Changes to 4-Character Headcode Conventions in recent years

[GordonT]

I happened to notice that the 0951 ex Blackpool North-Euston has the reporting number "9M51" which breaks the originally devised integrity of the 4-character headcode system in two respects. "9" as the first character was originally used to denote a light loco movement. I believe at some stage a decision was taken to utilise it to denote specific WCML trains which were to be given higher priority for regulation purposes but it seems to have become more common. "M" as the second character was originally used to denote an inter-regional train bound for a destination within what was the London Midland Region. It seems odd to use it for a service entirely within the "M" region. Not that it matters a great deal as the former inter-regional letters are now commonly used for non inter-regional services as well as inter-regional services. The "system" now seems a bit muddled although I appreciate that a system which restricts the end number to numbers between 01 and 99 is restrictive when trying to avoid confusing duplication of use. I'm wondering if folk on here would comment on some of the changes to the system which have taken place, why they were made and whether the changes have helped or hindered.

 

[Mag_seven]

I believe at some stage a decision was taken to utilise it to denote specific WCML trains which were to be given higher priority for regulation purposes but it seems to have become more common.

My understanding is that the "9" is used to designate a service that is running via the West Midlands rather than via the Trent Valley. The code applied for higher regulation (on the WCML) is "R" and applies to most up morning peak services into Euston e.g.

Realtime Trains - 1R08 0555 Manchester Piccadilly to London Euston

Realtime Trains provides live realtime running information for the Great British railway network using open data.

www.realtimetrains.co.uk

 

[bb21]

Class 9's these days are essentially a catch-all for "special routing instructions" and used for all sorts of purposes according to local instructions. In a sense they are good as it aids clarity in an operational context.

Class 3's are also serving a similar purpose to Class 9's in respect of ECS's.

 

[CW2]

Originally class 9s were unbraked freight trains. When they were no longer in traffic the classification became redundant. When the 2008 West Coast Route Modernisation took place the London - Scotland via West Midlands services were given the class 9 designation, to avoid any potential misrouteing at Rugby or Stafford.
The Blackpool service in question is one that runs in one of these Euston - Scotland via West Midlands and v.v. paths, which has been amended in recent timetables to serve Blackpool.

 

[Gloster]

Recollection is that originally 9 was used for the goods trains with the lowest proportion of fitted vehicles (or no fitted vehicles) or, possibly only later on, for the slowest goods trains (maximum 35 mph at one time , I think). It was also used for Eurostar trains, there being few slow goods trains around by the mid1990s. 0 (zero) was used for light locos or those with only brake vans - no more than two - in tow.

 

[Ianno87]

Class 9's these days are essentially a catch-all for "special routing instructions" and used for all sorts of purposes according to local instructions. In a sense they are good as it aids clarity in an operational context.

Class 3's are also serving a similar purpose to Class 9's in respect of ECS's.

I think with Class 9s it's a case of "think before you route - this train is different".

Other uses have been identifying 10-car suburban workings out of Waterloo (when most things were still 8-car), and when recovering on the West Anglia (e.g. a train that has been amended to run fast - possibly also to stop the Automatic Route Setting still regulating it via its originally booked stopping pattern).



Class 9 headcodes are of course also used routinely for all Thameslink core services, and all East London Line services.

 

[Eloise]

We are running out of headcodes hence more Class 9s being used in certain circumstances.

The Timetable Planning Rules should list letters for the second character. There is also a hidden fifth and sixth character we use for planning purposes.

 

[High Dyke]

Changes were made some years ago. Gone are the days of identifying services, particularly inter-regional, by their differing letters (Eastern - E, Midland - M, Southern - O and Western - V). Equally local services were also changed to an extent. It can be confusing at regulatory locations where the same letter may mean two different destinations. For example: services between Nottingham and Lincoln use 'L' mostly and services between Leeds and Lincoln also use 'L'. Both services are different class trains though, but it can lead to the occasional wrong routing. Just this afternoon I'm contending with services using the letter 'S' (Nottingham - Skegness). Even numbers travel inland whilst odd numbers make their way to the seaside. A while back an experienced signaller complained that the same letter added to the confusion and wanted to return to different identifying letters, but to no avail.

 

[StephenHunter]

Eurostar also uses Class 9 and their use of O and I allows them to fit into the continental system without problems.

 

[Eloise]

Inter-regionals still exist in the main

 

[RichJF]

Class 9 headcodes are used down here in Thameslink land too.

 

[Eloise]

East London Line and any Thameslink through the Core are Class 9.

 

[bramling]

Inter-regionals still exist in the main

Certainly on the ECML side we have 1Axx for Leeds to King's Cross, 1Exx for Scotland to King's Cross, 1Sxx for King's Cross to Scotland, however the latter has been amended in recent years for 1Wxx for services to Aberdeen, Stirling and Inverness. That would presumably count as what the OP had in mind.

Thameslink also brought some changes to what had been conventions on the GN side. As well as the class 9 numbers which others have mentioned, the second letter is very much service pattern based, so from May 18 anything on what was planned to be Cambridge to Maidstone had a 2Cxx number, though interestingly a 5Uxx managed to slip in as well - I believe 9Uxx was to be Cambridge to Maidstone. Where this was different to GN convention was that previously anything starting or terminating short of Cambridge at Letchworth or Royston would get a 2Rxx number. In subsequent timetables this has returned for the few such services.

Likewise the sole daily Brighton to Royston and Royston to Brighton service had a 9Sxx code as standard with other Cambridge to Brighton services - this service is now extended to Cambridge so this is no longer an anomoly.

 

[SteveM70]

"9" as the first character was originally used to denote a light loco movement.

I thought light engine movements always began with “0”?

 

[LNW-GW Joint]

Headcodes starting with "9" also apply to TPE Liverpool-York-Newcastle-Edinburgh trains.
Probably to distinguish TPE trains heading west to Liverpool rather than south to Manchester Airport, at the Ordsall Chord junction.
(Actually it can't be that because there are some "9" trains to/from the Airport too...).

There's no reason to retain the inter-regional codes now the regions don't exist, but they still seem to be used like that in places.
There are some odd ones like on the Marches line, it's V southbound but W northbound (not M).
On the other axis through Shrewsbury it's I towards Birmingham, and J towards Cambrian/Chester (you'd think they would avoid using I and O).
NR route/region boundaries keep changing too, as signalling areas expand.
The Midland main line south of Chesterfield is now in LNE territory, for instance (where trains to Corby use code M!).

With Eurostar there was some complicated reason why train numbers starting "9" also worked for Eurotunnel and SNCF/SNCB control systems.
Presumably it also works in the Netherlands too.

 

[StephenHunter]

1xxx is used in Belgium for various intercity and regional services; Thalys uses 9xxx too.

 

[Deepgreen]

9XXXs are also used for class 442s at Waterloo to avoid using platforms which can't take them - or has that now been resolved?

 

[Tomnick]

Changes were made some years ago. Gone are the days of identifying services, particularly inter-regional, by their differing letters (Eastern - E, Midland - M, Southern - O and Western - V). Equally local services were also changed to an extent. It can be confusing at regulatory locations where the same letter may mean two different destinations. For example: services between Nottingham and Lincoln use 'L' mostly and services between Leeds and Lincoln also use 'L'. Both services are different class trains though, but it can lead to the occasional wrong routing. Just this afternoon I'm contending with services using the letter 'S' (Nottingham - Skegness). Even numbers travel inland whilst odd numbers make their way to the seaside. A while back an experienced signaller complained that the same letter added to the confusion and wanted to return to different identifying letters, but to no avail.

The system of identifying inter-regional services by 'reserved' letters is still alive, but not so well these days. It still stands for many longer distance class 1s and most freights. It falls to bits with trains to the former LM though, because there are so many that'd otherwise be 'M' headcodes nowadays! Similarly for class 2s between the Eastern and the Midland - there used (1990s, at least) to be a system for allocating these, with a narrow range dedicated to each of the regional boundaries, but it's presumably unworkable now that frequencies on most of those routes have increased quite drastically since then. Re-using 'inter-regional' letters for local class 2 services with no risk of conflict (you're unlikely to have a class 2 bound for Scotland at Grantham!) seems a sensible compromise, but then applying the same principle to class 1 Skegness HSTs has always seemed daft as there's then a serious risk of confusion. My perception has always been that there's a general lack of understanding amongst current planners of how the system originally worked and how headcodes are used by 'front line' staff, hence such things as STP'd freights running as 6Z09 and STP'd passenger services planned to run as 1Z99 (thankfully the latter was caught before it made it into reality!).

 

[I13]

Regarding the specific case mentioned, this is a quirk of the September Covid timetable change - this train usually runs Glasgow - Birmingham - Euston, so the 9 and the M would be correct, but for September it seems that rather than a new train being created the base working timetable train was amended, thus keeping the same headcode. Likewise you'll see some 9Sxx to Preston, and similarly some odd XC headcodes too (e.g. 1O to Reading). I'd guess that were the service to be introduced at one of the usual change dates (May/December) it would probably run as a 9A, but not necessarily.

 

[swt_passenger]

Regarding the specific case mentioned, this is a quirk of the September Covid timetable change - this train usually runs Glasgow - Birmingham - Euston, so the 9 and the M would be correct, but for September it seems that rather than a new train being created the base working timetable train was amended, thus keeping the same headcode. Likewise you'll see some 9Sxx to Preston, and similarly some odd XC headcodes too (e.g. 1O to Reading). I'd guess that were the service to be introduced at one of the usual change dates (May/December) it would probably run as a 9A, but not necessarily.

Presumably all the 1Onn at Reading at the moment are paths that normally run to Bournemouth, but alternate hour trains are cut short. In normal times the extensions to Southampton or Guildford would also get 1Onn.

 

[Taunton]

My perception has always been that there's a general lack of understanding amongst current planners of how the system originally worked and how headcodes are used by 'front line' staff,

There was an Ian Allan book in their usual series in the 1960s, which explained the whole structure quite well. 2 shillings and 6 pence if I recall correctly. Why not send the planning staff down to their shop at Waterloo before it closes and see if they have any left at the back of the stockroom ...

British Railways Headcodes

books.google.co.uk

 

[xotGD]

Is the headcode 0O00 ever used for a light engine heading onto the Southern?

 

[I13]

Presumably all the 1Onn at Reading at the moment are paths that normally run to Bournemouth, but alternate hour trains are cut short. In normal times the extensions to Southampton or Guildford would also get 1Onn.

That's right yeah.

 

[Eloise]

Certainly on the ECML side we have 1Axx for Leeds to King's Cross, 1Exx for Scotland to King's Cross, 1Sxx for King's Cross to Scotland, however the latter has been amended in recent years for 1Wxx for services to Aberdeen, Stirling and Inverness. That would presumably count as what the OP had in mind.

Thameslink also brought some changes to what had been conventions on the GN side. As well as the class 9 numbers which others have mentioned, the second letter is very much service pattern based, so from May 18 anything on what was planned to be Cambridge to Maidstone had a 2Cxx number, though interestingly a 5Uxx managed to slip in as well - I believe 9Uxx was to be Cambridge to Maidstone. Where this was different to GN convention was that previously anything starting or terminating short of Cambridge at Letchworth or Royston would get a 2Rxx number. In subsequent timetables this has returned for the few such services.

Likewise the sole daily Brighton to Royston and Royston to Brighton service had a 9Sxx code as standard with other Cambridge to Brighton services - this service is now extended to Cambridge so this is no longer an anomoly.

The 1Wxx was an ask from someone to aid improving performance of trains travelling beyond Edinburgh.

Finding headcodes for Thameslink was challenging given the number of Routes they travelled over, finding a headcode series where they didn't fall over with another service group was tricky, hence Class 9. Many a workshop held to discuss that.

 

[PHILIPE]

Class 9 trains are to serve as a tip to signallers when some type of attention is required to be given. As an example WCML trains between Glasgow and Euston that run via Birmingham are designated as Class 9 to indicate they run a different route rather than the usual Trent Valley.

 

[Class 170101]

Certainly on the ECML side we have 1Axx for Leeds to King's Cross, 1Exx for Scotland to King's Cross, 1Sxx for King's Cross to Scotland, however the latter has been amended in recent years for 1Wxx for services to Aberdeen, Stirling and Inverness. That would presumably count as what the OP had in mind.

Also 1Ws to stop them being routed into the new Eastern Terminal Bay at Edinburgh?

 

[150219]

I happened to notice that the 0951 ex Blackpool North-Euston has the reporting number "9M51" which breaks the originally devised integrity of the 4-character headcode system in two respects. "9" as the first character was originally used to denote a light loco movement. I believe at some stage a decision was taken to utilise it to denote specific WCML trains which were to be given higher priority for regulation purposes but it seems to have become more common. "M" as the second character was originally used to denote an inter-regional train bound for a destination within what was the London Midland Region. It seems odd to use it for a service entirely within the "M" region. Not that it matters a great deal as the former inter-regional letters are now commonly used for non inter-regional services as well as inter-regional services. The "system" now seems a bit muddled although I appreciate that a system which restricts the end number to numbers between 01 and 99 is restrictive when trying to avoid confusing duplication of use. I'm wondering if folk on here would comment on some of the changes to the system which have taken place, why they were made and whether the changes have helped or hindered.

The original 4-character train ID system did have some notable differences to that used today and has in fact been evolving ever since its inception, e.g. Class 5 being reclassified as Empty Coaching Stock, rather than it's original classification for freight trains.

The use of the letter was originally split between those services 'within region' and 'inter regional services'. The separate operating divisions within region would also have their own separate letters. X was originally used for Excursions and can now be used for out of gauge movements.

The two numbers/routing numbers for Class 2/3 services were split between 00-49 and 50-99 for more important and less important services respectively.

The two numbers for Class 1 services rose incrementally for each departure.

Light loco movements or trip/target freight services would have their own designated ID too.

In respect of your question about why the changes to the system have been made and whether they have helped, I would venture that they are much more helpful to the operator (and I'm one of them) than having each train displaying 2B74/2C74 (the letter changed when Marylebone changed region/division).

The use of letters have also increased with improvements to technology, such as the use of 'I' for Wembley Stadium terminating services. Again, much more helpful to track train movements and identify a train by looking at one ID than trying to distinguish between 2Hxx or 2Gxx.

To the best of my knowledge the first use of Class 9 for passenger services in our area, after those used by Eurostar services, was for an experiment for 'priority' Class 1 services operated by Cross Country. This would've been around the 2001/2002 time. Since that point, although abandoned by those Cross Country services, it has of course developed again and is now much more common place.

 

[306024]

I think with Class 9s it's a case of "think before you route - this train is different".

Other uses have been identifying 10-car suburban workings out of Waterloo (when most things were still 8-car), and when recovering on the West Anglia (e.g. a train that has been amended to run fast - possibly also to stop the Automatic Route Setting still regulating it via its originally booked stopping pattern).

Class 9 headcodes are of course also used routinely for all Thameslink core services, and all East London Line services.

And all MTREl (Crossrail in old money) trains that travel through the tunnel will be class 9s too. It was also originally an easy way to ensure to ensure there were no headcode clashes in the same area, but as more class 9s are introduced that becomes more difficult.

Class 3s should be reserved for time sensitive Empty Coaching Stock, e.g. ECS to form something rather than simply ECS to a depot.

 

[Gloster]

X was used for anything requiring special arrangements, which could be anything from an out-of-gauge load to the royal train. Z was used for trains not in the working timetable, although a train running on a day it didn’t normally run could also appear under its usual number: if the MWFO 6A01 ran additionally on Tuesday it could be either 6A01, 6Z01 or something else entirely. Locos or empty coaching stock going to work a train or coming from working one could use part of the train’s headcode: the loco for 1A01 could be 0A01 and the coaches 5A01. Trips often carried a Target Number which was reflected in the last two digits: Class 7 Target 85 could be 7T85; not all used the T: that was a local decision. I have used could so often because there were plenty of oddities and local differences.

EDIT: This was the late 1970s/early 1980s situation on the SR and WR

 

[YorksLad12]

Headcodes starting with "9" also apply to TPE Liverpool-York-Newcastle-Edinburgh trains.
Probably to distinguish TPE trains heading west to Liverpool rather than south to Manchester Airport, at the Ordsall Chord junction.
(Actually it can't be that because there are some "9" trains to/from the Airport too...).

TPE use 9Sxx for the services to Scotland via Newcastle and 9Mxx for their return to Liverpool. I took the letters to stand for Scotland and Merseyside.