Glossary of terms

For those of you who are not familiar with the many and myriad abbreviations, acronyms and odd terms which abound on the railway here are a few explanations regarding those which appear on these pages.

ACEC - Ateliers de Constructions Electriques de Charleroi - suppliers of the TBL ATP system used on GWML

ADB - prefix for numbering of former BR Departmental stock belonging to the regional DM&EE (A=CM&EE, D=Departmental B= British Railways designed & built)

AB - Air Braked

AL6 - AC Electric Locomotive type 6 - as designated when first built - later became class 86 - similarly for AL1, AL2, AL3, AL4 and AL5

APT-E - Advanced Passenger Train - Experimental - the gas turbine powered 4-car version

APT-P - Advanced Passenger Train - Prototype - the three 25kV electrically-powered trains

ATP - Automatic Train Protection train control system

ARL - Above Rail Level

AWS - Automatic Warning System - an simple magnetic induction warning system used on BR since early 1950s

Block - colloquial term for a temporary closure of a running line to enable (emergency) work to be undertaken

Bobby - a term for the signalman from the days when police controlled the movements on the railway. Robert Peel was the chief of police hence Bobby! Today we also have bobettes but they are officially known by the very dull name of 'signallers'!

BR - British Railways - British Rail after 1964

BRB - British Railways Board - it never changed to British Rail Board!

BSC - British Steel Corporation

BR/BW - British Rail / Brecknell Willis (pantograph)

Breather switch - a railway joint in continuous welded rail (CWR) to allow for expansion. They are placed between very long sections of CWR or at the transition between CWR and jointed track. The mating sections are tapered diagonally (unlike a butt joint between two lengths of rail), allowing smoother transitions and higher speeds across the gap.

BSK -  Second class Mk1 corridor coach with guard's brake and 2nd class compartment accommodation

BSO - Second class Mk1 open coach - with guard's brake and 2nd class open accommodation

C-APT - Control of APT - transponder-based automatic speed indication and stop system fitted to APT-P

Cess - Term for the space alongside the tracks

CK - Composite corridor coach - Mk1 coach with 1st and 2nd class compartment accommodation

CM&EE - The Chief Mechanical and Electrical Engineers' department (these were the regional equivalents and so there were London Midland Region, Southern Region, Western Region and Eastern Region, plus Scottish Region all based in the appropriate regional offices). The one at Derby was located in Nelson Street near the station

Conicity - the wheel tread taper is the slope of the tread or running surface of the wheel relative to the axis of the wheelset, sometimes referred to as conicity. Most wheels have a conical shape of about 1 in 20. The conical shape has the effect of steering the wheelset around curves, so that the flanges rarely come into play.

COSS - Controller Of Site Safety - person in charge of a group of people (2+) when on or about the track in a work party. Their primary role is to set up a safe system of work to protect staff from trains and trains from staff and activities.

CWR - Continuous Welded Rail - Most modern railways use continuous welded rail (CWR). In this form of track, the rails are welded together by utilising flash butt welding to form one continuous rail that may be several kilometres long. Because there are few joints, this form of track is very strong, gives a smooth ride, and needs less maintenance; trains can travel on it at higher speeds and with less friction.

DBS - DB Schenker Rail (UK) Ltd is an established major provider of a range of rail services in Britain. A joint train operating company of Deutsche Bahn and Schenker who now operate a large number of freight services in UK and all Network Rail test trains formerly operated by Serco.

Dipped Joint - A dipped (rail) joint is the phrase used to describe a fish-plated track joint which has deteriorated and which therefore ‘dips’ below the normal rail top when under load due to being traversed by a train. Prolonged use of track with dipped joints can lead to broken rail ends which have been the cause of a number of serious accidents on the world's railways

DLR - Docklands Light Railway

DM&EE - The Department of Mechanical and Electrical Engineers (based at the British Railways Board HQ, Derby)

DMU - Diesel (Mechanical) Multiple Unit sometimes written as DMMU

DEMU - Diesel Electric Multiple Unit

DOC - Director Of Control was a design organisation under the British Railways Board

Down line - a railway track on which traffic usually runs in the direction away from London

DP - Designated Person certificate allowing an individual to act as a COSS when required usually in the of an unplanned incident out on the line.

DSD - Drivers Safety Device - A 'vigilance device', often takes the form of a foot operated pedal which must be reset within a given time to prevent the train being stopped automatically. Usually, an advance warning is given to allow the driver to reset. 

DVT - Driving Van Trailer is a purpose-built railway vehicle which allows the driver to operate a locomotive at the opposite end of a train. In early days the conveyance of passengers in the leading vehicles at high speed was not allowed - hence DVTs. This eventually changed with the introduction of Alstom's class 180 200km/h 5-car DMU

ECML - East Coast Main Line - the route from London KX to Edinburgh

ECO - Electrical Control Office(r) which is responsible for safety of the OLHE including turning off the power as required.

ECS - Empty Coaching Stock

EDU - Engineering Development Unit workshop at RTC Derby - now just a depot for DBS

EMU - Electric Multiple Unit

EPS - European Passenger Services was the forerunner of Eurostar International. The privatisation of British Rail saw ownership of EPS transferred to London and Continental Railways (LCR) in 1996

ER - Eastern Region - area of BR operations stretching from London to Edinburgh and all areas of the former London and North Eastern Railway Co

ES - Engineering Supervisor - in charge of train movements within a track possession

ESR - an Emergency Speed Restriction is one which cannot be included in the train crew notices by its very nature

ETCS - European Train Control System

ETD - Electric Traction Depot

ETH - Electric Train Heating

ETRMS - European Rail Traffic Management System

EWS -  English, Welsh and Scottish Railway - a former freight train operating company on NR

Expansion joint - see breather switch

FK - First Class corridor coach - Mk1 coach with 1st class compartment accommodation

Flange (wheel) - A wheel flange is the rim (lip) on a railway wheel. It is profiled on the inside of each wheel and hence keeps the wheels from running off the rails.

FO - First Class open coach - Mk1 coach with 1st class open accommodation

Four Foot - common term for the space between the rails of one railway track

FRA - Federal Railroad Authority (USA)

Ground frame - consists of an open frame of levers to locally operate points and is operated by the driver, guard, shunter etc.

GWML - Great Western Main Line is a modern term for the former Great Western Railway's route from London to Bristol and Swansea

GWR - former Great Western Railway Company

HSFV - High Speed Freight Vehicle - R&DD Project to improve 4-wheel wagon suspensions

HST - High Speed Train also known as InterCity 125

HSTRC -see TRC below

Hunting -  Unstable dynamic motion comprising sustained oscillations in yaw and lateral displacement of the bogie frame and wheelsets from flange to flange.

IEE - Institution of Electrical Engineers whose regulations of the time forbidding a 25kV busbar connections between coaches on a train resulted in the APT-P having power cars in the centre

IEP - InterCity Express Programme - a major project in progress by Hitachi Rail Europe who will provide new class 800 and 801 electric and bi-mode trains, for both the Great Western Main Line and the East Coast Main Line as replacements for the much loved HST's.

IMechE - Institution of Mechanical Engineers

Indusi - Inductive train protection system used on Tyne & Wear Metro - supplied by Alcatel - SEL of Stuttgart and widely used in Europe

IWA - Individual Working Alone (certificate to allow an individual to work 'on or about the track')

Knitting - colloquial term for the overhead line equipment

LED - Light Emitting Diode - as used on ATP instruments for example

LMR - London Midland Region - area of BR operations stretching from London to Carlisle and including Liverpool and Manchester and routes of the former London Midland and Scottish Railway Co

LMSR - former London, Midland and Scottish Railway Company

LMW - Load Measuring Wheel - a specially constructed wheelset with spoked wheels and equipped with instrumentation which measures vertical, lateral and longitudinal force.

LNER - former London and North Eastern Railway Company

Loading Gauge - the space envelope through which a train must pass as defined by the proximity of bridges, tunnels and platforms. Today also known as the 'kinematic envelope'

MCB - Miniature Circuit Breaker - an electrical switch which visibly 'trips' when overloaded and can be reset

MENTOR - Mobile Electrical Network Testing, Observation and Recording - overhead line test coach extensively operated by BR and now NR

MetCam - colloquialism for the former train builder Metropolitan Cammell Carriage and Wagon Company (MCCW) of Birmingham

Mileposts - posts alongside the line indicating mileage - usually rising from London in one quarter mile increments

Mk1 coach - BR designed standard coach type built from the early 1950s to the mid-1960s

Mk2 coach - BR designed standard coach type built from the mid-1960s to the mid 1970s

Mk3 coach - BR designed standard coach type of 23m length built from the mid 1970s for use on HSTs and loco-hauled trains

Mk4 coach - BR designed standard coach type built from the late 1980s for use exclusively with class 91 locomotives on ECML

Modernisation Plan- The report formally known as 'Modernisation and Re-Equipment of British Railways', more commonly the "Modernisation Plan" was published in December 1954. It was intended to bring the railway system up to date.

MTU - Mobile Test Unit -purpose-built test vehicle fitted with the rheostatic brake to simulate loads for a locomotive under test

Nightstock - Known in some circles as 'The Nightstar', the 139 coaches ordered from MetCam were to form a proposed overnight sleeper service from various parts of United Kingdom to continental Europe, via the Channel Tunnel. Unfortunately the venture never took off and the order was finally completed and sold at a knockdown price to ViaRail in Canada where they still run today.

NMT - New Measurement Train - Network Rail's track recording HST - known in the trade as 'Top Banana'

NR - Network Rail is the present owner and operator of all railway infrastructure in UK

OHLE (or OLE) - OverHead Line Equipment  is used to transmit electrical energy to trains. In the UK this voltage is generally 25,000 AC (25kV)

Possession - is the pre-planned blockage of a running line, usually taken for work involving engineering trains.

PICOP  - The Person In Charge Of Possession, who normally arranges for detonators and a
possession limit boards to be placed at the possession limits. The PICOP controls train movements in and out of a possession.

PICOW - Person In Charge Of Work - inside a possession

PTS - Personal Track Safety -(certificate of competence to be 'on or about the track') -takes the form of a plastic card

Pway - (pronounced pee-way) colloquialism for the permanent way or more commonly the railway tracks

R&DD - The former Research & Development Division of the BRB was based mainly at Derby but had outposts at Rugby, Swindon and Muswell Hill, London.

RDB - prefix for numbering of former BR Departmental stock belonging to the R&DD (R=Research Department, D=Departmental B= British Rail designed & built)

Red Zone - also known as Open Line working which means that the lines are open to train movements; this carries more risk than Safeguarded areas (where staff are protected from train movements by a physical barrier) and hence is avoided where practicable.

RSC - Railway Safety Case - the necessary documents which a train operator requires to run trains on NR. One definition is 'A Safety Case is a structured argument, supported by evidence, intended to justify that a system is acceptably safe'.

RCF - Rolling Contact Fatigue - damage caused on wheel treads and rails due to high stresses- these can be caused for a variety of reasons

RCH - Railway Clearing House - The RCH set technical standards for cable connections between coaches for the remote operation of systems; they were initially used only for control of train lighting. These cables were known as RCH jumpers, and in the 1970s a system for push-pull trains was developed which used the RCH cable, eliminating the need for a separate control cable to be fitted to intermediate coaches. Not 100% successful unfortunately

RTC - the Railway Technical Centre at Derby - The RTC in London Road, Derby was built by the British Railways Board in the early 1960s to be its technical headquarters. British Rail was able to announce that "The Railway Technical Centre at Derby is the largest railway research complex in the world." It was formerly known to railwaymen as the 'Ivory Tower', 'Crystal Palace' or just 'the Centre of the Universe' and still exists as the RTC Business Park but is a shadow of its former self.

RVEL - Rail Vehicle Engineering Ltd took over the Vehicles Lab in the RTC and specialise in engineering work on traction and rolling stock

SAR - South African Railways

ScR - Scottish Region- area of BR operations in Scotland

SEL - Standard Elektrik Lorenz of Stuttgart, Germany - manufacturer of ATP and ATP systems - later Alcatel-SEL. Today (since 2006) Alcatel-Lucent.

SELCAB© - automatic train protection system used on Chiltern Railways - supplied by Alcatel - SEL of Stuttgart

SELTRAC© - automatic train control system used on the Docklands Light Railway - supplied by Alcatel - SEL of Stuttgart

Serco - Serco Group plc is an outsourcing company based in Hook, Hampshire. It bought the former Railtest organisation at the privatisation of BR and used to operate a large number of test and infrastructure monitoring  trains. It also part owns Northern Rail and Merseyrail.

Six Foot - common term for the space between the innermost rails of two sets of tracks

SO - Second class Mk1 open coach - with open accommodation

SPAD - a Signal Passed At Danger

SR - Southern Region - area of BR operations stretching from London to Southampton and all areas of the former Southern Railway Co

SGT - Structure Gauging Train - A railway vehicle must comply with the route loading gauge to ensure that it passes clear of all structures, principally over-bridges and tunnels but also features such as station platforms, canopies and overhead or lineside equipment .A special train was developed in the 1970s which was designed to measure the kinematic envelope surrounding the tracks. The SGT was the result but this has now been superseded by simpler and more compact technology and most of its vehicles are redundant

TASS - Tilt Authorisation and Speed Supervision system used on Voyagers and Pendolinos- similar in principle to C-APT using transponders only Virgin West Coast Voyagers and Pendolinos utilise this now

TBL - Transmission Balise-Locomotive - the type of ATP system used on GWML supplied byACEC consisting of balises (beacons) at signals supplemented by cables in the four foot

TCA - Track Circuit Actuator - a trainborne system which can break through insulated layers of dirt and leaf fall on a train's wheels by ionising the airgap between the wheel and rail thus restoring electrical continuity and allowing trains to bedetected by track circuits

Ten Foot - common term for the space between the innermost rails of two sets of parallel tracks

TIC -  Track Inspection Coach -  former coach operated by the BR Civil Engineers and latterly Serco to observe and record the state of the track - now superseded and redundant

TOWS - Train Operated Warning System for Pway staff . This is one of the automatic warning system used when working Red Zone. It is operated by a track circuit and gives a warning when the train enters the section.

TPWS - Train Protection and Warning System - a very simple train but effective on board control system for T&RS introduced instead of ATP.

Track gauge - distance between the inside corners of the rails - usually 4ft 8½ins (1435mm) for standard gauge track around the world

TRC - Track Recording Coach - (originally High Speed Track Recording coach) is a converted Mk2 coach used to record the condition of the tracks. It uses an inertial measuring system comprising transducers, including accelerometers, rate gyroscopes and displacement transducers which supply inputs to special-purpose electronic processing networks which provide the required profiles. Onboard computer systems analyse the data to form track-quality estimates which are listed and recorded on magnetic tape for transfer to a central mainframe data bank. Operation of the track-recording coach is controlled by an automatic route-definition procedure using data stored on a central track-route data bank.

TRS - Traction and Rolling Stock

TRU - Track Recording Unit - specially built class 150 DMU used to record the condition of the tracks similarly to the TRC

TSO - Tourist Standard Open is a later term for a Second class open coach

TSR - a Temporary Speed Restriction is one which is short term and included in the train crew notices

UIC - Union International des Chemin de fer - UIC is the worldwide organisation for railway cooperation. It is active in all the fields involved in developing rail transport.

Up line - a railway track on which traffic runs usually in the direction towards London

UTU - Ultrasonic Test Unit - former class 101 DMU which was used for monitoring the rail head for cracks when traversing the line. This type of work is now is carried out mainly using loco-hauled coaching vehicles

VB - Vacuum Braked

WCML - West Coast Main Line running from London Euston to Glasgow

Wheel tread - the part of the wheel in contact with the rail

Wheel flat - a damaged area of the wheel tread caused by the wheel sliding on the rail for a brief period

Wheel profile - the shape of the wheel tread cone which may be different between coaching stock and locomotives

Wheelset - A wheelset is the wheel-axle assembly of a railway vehicle usually comprising two wheels and the connecting axle.

WR - Western Region - area of BR operations stretching from London to Penzance and all areas of the former Great Western Railway Co

WSP -  Wheel Slide/spin Protection - automatic control system fitted to most traction units to prevent wheels from skidding or spinning - has sometimes has been known to work

Yellow vest - railwayman's name for what today is known as an orange High Visibility tabbard - of course every real railwayman knows that there is no such colour as orange on the railway

More will be added ...........

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