Paddington train regulation question

[whole diary]

[BBM]

I'm starting to get a little narked about an increasingly regular delay (at least once or twice a week now) of about 4 minutes to the departure of the 17:36 Paddington-Oxford. The reason why I'm cheesed-off is because it seems to be simply to allow the early arrival of a train from Bristol in an adjacent platform! Tonight's 4-minute late departure turned into a 9-minute late arrival at Twyford thanks to a loss of path so I feel it's time to ask those helpful people here 'in the know' if they could please help with any suggestions as to what's happening?

This is the scenario. The 17:36 is scheduled to leave from Platform 9 and travel on Line 4. I'm sitting on the left-hand side of the front coach at the far end of the platform where I can clearly see the signals and activity in the station 'throat' out as far as Royal Oak and just beyond. At 17:36 the departure signal remains at red even though the 'throat' is completely clear of trains (and I know for certain from observation that we have a driver!). At about 17:37 or even 17:38 an incoming HST^▸ (High Speed Train) appears passing Royal Oak on Line 3 and runs straight into Platform 8. According to planajourney.co.uk which has platform numbers, it looks like this train is the 16:00 from Bristol TM^‡(resolve) which is not due to arrive in Paddington until 17:42! Once this train is in Platform 8 the 17:36 then gets the green light from Platform 9 for Line 4 but by now the time is 17:40.

My questions are therefore as follows:

1. Why does this early arrival get so much precedence over an on-time departure?
2. Is there really a routing conflict which would prevent my train from departing on Line 4 whilst the other train arrives on Line 3?
3. Is there no way that my train could depart on Line 5?
4. Is there maybe some other reason for this? (e.g. points in the 'throat' currently out of commission or some fault with the Automatic Route Setting?)

I thank you in advance...

[Btline]

I'm starting to get a little narked about an increasingly regular delay (at least once or twice a week now) of about 4 minutes to the departure of the 17:36 Paddington-Oxford. The reason why I'm cheesed-off is because it seems to be simply to allow the early arrival of a train from Bristol in an adjacent platform! Tonight's 4-minute late departure turned into a 9-minute late arrival at Twyford thanks to a loss of path so I feel it's time to ask those helpful people here 'in the know' if they could please help with any suggestions as to what's happening?

This is the scenario. The 17:36 is scheduled to leave from Platform 9 and travel on Line 4. I'm sitting on the left-hand side of the front coach at the far end of the platform where I can clearly see the signals and activity in the station 'throat' out as far as Royal Oak and just beyond. At 17:36 the departure signal remains at red even though the 'throat' is completely clear of trains (and I know for certain from observation that we have a driver!). At about 17:37 or even 17:38 an incoming HST^▸ (High Speed Train) appears passing Royal Oak on Line 3 and runs straight into Platform 8. According to planajourney.co.uk which has platform numbers, it looks like this train is the 16:00 from Bristol TM^‡(resolve) which is not due to arrive in Paddington until 17:42! Once this train is in Platform 8 the 17:36 then gets the green light from Platform 9 for Line 4 but by now the time is 17:40.

My questions are therefore as follows:

1. Why does this early arrival get so much precedence over an on-time departure?
2. Is there really a routing conflict which would prevent my train from departing on Line 4 whilst the other train arrives on Line 3?
3. Is there no way that my train could depart on Line 5?
4. Is there maybe some other reason for this? (e.g. points in the 'throat' currently out of commission or some fault with the Automatic Route Setting?)

I thank you in advance...

[12hoursunday]

Direct your question to the signalman!

I too get frustrated when hammering along the up main through Iver and around the bend only to see a doulbe yellow signal on the end of West Drayton station. This tells me that once again a HST^▸ (High Speed Train) travelling at 125mph is brought to stand for a Heathrow Express going only at 50. This aint occasional either I would say it happens 75% of the time!

[Chris from Nailsea]

Fair comment, 12hoursunday.

As a matter of interest, is there any formal process for train staff to raise such concerns / issues with signal staff, with a view to resolving them by getting things changed, if necessary?

I've overheard a couple of staff on my local commuter train comparing notes about their experiences of apparently odd decisions by a signalman that have 'adversely' affected them, and I wondered then whether the signal staff themselves are actually ever made aware of these views?

[BBM]

From a passenger's point of view I agree with 12hoursunday, on many occasions over the past few years my morning train has been brought to a stand alongside the flyover at Airport Junction even though it's been on time. I'd love to hear a signaller's point of view to help me understand why these seemingly pointless delays take place. There may well be perfectly logical reasons and if so then fair enough, but I can't see any logic in them at the moment!

[devon_metro]

Didn't realise you were a driver 12hoursunday 

There are number of potential reasons (albeit very unlikely):
*Stock was needed to be stepped up to another service as the stock for that service got delayed
*There might have been a delayed train behind the Bristol train that needed to be in Paddington
*The train was not actually from Bristol!
etc

Although it is very annoying especially your path is very tight as I presume you have to slow down to cross over onto the reliefs to stop at Twyford?

[BBM]

There are number of potential reasons (albeit very unlikely):
*Stock was needed to be stepped up to another service as the stock for that service got delayed
*There might have been a delayed train behind the Bristol train that needed to be in Paddington
*The train was not actually from Bristol!
etc

Although it is very annoying especially your path is very tight as I presume you have to slow down to cross over onto the reliefs to stop at Twyford?

I'm wondering if the second of your reasons is the most likely, maybe to clear a queue of closely-running trains arriving almost together? But on the other hand I would think it equally important that the 17:36 gets through Reading on time in the middle of the evening peak!

The route of the 17:36 is to cross from the relief to main just before Ealing Broadway and then to cross back to the relief at Maidenhead where it has its first stop. Normally this works well if departure from PAD^» (Paddington (London) - next trains) is on time and it's not often that the train is brought to a stand. However last night, presumably because we had the 17:45 HST^▸ (High Speed Train) on our tail, we were switched to the relief at Slough West and had to run behind a stopper.

[eightf48544]

With the signalmen now working for Networkrail and the trains being run by TOCs^▸ (Train Operating Company) they are not their trains anymore. So what's the incentive. Although there was always rivalary between drivers and signalmen there was at least a Divisional manager who controlled both and could bang their heads together if the rivalry got too silly.

BBM With Padd it's probably not the signalmen but the programming of the ARS^▸ (Automatic Route Setting). Looking at the layout from platform 8/9 they converge at points 8022 and run bidirectional to 8042B crossover from Line 3 to 4. There is no link from platform 9 to line 5 before points 8022. So that's why the incoming HST^▸ (High Speed Train) blocks you. Need to check if ARS gives priority to incoming services. The delay in getting the green is that the ARS seems to take an innordinate amount of time to decide what to do next, considering it's supposed to be a computer.

Re West Drayton the single yellow on UM13 (auto)  is a persistant aspect because it is last Slough panel signal the next is the first Slough New, which because it's worked from the IECC^▸ (Integrated Electronic Control Centre) stays at red until cleared for a train. Also of course because BAA paid for the electrification for the Heathrow express they get priority. So coupled with the slow response time of the ARS, before it starts the sequence to clear the Up Main even if the Heathrow is off the junction and through Hayes you get checked. Couple this with APT^▸ (Advanced Passenger Train) which restricts the driver from accelerating until he picks up the next ATP^▸ (Automatic Train Protection) beacon. Which why you can go from a single yellow at West Drayton to a green at flyover junction. If there two HSTs following fairly closely and the first is checked then the knock-on effect for the second is considerably multiplied because it will be on green autos through Slough and Langley and then hit the double yellow. But because the IECC signal has to revert to danger and then be cleared by the ARS rather than  being cleared from track circuits  passed  by the previous train which is almost instantaneous. The following train  be on more yellows and, therefore, be speed restricted by its ATP for longer.

When I was travelling regularly we were often overtaken just ouside Slough by an HST going full chat on the Up Main, only to overtake it around West Drayton and for it not to pass us again until around Hanwell and we had stopped at Hayes.

Of course the Old route from 9 was Line 4 Westbourne Park line 3 to the dreaded SN109 then Down Main, interesting that they are still running Down Relief to Acton. I thought SN109 had been bought back into use now, the speed is restricted, TPWS^▸ (Train Protection and Warning System) is installed and flank protection has been provided..

[BBM]

Thank You eightf48544 for a long, interesting and informed reply!

BBM With Padd it's probably not the signalmen but the programming of the ARS^▸ (Automatic Route Setting).

Yes, the ARS is one of my theories as to the cause of delays.

Of course the Old route from 9 was Line 4 Westbourne Park line 3 to the dreaded SN109 then Down Main, interesting that they are still running Down Relief to Acton. I thought SN109 had been bought back into use now, the speed is restricted, TPWS^▸ (Train Protection and Warning System) is installed and flank protection has been provided..

That route was allegedly brought back into use over 2 years ago (I've just Googled for references and in February 2006 NR^» (Network Rail - home page) indeed announced that it had been brought back). Ever since then I've kept an eye open to see if any train I've taken which has left PAD^» (Paddington (London) - next trains) on Line 4 and which is due to go over onto the Down Main has ever taken that route. 16 months later I can confidently say that I have NEVER been on a train which has used that route in that time. The normal procedure for the 17:36 is that it runs on the Down Relief to Acton where it's usually slowed (but rarely stopped) to allow an up HEX to pass and then it continues on the Main to Maidenhead. Sometimes we leave PAD on Line 3 but it's not usually an advantage as then we normally get stopped at Westbourne Park to allow an incoming HST^▸ (High Speed Train) to cross ahead of us onto Line 1. On odd occasions we do get a clear run on Line 3 through to the Down main and then we're 2 minutes early into Maidenhead! 

[Ollie]

Could it be that the dispatcher hasn't yet started the Train Ready To Start button?
Which in turn tells the signaller that the service is ready to depart, and if clear, the route will be setup.

[BBM]

Could it be that the dispatcher hasn't yet started the Train Ready To Start button?
Which in turn tells the signaller that the service is ready to depart, and if clear, the route will be setup.

The dispatchers on Platform 9 seem to be pretty alert, I've often noticed them going to the front of the train a few minutes before departure to check that there's a driver although I must admit I can't say for certain that I remember seeing a dispatcher yesterday. I'll keep an eye on what happens over the next few weeks although I'll need to leave work early today so I won't be getting the 17:36 tonight.

[Super Guard]

As a matter of interest, is there any formal process for train staff to raise such concerns / issues with signal staff, with a view to resolving them by getting things changed, if necessary?

 

[Hafren]

My understanding (non-professional!) is that ARS^▸ (Automatic Route Setting) aims to set routes so that each train has two greens ahead where possible. So an incoming train will trigger ARS to set up the route into Paddington when it is still x distance away - so if the 1736 hasn't had its route set / TRTS^▸ (Train Ready To Start. A plunger/switch pressed by platform dispatch staff that informs the signaller that a train is ready to depart.) pressed when the incoming train has passed that 'x' point the line will be considered clear and the incoming train will be routed into the platform. A human might notice that the inbound HST^▸ (High Speed Train) has a few minutes to spare and have a quick check for imminent departures - but would ARS consider that?

I think the answer might lie in this quote from the Rules of the Plan for this area ^ http://www.networkrail.co.uk/browse%20documents/Rules%20Of%20The%20Route/Outrotp8/gw08p.pdf ^ page 95:

Note:- Pathing time must not be applied approaching ARS controlled junctions where a restart allowance would be incurred as it will be ignored by ARS equipment. This causes the route to be set too early creating delay to any preceding train planned ahead on minimum junction margin. Any pathing required should be inserted at the preceding dwell point.

Obviously on the final approach to Padd there's not much that can be done, apart from signallers staying on the ball and intervening soon enough if they're aware of any regular problem cases like the 1736 seems to be. I suppose platform staff being aware and operating TRTS 'too' early might look like a solution but I could see that being a problem itself (and would ARS just ignore until nearly 1736 anyway?).

[eightf48544]

My understanding (non-professional!) is that ARS^▸ (Automatic Route Setting) aims to set routes so that each train has two greens ahead where possible. So an incoming train will trigger ARS to set up the route into Paddington when it is still x distance away - so if the 1736 hasn't had its route set / TRTS^▸ (Train Ready To Start. A plunger/switch pressed by platform dispatch staff that informs the signaller that a train is ready to depart.) pressed when the incoming train has passed that 'x' point the line will be considered clear and the incoming train will be routed into the platform. A human might notice that the inbound HST^▸ (High Speed Train) has a few minutes to spare and have a quick check for imminent departures - but would ARS consider that?

I think the answer might lie in this quote from the Rules of the Plan for this area ^ http://www.networkrail.co.uk/browse%20documents/Rules%20Of%20The%20Route/Outrotp8/gw08p.pdf ^ page 95:

Note:- Pathing time must not be applied approaching ARS controlled junctions where a restart allowance would be incurred as it will be ignored by ARS equipment. This causes the route to be set too early creating delay to any preceding train planned ahead on minimum junction margin. Any pathing required should be inserted at the preceding dwell point.

Obviously on the final approach to Padd there's not much that can be done, apart from signallers staying on the ball and intervening soon enough if they're aware of any regular problem cases like the 1736 seems to be. I suppose platform staff being aware and operating TRTS 'too' early might look like a solution but I could see that being a problem itself (and would ARS just ignore until nearly 1736 anyway?).

Just checked with informed source ARS gives priority to incoming trains at Padd. The other points made above are also valid and help compound the seemingly slow response of the ARS.

With an NX box the signalman can to an extent preprogramme the next route even if it is not clear. As soon a the blocking train clears the final conflicting track circuit the relays start clicking and set the new route. Whilst ARs is still scratching its head and saying let's see what train is next.

[Chris from Nailsea]

Thanks, Hafren and eightf48544, for your very helpful replies to that question. 

As a matter of interest, is there any formal process for train staff to raise such concerns / issues with signal staff, with a view to resolving them by getting things changed, if necessary?

 

Yes, I did wonder whether that might turn out to be rather a silly question, when I posted it!