Jargon Buster

Like many organisations, the Gloucestershire Warwickshire Railway has its own 'industry jargon'. This can be confusing for many visitors and sometimes results in media stories beset with misunderstandings.

Railway terminology - common to Network Rail and other heritage railways as well as the GWR - presents some mystifying words and phrases to those unfamiliar with them. What is a 'fishplate'? Or a 'Dogfish', 'turnout' or 'runround loop'? What's the difference between a train and a locomotive? This alphabetical summary aims to clear some of the mystique and explain what volunteers on the GWR might be talking about!

Autotrailer (or autocoach)

A type of coach designed allow the driver to operate the train, via special linkages, from a driving compartment at the end furthest from the locomotive. A locomotive so equipped, such as 1400 class 0-4-2 tank locomotive, is often called an 'autotank'. The advantage is that the locomotive doesn't have to run round its train to return from the destination station. This type of train worked local services between Cheltenham and Honeybourne until 1960 and was known by many local people at the 'Coffee Pot'.

AWS, Automatic Warning System

The Great Western Railway pioneered an automatic warning system that significantly improved railway safety especially during poor visibility. The impetus for development followed a 'SPAD' (signal passed at danger) accident at Slough in 1900 which killed five people. Known technically as a voltage contact system, it comprised an electric shoe under the locomotive connecting with a ramp between the rails. The ramp was energised depending on the condition of the signals ahead of the train, sounding a bell (all clear) or a horn (caution or danger) in the cab. Trials of the system, initially known as Automatic Train control (ATC) were completed by 1910 and it was installed throughout the GWR over the following years. It remained in use until the mid-1960s. The British Railways system until the advent of the current TPWS (Train Protection and Warning System) used exactly the same principle as the GWR but using elecro -magnets instead of a contact shoe. Great Western locomotives operating on the GWR are all still equipped with the brass bell and electrical equipment in the cab and some have the pickup shoe fitted.


Approximately golf-ball sized pieces of crushed rock (usually granite or limestone), which holds the track in place, provides drainage and absorbs the shock and weight of passing trains. It takes over 2,000 tons of ballast per mile of track.


The four-wheeled (or sometimes six-wheeled) truck beneath each end of most carriages and some vans and wagons


A special overlapping joint in the rail found at the end of sections of continuously welded rail, designed to allow for thermal expansion and contraction. A length of continuously welded rail can expand by several centimetres between the coldest and hottest days.

Bull-head Rail

The type of rail once used throughout the national network but is used much less now. The shape of the rail is designed to fit within a 'chair' attached to the sleeper and held in place with a wooden or sprung-steel key. The GWR has some 'bull-head' rail in use, especially in station areas and sidings. 'Flat-bottom rail' (see below) is installed between Gotherington and Cheltenham as well as Toddington to Broadway.

Carriage, Coach

Railway vehicle for carrying passengers, usually carried on 'bogies' (see above). Also known as a coach.


The drainage system running along each side of the track to ensure ballast does not become waterlogged during wet weather. Volunteers on the GWR have carried out extensive work to clean and repair the 'cess' throughout the length of the line.

'Coffee Pot'

Colloquial term applied locally to the locomotive and autotrailer combination that once worked local trains between Cheltenham and Honeybourne. See Autotrailer.

CWR, Continuously Welded Rail

Lengths of rail are welded together end to end, forming one long, unjointed length. Results in smoother ride for passengers and less noise for bystanders, eliminating the familiar 'clickety-click' of carriages running over jointed track. The GWR has installed CWR through Bishops Cleeve and Woodmancote to reduce the noise and vibration from passing trains that might otherwise be experienced by residents. Believed to be the first CWR installed on a heritage railway. All of the line from Toddington to Broadway will use CWR. Much of the national network comprises CWR.

Diesel Multiple Unit (DMU)

A set of carriages, powered by diesel engines under the floor, with a driving cab at each end. These are also known as Diesel Railcars. Most modern passenger trains are Diesel or Electric Multiple Units.


A special type of hopper wagon designed to carry ballast. It has a capacity of 24 tons and is equipped with chutes to allow the ballast to fall on to the track.

Dolly or Dummy

A small, round semaphore shunting signal, normally at ground level, used to clear trains into sidings or to clear locomotives back onto their trains. You'll see these at all of our stations except Cheltenham.


The traditional term for a steam locomotive (steam engine). Strictly speaking, each cylinder and piston is a 'steam engine' and so a 2-cylinder locomotive has 2 steam engines. In a diesel locomotive, the 'engine' is the diesel motor, which drives the locomotive.

Fishplate, Fishbolt

Nothing to do with fish! Fishplates are heavy steel bars each with four holes, used to connect rail ends together. Four fishbolts pass through first one fishplate, the 'web' of the rail and through a fishplate on the opposite side, then tightened up using special nuts. The fishplates are greased regularly to allow the rail ends to expand and contract during extremes of temperature.

Flash butt welding

See CWR above. A method of welding rail ends together by passing an electrical current of about 30,000 amperes through them. The rail ends become red-hot and are forced together to form a fused joint. The excess metal is sheared off and the joint made smooth with a special grinder.


The levelled and graded stretch of land on which the track is laid.

Flat bottom rail

The type of rail used on the national rail network - it has a broad, flat base (hence the name), which is attached to the sleepers. This modern type rail is being used by the GWR outside station limits.

'Four-foot' and 'six-foot'

The track is sometimes colloquially known as the 'four-foot' (see 'gauge' below) and the space between two tracks (such as in stations on the GWR or double track main lines) is sometimes called the 'six-foot'.

Gauge (track gauge)

The distance between the rails. Throughout most of the world, 'standard' gauge is 4ft 8½in and this is the gauge of the GWR. 'Narrow' gauge refers to lines with a gauge less than this; 'broad' gauge is wider.


A length of track that allows shunting movements to be made in to and out of sidings

Light engine

An engine travelling on its own (with no train).

Locomotive (see also 'engine' above)

The correct terminology for the motive power unit - steam, diesel or electric - that can be found at the front of a train (or at both ends of some modern trains, such as high-speed trains). Locomotives may be designed for different purposes, i.e. 'freight locomotive', 'express locomotive', 'shunting locomotive'.

Panel, track panel

An assembled length of track (usually 60ft long) complete with sleepers and rail fastenings.

P/way, Permanent Way

A term coined in the 19th century to describe the original railway, including both construction and maintenance. It comprises rail, sleepers, fastenings and ballast, over which trains run. The 'P/Way Department' is one of the GWR's engineering departments and is responsible for replacing and maintaining the track over the whole route.


See 'Turnout'

Rail joint

The connection between two rail ends - may be jointed using fishplates or welded.


A self-contained, steam-powered railway coach accommodating about 70 passengers.  It comprised a small locomotive mounted on the front bogie and within the body of the coach, and a driving compartment at each end. Railmotors were widely used by the Great Western Railway and they worked services between Cheltenham and Honeybourne during the line's early years. They were superseded by 'autotrailers' (see 'A')

Run round loop

A length of track with a connection to the main running line at each end which allows a locomotive to be detached from its train, pass alongside the train and re-connect at the other end to make its return journey. Hence, the locomotive 'running round' its train.

Semaphore signals or 'semaphores'

The signalling system used almost since railways began. Semaphore signals can still be found on some secondary routes of the national network and on most heritage railways in the UK, including the GWR. They comprise steel arms mounted on posts . They are horizontal when at danger, exhibiting a red light at night. They are moved to a 45-degree angle either upwards (known as upper quadrant) or downwards (lower quadrant) when the line is clear, showing a green light at night. The GWR uses lower quadrant signals (the former Great Western Railway was the principal UK user of lower-quadrant signals). Colour light signals and electronic systems have largely superseded semaphores on the main line.

S & T and Signalbox

Signal and Telegraph. One of the engineering departments of the GWR responsible for installing and operating the railways signals and telephone, or 'telegraph' system of communication between 'signal-boxes' where the signalman controls the movement of trains. Signal-boxes are in operation at Toddington, Winchcombe, Gotherington and Cheltenham. A new signalbox is being built at Broadway.


Not the 'Jaws' type, but a brake van equipped with ploughs, which can be raised or lowered to level off tipped ballast.


Lengths of timber or pre-stressed concrete on to which the rails are fixed.  Concrete sleepers - which are almost maintenance-free - are now used extensively used by the GWR although we use wooden sleepers in stations. The national network mainly uses either concrete or steel sleepers. Wooden sleepers are mainly confined to pointwork and sidings.

Staff or Token

A vital safety device handed by the signalman to the driver or fireman of a train entering a single-track line. The staff, or token, carries a lock and the signalling equipment at the opposite end of the single track line cannot be operated without it. This ensures another train cannot enter the single track section in the opposite direction. The driver hands the staff or token to the signalman when he reaches the end of the single track section and collects the staff for the next section. The device is often carried on a large hoop to facilitate easy exchange, which can be seen at all of our signalboxes.

Steam locomotive (or steam engine)

See also 'locomotive' above. Steam locomotives that may be found on the GWR are of four main types:
Saddle Tank - a shunting locomotive whose water is carried in an inverted 'U' shaped tank over the top of the boiler. Coal is carried in a 'bunker' and the locomotive is completely self-contained.
Side Tank - or just 'Tank locomotive' (such as Thomas the Tank Engine) - a shunting or main-line locomotive with vertical tanks for water either side of the boiler. Again, coal is carried in a bunker.
Pannier tank - a type of tank locomotive almost exclusive to the Great Western Railway, where the water is carried in 'panniers' on either side of the boiler.  Coal is carried in a bunker.
Tender locomotive - there are no tanks on the locomotive, all water and coal is carried in a separate 'tender' coupled immediately behind it.  The largest express locomotives may carry up to 8,000 gallons of water and up to six tons of coal.

Switching out

Signal boxes can be 'switched out'. This means that the signals it controls in both directions are set to 'clear' and the box is then locked. We routinely switch out the Gotherington signal box and then the Winchcombe and Cheltenham signal boxes control the line between them. If only one train is running it is possible to switch out all of the signal boxes and carry a 'travelling signal man' who switches in and switches out the boxes as required down the line.


A special on-track machine, which raises, aligns and levels the track, consolidating the ballast beneath and beside the sleepers and providing a smooth, safe and level track.

TPWS, Train Protection and Warning System

This is the current train protection system fitted on the national network. It is a direct descendent of the Great Western Railway's Automatic Warning System which significantly improved railway safety (see AWS).


The collective term for the coaches or wagons being pulled by a locomotive ('the train is being pulled by a steam locomotive') or for the combined ensemble of locomotive and carriages / wagons. A locomotive should not normally be singly referred to as a 'train'.  For example:
Wrong: Foremarke Hall' is a beautifully restored steam train.'
Correct: 'Foremarke Hall' is a beautifully restored steam locomotive (or steam engine).'

Turnout (or Points)

A track installation that enables a train to change from one track to another.

Water Crane

A device for delivering a large quantity of water quickly in to a steam locomotive's tank. The crane comprises a large steel pipe with a flexible connection and is mounted alongside the track. The water may be supplied from a header tank integral with the crane or from a tank located elsewhere. A steam locomotive at the GWR will consume as much as 2000 gallons of water during a typical day. Water cranes are located at Toddington, Winchcombe and Cheltenham stations.

Water Troughs

Although the Cheltenham to Stratford line was never equipped with water troughs, many of the locomotives we operate on our line today are equipped with a 'water scoop' (although locked out of use). The scoop was lowered into the trough to collect water whilst the locomotive was travelling.Troughs could be found on most of the UK's main lines (except the Southern) and required a mile or so of level track. Water was automatically supplied with treated water from tanks at the side of the line. The troughs significantly increased the range of the locomotive, allowing non-stop runs over immense distances - for example London to Edinburgh. For more information visit our footplate guide.

Whyte System for Wheel Arrangement*

In 1900 the American engineer F W Whyte - a Dutch New York Central Railroad mechanical engineer - devised a system to describe the wheel arrangement of a locomotive. The number of wheels is counted starting with leading, undriven, carrying wheels, followed by the number of coupled driving wheels and then the number of another undriven trailing wheels, each number separated by a dash and starting from the front. Thus 2-8-0 indicates two leading wheels, eight driven coupled wheels and no trailing wheels. Tank engines are indicated by appending a 'T' to the wheel arrangement (e.g. 0-6-2T). This can be further refined by using 'ST' to indicate a saddle tank (e.g. 0-4-0ST), 'PT' for pannier tanks (e.g. 0-6-0PT) and 'WT' for a well tank (e.g. 0-4-2WT). 'T' on its own indicates side tanks. Articulated locomotives such as those built by Beyer-Garret are indicated with addition of a '+': for example, 2-6-0 + 0-6-2.

Diesel and electric locomotives in the UK use the UIC (International Union of Railways) system. This uses the number of axles rather than the number of wheels. Powered axles are denoted by letters and unpowered axles by numbers; additionally, independently powered axles have an 'o' suffix. So a loco, like a Class 37 or 47 with two independenly powered 3-axle bogies is a Co-Co. The Class 45 has additional unpowered axles and so is a 1Co-Co1. Diesel hydraulic locos such as the Warship Class have drives to both axles and so are B-B.

*Some wheel arrangements were so common they also had names and those that fell into use in the UK included:

  • Prairie: 2-6-2 (such as the Great Western 'Prairie' tanks)
  • Atlantic: 4-4-2 (such as 'Brighton' Atlantics)
  • Pacific: 4-6-2 (most later express locomotives in the UK such as our Merchant Navy class - Peninsular & Oriental SN Co)
  • Mogul: 2-6-0 (a popular arrangement for mixed-traffic locomotives)