Haywain
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- 3 Feb 2013
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That's because it's an interim report.That gives us a chronology, but very little in the way of explanation
That's because it's an interim report.That gives us a chronology, but very little in the way of explanation
This feels a little pedantic - surely by "encountered" they mean at the point a driver would respond to the signal.One wonders if what the RAIB have written is a little unclear on this. I’d be surprised if no train crossed over with the signal initially displaying red. What they presumably mean is that on all occasions it had stepped up to a proceed aspect by the time the approaching train reached it.
This would be the only time it *remained* at danger, which is quite an important distinction.
This will probably come out in the final report. RAIB colocate with AAIB who are human factors experts. We can only hope there is a detailed deep dive into the human factors for this incident as it seems abundantly clear that was the proximal cause of the accident.It’s notable there is pretty much nothing on human factors relating to the 360 driver.
I agree that areas of investigation should not be dropped at this stage, but it is also important the investigation not just focusing on immediate chain of technical events, but also the hidden link in systematic and human factorsIt was a link in a chain that caused the collision, the right side failure had it been acknowledged, said train carries on, no collision. That isnt blaming anyone its just a fact, same as had that same train(1B67) not been late, again the same event, no collision. Investigators won't just look at one thing and say thats the reason, they look at all possible links in the chain including those major and make recommendations based on those to prevent the next as every link can hold the opportunity to deal with an issue that may cause the next unfortunate event.
I can't see how they could know that. I doubt they can do any more than analyse data logs to see what the signal was showing at the time its berth track circuit went occupied, and with no pointwork on the approach this track circuit probably goes back to signal 343 or at least to the end of its overlap. Maybe they could include a time lag, but that would involve estimating the time from occupying the track circuit to sighting the signal, which in turn depends on how fast the train was approaching and therefore indirectly on the signal aspect, which sounds a bit like using the answer to prove the answer. A signal leading out of a complex area into a long stretch of plain line is unlikely to be approached at red unless there's some out of course event beyond it as happened here.One wonders if what the RAIB have written is a little unclear on this. I’d be surprised if no train crossed over with the signal initially displaying red. What they presumably mean is that on all occasions it had stepped up to a proceed aspect by the time the approaching train reached it.
They note that why the driver passed the signal is the big question here, and they aren't going to present part of the answer until they have all the relevant information. But as someone mentioned above, it's unlikely we will ever know for certain.It’s notable there is pretty much nothing on human factors relating to the 360 driver.
Are systems available where the recording server constructs the file from a camera live stream and can neatly conclude it at any time if the feed is interrupted?
Very important. Stepping up from red may be an occasional experience for trains joining the up fast closely following an express, but an unrestricted run on the fast is likely to be well ahead as the second train snakes across the junction at less than half its speed. A cautionary proceed aspect typically seen at WH154 is more likely. This is why I'm so concerned about the possible reading through of WH152, as that showing a green may have been very persuasive reinforcement of the mistaken notion that the forward train is racing on ahead, not stopped immediately beneath the signal.One wonders if what the RAIB have written is a little unclear on this. I’d be surprised if no train crossed over with the signal initially displaying red. What they presumably mean is that on all occasions it had stepped up to a proceed aspect by the time the approaching train reached it.
This would be the only time it *remained* at danger, which is quite an important distinction.
I would expect a lock if the signal post and its telephone were in an area accessible to the public, such as a station platform, but not otherwise.I don't believe they are - I can't recall ever seeing a lock on the door of the box containing a signal post phone.
From how far away can WH152 be seen? Would a driver passing WH154 be able to see it, even when a train is standing underneath it?This is why I'm so concerned about the possible reading through of WH152, as that showing a green may have been very persuasive reinforcement of the mistaken notion that the forward train is racing on ahead, not stopped immediately beneath the signal.
WH152 is round a curve from 1H46's direction of approach, and I doubt it can be seen from WH154.I would expect a lock if the signal post and its telephone were in an area accessible to the public, such as a station platform, but not otherwise.
== Doublepost prevention - post automatically merged: ==
From how far away can WH152 be seen? Would a driver passing WH154 be able to see it, even when a train is standing underneath it?
The way I read @MarkyT's point was that, having passed WH154 at danger, the driver of 1H46 may have seen WH152 at green before seeing 1B67 stopped, and seeing that green may have reinforced the notion that 1B67 was racing ahead.From how far away can WH152 be seen? Would a driver passing WH154 be able to see it, even when a train is standing underneath it?
I’d agree. Just very good railway work and a task that isn’t needed that often.Train Manager AND driver. And I think "heroic" overplays it a touch.
I reckon at around 700m on approach to WH152, based on the video I linked above, and that is ~600m after passing WH154.From how far away can WH152 be seen? Would a driver passing WH154 be able to see it, even when a train is standing underneath it?
The way I read @MarkyT's point was that, having passed WH154 at danger, the driver of 1H46 may have seen WH152 at green before seeing 1B67 stopped, and seeing that green may have reinforced the notion that 1B67 was racing ahead.
I would expect a lock if the signal post and its telephone were in an area accessible to the public, such as a station platform, but not otherwise.
That normally means putting them in a lockable enclosure with a drivers No 1 key lock. In reality that depends on where they are being installed."In areas of high vandalism equipment and telephones may require suitable protection or provision of vandal resistant types".
The significance might depend on whether a single yellow with feathers is the expected signal for a 1Hxx train at that signal.forgetting the significance of the single yellow
There are plenty of video formats that can be played back without "gracefully" ending the recording. I would assume it's to do with filesize but it does seem quite silly to make the most important parts of a recording be so fragile.<CCTV generally records in 5 or 10 minute blocks, the missing video will simply be due to the file not having been completely written to disk.> Seems unnecessarily cumbersome for a professional grade system.
I haven't seen anything about what approach control conditions apply to this signal (WH356), which might keep it at single yellow for any diverging route.The significance might depend on whether a single yellow with feathers is the expected signal for a 1Hxx train at that signal.
I'm concerned that the electro-magnet for WH154 AWS was not mounted at the correct height with respect to the rail level.83. On 9 July 2026, another class 810 unit approaching signal WH154 incorrectlyreceived an AWS warning indication while this signal was displaying a green aspect. In this case, the driver acknowledged the incorrect warning indication within the 2.7 second response window. They reported the matter to the signaller immediately, and the train was able to continue its journey.
84. Further investigation following this second incident found that the electromagnet within the AWS track equipment (which is energised only when a green aspect is shown, and interfaces with the AWS equipment on the train to produce the AWS clear indication) was positioned lower than the associated permanent magnet. It was also positioned 16 mm below railhead level, outside the required tolerance of ±12 mm. Work is continuing to understand the interface between the AWS electromagnet at signal WH154 and the AWS equipment on train 1B67, which led to the driver receiving a warning indication with the signal displaying a green aspect. RAIB has found no evidence that the AWS electromagnet was not correctly energised.
SERVICE B
2. Full Inspection and Test
...
2.5 Gauge the top of the AWS magnet with respect to rail head (±12mm from rail level).
This should be done by use of a line / bob weights and associated plastic gauge or rule.
2.6 Carry out NR/SMS/PartB/Test/024 (AWS Tests).
Note that NR/SMS/PartB/Test/024 is the electrical and magnetic AWS Tests.SERVICE RE
Fix on failure.
The failure of any GSM-R to fail to operate in an emergency is a concern. For it not to work on both trains is extremely concerning.58 In the immediate aftermath of the collision, the driver of train 1B67 realised that their train had derailed and that this presented a potential risk of collision with a train passing on an adjacent line. As the train had lost power in the collision,the driver could not make a GSM-R REC. They therefore worked with the train manager to place track circuit operating clips on the adjacent lines (these clips are emergency equipment which simulates the presence of a train, causing signals on the approach to change to red).
Thanks. Could you identify which signal is which on that video, as i'm finding it hard to follow (the signal number plates are not clear)I reckon at around 700m on approach to WH152, based on the video I linked above, and that is ~600m after passing WH154.
I suggest the signal, high up on the gantry, is far more visible than a short dark-hued train stopped below it. The report states the train becomes visible in FFCCTV around the signal sighting point, but that doesn't mean the driver noticed it.
It can’t be seen from WH154 , correct.WH152 is round a curve from 1H46's direction of approach, and I doubt it can be seen from WH154.
I've set the video link to start roughly at the sighting point for WH152. If you pause and step back and forth using L/R arrow keys, the previous signal WH154 can be found, and you can step all the way back through Bedford station to view the whole approach. If you set playback speed to 0.25, arrow steps are ~1s rather than default 5s. (Edit: note the finer stepping only works at YouTube, not using the embedded player here, where the step is always 10s regardless of playback speed setting).Thanks. Could you identify which signal is which on that video, as i'm finding it hard to follow (the signal number plates are not clear)

I have not read the interim report yet, but one thing i have not seen mentioned is the location of the class 360 that was on the down slow line in the are of the yellow dot.I've set the video link to start roughly at the sighting point for WH152. If you pause and step back and forth using L/R arrow keys, the previous signal WH154 can be found, and you can step all the way back through Bedford station to view the whole approach. If you set playback speed to 0.25, arrow steps are ~1s rather than default 5s. (Edit: note the finer stepping only works at YouTube, not using the embedded player here, where the step is always 10s regardless of playback speed setting).
Here's a still from the video above showing the approach to WH154 from the trailing crossover where a move from up slow joins the up fast.
The signal, here at green, is clearly visible from this point just under 1km away. It is the tiny point light source I have circled in yellow. That's excellent sighting in my experience.
View attachment 212529
Precisely my pointThat's because it's an interim report.
I'm concerned that the electro-magnet for WH154 AWS was not mounted at the correct height with respect to the rail level.
That’s interesting, because the Carmont (the last but one) interim report gave clear causes. As did the previous Margam report. Maybe the policy changed between 2021 and 2025.That's because it's an interim report
I've set the video link to start roughly at the sighting point for WH152.
I understand now, it was the sighting of signal 152 I was interested in. That is the one first seen at about 1:01:54 and passed at 1:02:00.I've set the video link to start roughly at the sighting point for WH152. If you pause and step back and forth using L/R arrow keys, the previous signal WH154 can be found, and you can step all the way back through Bedford station to view the whole approach. If you set playback speed to 0.25, arrow steps are ~1s rather than default 5s. (Edit: note the finer stepping only works at YouTube, not using the embedded player here, where the step is always 10s regardless of playback speed setting).
Here's a still from the video above showing the approach to WH154 from the trailing crossover where a move from up slow joins the up fast.
The signal, here at green, is clearly visible from this point just under 1km away. It is the tiny point light source I have circled in yellow. That's excellent sighting in my experience.
Maybe it's because of human factors? They can't say something like "1H46 received a wrong-side AWS bell vice horn at WH154 and then passed it at red" because it's not that simple.That’s interesting, because the Carmont (the last but one) interim report gave clear causes. As did the previous Margam report. Maybe the policy changed between 2021 and 2025.
I understand now, it was the sighting of signal 152 I was interested in. That is the one first seen at about 1:01:54 and passed at 1:02:00.
signal 154 is passed at 1:01:50 and first seen at about 1:01:19 (maybe earlier if there hadn't been a train coming the other way with a bright headlight)
Because of the curves there is no way that 152 could be "read through" from the preceding signal 154, but the reverse curves could make it difficult to realise that there was a train under the signal (with no yellow nose, and no tail lights either if the reboot knocjked them out as well as GSM-R)
It's also notable that the information in this report is all attributable to what's been electronically logged. That gives us a chronology, but very little in the way of explanation