Chiltern parliamentary - RAIB investigation

[Muzer]

Ah, that makes much more sense! You had me worried for a minute, there. So is it permissible to drive ECS/freight without TPWS equipment (genuine question)?

 

[Tomnick]

So is it permissible to drive ECS/freight without TPWS equipment (genuine question)?

Surely not! A non-passenger train proceeding without authority is just as likely to collide with a passenger train.

 

[driver9000]

Re driving with the TPWS in self isolated mode, the train from Guildford to Aldershot in question is an ECS move, I would never drive a train in passenger service with the TPWS in that position,at least not without some other safeguards in place as per the rools. Sorry for not making that clear in my first post. I have probably driven with it flashing on 6 or 7 occasions over the last few years, it certainly isnt a lot.
Oh they can monitor it as much as they like, I dont have any booked 458 work now. Its 456s now.

I have refrained from posting in this thread but this alarms me. I hope I have the wrong end of the stick but it reads to me as though you drove a train along a mainline with the TPWS in a failed mode because you got fed up of resetting the fault. Did you inform the signaller and your control to what you were intending to do each time you did this or was it case of it'll be alright? I would hope fellow drivers would never drive with TPWS failed/isolated without following the correct procedures and not simply because they were fed up moving 6ft to clear the grids and keying out and back in. Again sorry if I have the wrong end of the stick on this or it's some sort of wind up but I can't believe what I've read!

 

[455driver]

Ah, that makes much more sense! You had me worried for a minute, there. So is it permissible to drive ECS/freight without TPWS equipment (genuine question)?

No its not, all safety systems should be working at all times, I am fully aware that what I did was wrong but not a serious issue.
Would I do it now, nope not a chance in hell but that was then and this is now.
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Again sorry if I have the wrong end of the stick on this or it's some sort of wind up but I can't believe what I've read!

Okay I did wrong, I wont do it again, even if the situation reoccured, I would move the 6 feet and key out etc.

 

[34D]

Okay I did wrong, I wont do it again, even if the situation reoccured, I would move the 6 feet and key out etc.

Trial by forum......

 

[TDK]

No its not, all safety systems should be working at all times, I am fully aware that what I did was wrong but not a serious issue.
Would I do it now, nope not a chance in hell but that was then and this is now.
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Okay I did wrong, I wont do it again, even if the situation reoccured, I would move the 6 feet and key out etc.

I am pleased you posted this one 455 or you may have had your collar felt. To be honest I was told by a manager that if the yellow light is flashing the TPWS will still stop the train so go to the next stopping point and reset the system. That was then and this is now. I do find it quite strange how messages about the TPWS self isolating itself have now been introduced into the late/new notice cases as if it is a new phenomenon. I still believe many people including Network Rail did not realise this was a high risk.
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Ah, that makes much more sense! You had me worried for a minute, there. So is it permissible to drive ECS/freight without TPWS equipment (genuine question)?

It is not permissible for any train to enter service with non functional TPWS system be it ECS/Freight or passenger. If the TPWS becomes faulty en route there are rules in place and the first is to stop your train and contact the controlling signalman

 

[DDB]

It is not permissible for any train to enter service with non functional TPWS system be it ECS/Freight or passenger. If the TPWS becomes faulty en route there are rules in place and the first is to stop your train and contact the controlling signalman

Can I ask a quick question. What does the signalman do with this information?

DDB

 

[carriageline]

To be honest, not a great deal. Inform control, and then keep the train two signals away from a conflicting or covering movement (so the signal in advance of the signal protection a train crossing that line to use a branch line for example!), if it's an AB line, line must be clear to section signal before being accepted


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[O L Leigh]

To be honest I was told by a manager that if the yellow light is flashing the TPWS will still stop the train so go to the next stopping point and reset the system. That was then and this is now. I do find it quite strange how messages about the TPWS self isolating itself have now been introduced into the late/new notice cases as if it is a new phenomenon. I still believe many people including Network Rail did not realise this was a high risk.

I've been told so many different things about TPWS, IVRS, GSM-R and other systems, often totally contradictory. I've even seen driver managers arguing because they have different understandings on something and, over the course of almost two weeks, had to explain and even demonstrate that their understandings are wrong. Sometimes the managers really don't know what they are talking about.

I keep saying it. The fault status on TPWS is not a high risk provided that drivers check that it is working and take the necessary action to deal with the fault status before setting sail. It's not so much different from ensuring the radio is correctly set up, etc. It's quick and easy to do and, as I've said before, I don't know any drivers who are unaware of the fault status and how to deal with it.

O L Leigh

 

[TDK]

Can I ask a quick question. What does the signalman do with this information?

DDB

The signalman will authorise you to move or not move the train in liaison with your company control and their control.

 

[carriageline]

The signalman will authorise you to move or not move the train in liaison with your company control and their control.

Plus they signal the train as i said above, but of course the driver may or may not realise!!


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[TDK]

Plus they signal the train as i said above, but of course the driver may or may not realise!!


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Double blocking and most drivers do realise what is involved.

 

[dysonsphere]

Its funny what the mind will not notice as a PPL we are probably more aware than most about checklists but a few years ago still managed to take of with alternator turned off. ( an odd version with a spilt mains switch 1 side for lx on and the other to exicte the alternator). But the thing is it was something I was doing everyday and just didnt notice no charge etc.

 

[TheLastMinute]

The report into the SPAD at Greenford has been released http://www.raib.gov.uk/publications/investigation_reports/reports_2014/report292014.cfm.

The report doesn't really get to any conclusions as to why the SPAD occurred. It does suggest that the driver may have been misled by what may have been the early clearing of G56 (the semaphore in the rear of the two passed at danger) due there being no berth track circuit at that location. One of the learning points is that signalers should be sure of the exact location of train before clearing a semaphore in the rear of another at danger, the implication being that they should perhaps wait for the "waiting at signal" GSM-R message before clearing the signal if there is no berth track circuit.

As for the TPWS, the report states that driver was aware that the system was displaying a fault when setting up the desk at Paddington, but was under the impression that the system would still operate and stop the train if required hence he drove while TPWS was self isolated. It turns out that Chiltern's driver management system didn't test drivers on their knowledge of TPWS in this failed state, and all information about it was learned by mess room gossip. As we've seen from this thread, there are quite a few different understandings out there on how TPWS ver. 1 behaves when setup over the grid so sounds like he may well have been setup for a fall by the lack of proper on-going training and competence management. Another point was that Chiltern don't use their driving simulator to test/train their existing drivers for out-of-course events which I find quite surprising in this day and age.

TLM

 

[PG]

For those who are interested the RAIB have now published their report on this.

It is available from this page on their website, while the actual report pdf is at this link:
http://www.raib.gov.uk/cms_resources.cfm?file=/141222_R292014_Greenford.pdf

RAIB summary for the benefit of those who may not be able to access the links.

At around 11:55 hrs on Thursday 20 March 2014, the 11:36 hrs passenger train from
London Paddington to West Ruislip, operated by Chiltern Railways, passed two
consecutive signals at danger near Greenford, west London. It was stopped when a
signaller sent an emergency radio message to the driver. Although no-one was hurt
in the incident, the unauthorised entry of a train onto a single line creates the potential
for a serious collision.

A freight train had passed the junction at Greenford shortly before the passenger train
was due. Because the freight train was still occupying the line between Greenford
and South Ruislip, the signaller at Greenford kept the signal at the junction at danger.
The passenger train, travelling at about 20 mph (32 km/h), passed this signal and the
next one, 142 yards (130 metres) further on, which was also at danger. It passed over
the junction and onto the single-track section towards South Ruislip, which was still
occupied by the freight train. The train had travelled about one mile (1.6 km) beyond
Greenford by the time that the driver received the emergency radio message.

The investigation found that the driver of the passenger train did not react to the two
signals at danger, for reasons which are not certain. It is possible that he had formed
the impression that the train had been given clear signals through Greenford, because
of his interpretation of the meaning of the signal preceding those that he passed at
danger, and he had not been stopped by signals at Greenford in the recent past.

The Train Protection and Warning System (TPWS) was fitted to the train and to
both the signals, but it did not intervene to apply the brakes of the train, as it was
intended to do. This was because the on-train TPWS equipment had self-isolated
when the driver prepared the train for departure from Paddington. The isolation of
the equipment was indicated by a flashing light in the cab, but the driver still drove the
train.

Although the signaller at Greenford wished to stop the train by sending an emergency
call on the GSM-R radio system, he did not attempt to do so because the information
presented by the radio equipment in the signal box suggested to him that any
message he sent would not reach the train. Instead, he contacted Marylebone signal
box, which was able to send a message to the train.

The RAIB has made three recommendations. One is addressed to Chiltern Railways,
and covers the need for a review of the company’s driver management processes.
The other two, addressed to Network Rail, cover the configuration of the GSM-R radio
system as it affects the ability of signallers to directly contact trains that are within their
areas of control, and the training given to signallers in the use of the GSM-R system.
The RAIB has also identified two learning points: one for signallers, relating to the use
of delayed clearance of signals to warn train drivers of the state of the line ahead, and
the other for train operating companies, relating to the upgrading of on-train TPWS
equipment.

 

[talltim]

While I gather it has been corrected in later TPWS versions, I still find it strange that that it wasn't configured to be able to be set-up while sitting on a grid.

 

[TheLastMinute]

While I gather it has been corrected in later TPWS versions, I still find it strange that that it wasn't configured to be able to be set-up while sitting on a grid.

I think I read either in this thread or the report that the reason that TPWS ver. 1 can't be setup over a energised loop is that radio frequencies of the track loop and the self test process interfere with each other causing the self test to fail. It is quite possible (I would even say quite likely) that when TPWS was designed by BR back in the early/mid 90s, the equipment available just wasn't sophisticated enough to easily overcome the interference problem and it was decided the best way forward was to deal with it via the rule book, as it done when AWS stops over a magnet.

I would also think that as privatisation was going on at the time, there would have been very little appetite to introduce a new system on trains that would stop the train moving if it failed. In fact, I've a dim and distance memory that it was talked of at the time as an advantage that TPWS wouldn't disable the train if it failed but I could well be wrong on that.

TLM

 

[Taunton]

I would also think that as privatisation was going on at the time, there would have been very little appetite to introduce a new system on trains that would stop the train moving if it failed.

Wasn't this exactly what contributed to the Southall accident back in the 1990s, that the HST was one of the first to be fitted with pioneer TPWS (ATP), likewise the track, but it wasn't compulsory to use it and although the last months of BR did so, once privatised the new operator switched it all off.

 

[PermitToTravel]

It really is surprising, the state of the ex-GCR/GWR joint route. It took over an hour for a replacement driver to get to the train while it was stopped on the single line. There were no other trains that would have used the line in this time, and no passengers aboard. This on a line in London zones 4/5 that once carried 8tph.

 

[edwin_m]

I would also think that as privatisation was going on at the time, there would have been very little appetite to introduce a new system on trains that would stop the train moving if it failed. In fact, I've a dim and distance memory that it was talked of at the time as an advantage that TPWS wouldn't disable the train if it failed but I could well be wrong on that.

TPWS was designed with a temporary isolation facility for use when instructed to pass a signal at danger, and a "permanent" isolation if there was no other way to get the brakes off. As with the similar isolation feature on AWS, there are now rules that the train is only allowed to continue in very limited circumstances if the isolation has to be used (and no doubt somebody will be along soon to quote them).
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Wasn't this exactly what contributed to the Southall accident back in the 1990s, that the HST was one of the first to be fitted with pioneer TPWS (ATP), likewise the track, but it wasn't compulsory to use it and although the last months of BR did so, once privatised the new operator switched it all off.

ATP and TPWS are different systems, one didn't evolve from the other. At the time of Southall it was permitted to operate with both isolated but since then the rules have been tightened up, as per my post above.
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While I gather it has been corrected in later TPWS versions, I still find it strange that that it wasn't configured to be able to be set-up while sitting on a grid.

At the time TPWS was designed, it wasn't intended to fit grids on the approaches to buffer stops, so it would be very unlikely that the cab would be standing on a grid when it was opened up.

 

[MichaelAMW]

It really is surprising, the state of the ex-GCR/GWR joint route. It took over an hour for a replacement driver to get to the train while it was stopped on the single line. There were no other trains that would have used the line in this time, and no passengers aboard. This on a line in London zones 4/5 that once carried 8tph.

When did that line ever carry 8 trains an hour?

 

[js47604]

It really is surprising, the state of the ex-GCR/GWR joint route. It took over an hour for a replacement driver to get to the train while it was stopped on the single line. There were no other trains that would have used the line in this time, and no passengers aboard. This on a line in London zones 4/5 that once carried 8tph.

It could easily take over an hour. Spare driver to locate if not readily available,DSM to arrange, then taxi through London traffic in the middle of the day.

 

[khib70]

From the RAIB report, it doesn't look good for the driver. I'm not one of those self-appointed, Train Simulator trained drivers, so I'm not going to pass an opinion on the detail of what happened. But I hate the thought of anyone losing their job at this time of year.

To those who do know about these things, what's likely to happen to the driver in this situation? Clearly that's a matter for the TOC rather than the RAIB. Is some sort of retraining an option?

 

[Dieseldriver]

TPWS was designed with a temporary isolation facility for use when instructed to pass a signal at danger, and a "permanent" isolation if there was no other way to get the brakes off. As with the similar isolation feature on AWS, there are now rules that the train is only allowed to continue in very limited circumstances if the isolation has to be used (and no doubt somebody will be along soon to quote them).

No. TPWS has a Trainstop Override for passing an individual signal at danger. The system can be Temporary Isolated for various procedures (Temporary Block Working etc) and there is also a Full Isolation for dealing with faults.

 

[Howardh]

Quote from the report

review of the company’s driver management processes

Very uncear - does this apply to the training of ONE particular driver (ie the one concerned) or ALL drivers in the company - which I think it means?

 

[swt_passenger]

...Very uncear - does this apply to the training of ONE particular driver (ie the one concerned) or ALL drivers in the company - which I think it means?

There are some criticisms of training that appear fairly general. They are questioning why the driver simulator at Aylesbury was only used for new trainees, and not as part of competence management. (para 98)

There's also the section that implies that some aspects of TPWS operation were passed on by driver to driver, but had not ever been briefed by Chiltern. (para 96)

 

[RPM]

It could easily take over an hour. Spare driver to locate if not readily available,DSM to arrange, then taxi through London traffic in the middle of the day.

Indeed. Only 48 Chiltern drivers actually sign the route to PAD. Divide that in half because there are two shifts, allow for leave/sickness and you're talking about slightly fewer than 20 drivers that could even potentially be approached to go and take over the train. If one of those happens to be spare they'll be located at Aylesbury, not Marylebone. Most likely a route-competent driver would have had to be pulled off their job at Marylebone and another driver found to complete the job they were on. Then the driver and DSM have to be taxied over to Greenford. Then they have to walk to the train from the nearest access point. To be quite honest an hour is pretty impressive.
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It really is surprising, the state of the ex-GCR/GWR joint route. It took over an hour for a replacement driver to get to the train while it was stopped on the single line. There were no other trains that would have used the line in this time, and no passengers aboard. This on a line in London zones 4/5 that once carried 8tph.

Well it's not technically the joint line as it is south of Northolt Junction. These were only ever GWR metals. The state of the route is not really surprising. It is essentially now a freight backwater with only the Chiltern parly using it for passengers plus occasional diversions.

 

[PermitToTravel]

When did that line ever carry 8 trains an hour?

Before the Central line reached West Ruislip :P

I do agree that an hour is very impressive for getting a driver and manager to the train, especially given how far the train got - further than the footpath overbridge just before Northolt station! I wonder if they'd have been able to use the lineside access point at the bridge, or trek all that way from Greenford on the ballast

 

[TDK]

Wasn't this exactly what contributed to the Southall accident back in the 1990s, that the HST was one of the first to be fitted with pioneer TPWS (ATP), likewise the track, but it wasn't compulsory to use it and although the last months of BR did so, once privatised the new operator switched it all off.

I think you will find it was the AWS that was isolated in the Southall incident
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Quote from the report

Very uncear - does this apply to the training of ONE particular driver (ie the one concerned) or ALL drivers in the company - which I think it means?

This indicates that the complete management of drivers for Chiltern needs to be reviewed not just for one driver, obviously the RIAB see a flaw in the current procedures.

 

[Taunton]

I think you will find it was the AWS that was isolated in the Southall incident.

Actually it was everything was dispensed with - the original 125mph requirement for two drivers stopped because the automatics were now felt to be adequate, then the pioneer ATP (TPWS precursor) fully installed on the train and track was not maintained by the newly privatised operator as it was seen "not to matter", then the AWS failed on the train and was isolated, then the requirement to "advise the signalman" if AWS was isolated was not done.

Sloppy all round.