Missing the AWS warning

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JoeGJ1984

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A hypothetical question - if a driver was to miss the AWS and get braked at either a double or single yellow, I think by the book he is supposed to contact the signaller, but I wonder if a driver would instead, after coming to a stand, if he knows he has not committed a SPAD, just reset the system and restart? Would he get in trouble for doing this? (Obviously if he had committed a SPAD he would get in trouble, but if he was sure that he was only on a double or single yellow signal, restarting would not cause any problems so long as he is prepared to stop at the next signal). Because this would probably reduce the disruption caused by the stoppage.
 
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pendolino

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A hypothetical question - if a driver was to miss the AWS and get braked at either a double or single yellow, I think by the book he is supposed to contact the signaller, but I wonder if a driver would instead, after coming to a stand, if he knows he has not committed a SPAD, just reset the system and restart? Would he get in trouble for doing this? (Obviously if he had committed a SPAD he would get in trouble, but if he was sure that he was only on a double or single yellow signal, restarting would not cause any problems so long as he is prepared to stop at the next signal). Because this would probably reduce the disruption caused by the stoppage.
At my TOC any unsolicited emergency brake application must be reported to the signaller. 'Reset and go' would be greatly frowned upon, as it is for TPWS activations. 'I wanted to minimise disruption' is never a valid excuse. Besides, it takes a couple of minutes for the emergency brake to release, during which time the driver has the opportunity to contact the signaller.

Oh and it's not really a hypothetical question - it does happen!
 

rail-britain

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This has great parallels to AWS failure
The driver then has no choice but to contact the signaller

I was on a Class 158 recently and the AWS failed, the driver got out of the cab then stood in the vestibule to escape the noise in order to make the phone calls

Equally, even on a clear signal the AWS can offer a warning, sometimes catching the driver out
Most drivers will remove the power, assuming the next signal is showing caution or danger, and contact the signaller to advise of the issue (even if they have driven over the route and same issue recently)

The worst scenario is receiving a AWS warning and then approacing a signal with no lamps showing
The driver has to assume it is danger, but the previous signals should have been set to caution anyway
However, if the bulbs has just blown it can come as quite a shock to go from a green signal to nothing!
 

Cherry_Picker

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It's good practice to stop and report incidents such as this. If you don't then it opens up all kinds of opportunities for a SPAD from a driver who thought the AWS had applied the brakes at a single or double yellow. Taking those few seconds to contact the signaller and confirm everything is as it should be really does help reduce the number of safety of the line incidents.
 

MarkyT

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It's good practice to stop and report incidents such as this. If you don't then it opens up all kinds of opportunities for a SPAD from a driver who thought the AWS had applied the brakes at a single or double yellow. Taking those few seconds to contact the signaller and confirm everything is as it should be really does help reduce the number of safety of the line incidents.
If a train was fitted with a 'black box' recorder, AWS and emergency braking events would probably be logged, so might be questioned if the data is reviewed by management later. I don't know what proportion of the UK fleet is fitted with data recorders.
 

Southern313

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Would have thought all mainline passenger stock has data recorders nowadays? 313s certainly have them fitted and they are one of the oldest types running around.
 

ainsworth74

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It is a requirement for just about everything that runs on Network Rail infrastructure to be fitted with OTMR equipment (the 'black box'). I think steam might be exempted but certainly everything else has to have it.
 

matt

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It is a requirement for just about everything that runs on Network Rail infrastructure to be fitted with OTMR equipment (the 'black box'). I think steam might be exempted but certainly everything else has to have it.
Steam must have otmr to run on the mainline
 

Kneedown

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At my TOC any unsolicited emergency brake application must be reported to the signaller. 'Reset and go' would be greatly frowned upon, as it is for TPWS activations. 'I wanted to minimise disruption' is never a valid excuse. Besides, it takes a couple of minutes for the emergency brake to release, during which time the driver has the opportunity to contact the signaller.

Oh and it's not really a hypothetical question - it does happen!
Just to confirm Pendolino's post, if the AWS is not reset in time (normally 3-5 seconds after sounding) then the brakes will apply. The TPWS "Brake Demand" will flash, hence the Driver must treat the incident as a TPWS activation, even if he knows full well he hasn't had a SPAD. A "Reset and Go" incident, where the Driver proceeds without contacting the Signaller and obtaining permission to proceed, is a very serious operational incident, and could potentially be career threatening for the Driver. As Pendolino rightly points out, minimising disruption is not a defence.
Far better to follow the correct procedure and inform the signalman. I think most Drivers have missed the AWS at some point. It's no big deal. Any number of factors could cause it, from defective equipment to driving with the window open and not hearing the horn. I know i've done that, and i also did it on my second ever trip on an HST (which has a notoriously short time between horn sounding and brakes applying) when the horn sounded and i automatically went for where the AWS button would be on a 170 (which happens to be the buzzer on an HST) before realising and pressing the correct button to my right. In that short time the brakes had applied. Simple force of habit caused that one.
It's an everyday occurrence.
 
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Tomnick

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Just out of interest, what would happen if a Driver missed the AWS and stopped somewhere in the middle of a long tunnel (with no chance of communicating with the Signalman)? I can't think of many options other than a 'reset and go' (and then stopping at the first suitable location to contact the Signalman), or taking his key off and leaving the train (which will possibly shut down after a while, leaving the passengers with just emergency lighting?) to walk out of the tunnel to contact the Signalman.
 

Kneedown

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Just out of interest, what would happen if a Driver missed the AWS and stopped somewhere in the middle of a long tunnel (with no chance of communicating with the Signalman)? I can't think of many options other than a 'reset and go' (and then stopping at the first suitable location to contact the Signalman), or taking his key off and leaving the train (which will possibly shut down after a while, leaving the passengers with just emergency lighting?) to walk out of the tunnel to contact the Signalman.
Unfortunately, the Driver would indeed have to secure the train and walk out of the tunnel if neccessary to communicate with the signalman. This situation should not happen once GSMR radio is fully up and running.
There is only one occasion when a Driver is allowed to reset and go, and that is when entering a dead end bay platform and he activates the miniature overspeed TPWS loops. He is then allowed to reset and proceed to the platform end before contacting the Signaller.
There are NO other exceptions.
 

Tomnick

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Thanks - just wondered whether it'd be seen as acceptable to (very cautiously) take the train forward, rather than potentially leaving the passengers in darkness for an hour or so! I can understand that Drivers wouldn't be willing to take the chance with the current culture though.
 

Southern313

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CSR generally works fine in tunnels. I was still a guard when the driver missed the AWS half way through Merstham tunnel. Called up signaller, waited for brakes to come off and away we went to Redhill.
 

LE Greys

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This is a surprisingly old problem. The GWR ATC system worked by direct electrical contact under the cab, so sometimes the contact failed (due to ice or a layer of dirt or whatever) and so the driver got a false-caution. I believe there was one cold day where the false-cautions happened at every signal, one driver ignored them and ran into the back of another train, prompting Hudd to develop the contactless system. I'm not quite sure how they coped with a driver missing a distant, but I think it involved leaving the cab - I'll have to ask next time I'm at Didcot.

I've always wondered how BR swapped ATC and AWS, considering that they did basically the same thing and it would have taken ages to replace one with the other. Were both used in parallel at one point? If so, how did they interface?
 

Big Jim

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Just out of interest, what would happen if a Driver missed the AWS and stopped somewhere in the middle of a long tunnel (with no chance of communicating with the Signalman)? I can't think of many options other than a 'reset and go' (and then stopping at the first suitable location to contact the Signalman), or taking his key off and leaving the train (which will possibly shut down after a while, leaving the passengers with just emergency lighting?) to walk out of the tunnel to contact the Signalman.
Signals would be sited at the start of a tunnel, pretty much never at the end. AWS magnets are about 180 metres back from the signal. So would be very unlikely to be stuck in the middle of a long tunnel. This is what we try and avoid as signal engineers.
 

Welshman

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I've always wondered how BR swapped ATC and AWS, considering that they did basically the same thing and it would have taken ages to replace one with the other. Were both used in parallel at one point? If so, how did they interface?
As I understand it, ATC was developed by the GWR, as you say, and used on their main lines out of Paddington.
In the meanwhile, other railways experimented with some form of warning system, particularly following the Harrow & Wealdstone accident in 1952. The system adopted, known as AWS, was introduced to the other regions from 1956 onwards.
Ex GWR engines were then dual-fitted with both devices until ATC could be phased-out, or the engines withdrawn, whichever came first.
 

TDK

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Just to confirm Pendolino's post, if the AWS is not reset in time (normally 3-5 seconds after sounding) then the brakes will apply. The TPWS "Brake Demand" will flash, hence the Driver must treat the incident as a TPWS activation, even if he knows full well he hasn't had a SPAD. A "Reset and Go" incident, where the Driver proceeds without contacting the Signaller and obtaining permission to proceed, is a very serious operational incident, and could potentially be career threatening for the Driver. As Pendolino rightly points out, minimising disruption is not a defence.
That is incorrect, if you have an AWS brake demand you should never treat it as a TPWS brake demand unless you are not 100% certain it was AWS. A TPWS brake demand is completely different and has different procedures that an AWS brake demand, where did you get this information from? If you treat an AWS brake demand as a TPWS brake demand this causes hell of a lot more delays and also you will need to be interviewed if the TPWS brake demand was an intervention or an activation with AWS you just contact the signaller and inform them that you have missed the AWS and you will be on your way - A reset and gor AWS activation will not cause the driver to be disciplined but a TPWS one certainly would -there are many drivers who confuse these 2 incidents and to be honest there shouldn't be.
--- old post above --- --- new post below ---
Unfortunately, the Driver would indeed have to secure the train and walk out of the tunnel if neccessary to communicate with the signalman. This situation should not happen once GSMR radio is fully up and running.
There is only one occasion when a Driver is allowed to reset and go, and that is when entering a dead end bay platform and he activates the miniature overspeed TPWS loops. He is then allowed to reset and proceed to the platform end before contacting the Signaller.
There are NO other exceptions.
You are confusing AWS with TPWS you will not gst an AWS magnet approaching a bay platform you need to get this right, AWS and TPWS brake demands have 2 separate actions from a driver
--- old post above --- --- new post below ---
Thanks - just wondered whether it'd be seen as acceptable to (very cautiously) take the train forward, rather than potentially leaving the passengers in darkness for an hour or so! I can understand that Drivers wouldn't be willing to take the chance with the current culture though.
If you miss an AWS magnet for a caution signal or approaching a PSR/TSR/ESR it will not infringe safety if you you m,ove your train forward
--- old post above --- --- new post below ---
Signals would be sited at the start of a tunnel, pretty much never at the end. AWS magnets are about 180 metres back from the signal. So would be very unlikely to be stuck in the middle of a long tunnel. This is what we try and avoid as signal engineers.
Some tunnels do have signals in them, there are 3 on the WCML, one approaching and departing Marylebone and many others that I am sure can be listed.
 
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