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How realistic is it for drivers to be told of amented TTs?

You are here: Home > Forum > General > General questions, comments, and issues > How realistic is it for drivers to be told of amented TTs?

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How realistic is it for drivers to be told of amented TTs? 07/01/2015 at 23:06 #67506
Steamer
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It's probably a culture thing- American companies have gradually developed standards which give them what they have today, the British have done the same. From reading other forums, I suspect drivers would get a bit annoyed to have to tell another member of traincrew what signal they had. As you mention, we do have AWS and also a driver vigilance system (a warbling tone every 50(?) seconds that has to be acknowledged) to ensure attentiveness.

" said:
I believe that getting updated platform information would be a valid communication related to the train movement.
It's less of an issue here- the problem of passengers crossing live tracks to board/alight trains doesn't apply in the UK. The driver receives a route indication on the signal before the platform so he knows where he's going. If a reduction in speed is required, normal approach control(signal clearing from red as he approaches it/flashing yellows prior to signal) applies. The guard simply releases the doors on whatever side of the train the platform is when the train stops. They're required to open their door and check that the whole train is platformed (I suspect platform lengths etc. form part of their route knowledge) before releasing the rest of the doors.

"Don't stress/ relax/ let life roll off your backs./ Except for death and paying taxes/ everything in life.../ is only for now." (Avenue Q)
Last edited: 07/01/2015 at 23:35 by Steamer
Reason: Editied first paragraph in light of Driver Curran's post.

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How realistic is it for drivers to be told of amented TTs? 07/01/2015 at 23:12 #67507
DriverCurran
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DVD will operate every 60 seconds if there is no positive control action undertaken by the driver, for example movement of the CPBC, cancellation of the AWS etc.

There are some very set in stone times when the driver is required by the rules to advise another member of train crew of the aspect of signals passed, along with a requirement to commentary drive under cautionary aspects, i.e saying aloud to yourself "two yellows at signal y the red is at location x"

Paul

You have to get a red before you can get any other colour
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How realistic is it for drivers to be told of amented TTs? 07/01/2015 at 23:22 #67509
Steamer
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" said:


There are some very set in stone times when the driver is required by the rules to advise another member of train crew of the aspect of signals passed, along with a requirement to commentary drive under cautionary aspects, i.e saying aloud to yourself "two yellows at signal y the red is at location x"
I take back part of my previous post in that case, hadn't heard of any of that. When would a driver need to inform other members of train crew? Is the 'commentary driving' a TOC-specific thing?

"Don't stress/ relax/ let life roll off your backs./ Except for death and paying taxes/ everything in life.../ is only for now." (Avenue Q)
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How realistic is it for drivers to be told of amented TTs? 08/01/2015 at 08:50 #67526
Peter Bennet
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Of course on the GN we have DOO, so there's no one but the passengers to commentate to and generally the level of commentary is about right.

Peter

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How realistic is it for drivers to be told of amented TTs? 08/01/2015 at 13:35 #67532
whitetigger
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" said:
Again, not making evaluations but airline pilots and engineers in the US hear constant radio chatter. Drivers in the UK have a silent cab and have to perform a manual activity to speak so there is a much bigger situation change.
As an airline pilot myself, what I can say is that it can get quite distracting hearing lots of chatter around but if you know that someone will say you callsign just before speaking to you, it's not too bad - you get used to it after a while.
However, as Finger said, we aren't looking for a small signal whilst travelling at 125mph but if you compare it to approach, most airlines have a 'sterile cockpit' rule below 10,000ft whereby only essential communication is made and that includes to signallers as that's the most critical time of the whole flight.

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How realistic is it for drivers to be told of amented TTs? 08/01/2015 at 14:12 #67534
AlexH
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Nothing to do with the Taunton original post, but similar theme.

Whilst at Taunton it doesn't appear to make any difference, as the driver who posted that from either platform you can escape at the other end.

But visiting New Street a few months ago, there didn't seem to be any platform indication to the driver (aware of course I cannot see as far ahead as a driver), and there could be a problem if the wrong platform is selected (and having played the sim it is easy done, aware I am by no means a professional). An 8 car Voyager into 4C does not seem to end terribly well for all concerned. Not only the length of the platform for disembarking, but surely a slower speed is required to not hit the buffers? Also, if you just receive a proceed aspect you could end up in the wrong half of the station quite easily. Is there someway of telling which platform you are aiming for? There seems a lot of scope for human error.

Sub question: route indicators are of course common, but for example at a high speed junction, is there such a thing as a route indicator repeater? I'm sure that seeing the 'feather' at 125mph and then realising you should not be getting a 'feather' might result in an overshoot to the wrong direction.

Sorry for the probably obvious questions

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How realistic is it for drivers to be told of amented TTs? 08/01/2015 at 14:16 #67535
Jersey_Mike
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Ideally railway signals should be well placed and visible from some ways off and drivers should be expecting to see them. Even if that all fails AWS is on hand to provide all sorts of warning cues until the train is back on the green.

However all that can be undermined by the British railway system failing to address the "riding the yellows" problem where trains run at high speed under both double and single yellow aspects and rely on drivers to spot signals at danger in time to stop short of them. Requiring some sort of minimal train control like a brake application or speed restriction to ~45mph would make driver attention less critical and would work with the existing AWS technology.

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How realistic is it for drivers to be told of amented TTs? 08/01/2015 at 14:44 #67537
Muzer
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" said:
Nothing to do with the Taunton original post, but similar theme.

Whilst at Taunton it doesn't appear to make any difference, as the driver who posted that from either platform you can escape at the other end.

But visiting New Street a few months ago, there didn't seem to be any platform indication to the driver (aware of course I cannot see as far ahead as a driver), and there could be a problem if the wrong platform is selected (and having played the sim it is easy done, aware I am by no means a professional). An 8 car Voyager into 4C does not seem to end terribly well for all concerned. Not only the length of the platform for disembarking, but surely a slower speed is required to not hit the buffers? Also, if you just receive a proceed aspect you could end up in the wrong half of the station quite easily. Is there someway of telling which platform you are aiming for? There seems a lot of scope for human error.

Sub question: route indicators are of course common, but for example at a high speed junction, is there such a thing as a route indicator repeater? I'm sure that seeing the 'feather' at 125mph and then realising you should not be getting a 'feather' might result in an overshoot to the wrong direction.

Sorry for the probably obvious questions
I can't comment about New Street (I suspect there are platform indicators you just haven't seen, but maybe I'm wrong), but as for the second question, there are a few methods:



If the junction is high speed but still has a reasonable differential between the diverging route and the straight route, flashing yellows will be used which will give drivers more of a warning of the route

If there are multiple such divergences in quick succession or some other thing to add confusion, split distants may be used (this is quite rare in practice)

If neither of these apply, ie you have a junction that's 125mph straight and 125mph diverging (±5mph I believe), previously there was no warning of route given, but now non-safety-critical "Preliminary route indicators" are being installed in such situations where a wrong route would cause operational difficulties. These take the form of LED dot-matrix boards (in a similar style to alphanumeric route indicators but bigger, I believe) which display an arrow at braking distance to the divergence.

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How realistic is it for drivers to be told of amented TTs? 08/01/2015 at 15:48 #67540
lazzer
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" said:
Sub question: route indicators are of course common, but for example at a high speed junction, is there such a thing as a route indicator repeater? I'm sure that seeing the 'feather' at 125mph and then realising you should not be getting a 'feather' might result in an overshoot to the wrong direction.

That's what flashing yellows are for. :whistle:

Having said that, at Cogload Junction on the up, there is no preliminary route indicator for signal 193, and it's round a left-hand curve with a linespeed of 100 (although if you are expecting to go onto the Up Athelney line you're slowing down to 90). If you come off that curve and see the wrong route, you have no chance of stopping - you're going to go past the signal and take the wrong route. You'd have to get permission to set back and try again.

Not all junctions have the luxury of PRIs.

Last edited: 08/01/2015 at 15:48 by lazzer
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How realistic is it for drivers to be told of amented TTs? 08/01/2015 at 15:48 #67541
Steamer
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" said:
But visiting New Street a few months ago, there didn't seem to be any platform indication to the driver (aware of course I cannot see as far ahead as a driver), and there could be a problem if the wrong platform is selected (and having played the sim it is easy done, aware I am by no means a professional). An 8 car Voyager into 4C does not seem to end terribly well for all concerned. Not only the length of the platform for disembarking, but surely a slower speed is required to not hit the buffers?
There will be theatre box indicators at NS151, 154, 243 and 244 displaying the platform number to the driver. You can see the one on NS154 in this video, just after 7:35, displaying a '6'.

Braking distance isn't much of a problem- the speed limit throughout New Street is 10mph, so the driver will have plenty of time to stop. At other locations, approach control etc. will be arranged such that the driver sees the junction indicator at a speed which will allow him to stop before the buffers.

" said:
If neither of these apply, ie you have a junction that's 125mph straight and 125mph diverging (±5mph I believe), previously there was no warning of route given, but now non-safety-critical "Preliminary route indicators" are being installed in such situations where a wrong route would cause operational difficulties. These take the form of LED dot-matrix boards (in a similar style to alphanumeric route indicators but bigger, I believe) which display an arrow at braking distance to the divergence.
To add to this explanation, a set of photos can be found here.

An overshoot in the wrong direction is possible, but it's an operational inconvenience rather than a safety issue- the driver would probably notice a lack of approach control where he was expecting it, even if he didn't the route in question would be the main one so he wouldn't be exceeding the speed limit. If the route is set in error towards the slower route, the driver will receive approach control, slow down, and be travelling at a speed which would enable him to stop (or, at worst, not exceed the turnout speed) when the junction indicator comes into view.

" said:
However all that can be undermined by the British railway system failing to address the "riding the yellows" problem where trains run at high speed under both double and single yellow aspects and rely on drivers to spot signals at danger in time to stop short of them. Requiring some sort of minimal train control like a brake application or speed restriction to ~45mph would make driver attention less critical and would work with the existing AWS technology.
It's a valid point, and is now mitigated against: TPWS was installed in the early 2000s, and will apply the brake should a driver pass a signal at red, or be exceeding 40mph a certain distance from it. TPWS is provided at most controlled signals (i.e. those protecting junctions etc.), and some have an enhanced version which stops the train if it's exceeding 75mph at a certain point. Further reading here.

"Don't stress/ relax/ let life roll off your backs./ Except for death and paying taxes/ everything in life.../ is only for now." (Avenue Q)
Last edited: 08/01/2015 at 16:07 by Steamer
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How realistic is it for drivers to be told of amented TTs? 08/01/2015 at 16:02 #67542
Muzer
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I don't think it's installed at ALL controlled signals, is it? I thought only ones that protect against things other than a rear-end collision.
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How realistic is it for drivers to be told of amented TTs? 08/01/2015 at 16:06 #67543
Steamer
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" said:
I don't think it's installed at ALL controlled signals, is it? I thought only ones that protect against things other than a rear-end collision.
You're right, I should have said 'most'.

"Don't stress/ relax/ let life roll off your backs./ Except for death and paying taxes/ everything in life.../ is only for now." (Avenue Q)
Last edited: 08/01/2015 at 16:07 by Steamer
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How realistic is it for drivers to be told of amented TTs? 08/01/2015 at 16:11 #67544
DriverCurran
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" said:
" said:


There are some very set in stone times when the driver is required by the rules to advise another member of train crew of the aspect of signals passed, along with a requirement to commentary drive under cautionary aspects, i.e saying aloud to yourself "two yellows at signal y the red is at location x"
I take back part of my previous post in that case, hadn't heard of any of that. When would a driver need to inform other members of train crew? Is the 'commentary driving' a TOC-specific thing?
This is required in the rule book when dealing with defective and/or isolated AWS and states that the driver in charge must call out the signal aspect and any associated indication to the competent person regardless of aspect on the approach to each signal, and when approaching a reduction in permissable speed the driver must advise the competent person that they are applying the brakes to comply with the restriction.

The competent person must acknowledge the call outs from the driver.

Details are in the on-line rule books.

Regarding commentary driving it is part of the professional driving policy for the company I work for, again I am unable to speak for other companies.

Paul

You have to get a red before you can get any other colour
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How realistic is it for drivers to be told of amented TTs? 08/01/2015 at 16:12 #67545
Zoe
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" said:
Having said that, at Cogload Junction on the up, there is no preliminary route indicator for signal 193, and it's round a left-hand curve with a linespeed of 100 (although if you are expecting to go onto the Up Athelney line you're slowing down to 90). If you come off that curve and see the wrong route, you have no chance of stopping - you're going to go past the signal and take the wrong route. You'd have to get permission to set back and try again.

If the train was booked non-stop to Reading via Castle Cary would it always be required to set back and take the booked route or could it be allowed to continue via Bristol?

Last edited: 08/01/2015 at 16:12 by Zoe
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How realistic is it for drivers to be told of amented TTs? 08/01/2015 at 16:14 #67546
Muzer
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I'm not in the industry, but my instinct would tell me that it would probably be easier, safer and cause less delay to continue via Bristol, so this is what would probably be done. But I might be totally wrong.
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How realistic is it for drivers to be told of amented TTs? 08/01/2015 at 16:39 #67547
AndyG
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" said:
" said:
Having said that, at Cogload Junction on the up, there is no preliminary route indicator for signal 193, and it's round a left-hand curve with a linespeed of 100 (although if you are expecting to go onto the Up Athelney line you're slowing down to 90). If you come off that curve and see the wrong route, you have no chance of stopping - you're going to go past the signal and take the wrong route. You'd have to get permission to set back and try again.

If the train was booked non-stop to Reading via Castle Cary would it always be required to set back and take the booked route or could it be allowed to continue via Bristol?
Driver signing the diverted route probably comes into play.

I can only help one person a day. Today's not your day. Tomorrow doesn't look too good either.
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How realistic is it for drivers to be told of amented TTs? 08/01/2015 at 16:45 #67548
AlexH
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Thank you all.

I should have added the stupid question caveat. Having spent quite a bit of my formative years in Kenya, I didn't get a lot of experience in high speed junctions.

I did not realise flashing yellows were used in this context. I have seen them in simulations, and in various places on the railways, but I assumed this was for a different type of junction. My apologies.

Thank you for answering.

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How realistic is it for drivers to be told of amented TTs? 08/01/2015 at 17:16 #67549
Muzer
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No, it's quite a sensible question really, one that the industry only recently seems to have fully answered ;)

But yeah, since it's relatively uncommon to get a diverging route with a close enough speed to the straight route to have free greens (ie green aspects on approach for both routes), flashing yellows are the most common means of providing early route indication at high speed junctions.

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How realistic is it for drivers to be told of amented TTs? 08/01/2015 at 17:23 #67550
lazzer
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" said:
If the train was booked non-stop to Reading via Castle Cary would it always be required to set back and take the booked route or could it be allowed to continue via Bristol?
Our trains regularly run non-stop Taunton to Reading, but the booked route is always via Westbury. So if I came round the corner and saw a green aspect with no junction indicator I would still slam the brake in and query it. This is one location where we simply can't accept either route, as there is the issue of timings and paths to consider. I would only accept the route for Bristol if I was previously told by the signaller and control that I was being sent that way.

Edit: for the non-stop journeys TAU to RDG, our diagrams actually show that we are booked to go via Westbury. Therefore that is the way I expect to go. I would not be popular if I simply accepted the wrong route at Cogload and kept going.

Last edited: 08/01/2015 at 17:25 by lazzer
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How realistic is it for drivers to be told of amented TTs? 08/01/2015 at 17:46 #67553
Hooverman
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" said:
But yeah, since it's relatively uncommon to get a diverging route with a close enough speed to the straight route to have free greens (ie green aspects on approach for both routes), flashing yellows are the most common means of providing early route indication at high speed junctions.
Balcombe Tunnel Junction is one of those rare junction where a driver can approach on a string of greens regardless of route set. The amount of times the a Virgin Voyager had to go via Gatwick when going back to depot at Three Bridges when the route had been left in auto for the up fast and with the trains not having a radio to contact the driver to get the route replaced and reset. The drivers stood no chance coming out of the tunnel round a right hand bend and under a bridge on greens, if it was set for the fast that's where they went :-(

Last edited: 08/01/2015 at 17:47 by Hooverman
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How realistic is it for drivers to be told of amented TTs? 08/01/2015 at 18:15 #67557
GeoffM
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" said:
However all that can be undermined by the British railway system failing to address the "riding the yellows" problem where trains run at high speed under both double and single yellow aspects and rely on drivers to spot signals at danger in time to stop short of them.
This was addressed a long time ago with defensive driving techniques.


" said:
Requiring some sort of minimal train control like a brake application or speed restriction to ~45mph would make driver attention less critical and would work with the existing AWS technology.
Indeed, and there are lines where this happens.

PTC in the US should start to address this if they can get it to work properly, although again there are lines where some form of this does happen but is far from widespread.

SimSig Boss
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How realistic is it for drivers to be told of amented TTs? 08/01/2015 at 18:25 #67560
Finger
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" said:
However all that can be undermined by the British railway system failing to address the "riding the yellows" problem where trains run at high speed under both double and single yellow aspects and rely on drivers to spot signals at danger in time to stop short of them. Requiring some sort of minimal train control like a brake application or speed restriction to ~45mph would make driver attention less critical and would work with the existing AWS technology.

Seriously, you don't want to base an ATP system on top of AWS. That's only asking for trouble and a reduction in track capacity.

Last edited: 08/01/2015 at 18:32 by Finger
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How realistic is it for drivers to be told of amented TTs? 08/01/2015 at 18:30 #67561
Zoe
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" said:
for the non-stop journeys TAU to RDG, our diagrams actually show that we are booked to go via Westbury. Therefore that is the way I expect to go. I would not be popular if I simply accepted the wrong route at Cogload and kept going.

I was not asking if you should accept the incorret route (which as you say you should not) but actually if you would you always be required to set back and go via Castle Cary after stopping and querying it route or could you be told to continue via Bristol.

Last edited: 08/01/2015 at 18:53 by Zoe
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How realistic is it for drivers to be told of amented TTs? 08/01/2015 at 19:20 #67566
lazzer
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" said:
" said:
for the non-stop journeys TAU to RDG, our diagrams actually show that we are booked to go via Westbury. Therefore that is the way I expect to go. I would not be popular if I simply accepted the wrong route at Cogload and kept going.

I was not asking if you should accept the incorret route (which as you say you should not) but actually if you would you always be required to set back and go via Castle Cary after stopping and querying it route or could you be told to continue via Bristol.
I would be told to set back and take the correct route via Westbury. The reason being that going via Bristol adds at least 25 to 30 minutes to the journey time, so I would be late into Reading.

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How realistic is it for drivers to be told of amented TTs? 08/01/2015 at 19:47 #67567
Forest Pines
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The best-known example of a junction where lack of warning caused operational problems was probably Colton Jn, South of York. 125mph line speed for either route, so the driver originally received no prior indication of route until the junction signal itself. This became a problem after the ECML electrification - only one route was wired. If a driver of an electric train saw a Position 4 feather instead of the Position 1 he/she expected, there was no way to stop before the train was off the juice.

I understand it has a PRI now for understandable reasons!

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