Priorities on train lines

[voyager1]

I commute between Luton and St Pancras travelling southbound on Thameslink and northbound on East Midlands. I'm not technical when it comes to signalling but some things I seem to notice - might all turn out to be nonsense but I thought I'd mention ....

1. Does the off peak direction have priority over the peak direction? I sometimes notice the southbound Thameslink in the morning is held at a red light at Harpenden to allow a northbound Thameslink to arrive at platform 2 before it is allowed to proceed and cross over on to the fast line. Also the northbound EMR Connect in the evening sometimes gets delayed if the signaller decides to hold a late running Thameslink on the fast line all the way to Harpenden when its supposed to cross over to the slow line at Radlett - again, seems to happen if allowing a crossover at Radlett would interfere with a southbound train.

2. At St Pancras (Thameslink) - does the Great Northern trains from Cambridge/Peterborough have priority over the trains from Bedford? Always seem to have to wait outside St Pancras and the driver sometimes announces we're waiting for a Great Northern train to use the platform. Is this because of the operations of the Great Northern line? i.e. get the slow trains out of the way to avoid interfering with multiple fast operators or is it simply down to Cambridge/Peterborough rail users paying more for their season tickets?

3. If trains are going to conflict i.e. EMR/Thameslink - is the decision making done by a computer or a person? I remember asking this question years ago only to be told "it depends on who is on shift". How is a decision reached and why could one person favour a particular train over another - do the people in the control rooms have their own individual interests? Don't know if this process has evolved.

4. Is there ever any collaboration between rail companies and bus companies. For example, Arriva is changing the departure time of their F70/F77 buses from Luton interchange and some of the new evening bus departure times result in the buses leaving 1 minute after the EMR/TL trains arrive - which effectively break the rail/bus connection.

 

[t0ffeeman]

Most is automated now, basically whatever is booked to go in front does so. PBO line trains run late for various reasons so delay those from BDM at STP

 

[Bald Rick]

Does the off peak direction have priority over the peak direction? I sometimes notice the southbound Thameslink in the morning is held at a red light at Harpenden to allow a northbound Thameslink to arrive at platform 2 before it is allowed to proceed and cross over on to the fast line. Also the northbound EMR Connect in the evening sometimes gets delayed if the signaller decides to hold a late running Thameslink on the fast line all the way to Harpenden when its supposed to cross over to the slow line at Radlett - again, seems to happen if allowing a crossover at Radlett would interfere with a southbound train.

No. At Harpenden, if there is a conflict between northbound down fast to down slow trains vs southbound up slow to up fast trains, the northbound will usuallyget priority. Simoly because there is usuallyan EMR hard on its tail, and delaying the northbound TL will delay the EMR (and by extension, at least one other EMR behind it). All southbound trains have recovery time approaching the core so can recover then 2 minutes it might cost them.

Most down TL fast servcies are booked to cross at Harpenden, the few booked at Radlett eill be sent on to Harpenden if a) there is a St Albans terminator in the way, or b) the signaller forgets (not uncommon).

At St Pancras (Thameslink) - does the Great Northern trains from Cambridge/Peterborough have priority over the trains from Bedford? Always seem to have to wait outside St Pancras and the driver sometimes announces we're waiting for a Great Northern train to use the platform. Is this because of the operations of the Great Northern line? i.e. get the slow trains out of the way to avoid interfering with multiple fast operators or is it simply down to Cambridge/Peterborough rail users paying more for their season tickets?

No. Again it’s prioritised on keeping the service in order as far as practical and minimising delay.

If trains are going to conflict i.e. EMR/Thameslink - is the decision making done by a computer or a person? I remember asking this question years ago only to be told "it depends on who is on shift". How is a decision reached and why could one person favour a particular train over another - do the people in the control rooms have their own individual interests? Don't know if this process has evolved.

A person. The process is the same for everyone on shift. There are no computer based decision tools in use on the MML south of Bedford.

Is there ever any collaboration between rail companies and bus companies. For example, Arriva is changing the departure time of their F70/F77 buses from Luton interchange and some of the new evening bus departure times result in the buses leaving 1 minute after the EMR/TL trains arrive - which effectively break the rail/bus connection.

Yes. But train timetables take a lot longer to prepare than bus timetables. So basically to keep connections, bus companies need to work around the railway, in most cases.

 

[NSE]

2. At St Pancras (Thameslink) - does the Great Northern trains from Cambridge/Peterborough have priority over the trains from Bedford? Always seem to have to wait outside St Pancras and the driver sometimes announces we're waiting for a Great Northern train to use the platform. Is this because of the operations of the Great Northern line? i.e. get the slow trains out of the way to avoid interfering with multiple fast operators or is it simply down to Cambridge/Peterborough rail users paying more for their season tickets?

3. If trains are going to conflict i.e. EMR/Thameslink - is the decision making done by a computer or a person? I remember asking this question years ago only to be told "it depends on who is on shift". How is a decision reached and why could one person favour a particular train over another - do the people in the control rooms have their own individual interests? Don't know if this process has evolved.

It won’t ever have anything to do with who pays more for their tickets. Signallers won’t have a clue what they pay and won’t have any preference. They’re solely focused on keeping everything moving and working with minimal delays.

 

[voyager1]

Yes. But train timetables take a lot longer to prepare than bus timetables. So basically to keep connections, bus companies need to work around the railway, in most cases.

I understand this. However, I wondered if Arriva themselves work with the rail companies to identify train times and for reasons unknown, they decide to break the links. Okay, that question might be better off on a bus forum than a rail forum. Someone else told me that in Liverpool (or somewhere up there) the buses are timed to leave their interchange at the exact moment a ferry arrives. I wondered if there was a stupid reason behind it (i.e. crowd control)

Most down TL fast servcies are booked to cross at Harpenden, the few booked at Radlett eill be sent on to Harpenden if a) there is a St Albans terminator in the way, or b) the signaller forgets (not uncommon).

I sometimes wondered whether the signaller forgets as I've seen it go to St Albans platform 4 for no apparent reason.

If they reach Harpenden and crossing over causes a clash, does it get elevated priority and southbound services halted to allow it to cross over so it doesn't have to wait until Luton/Leagrave to cross over?

 

[Deafdoggie]

I wondered if Arriva themselves work with the rail companies to identify train times and for reasons unknown, they decide to break the links. Okay, that question might be better off on a bus forum than a rail forum. Someone else told me that in Liverpool (or somewhere up there) the buses are timed to leave their interchange at the exact moment a ferry arrives. I wondered if there was a stupid reason behind it (i.e. crowd control)

I would be surprised if Arriva considered rail passengers at all. Most bus companies produce a timetable that suits them. They are then left scratching their heads wondering why less people now catch it! But they will know who catches the bus and where & will be looking at the bigger picture.

 

[Bald Rick]

If they reach Harpenden and crossing over causes a clash, does it get elevated priority and southbound services halted to allow it to cross over so it doesn't have to wait until Luton/Leagrave to cross over?

Depends on what else is around.

 

[voyager1]

It happened again this evening - where the 1647 EMR Connect from London St Pancras to Luton was delayed 4 minutes because a signaller decided to have the 1636 TL from St Pancras use Platform 4 at St Albans instead of its designated Platform 2. Whilst 4 minutes doesn't sound like a lot in the grand scheme of things, it can add half an hour to people's journeys if they miss connections. I found myself running for the bus at Luton that was just about to pull away but luckily the driver was kind and waited.

If the signaller is prone to forgetting to cross the TL over at Radlett, isn't it about time that signaller is either replaced with a computerised/AI solution or a hybrid solution that combines both signaller and technology to eliminate human error? Isn't the TL core and TFL itself computerised within certain zones? (I know someone who drove a tube train and he always said that most of his life was pressing three buttons and that the train "drove" itself).

 

[louis97]

It happened again this evening - where the 1647 EMR Connect from London St Pancras to Luton was delayed 4 minutes because a signaller decided to have the 1636 TL from St Pancras use Platform 4 at St Albans instead of its designated Platform 2. Whilst 4 minutes doesn't sound like a lot in the grand scheme of things, it can add half an hour to people's journeys if they miss connections. I found myself running for the bus at Luton that was just about to pull away but luckily the driver was kind and waited.

If the signaller is prone to forgetting to cross the TL over at Radlett, isn't it about time that signaller is either replaced with a computerised/AI solution or a hybrid solution that combines both signaller and technology to eliminate human error? Isn't the TL core and TFL itself computerised within certain zones? (I know someone who drove a tube train and he always said that most of his life was pressing three buttons and that the train "drove" itself).

Tonight seems more like a decision made to keep the job moving. The stopper on the down slow was running late today. Yes maybe it could have followed it along the down slow, however its one of those where if the stopper had dwelled at Radlett longer than booked you'd have brought the 1636 from St Pancras to a stand shortly followed by the Corby. You can't cross onto the down slow until a train has departed the platform at Radlett.

The whole West Hampstead signalling area is due to be re-controlled to new workstations over Christmas, which could include the introduction of Automatic Route Setting (I have the documentation somewhere but not to hand). I'd like to say Automatic Route Setting will help solve this, but today it could very well have brought you to a stand/slowed you waiting behind the Thameslink at Radlett to cross over and leave you in the same situation.

 

[Bald Rick]

If the signaller is prone to forgetting to cross the TL over at Radlett, isn't it about time that signaller is either replaced with a computerised/AI solution or a hybrid solution that combines both signaller and technology to eliminate human error? Isn't the TL core and TFL itself computerised within certain zones?

The Thameslink core has Automatic train operation, which meansthe train drives itself. However the signalling is still controlled by a person.

The good news, for you, is that as of Sunday the old signalling sysytem at West Hampstead is decommissioned , and a new computerised system is installed that will have the computer setting the routes. I’m willing to bet that the computer makes more errors than the signallers (who in my experience are amongst the best on the network).


In this case, as stated above there was a late train on the slow lines, and that would have caused 9R44 (the Thaneslink service) to have been at least 5 minutes late into St Albans. As there are typically twice as many people on the Thameslink service than the Corby, the signaller - correctly - decided to delay half as many people for two minutes rather than the Thameslink service for 5.

 

[voyager1]

The Thameslink core has Automatic train operation, which meansthe train drives itself. However the signalling is still controlled by a person.

The good news, for you, is that as of Sunday the old signalling sysytem at West Hampstead is decommissioned , and a new computerised system is installed that will have the computer setting the routes. I’m willing to bet that the computer makes more errors than the signallers (who in my experience are amongst the best on the network).


In this case, as stated above there was a late train on the slow lines, and that would have caused 9R44 (the Thaneslink service) to have been at least 5 minutes late into St Albans. As there are typically twice as many people on the Thameslink service than the Corby, the signaller - correctly - decided to delay half as many people for two minutes rather than the Thameslink service for 5.

Doesn't the above scenario sometimes affect the Nottingham bound train that leaves St Pancras at 1635? Maybe not tonight but there have been times where it seems as though we get held back longer even though the TL has crossed over - as though something else was in front, which I assume to be the Nottingham bound EMR.

As for the computer solution - yes, it will probably make mistakes to begin with. Will be interesting to see how it goes. Will it have an element of AI that learns from its mistakes? What will happen to the signallers - will they still be able to oversee things?

I would be most happy if AI could replace the role of whoever sets timetables/routes at the bus companies, for they are the root of this problem. In the UK, a four minute delay on the trains still actually represents a good train service!!

But, thanks Bald Rick, for explaining things very well and illustrating the wider picture - and also louis97.

 

[Bald Rick]

As for the computer solution - yes, it will probably make mistakes to begin with. Will be interesting to see how it goes. Will it have an element of AI that learns from its mistakes? What will happen to the signallers - will they still be able to oversee things?

Automatic Route Setting (ARS) is a ‘dumb’ system - it does what it is told. It doesnt learn. The ARS system at Liverpool St still makes lots of mistakes despite being 34 years old. For this reason, a good and attentive signaller will always outperform ARS. However ARS can tackle more workload.

The signallers at West Hampstead will still be watching, and controllign out of course mobements, and (hopefully) continuing to intervene when there is out of course running and the ARS wants to do something standard in a non standard situation

 

[Route115?]

There is a long learning curve in signalling. When West Hampstead power box was opened I heard unfavourable comparisons with Kings X p.b. but as a colleague said, once the signallers learnt the ropes things would improve, and they did. ARS should help. You may have read Roger Ford on Resonate's new software. Timetables are to the minute, or less, and services like Thameslink (and the Liz line) are often a few minutes late arriving at the core section which often means reactionary delays. At the end of the day humans will always be the final link in the chain. A good signaller will know when to rely on ARS & when to take over but that is certainly an acquired skill.

The other thing to say is that different services may have different amounts of recovery time (or padding) and if a service is often held it may be running early. Running trains out of sequence causes problems.

 

[The Planner]

There is a long learning curve in signalling. When West Hampstead power box was opened I heard unfavourable comparisons with Kings X p.b. but as a colleague said, once the signallers learnt the ropes things would improve, and they did. ARS should help. You may have read Roger Ford on Resonate's new software. Timetables are to the minute, or less, and services like Thameslink (and the Liz line) are often a few minutes late arriving at the core section which often means reactionary delays. At the end of the day humans will always be the final link in the chain. A good signaller will know when to rely on ARS & when to take over but that is certainly an acquired skill.

The other thing to say is that different services may have different amounts of recovery time (or padding) and if a service is often held it may be running early. Running trains out of sequence causes problems.

You have to be careful with the type of allowance as well as ARS ignores some.

 

[Bald Rick]

There is a long learning curve in signalling. When West Hampstead power box was opened I heard unfavourable comparisons with Kings X p.b. but as a colleague said, once the signallers learnt the ropes things would improve, and they did. ARS should help. You may have read Roger Ford on Resonate's new software. Timetables are to the minute, or less, and services like Thameslink (and the Liz line) are often a few minutes late arriving at the core section which often means reactionary delays. At the end of the day humans will always be the final link in the chain. A good signaller will know when to rely on ARS & when to take over but that is certainly an acquired skill.

The other thing to say is that different services may have different amounts of recovery time (or padding) and if a service is often held it may be running early. Running trains out of sequence causes problems.

The Thameslink core doesnt have ARS.

 

[greenline712]

I would be most happy if AI could replace the role of whoever sets timetables/routes at the bus companies, for they are the root of this problem. In the UK, a four minute delay on the trains still actually represents a good train service!!

On so many occasions over my 45-year bus career, I have asked rail operators for details of any timetable changes, in order that my company might adjust bus times to maintain connections. On so many occasions, I have received either no answer, or an answer that is too late to allow for the bus timetable to be adjusted.
Remember that bus operators, since 1986, have required a minimum of 42 days notice, now set at 72 days notice (in total), to change timetables . . . and we need a few weeks to actually adjust timetables and driver duties as well!!
Even bus routes specifically operated to connect with trains are ignored . . . surprisingly bus companies now simply don't bother.

Sorry and all that, but when you bang your head against a brick wall and it starts to hurt . . . it's a good idea to stop!!

 

[Taunton]

You can argue this for ever.

Only last week I was on a late evening Nottingham to St Pancras, which made such good progress on the last non-stop leg that I (and doubtless the driver) were anticipating arrival 10 minutes early. But then stopped outside the station for the full 10 minutes while not one but two ECS were eventually sent out. Arrive to most platforms empty. I'm sure there was every excuse, but time was when an express would be seen as priority.

 

[Horizon22]

The Thameslink core has Automatic train operation, which meansthe train drives itself. However the signalling is still controlled by a person.

The good news, for you, is that as of Sunday the old signalling sysytem at West Hampstead is decommissioned , and a new computerised system is installed that will have the computer setting the routes. I’m willing to bet that the computer makes more errors than the signallers (who in my experience are amongst the best on the network).


In this case, as stated above there was a late train on the slow lines, and that would have caused 9R44 (the Thaneslink service) to have been at least 5 minutes late into St Albans. As there are typically twice as many people on the Thameslink service than the Corby, the signaller - correctly - decided to delay half as many people for two minutes rather than the Thameslink service for 5.

I presume as well EMR/GTR/NR have some regulation policies too?

And yes ARS (Automatic Route Setting) can sometimes mask issues which could have been resolved quicker by human intervention. The human might have taken their “eye off the ball” and be focussing on another part of the panel assuming ARS is doing its job, particularly at the boundary sections of the signaller’s patch. It’s not always the panacea some think it will be!

 

[6Gman]

I understand this. However, I wondered if Arriva themselves work with the rail companies to identify train times and for reasons unknown, they decide to break the links. Okay, that question might be better off on a bus forum than a rail forum. Someone else told me that in Liverpool (or somewhere up there) the buses are timed to leave their interchange at the exact moment a ferry arrives. I wondered if there was a stupid reason behind it (i.e. crowd control)

I would find that very hard to believe since the Mersey Ferry is pretty much a leisure service these days. The numbers transferring from ferry to bus would be so small that I doubt crowd control would be an issue!

Possibly 50+ years ago when the ferries were used more by commuters/shoppers and when buses didn't operate through services between Wirral and Liverpool.

 

[voyager1]

There appear to be signalling issues on the line today. Is this due to the new computerised system having a meltdown on day one?

 

[louis97]

There appear to be signalling issues on the line today. Is this due to the new computerised system having a meltdown on day one?

A fault on one of the workstations after commissioning, unable to set routes.

 

[D7666]

I may be wrong but I thought none of the "BedPan" FL/SL bog standard ladder junctions (Radlett, Harpenden, Leagrave, Flitwick) have ARS but are all entirely manual ?

Pretty sure it was posted a while back somewhere no ARS. I might be confusing. I have no knowledge on the matter myself only repeating what I think I have read.

Not pointing fingers, but "it is ARS" is unfortunately an all too often knee jerk response answer from the uninformed. Which is really why I question it here. For example, elsewhere - Thameslink but south of the river- when I visited Three Bridges panel(s) back in 2015 or so, there was no ARS at all there; I remember the shift signalling manager waxing lyrical on that subject. Keymer Junction was an early - if not the pilot - ARS junction, but the early/pilot gubbins was removed after trials and never restored nor ARS put in anywhere else there. Yet you can find post after post talking about Three Bridges ARS with exactly the same sort of question about Gatwick Airport and the via Redihill / via Quarry junctions as had been put about Harpenden here.

I am a Luton commuter too - all TL - and while I agree with your assessment of fact about the ways trains are held at Harpenden station or Harpenden Junction but must admit had never given it any thought how that fitted in with peak v. contra flows.

Interesting point.

Especially as Class 9 is supposed to be the priority train so at least 9 over 1 should give TL over EM priority - but how 9 against 9 is dealth with is perhaps more your point ?

 

[louis97]

I may be wrong but I thought none of the "BedPan" FL/SL bog standard ladder junctions (Radlett, Harpenden, Leagrave, Flitwick) have ARS but are all entirely manual ?

That was correct, however following work over Christmas they are now controlled via computerised workstations, rather than a push button panel. The Computerised workstations have ARS.

Especially as Class 9 is supposed to be the priority train so at least 9 over 1 should give TL over EM priority - but how 9 against 9 is dealth with is perhaps more your point ?

Regulation via ARS isn't just about the headcodes, it will factor into the decision but being a Class 9 alone does not mean priority over a class 1, the type of movements involved also factor into the decision by ARS. ARS does not necessarily know the Regulation Policy either, so it is up to the signaller to enforce this. One great thing about the control remaining at West Hampstead is that the knowledge of signallers who would not have relocated elsewhere is not lost.

 

[voyager1]

So there are priority trains? How does that work? I thought a priority train would be an express.

What is a class 1 and class 9 ? Sorry, I don't understand the technical terminology. I'm just a commuter.

 

[CarrotPie]

So there are priority trains? How does that work? I thought a priority train would be an express.

What is a class 1 and class 9 ? Sorry, I don't understand the technical terminology. I'm just a commuter.

0 - Light loco
1 - Generally Express Passenger/Postal trains. Not freight trains.
2 - Standard Passenger (Acme stopping service)
3 - Usually an RHTT or UTU. Can also be used for priority ECS where delaying this service will directly impact a class 1. Some freights can also be authorised under class 3 depending on contents and routing.
4 - Freight, max 75mph
5 - ECS (Empty Coaching Stock: an passenger train positioning move)
6 - Freight, max 60mph
7 - Freight, max 45mph
8 - Freight, max 35mph
9 - Now effectively synonymous with class 1. Used to differentiate trains taking a different route on lots of lines. i.e. all Class 9s on WCML go via Birmingham. Also for Eurostar, Thameslink etc.

Finally:
0Z99 is a rescue loco
1Z99 is a rescue train or snowplough
2Z01 is an officers special

 

[FGW_DID]

Finally:
0Z99 is a rescue loco
1Z99 is a rescue train or snowplough

1Z99 used for traction unit (regardless of whether it’s a Loco or Unit) going to assist a failed train.
1Z99 also used for: a snowplough going to clear the line, a breakdown or OLE train going to clear the line.

 

[D7666]

That was correct, however following work over Christmas they are now controlled via computerised workstations, rather than a push button panel. The Computerised workstations have ARS.

Regulation via ARS isn't just about the headcodes, it will factor into the decision but being a Class 9 alone does not mean priority over a class 1, the type of movements involved also factor into the decision by ARS. ARS does not necessarily know the Regulation Policy either, so it is up to the signaller to enforce this. One great thing about the control remaining at West Hampstead is that the knowledge of signallers who would not have relocated elsewhere is not lost.

So my answer was more than correct then, as the OP question posed was clearly based in the past from travel experience.


It was other posters who, predictably incorrectly (my point), introduced ARS as an answer when there has no ARS (my point), ever, at the junction referred at the period the question referred to, and never had been until today. As I said, "it is ARS" is a knee jerk response by the uninformed who seem to think that because ARS exists it must be everywhere, QED on that one then.

ARS introduced over this xmas i.e. today does not alter the basis of all that happened before this xmas. It is a valid answer, but not an answer to the OP question put here.


I did not say or imply regulation was "just" about train reporting numbers (or the term "headcode" if you must) - that is reading far too many lines between my few words. Having worked on implementing revised ARD as we call (automatic route determination) on an ATO railway (so not a main line) I do know a little about my day job.

All it was meant to be read as is info that a Class 9 is supposed to take priority over a Class 1 when there is potential conflict - not how that conflict is resolved. That IS the whole reason TL trains are class 9 - they are higher up the priority ladder than a class 1 when it comes to conflict. It could be done without "headcodes". Indeed, as you read that I rightly commented ARS was not at the junction in question, pretty obviously it follows from that I could not have implied there was "headcode" < > ARS relationship.

So there are priority trains? How does that work? I thought a priority train would be an express.

What is a class 1 and class 9 ? Sorry, I don't understand the technical terminology. I'm just a commuter.

The numbers /were/ in last years NR pdf timetable files but not this year. Last year was the first year they appeared anyway.

 

[louis97]

So my answer was more than correct then, as the OP question posed was clearly based in the past from travel experience. It was other posters who, predictably incorrectly (my point), introduced ARS as an answer when there has no ARS (my point), ever, at the junction referred at the period the question referred to, and never had been until today. As I said, "it is ARS" is a knee jerk response by the uninformed who seem to think that because ARS exists it must be everywhere, QED on that one then.


I did not say or imply regulation was "just" about train reporting numbers (or the term "headcode" if you must) - that is reading far too many lines between my few words. Having worked on implementing revised ARD as we call (automatic route determination) on an ATO railway (so not a main line) I do know a little about my day job.

All it was meant to be read as is info that a Class 9 is supposed to take priority over a Class 1 when there is potential conflict - not how that conflict is resolved. That IS the whole reason TL trains are class 9 - they are higher up the priority ladder than a class 1 when it comes to conflict. It could be done without "headcodes". Indeed, as you read that I rightly commented ARS was not at the junction in question, pretty obviously it follows from that I could not have implied there was "headcode" < > ARS relationship.


The numbers /were/ in last years NR pdf timetable files but not this year. Last year was the first year they appeared anyway.

Apologies I think we were at cross purposes, I didn't realise you were responding to the OP. Re-reading your post I see what you were saying now!

 

[D7666]

Apologies I think we were at cross purposes, I didn't realise you were responding to the OP. Re-reading your post I see what you were saying now!

ok! understood!