Train reporting number

A train reporting number is used by railway staff in Great Britain to identify a particular train service. It consists of:

• A single-digit number, indicating the class (type) of train
• A letter, indicating the destination area
• A two-digit number, identifying the individual train, or indicating the route (the latter generally for suburban services).

The train reporting number is often called the headcode, a throwback to when the number was physically displayed at the head of a train.

History

Headcodes

Headcodes were originally introduced around 1850 and were shown by a number of oil lamps facing forward on the front of the locomotive. The position of these lamps on the locomotive denoted the class of train, which assisted the signalmen to determine the gaps between trains required in the interval-based signalling system that was used at the time. The lamps would be lit at night and were usually painted white to assist with sighting by day. On some lines white discs would be used by day in the place of lamps.

With the coming of absolute block signalling, the class-based headcodes allowed signallers to identify and regulate trains properly. However on some busy lines, particularly busy suburban ones, the headcode denoted the route of the train rather than the class of train. In these areas junctions were complex and timetables were intense: it was more important that signallers routed the trains correctly than regulated trains by class. This was prevalent in the south of England, where companies used six headlamp positions to show the route of train.

The various companies throughout Great Britain each had their own code format which lead to some confusion where trains from one company ran on to other companies' lines. The Railway Clearing House (RCH) intervened to standardise headcodes – these standard headcodes were based upon four headlamp positions and were adopted by the majority of lines outside the south of England. At the time of the 1923 Grouping the standard headcodes were simplified so that only two lamps were used at any one time, and these codes were adopted by the post-grouping London Midland and Scottish Railway, the Great Western Railway (GWR) and the London and North Eastern Railway. The new Southern Railway retained a route-based headcode system. Notable exceptions were the former Glasgow and South Western Railway and the Somerset and Dorset Joint Railway lines which continued with their own headcodes on internal trains.

Train reporting numbers

Southern Region electric multiple units show two-character roller-blind headcodes where the code denotes the route of the train

Historically train reporting numbers were used to denote trains in the internal working timetable. These contained one or more letters or numbers either to uniquely identify a particular train, or to denote its route (particularly on busier lines). Not all lines used these and the actual details and extent of the practice varied widely between companies. Although these numbers were in many places confined to timetables and other documentation, in some busier areas they were actually shown at the head of the train.

On the Southern Railway lines, a single alphabetic character system of denoting routes used on suburban lines grew into a two character route-based system. This was developed at the same time as a significant program of electrification and the consequent introduction of a large number of multiple unit trains. Many of these trains were fitted with display devices to show the route code instead of a lamp or disc-based headcode. Originally this was a back-lit stencil with the single letter code, later a two-character roller-blind system was used. The code system had equivalence with the lamp or disc route-based headcode system in assisting signallers with routing trains.

On the other railways, the reporting number was on occasion displayed at the head of the train along with the lamp headcode. This happened more often than not with special trains or other unusual trains (e.g. summer Saturday timetables), to allow signallers to identify unfamiliar trains and route them correctly. This code was sometimes either chalked on to the locomotive front or pasted as paper characters on to a headcode disc. The GWR sometimes used a three-character frame mounted on the locomotive smokebox in which the train reporting number could be displayed.

After nationalisation British Railways continued with these headcodes and the new diesel and electric locomotives and multiple units were built either with a disc/lamp system (now powered by electricity) or a two- or three- character roller-blind display system depending on what part of the network they were to work.

1960 headcode/reporting number merger

Class 37 locomotive with its headcode panel converted to two marker lights

In 1960, the current format was introduced where train class, route and reporting number information are combined in four characters. All diesel and electric locomotives and multiple units built after that date were fitted with a roller-blind display system that could display the full reporting number. The exception once again was those locomotives and multiple units destined for the Southern Region, which continued that region's by now long-standing practice of fitting two-character numeric displays.

By 1976, the replacement of the huge number of manual signal boxes with centralised power-signalling, coupled with the coming of computer-based train control and more modern telecommunications systems, meant that it was no longer necessary to mandate the display of headcodes throughout the railway network. Outside the Southern Region blinds were set to 00 or 0000; discs/lamps to the former express passenger code. Roller blinds were later blanked or plated over to show two dots and new trains introduced for service outside the Southern region after this time usually had no train reporting number display equipment fitted. However after this time, many trains intended to run over Southern Region lines were designed to display the numeric route-code portion of the train reporting number at the head of train, which they still display to this day, usually on dot-matrix displays.

Components

The main purpose of the headcode is to assist the signaller in routing and regulating the train correctly, and it is especially useful if services are disrupted. After the introduction of the four-character codes, originally it was intended for the signallers to visually recognise the train by the number displayed on its front; with the coming of automated systems the number has been retained internally within timetables and signalling systems but with some exceptions detailed above is no longer displayed on trains.

Train classes

For operational reasons, certain trains have priority in running. To help operating staff, they are grouped into classes:

1. Express passenger train, nominated postal or parcels train, breakdown or overhead line equipment train going to clear the line or returning from there (Code 1Z99), traction unit going to assist a failed train (1Z99), or a snowplough going to clear the line (1Z99)
2. Ordinary passenger train, breakdown or overhead line equipment train not going to clear the line (2Z99), or an Officers’ special train (2Z01)
3. Freight train which can run at more than 75 mph, parcels train, or empty coaching stock train if specially authorised
4. Freight train limited to 75 mph
5. Empty coaching stock train
6. Freight train limited to 60 mph
7. Freight train limited to 45 mph
8. Freight train limited to, or timed to run at, 35 mph or less
9. Eurostar train. Also since 2010 London Overground passenger services on the East London Line, to avoid confusion with the large number of Southern and South Eastern services, have been allocated 9xxx headcodes. In 2006, certain long distance Virgin Cross Country services were allocated 9xxx headcodes to help signallers identify a long-distance inter-regional express passenger service from a local Class 1 express service. This was to help the Class 9 Virgin Cross Country get higher priority. This agreement ended when the franchise changed to Arriva CrossCountry, and have now reverted to their former Class 1 designation.

Class 0 is used for light locomotives. Newspaper and postal trains are consigned to history. The classes' definitions have changed several times since being introduced: Class 3 was formerly used for parcels trains, and Class 9 for freight trains without fitted brakes.

Destination letters

For long distance trains, the country is split up into areas based upon the old British Rail regions. Each one is assigned a letter as follows:

• E: Eastern
• L: Anglia
• M: Midland
• O: Southern
• S: Scotland
• V: Western

A train going from one region to another is given the letter of the destination region in its headcode. Prior to 1967 N was used to signify trains destined for the erstwhile North Eastern region.

For trains internal to a region, the remaining letters can be used to indicate either:

• A destination zone inside that region, or
• A route within that region.

Some areas within the Midland region are:

• A: London
• D: North Wales
• G: Birmingham
• H: Manchester

Other regions can use these letters for different areas, but the inter-regional codes have the same meaning throughout the country.

In 2007, a special letter Q was introduced for track recording trains, such as the Network Rail New Measurement Train. The Q emphasises to Signallers that the train is to run its booked route as it is recording. It is not to be diverted without the prior knowledge of the Controller. Prior to this, trains operated by British Rail Research Division would use the letter T.

The letters X and Z are generally reserved for special use – see below.

Individual identifier

Because there are many trains of the same type heading for similar destinations (for example, most expresses to Scotland have headcodes beginning with 1S) the last two digits are used to separate individual services, or to indicate the route (generally for suburban services).^{[citation needed]}

There is sometimes duplication because there are only two digits, so it is the rule for individually-numbered trains that there must be six hours between services with the same headcode.^{[citation needed]}

Examples

• The 0625 Plymouth – Glasgow Central service is an express passenger service, so it is a class 1 train. It is going from the south-western to the Scottish region, so it is given the letter S for its destination. It is one of the first services in the day, so its headcode is 1S35.
• The 1640 express London Euston – Manchester Piccadilly is internal to the Midland region, so it uses the Manchester letter H for its destination. Its headcode is 1H71.
• On the Western region, the letter K signifies trains running between Paddington or Reading and the Bedwyn/Newbury area. Up (London-bound) services have odd numbers, and Down services have even numbers. The 2233 London Paddington – Bedwyn is numbered 2K82 and the return journey 2K85.
• The china clay train from Cliff Vale (Stoke-on-Trent) – St Blazey (Cornwall) is limited to 60 mph, so it is a class 6 train. It is going to the Western region, and its headcode is 6V70.
• However, if 6V70 ran with a different, slower set of wagons restricted to 45 mph, it could run as 7V70, and if no wagons needed to be moved, it could run as 0V70 (engine only) – assuming that these do not clash with any other trains along the route, as having 2 0V70s running at the same time would not be allowed by TOPS and other systems.

Special numbering

It is common practice for empty coaching stock (class 5) trains on the way to form a service or returning to depot having completed a service, to run with the same code as that service, with the 5 prefix. For example, 5M37 may be going to form or coming off either 1M37 or 2M37. Similarly, locomotives on the way to pick up a train or running round to change the direction of travel are given the train number but with a 0 prefix.

An unusual situation arose with the opening of the Channel Tunnel: many continental train reporting numbers are all numeric. Eurostar trains therefore have a 9Oxx or 9Ixx reporting number in Britain and a corresponding 90xx or 91xx number on the continent, neatly utilising the similarity between the letters O and I, and the numbers 0 and 1 to unite the two reporting number systems.

Trains with some specific requirements, such as out-of-gauge loads or the Royal Train, run with the letter X, and special trains not in the regular train service (e.g. charter services, railtours, emergency trains or as-required locomotive moves) have Z. Automatic Route Setting code prevents the automatic routing of trains with the letter X in their headcode and signallers must route these trains manually. The former White Rose service from London King's Cross to Leeds ran with a prefix of 1X due to the train's unusually long length.

External links

• Headcodes: Passenger Headcodes Database
• 2D53: Headcodes – a site with example photos.
• scot-rail.co.uk: Scottish Headcodes Explained – full list of the various destination letters and where they refer to in Scotland