed over a different set of AWS magnets until the final one which is why I’m sceptical

Still lots of unanswered questions, which will be answered by RAIB
Was the AWS fault the 810 experienced due to a fault at WH154. The section doesn't seem very long so an AWS brake application at WH154 could have brought the train to a stand in the area of WH152, depending on the trains speed.
We know the 360 passed a red signal but don't know yet what if any AWS indication was recieved by the driver.

The AWS fault which caused the 810 to stop may be significant. RTT shows no other train on the fast line nearer than St Albans at the time of the accident, so the 810's driver should have been seeing green signals and getting an AWS bell. If either of those didn't happen (and in particular if only one of them did) the driver would have noticed something amiss and stopped. (there are three possibilities, a fault with the signal itself, a fault with the trackside part of the AWS equipement, or a fault with the trainborne AWS equipment)
Again, if the 810 was under green signals it might have taken more than one block to stop - that is after all why double yellows exist.
So an important question will be what the driver of the 360 saw and heard when passing the same signal.

The only "same signal" that the 360 passed was WH154 which, we know, was displaying a red aspect.

Yes. And it will be RAIB's work cut out to see what underlying factors there were. It will be interesting to see if there was wrong side failure of the AWS.

A couple of points:

For a unidirectional signalled line, the trackside AWS equipment that causes the train cab equipment to produce a horn, followed by a full brake application if the driver does not acknowledge it, is just a permanent magnet. So the chances of a wrong side (unsafe) failure on this equipment is extremely small.

A failure of the track and location cupboard equipment that should cause the train cab equipment to produce the bell (the AWS electro-magnet being "energised"), should just result in a horn instead. The system was deliberately designed to work in this way.

Further, even if the AWS track equipment did have a fault (the AWS electro-magnet NOT being "energised"), the 810 braked, so it would most likely have been a code 2 fault - horn when expecting a bell.

Further, going on the information from the RAIB, 1H46 at all the signals since leaving the station, should only have received a horn at each signal (yellow aspect = AWS horn, red aspect = AWS horn).

The real questions are: did the train AWS equipment work correctly for 1H46? Did the train equipment register a horn when it should have?

The other question is what caused the AWS issue with 1B67?

So I think it unlikely that the AWS issue experienced by 1B67 also directly caused an AWS issue for 1H46.

 

[Krokodil]

The lunatics are having a great time on Facebook

I don't miss being on that site.

 

[bramling]

The lunatics are having a great time on Facebook. Apparently the driver is being made a scapegoat...even when more than one person pointed out that RAIB have only published a finding that the 360 passed a red signal and didn't give a reason because they don't know yet, the rants continued! A mention that the driver isn't being blamed because RAIB don't apportion blame produces much frothing at the mouth. The power of social media.

I feel the industry could have avoided this by getting some facts out sooner.

A lot of people have been quite reasonably asking “how could this happen?”, remember that most of the population under the age of about 40 won’t have much recollection of a British train crash caused by a signal being passed at danger. This isn’t the 1990s where there was a string of high-profile serious accidents, such that the term SPAD even entered the national vocabulary for a time. A lot of people just take it for granted that trains don’t crash into one another, so it will naturally be quite unsettling that this happened.

Just providing a simple and concise explanation for what *should* have happened would have sufficed. “The first train stopped out-of-course for some reason, railways are designed so that if this happens there should always be a red signal protecting it from other trains, it’s primarily the responsibility of drivers to respond correctly to red signals though there is a wide range of measures and systems designed to assist them in this, the investigation will be urgently looking to see what has broken down in that process”.

 

[Bedford Rail]

I noticed it (1H46) was on the section at the Railcam position as ‘passing’. Where is the Railcam in relation to the collision site? Would the trains have gotten past it ? If so, there’ll be more evidence.

Yes, both trains will have passed it. Don't know exactly what property it's on, but it's around 700m or so north of WH154, and roughly 2km in total north of the crash site. Whether the footage provides any useful information is another question entirely, but one for RAIB.

 

[Signal Head]

The location of the two trains after the collision is just past WH152. With the best will in the world a 49mph collision isn't going to allow a class 360 to shunt a much heavier class 810 as much as 700m along the track.

Where do you get the 700m figure from?

The 810 was apparently standing at (the report says "next to") WH152. 5 car train of 24m car length: 120m. Add nominal standback distance of 25m, so rear of that train approximately 145m in rear of WH152.
It looks like it's been pushed maybe 3.5 coach lengths past the signal. 3.5 x 24, plus the standback of 25m = 109m.

We also don't know if the brakes were on or off on that unit, I would guess off, because if they had been fully applied is it not more likely the 360 would have climbed over the rear cab of the 810, and for there to have been even more damage to both?

 

[zwk500]

This is a good reason why discussion should be encouraged not suppressed. I’ve been sick of reading the smart-arse “oh who needs RAIB when we have a bunch of armchair investigators” type comments - not here, but very present on other platforms especially Facebook.

The message that should be going out is that the root causes will be extremely complex, there is going to be a lot to unpick from here, even if the immediate cause is very simple.

Informed discussion is much better than rubbish circulating around which goes uncorrected if people are denied the opportunity to inject facts.

It was always likely that this was going to turn out to be a SPAD, simply on balance of probability because wrong-side failures of the signalling infrastructure are so incredibly rare, and when one considers how unusual it would have been for the 810 to stop where it did. Hence a lot of the frenzy now being seen on Facebook and elsewhere could have been avoided by some factual balanced discussion.

The problem with informed discussion is that it requires information, and until the RAIB had published anything there wasn't any confirmed information to discuss.

Now that the RAIB have published the sequence of events, there is meaningful discussion that can be had.

 

[SilentGrade]

For a unidirectional signalled line, the trackside AWS equipment that provides causes the train cab equipment to produce a horn, followed by a full brake application if the driver does not acknowledge it, is just a permanent magnet. So the chances of a wrong side (unsafe) failure on this equipment is extremely small.

Even a right side failure of AWS has consequences though, especially if the fault is not rectified as it conditions drivers to simply cancel the warnings off

 

[Haywain]

However, the far more significant point here is not simply the sighting distance of WH154 which was red (protecting the stopped train ahead) but why the driver did not react to the previous signal (WH356) showing a signal yellow.

Why do you say the driver did not react to the single yellow at WH356?

 

[bramling]

The problem with informed discussion is that it requires information, and until the RAIB had published anything there wasn't any confirmed information to discuss.

Yes there was. It was immediately clear that WH154 had been passed (*) and the second train had entered into a section it wasn’t meant to be in. That immediately narrows things down to essentially three potential immediate causes. That is more than enough to be able to have a sensible factual discussion.

(* note I have not said what aspect it was displaying, just that it should have protected the Nottingham train).

 

[Signal Head]

The lunatics are having a great time on Facebook. Apparently the driver is being made a scapegoat...even when more than one person pointed out that RAIB have only published a finding that the 360 passed a red signal and didn't give a reason because they don't know yet, the rants continued! A mention that the driver isn't being blamed because RAIB don't apportion blame produces much frothing at the mouth. The power of social media.

I saw some right nonsense the other day. Along the lines of "if the TPWS & AWS on the front train was faulty, then that would cause the second train to get a green signal."

It beggars belief the misconceptions some people have about how the railway works, even worse that they are happy to jump on social media and blurt them all out. Then another layer of idiots will absorb their nonsense as facts, and the process repeats.

I thought about correcting it, but decided not to bother.

 

[Towers]

A lot of people have been quite reasonably asking “how could this happen?”, remember that most of the population under the age of about 40 won’t have much recollection of a British train crash caused by a signal being passed at danger. This isn’t the 1990s where there was a string of high-profile serious accidents, such that the term SPAD even entered the national vocabulary for a time. A lot of people just take it for granted that trains don’t crash into one another, so it will naturally be quite unsettling that this happened.

It has to be said, even for those of us with an interest in the industry, it’s sobering that one train can potentially plough into the back of another on a busy main line without definitive, overarching intervention from “a safety system”, i.e. TPWS, and even moreso when one possible cause may be simple driver error. It easy to appreciate that the general public would expect that simply not to be possibe in this day and age.

 

[Annetts key]

Even a right side failure of AWS has consequences though, especially if the fault is not rectified as it conditions drivers to simply cancel the warnings off

Absolutely. Ideally AWS failures should be attended to and repaired as soon as practical.

Why do you say the driver did not react to the single yellow at WH356?

Maybe I should have worded that differently. We currently don't have many details, but we do know that before the brake activation, the train was travelling at approximately 76 mph. That does not sound normal for a driver that is expecting the next signal to be red.

 

[Haywain]

Maybe I should have worded that differently. We currently don't have many details, but we do know that before the brake activation, the train was travelling at approximately 76 mph. That does not sound normal for a driver that is expecting the next signal to be red.

It is true that travelling at 76 MPH just after passing a signal (WH154) at red is far from normal, but it wasn't WH356 that was passed at red. WH356 protects the 50 mph crpossovers from up slow to up fast and there is no idication that there is anything untoward in the reaction to WH356 other than possible assumptions about the next signal.

 

[sharpener]

That only applies to an isolated system. The braking forces here alter that (momentum is transferred to the Earth).

I think it is still correct that (for the example given) immediately after the impact the combined consist would be moving at 16mph.

The impulse of momentum transferred to the earth is Pt where P is the braking force and t is the time until it all comes to rest. Straight after the impact t=0 so Pt = 0.

 

[bramling]

Absolutely. Ideally AWS failures should be attended to and repaired as soon as practical.

Maybe I should have worded that differently. We currently don't have many details, but we do know that before the brake activation, the train was travelling at approximately 76 mph. That does not sound normal for a driver that is expecting the next signal to be red.

Not necessarily, with performance of modern trains a train could quite easily be planning to stop at a red signal and then “open up”. We don’t yet have enough information to be able to say either way. However what does seem clear is that, for whatever reason, the red aspect on WH154 was driven through. This makes the incident more akin to Ladbroke Grove compared to, say, Southall or Watford where the red aspect was reacted to but too late. Unfortunately the prospect of this does send a bit of a chill down the spine.

 

[Ferret]

I have a whole heap of questions which only RAIB can answer. A key piece of information is what AWS indication(s) the 360 driver received.

It seems to me that he clearly wasn’t expecting the red signal to be red - when on restrictives, you just do not chase the red at 76mph. So, did he get bell vice horn, nothing vice horn?

RAIB will look at the sun angles to see if there’s a chance of misreading due to sun illumination.

They’ll also look at whether there was a potential read across to the adjacent signal on the slows.

They’ll look at his training records. Any prior incidents and Competence Development Plans arising.

They’ll look at possible driver fatigue - rostering etc.

There are many possibilities, not limited to the above. I urge all to remember that the Swiss cheese model is real - incidents of this nature rarely have a single point of failure…

I await the RAIB’s further contributions with interest.