Understanding a Headcode

All trains which run on the UK Rail Network are allocated a headcode – a 4 digit alphanumeric code used to identify a train service. 

Before we look at example headcodes, it is important to know how they’re broken down.

1. The first digit is the train class category.

0 represents a light engine movement, or locomotive convoy. An example of a light locomotive convoy headcode could be 0V60, because the first digit is a zero.

1 represents an express train / fast train. A 1 followed by a Q will represent a Network Rail Test Train. 1 is also used for rail charters, usually when the 1 is followed by a Z.

2 represents a semi fast or slow passenger train, which frequently stops at stations. A 2 followed by a Q would represent Network Rail Class 950 test train. 2Z02 is also often used for DRS inspection coach trains.

3 is a priority ECS (empty coaching stock) train, parcels, or a seasonal / weather related vehicle used to spray the rails or weeds.

4 is a fast freight train.

5 is an empty coaching stock train not in passenger use.

6 is an aggregates train, building materials, or other freight which is slower than a class 4 train.

7 is even slower than a class train, usually doing no more than 45mph.

8 is often weather related vehicles, and very slow trains.

9 is high speed services such as channel tunnel passenger services, Virgin trains and some VSTP planned passenger services. Class 9 headcode is also used for passenger services that are running with restrictions or out of gauge in places, that require special routing. The 9 headcode tells the signaller that this is a train with special requirements.

2. The second digit is route identifier

Some freight services and non-passenger workings may obscure the last 3 digits, in which case, only the first digit is meaningful and the rest can be ignored. If the 4th digit of a headcode is a letter then it is a masked headcode.

Regionally, most routes will have their own letter. For example (as of July 2018), the Brighton to Seaford trains use a C. Different local routes will have a different letter to tell apart train services. Q is usually used for test trains, and Z is usually used for Short Term Plan workings which don’t usually run. Z can be used for test trains, and charter trains.

For timetabled freight, a V or an A usually indicates a western region freight working (such as from Theale, or Acton). An O might apply for the Southern region, eg from Grain, Tonbridge or Newhaven. An M tends to apply for Midland freight, E for eastern and S for Scotland eg Aberdeen Waterloo.

3 and 4. Digits 3 and 4 are incremental for standard passenger services, and quite simply, identify particular train services. For example 0900 Brighton to Victoria will have maybe 1A01, and then the 0911 may have 1A02. The last two digits just identify the service on that day. This doesn’t apply to freight services as there aren’t quite as many services as passenger trains, each day.

Lets take a look at some example headcodes.

6V00 – the 6 represents a freight train. The V00 represents its route of Newhaven to Acton TC. It only ever needs V00 because there is only 1 a day.

2C49 – the 2 represents a stopper, or semi fast. The C represents the regional area, so in Sussex, the C would be the Brighton to Seaford services. The 49 represents the service number for that day. 2C50, 2C51, 2C52, 2C53 to name but a few, could be other Seaford Branch Services on that day.

1Z55 – the 1 represents a fast service, or one which infrequently stops at stations. The Z often refers to a STP short term planned service. 55 could be a hint to the traction if it is a railtour. Otherwise the 55 could be random.

0Z55 – The 0 represents a light locomotive movement, and the Z could refer to a short term planned service.

 

Some Open Rail Data Issues on Signal Diagram Maps

If one train shares the same headcode as another train, this can cause some conflicts shown on signalling map websites such as Traksy and Opentraintimes, most notably if the first instance of the headcode is obfuscated.

For example:

  • 5Z11 may be a test train operated by a freight company who wishes for their headcodes to be obfuscated in public data.
  • Another 5Z11 may be a passenger ECS train, which becomes “activated” during the same timeframe in which the non-passenger 5Z11 also runs.
  • The “obfuscode” for the freight service, is passed on to the later-activated train and the later-activated service uses the freight’s “obfuscode” on signalling diagrams.

If the above instance’s freight service runs as “546Q”, a scrambled version of 5Z11, some (or all) subsequent 5Z11 trains activated on the same day as 546Q , will show on maps as 546Q.

This shouldn’t affect reports from TRUST, but will affect TD reports for the first occurrence of “546Q”. This has been an issue for some time, and there are no immediate signs of this being fixed by open data suppliers.

 

matt
Author: matt

Owner of Rail Record

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[…] – The headcode. Check the page (understanding a headcode) C – The schedule type. 3 – The time frame at which the train leaves it’s origin* […]

Richentblog
3 years ago

nice post, very clear and understandable. do check Richentblog

A Wilson
A Wilson
1 year ago
Reply to  Richentblog

But unfortunately not factually correct. For example Q headcodes are used where the train has guage restrictions.

Elmer R Hemingway
Elmer R Hemingway
3 years ago

Hi..I’m a newcomer to British Rails. This is very informative as I am a member of RaiCam. I have seen 2 other codes I am curious about: SHUT and TBRD. I am thinking these are maintenance codes of some sort?

Matthew
Matthew
3 years ago

Hi, normal train headcodes will be things like 2N30, 6V00 and 0S00. Signallers can also put whatever they like on a signal berth, like you say SHUT (presumably line shut). Engineering possessions will also show -T3-, and when something is on the track (eg a track machine) in a engineering possession, *X** will show.

John
John
2 years ago
Reply to  Matthew

Thanks Matthew, but what about TBRD? I googled and this is all that’s come up for it. Track Machine perhaps?

EDIT: Ah got it – TBRD means Thunderbird, which is a rescue locomotive, usually a Class 57/3

Last edited 2 years ago by John
Peter
Peter
3 years ago

So, when I see a head code on Real time train sites of 2-IN, I am totally confused!

Matthew
Matthew
3 years ago
Reply to  Peter

If you are referring to the signal diagrams, 2-IN means 2 separate units are in a siding or platform. Not sure where else it appears on other websites, but usually anything that’s not in the number letter number number format is usually a reminder for the signaller.
Other examples, -T3- – engineering work, and some self explanatory ones like CLSD (closed), NOGO, RUST, LOCO all reminders for signaller.

Ellis
Ellis
2 years ago

What does Z mean Enyone

Matt Burett
Matt Burett
2 years ago
Reply to  Ellis

Z is usually used on short term planned trains, like emergency timetable for passenger trains, and special trains as well.

travis
travis
1 year ago

what does it mean if a trains head code is LUKE

Matthew Burdett
Matthew Burdett
1 year ago
Reply to  travis

Name related berths on opentraintimes etc are often names of the people on charge of the engineering possession or yard

MR ALAN WHITTAKER
MR ALAN WHITTAKER
1 year ago

How can we tell from a photo, [say, showing a headcode 8E17], what route the particular train is on ??

Matthew Burdett
Matthew Burdett
1 year ago

Originally trains would have the headcode on the front (like old class 25, 37 etc) but no more. Can’t tell from a photo without internal info

Niall
Niall
11 months ago

I’ve noticed headcodes like SIPO and LBTC on traksy, any idea what those are?

Jonathan Anderson
Jonathan Anderson
10 months ago

Thanks Matt. Code 4 normally refers to container/Intermodal

anthony mcdonnell
anthony mcdonnell
8 months ago

what does STOP in red as a headcode mean

Bill McQueen
Bill McQueen
7 months ago

What does the W stand for on 1W20?

Matt
Matt
7 months ago
Reply to  Bill McQueen

In the past the W would have been region specific, but these days the W usually just refers to a particular route or service on a region network

James Hardy
James Hardy
7 months ago

I’ve got a model of a Class 25 and one of the headcodes on it is 1D33. I know 1 is an express/fast train but what does the D mean?

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