Near miss at Chalfont

[seaeagle]

Two trains, (one Met & one Chiltern) in a near miss at Chalfont

[rincew1nd]

Admin Comment

Forum Rules state

Sept 19, 2008 12:14:04 GMT Admin Team said:

7.3 (Serious Incidents and/or Major Events)

Serious incidents or other major events such as derailments, crashes, fires, weather, terrorist, etc (to give a few examples - this list is not exhaustive) can also prove to be a particularly difficult subject, especially in the early stages. These type of events will always lead to speculation and internal investigations. As a result the following applies on this forum:
(7.3a) Forum staff members will confirm the facts when they have them to hand, though it may be some time time before this is possible.
(7.3b) LU staff that are directly involved in an incident may post a brief outline if they feel it is appropriate - however as with our one under rule above, details of a fatal incident are not allowed in case of any prejudice at a future inquest.
(7.3c) Discussion will be at the discretion of the forum staff, however in most cases once the facts have been confirmed, a given thread will most likely be locked to prevent non-factual speculation.
(7.3d) Should an official report be released, a request can be made to a member of forum staff to have a link added to the original locked thread. For further discussion after an official report has been released, a new thread should be started.

Given that this type of incident/event will be subject to official lines of enquiry and/or investigation, it is important that we do not allow this forum to become involved with speculation that would detract from the facts. Information may or may not be found within websites elsewhere on the internet - just because it's on another website, it doesn't mean it is factually correct or that we can or will allow it here; again the forum staff cannot 'police' other websites, but we are responsible for what appears on this forum.

Given that this is a very serious near miss which, in slightly different circumstances, could have resulted in a serious collision it is highly likely that RAIB will be investigating. As such, in accordance with forum rules this thread will remain locked. The forum staff will update it as and when press releases are made and/or formal reports published.

[rincew1nd]

BBC News have published an article about the incident

BBC News - Train travels wrong way down London Tube track
www.bbc.co.uk/news/uk-england-london-53150748

[Dstock7080]

www.gov.uk/government/news/signal-passed-at-danger-and-subsequent-near-miss-at-chalfont-latimer-station

At around 21:45 hrs on 21 June 2020, a Chiltern Railways passenger train travelling southbound on the Metropolitan line of the London Underground network, passed a signal at danger (red) without authority. The signal was protecting a junction through which a route was already set for a northbound train, waiting in Chalfont & Latimer station, to cross in front of the southbound train. Passing the signal at red resulted in an automatic brake application which stopped the southbound train around 310 metres beyond the signal. Shortly afterwards, the train driver reset the automatic brake equipment and the train continued towards Chalfont & Latimer station, around 620 metres away. As a result of the position of the points at the junction, its route towards the station took it onto the northbound line. The northbound London Underground train on this line was stationary because the signal in front of it had changed to red as a result of the southbound train passing the red signal. The two trains stopped about 23 metres apart.

There were no reported injuries but some track components were
damaged as the southbound train had proceeded through a route that was not set for it.

Our investigation will identify the sequence of events which led to the signal being passed at danger and the subsequent near-miss. It will also consider

- the actions of the people involved
- Chiltern Railways’ arrangements regarding the training, competence and fitness of its train drivers
- Chiltern Railways’ management of risk associated with its drivers operating on the London Underground network
how risk associated with signals passed at danger by non-London Underground trains is managed on the London Underground network
any relevant underlying factors

Forward-facing CCTV image from southbound train, showing stopping positions of the trains involved (image courtesy of Chiltern Railways)

[Deleted]

The report is now published

www.gov.uk/government/news/report-042021-signal-passed-at-danger-and-subsequent-near-miss-chalfont-latimer-station

Summary​
At around 21:43 hrs on Sunday 21 June 2020, a near miss occurred between two passenger trains at London Underground’s Chalfont & Latimer station on the Metropolitan line. A few minutes earlier a southbound Chiltern Railways train had passed a signal displaying a red (stop) aspect (known as a signal passed at danger or a ‘SPAD’). This resulted in the train being automatically stopped by a safety system, known as a tripcock, which had applied the train’s emergency brake. Without seeking the authority required from the service operator (signaller), the driver reset the tripcock before continuing towards Chalfont & Latimer station, where the train was routed towards the northbound platform, which was occupied by a London Underground train.

The Chiltern Railways train stopped about 23 metres before reaching the other train, which was stationary. There were no reported injuries, but there was minor damage to signalling equipment and a set of points.

The probable cause of the SPAD was that the driver of the Chiltern Railways train was fatigued. The driver stated that he decided to proceed without authority because he did not recall passing the stop signal and believed the tripcock safety system activation had been spurious. This decision may also have been affected by fatigue.

RAIB found that Chiltern Railways’ processes for training and testing a driver’s knowledge of what to do following a tripcock activation were not effective. A probable underlying factor was that Chiltern Railways’ driver management processes did not effectively manage safety-related risk associated with the driver involved in the incident. It is possible that this was a consequence of a high turnover of driver managers, insufficient driver managers in post and their high workload. Although not causes of the incident, RAIB also found shortcomings in other aspects of these driver management processes, and in risk management at the interface between Chiltern Railways and London Underground.

Recommendations​
RAIB has made three recommendations and identified one learning point. The first recommends that Chiltern Railways improves its driver management processes. The second recommends that Chiltern Railways and London Underground Ltd jointly establish an effective process for the management of safety at the interfaces between their respective operations. The third recommends that Chiltern Railways, assisted by London Underground, reviews the risk associated with resetting train protection equipment applicable to Chiltern Railways’ trains on London Underground infrastructure. The learning point concerns the importance of considering sleep disorders during routine medical examinations of safety critical workers.

[PiccNT]

And a bit more reported here by the BBC

www.bbc.co.uk/news/uk-england-beds-bucks-herts-57969283

[Chris M]

I wouldn't call that article "a bit more", as it's just a very condensed, non-expert summary of the RAIB report. At least they illustrated it with the correct type of train for once.

[jimbo]

The Chiltern driver did not think his train was tripped by a signal, and was able to reset the tripcock and restart the train within 9 seconds, accelerating downhill to 27mph to run through the Chesham branch points set for a northbound train, only making an emergency brake application due to being unexpectedly thrown by crossing to the northbound line at 10mph over the speed limit there of 15mph. The Chiltern train stopped just over a car short of the Chesham train standing at the platform. LU were unaware that Chiltern trains were not equipped with an effective Speed Control After Tripping (SCAT) system which on LU limits trains to 10mph for three minutes.

[superteacher]

Jul 27, 2021 11:07:53 GMT Chris M said:

I wouldn't call that article "a bit more", as it's just a very condensed, non-expert summary of the RAIB report. At least they illustrated it with the correct type of train for once.

Shame - I miss the token 1967 stock picture!

[joshua]

Jul 28, 2021 5:01:05 GMT jimbo said:

The Chiltern driver did not think his train was tripped by a signal, and was able to reset the tripcock and restart the train within 9 seconds, accelerating downhill to 27mph to run through the Chesham branch points set for a northbound train, only making an emergency brake application due to being unexpectedly thrown by crossing to the northbound line at 10mph over the speed limit there of 15mph. The Chiltern train stopped just over a car short of the Chesham train standing at the platform. LU were unaware that Chiltern trains were not equipped with an effective Speed Control After Tripping (SCAT) system which on LU limits trains to 10mph for three minutes.

Why was the Chiltern Railway train not fitted effective SCAT system and would they have an effective SCAT system fitted to the fleet which are capable of running on that bit of line?

[metman]

I don’t think SCAT (Speed Control After Tripping) is fitted to most National Rail trains but obviously this is a different situation. I can see it happening to be on honest it’s probably more of an operating policy adjustment that needs to be made which if I remember was one of the takeaways from the report.

[Chris M]

Mar 15, 2022 16:54:27 GMT joshua said:

Jul 28, 2021 5:01:05 GMT jimbo said:

The Chiltern driver did not think his train was tripped by a signal, and was able to reset the tripcock and restart the train within 9 seconds, accelerating downhill to 27mph to run through the Chesham branch points set for a northbound train, only making an emergency brake application due to being unexpectedly thrown by crossing to the northbound line at 10mph over the speed limit there of 15mph. The Chiltern train stopped just over a car short of the Chesham train standing at the platform. LU were unaware that Chiltern trains were not equipped with an effective Speed Control After Tripping (SCAT) system which on LU limits trains to 10mph for three minutes.

Why was the Chiltern Railway train not fitted effective SCAT system and would they have an effective SCAT system fitted to the fleet which are capable of running on that bit of line?

These questions are answered by Paragraphs 135-138 of the report (PDF page 43).

[d7666]

Mar 15, 2022 20:12:01 GMT metman said:

I don’t think SCAT (Speed Control After Tripping) is fitted to most National Rail trains but obviously this is a different situation. I can see it happening to be on honest it’s probably more of an operating policy adjustment that needs to be made which if I remember was one of the takeaways from the report.

Not sure it is fitted to ANY main line trains other than 168s referred to in the report ??! If such a system is, I don't think it goes by that name.

Whether something was fitted to EMU for operation over train stop fitted routes e.g. 313s (in the past when they went to Moorgate) or embedded on 717s now, or 507\508 on Merseyrail now or on 777s, no idea. Never heard of it; will make enquiries.

[d7666]

Mar 16, 2022 21:44:10 GMT d7666 said:

Mar 15, 2022 20:12:01 GMT metman said:

I don’t think SCAT (Speed Control After Tripping) is fitted to most National Rail trains but obviously this is a different situation. I can see it happening to be on honest it’s probably more of an operating policy adjustment that needs to be made which if I remember was one of the takeaways from the report.

Not sure it is fitted to ANY main line trains other than 168s referred to in the report ??! If such a system is, I don't think it goes by that name.

Whether something was fitted to EMU for operation over train stop fitted routes e.g. 313s (in the past when they went to Moorgate) or embedded on 717s now, or 507\508 on Merseyrail now or on 777s, no idea. Never heard of it; will make enquiries.

,

I've asked the question in several places, to direct contacts as well as on a couple of forums. Doing this as it is something that interests me, and had never thought of it before.

One answer so far on wnxx forum is that Tyne Wear metro do have a speed control after tripping function; their tripping by safety system is from Indusi (that is, a form of Indusi used on German railways), and after an Indusi trip units are limited to 30 km/h. I did go look up the technicalities of Indusi on German web sites, my German is good enough for that, but even with google xlating, despite interminable detail (replicated in several places) about how Indusi works to trip a train, none of it explains what happens after a train does get tripped.

As yet, no-one has been able to yea or nay if any of main line 313 319 507 508 717 777 have any system; a couple of answers have said "never heard of it" but also were not ruling out there is or was one, they just didn't know either way.

[Tom]

I've moved a couple of recent posts from this thread to SSR Resignalling as they were more appropriate there.

Members are also reminded of Our Rules regarding the 'bumping' of old threads. Rule 6(f) refers.