Yeovil Town through the shed
Skip Navigation LinksHome > Glossary

Glossary

# A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

#

2mm scale

1318
Views
9.5 mm gauge, 2 mm to the ft, 1:152.4 scale.

A

Absolute block

1196
Views
This describes a system of train working whereby only one train is allowed to occupy one stretch of line at any one time.  All passenger lines are worked on this principle.

AC

1086
Views
The electric current that flows alternately in a rapid sequence called "a cycle".  Mains electriity supply is Alternating Current (AC), as is the continuous 16V supply used on DCC layou... Read more

a

ac

1209
Views
Alternating current.

A

Accessory decoder

1215
Views
In DCC: A decoder that is not intended to be installed in a locomotive, but remains in a fixed location and controls accessories such as signals or track switches/turnouts.  Also known as &q... Read more

Address

1690
Views
In DCC: The address is the identification number used by the decoder to identify which communication it must act on.  The address is usually unique for each decoder, but this is not a requirement... Read more

a

adhesive weight

1149
Views
proportion of locomotive weight borne by driving wheels.

A

Advanced consisting

1161
Views
Operating and controlling several locomotives as if they were a single entity by sending speed and direction commands to a common address.  Also called decoder assisted consisting.  See also... Read more

AHB

975
Views
This is a type of level crossing, introduced in the 1950s to replace traditional manual gates on less busy roads.

Airbrush

901
Views
A minature paint spray gun that provides a controlled application of thinned paint can be used for spraying large or small areas of paint or varnish.  Good for wethering effects too.

Alternating Current

944
Views
The electric current that flows alternately in a rapid sequence called "a cycle".  Mains electriity supply is Alternating Current (AC), as is the continuous 16V supply used on DCC layou... Read more

Ammeter

1179
Views
Meter which measures current flow in amperes.

Amp

1425
Views
Short for Ampere, the current flowing in an electrical circuit that provides the energy for movement.

Ampere

1143
Views
The unit of electrical current, generally written as amps.

Analog control

1232
Views
Conventional track voltage (NMRA Standard S-9) typically varying between zero and tweleve volts for speed control and polarity reversal for direction control.

Analog signals

1169
Views
Voltages and/or frquencies which convey information and are not digital.

Analogue control

893
Views
Conventional track control using voltage that typically varies between O and 12 volts DC for train speed control and polarity reversal for direction control, still the most popular method of train con... Read more

APT

919
Views
Advanced Passenger Train.  Conceived in the late-1960s, APT was Britain's first attempt at a tilting train, which could take curves at greater speed without discomfort for the passenger.  Ga... Read more

a

aqueduct

1236
Views
structure carrying water over depressed ground.

armature

1220
Views
wire-wound rotating bobbin core of electic motors used in models.

ash trolley

1272
Views
wheeled container running on narrow rails between and beneath normal rails for removal of locomotive clinker and ash.

A

Aspect

1136
Views
More usually this term is used in conjunction with colour light signals.  It refers to the indication given by the signal, a red "aspect" for instance, instructs the driver to stop.&nbs... Read more

Atlantic

976
Views
Commonly used nickname for a steam locomotive with a 4-4-2 wheel arrangement.

Atmospheric Railway

1190
Views
The brilliant but, fatally flawed railway propulsion idea pioneered by Brunel.  Trains were connected to a sliding piston within a pipe which was laid along the centre of the track and propelled ... Read more

ATOC

1186
Views
Abbreviation for Association of Train Operating Companies.  Body formed to represent the post - privatisation train operating companies.

Autocoach

986
Views
Also known as an "autotrain", the GWR term for a push-pull vehicle.  The GWR made considerable use of such trains on branch and secondary services, a mechanical linkage enabling the reg... Read more

Automalic (polarity) reversing

1164
Views
Control circuits which sense opposite polarities at rail gaps and automatically reverse the polarity of the rails to allow smooth continuation of the motive power.  Applications include: reversin... Read more

Automatic control

1313
Views
Operation of trains through relay banks, etc, without human.

Automatic Half Barrier

936
Views
This is a type of level crossing, introduced in the 1950s to replace traditional manual gates on less busy roads.

AWS

1127
Views
Abbreviation for Automatic Warning System.  A system incorporating electromechanical devices set between the rails which give audible and visual confirmation of signal aspects to a driver in his ... Read more

Axlebox

1095
Views
A box in which the axle end is located so as to act as a bearing.  These were packed with grease for lubrication.  Modern axles now have roller bearings.

B

B.R.

1522
Views
British Railways (1948 - 64), British Rail (1964 - 94).  The nationalised UK railway system.  Under this, all railways were subject to the central control of the British Railways Board, alth... Read more

Back-EMF

1134
Views
Some locomotive decoders can sense the rotational speed of the motor and automatically adjust future digital pulses to the motor to maintain a desired speed.  Also called load - compensating deco... Read more

Back-to-Back

966
Views
This is the Measurement between the back of the running wheels on rolling stock.

Backscene

889
Views
A painting or photograph or purchased sheet(s) on a board behind the layout to give it visual depth.  It may just be blue sky or an industrial or a rural scene.

Backscene

987
Views
A painting or photograph or purchased sheet(s) on a board behind tha layout to give it visual depth.  It may just be blue sky or an industrial or a rural scene.

b

ballast

1148
Views
chippings spread between and around sleepers.

B

Bandwidth

1339
Views
The amount of information that can be transmitted between the command station and decoder(s) in a certain amount of time.

Banker

992
Views
A locomotive assigned to assist heavy trains up inclines - often known on the railway as "banks" -  by pushing from the rear.

Banner repeater

1275
Views
This is a mechanical disc signal used to repeat the setting of the signal ahead.  They are used when signals are sited in awkward locations, say beyond an overbridge.  They are mostly of the... Read more

Barrier Vehicle

880
Views
A wagon or coach marshalled into a train for the sole purpose of providing protection of fragile loads or for train crews from dangerous loads such as radioactive material, explosives or harmful chemi... Read more

Base Unit

946
Views
This is the brains behind a DCC-operated model railway.  Also known as a command unit.

Baseboard

1722
Views
The structure - often timber frames with plywood or MDF tops - on which to build a model railway layout.

Basic consisting

1144
Views
Operating and controlling several locomotives as if they were a single entity by sending discrete speed and direction commands to each locomotive in the consist.  See also "Consist". Read more

Beeching Report

1115
Views
The name given to "The Reshaping of British Railways" report of 1963.  This report heralded the famous railway line closure programme of the mid 1960s.

Belpaire

1198
Views
type of flat-topped firebox on locomotive.

Bi-polar signal

1150
Views
The electrical waveform of digital packets transmitted along the rails is known as a bi-polar signal.  Positive pulses followed by mirror image negative pulses are the key characterisation. Read more

Bi-stable relay

1176
Views
A relay (qv) which will hold in either of two positions.

Big Four

1046
Views
Colloquial term describing the four big railway companies set up at the grouping in 1923, i.e., LMSR, LNER, GWR, and SR.

Bit

1495
Views
A logical value that can be either a one or a zero.

Black box

1169
Views
A device, generally electronic (qv) whose function is understood even though its operation remains a mystery.

Block Section

1056
Views
This describes the "AREA" controlled by a signal box, (sometimes called a block post).  It refers to the distance between the previous signalbox's advanced starter signal and the first ... Read more

b

block train

1189
Views
train made up of identical wagons or vans etc.

B

BLT

905
Views
A popular abbreviation for "Branch Line Terminus", a type of station that lends itself to modelling in relatively small spaces.  "Sutton Parva" (pictured) is a goodexample of ... Read more

Bo-Bo

1134
Views
diesel or electric locomotive having two driven axles, i.e. four driving wheels, on each of two bogies.

Board

1582
Views
Colloquial term often used by railwaymen to describe the arm of a semaphore signal.  The "board is off" means that the signal is raised or lowered to the line clear position.

b

bogie

1314
Views
a swivelling assembly carrying usually four wheels (sometimes six) mounted below a locomotive or coach.

bolster

1121
Views
principal cross-member of a bogie carrying the pivot.

B

Bond

1114
Views
A link in a circuit; often a wire linking two parts to ensure electrical continuity.

Booster

1127
Views
See "Power satations".

BR

2072
Views
Barry Railway.  Based in South Glamorgan.  This was a small but highly profitable concern also carrying minerals.

BR Barry Railway

1137
Views
Based in South Glamorgan.  This was a small but highly profitable concern also carrying minerals.

Bracket signal

1083
Views
A single support post fitted with two or more individual signals.  Junction signal are more often bracket signals

Bradshaw

1139
Views
The independently published "all line" railway timetable.  First published in the 19th Century.

Brake lever

1081
Views
A metal lever used mainly on wagons to operate the vehicle's brakes manually whilst stationary in sidings.

Brake standard

1110
Views
The vertical support for a guard's handbrake wheel in brake vans.

Brake Van

1025
Views
A vehicle with a heavy chassis and handbrake for loose-coupled trains, or with a brake valve for continously-braked trains.  The guard travelled in the brake van in order to operate the brake to ... Read more

Break

1376
Views
Short for rail break (qv).

b

break van

1140
Views
usually the last vehicle in a train from which the guard (conductor) can operate the train's brakes if neccessary.  

B

Bridge rectifier

1138
Views
A rectifier consisting of four diode elements connected in a square (bridge) formation to provide a reasonably level dc output. see rectifier.

Broad

1180
Views
Colloquial term often used by railwaymen to describe the arm of a semaphore sognal.  The "board is off" means that the signal is raised or lowered to the line clear position. Read more

Broad gauge

968
Views
Any truck gauge greater than the standard 4ft 8½.  It is particularly associated with Brunel's 7ft 0¼ in gauge on the GWR.

Broadcast packet

1134
Views
A specially encoded digital packet that will be acted upon by all decoders that receive the packet.  Commonly used in service mode programming and for stopping a locomotive in front of a red sign... Read more

Brushes

1132
Views
Pieces of carbon fitted either side of the commutator on an electric motor.  These are often copper or phosphor-bronze strips that touch either side of the commutator.

Buckeye

890
Views
A type of semi-automatic coupler adapted from American practic, initially used on LNER coaching stock and gradually adopted for use on most British passenger coaches.

Buffer

1148
Views
Shockabsorbing device of which two are normally fitted to the ends of rail vehicles.  Designed to absorb impact and keep adjacent vehicles from damaging each other.

Buffer beam

1097
Views
Lower outer crossmember of a railway vehicle underframe onto which buffers, coupling hooks, brake hoses and cables are fixed.  Often, the headstock forms this part of the vehicle.

Buffer stop

1176
Views
Frame or fabrication placed at the end of a line to stop vehicles from running off the track.

Bufferbeam

868
Views
The transverse beam at either end of a locomotive, coach or wagon that carries the buffers

b

buffers

1110
Views
strongly sprung shock-absorbing fittings at each end of all railway vehicles.

bunker

1085
Views
coal receptacle at rear of tank locomotive.

B

Bus

1189
Views
A set of wires that serves as a conduit for electrical signals and distributes them around the layout.

Bus wire/bus bar

971
Views
A contionuous wire or copper strip under a baseboard, connected to the track at frequent intervals to ensure continuity of current supply.

Bustitution

1026
Views
A colloquial expression originating in the 1980s which describes the provision of buses to replace train services and allow rail closures.

Byte

1001
Views
A group of eight bits.

C

Cab

973
Views
A device used by model railroad engineers (operators) to control motive power and accessories by sending electrical or electronic instructions to the locomotive (via the DCC command station).

Cab bus

1051
Views
The bus used for cab - to - command station communication, and vice - versa.

c

cab control

1070
Views
separation of layout into indendently - controlled blocks.

caboose

1102
Views
U.S. equivalent of guard's van/brake van.

C

Calipers

828
Views
Precision measuring tool using a rule, scale, dial or digital readout to express exact dimensions.

Calling on signal

990
Views
A small subsidiary signal, fixed below the main arm which when cleared allows a train to enter an occupied section of line and proceed with caution.

Cam Rys

1018
Views
Cambrian Railway.  This Welsh company had its headquarters curiously situated in North Shropshire, England!.  Its main lines were from Shrewbury to Aberystwyth and Pwhelli.  Based on ro... Read more

Cam Rys Cambrian Railways

1021
Views
This Welsh company had its head quarters curiously situated in North Shropshire, England!.  Its main lines were from Shrewsbury to Aberystwyth and Pwhelli.  Based on route length and area co... Read more

c

can motor

1051
Views
electric motor with side magnets enclosed in thin metal box, developed originally for slot car racing.

C

Cantrail

863
Views
The point at which the bodyside of railway vehicle meets the roof.  Denoted since the 1980s by an orange horizontal line.

Capacitor

1099
Views
A device for storing a charge of electricity.

c

carriage

1054
Views
common English term for passenger coach.

cascading down

1083
Views
gradual relegation of wearing rolling stock to less demanding or pretigious uses.

C

Catch Point

934
Views
A single trailing point blade set into a siding or loop track to derail wagons to prevent runaways or trains which have passed a signal at danger (see spad) from fouling a running line, by derailing t... Read more

c

catenary

1139
Views
arrangement of suspended wires for overhead current collection.

C

CCT

910
Views
Covered Carriage Truck Dating from the days of conveying horse-drawn carriages in covered vans.  A large open van with end doors able to run at express passenger speed for the conveyance of parce... Read more

CDU

890
Views
Capacitor Discharge Unit: stores energy to give a burst of power for changing point motors.

c

centre-swing

1045
Views
the overhang of the centre of a long vehicle on the inside of a sharp bend.

C

Chain

848
Views
Archaic term of measurement, equalling 66ft or 22 yards.  Still used by by the railway, for identifying exact locations or the redius of curves.

c

chairs

1236
Views
iron castings spiked to sleepers (ties) to secure rails.

C

Checkrail

868
Views
A rail inside the running rails seen on curves and points to prevent the flanges of the wheels from riding up and causing derailments.

Choke

1069
Views
An impedance, used to damp out ac ripples in a rectified circuit.

Clerestory

1031
Views
Raised longitudinal section of a carriage roof, used to give additional daylight and ventilation for gas lighting.  Common in late 19th Century carriage design.

c

clerestory roof

1128
Views
roof with central vertical extension the sides of which are glazed.

C

CME

812
Views
Cheif Mechanical Engineers oversaw the design and construction of motive power and rolling stock, with all designs of the period being attributed to the incumbent.  Famous examples include Stanie... Read more

Co-Co

1060
Views
locomotive with three driving axles (six wheels) on each bogie.

c

coach

1449
Views
vehicle for accommodation of passengers (car in U.S.)

collector

1148
Views
contact rubbing on live rail or wire to pass electricity.

C

Colour light signals

1008
Views
Term used to describe signals which are electrically operated and use lamps with coloured lenses to display the aspects (see MAS).

Command station

1169
Views
The command station receives electrical signals (operator instructions) from the cab.  The command station then creates  NMRA DCC digital packets in accordance with NMRA  spec... Read more

Common return

1064
Views
A system of wiring where a number of controllers, each with its own independent power supply, are connected to a common return rail.

c

commutator

1145
Views
contact ring on armature shaft split into segments corresponding to number of windings, receiving current from brushes.

C

Compatibility

1004
Views
A claim made by a manufacturer that their product will generally work with other compatible devices in areas where both devices support a given function.

Compliant

1011
Views
Same as conformance.  A compliant product is one that has passed NMRA tests and earned an NMRA Conformance Warrant.

Compound

811
Views
A steam locomotive that uses steam twice (or more) to increase efficiency and power.  steam passes through high - pressure cylinders first, moving to low -pressure cylinders as it cools and expan... Read more

c

concertina connection

1071
Views
U.S. term for bellows gangway between coaches.

conductor

1047
Views
U.S. equivalent of guard, in charge of train.

C

Configuration register

838
Views
Configuration variable (CV 29).  This CV contols some of the most basic aspects of decoder operation.  These are normal direction of travel, 14 or 28 or 128 speed steps table on or off and t... Read more

Configuration variable

1058
Views
A configuration variable, or CV, is a defined piece of information used by the decoder to adjust its operation.  This information is permanently stored inside the decoder until the user wishes to... Read more

Conformance

1036
Views
Products that have passed the NMRA's extensive testing procedures are eligible for a Conformance Warrant if the manufacturer also agree to fix any discrepancies that might become apparent in the futur... Read more

Conformance warrant

1018
Views
An official document awarded by the NMRA to a manufacturer for a specific product that has demonstrated conformance to NMRA Standards and applicable Recommended Practices by virtue of Passing all appr... Read more

Connecting rods

982
Views
Heavy section metal rods on a steam locomotive.  These transfer the liner tractive force from the pistons into reciprocating motion which turn the driving wheels and propel the locomotive forward... Read more

Connector

1021
Views
A device to connect wires, etc.

Consist

1082
Views
Operating and controlling several locomotives as if they were a single entity.  For example, several diesels might be connected together to provide more power for a steep grade.  Also called... Read more

Contact

1617
Views
A device for completing a circuit, usually in switches and relays (qv).  Normally "a pair of contacts" or "contacts".

Control bus

1113
Views
The bus used for transmitting digital packets from the command stations to power station.

Control panel

1166
Views
A selection of switches and other devices, mounted on a board, to provide control for a model railway.

Controller

1363
Views
A device for controlling the speed, and generally the direction of travel of a locomotive.

Cored solder

1047
Views
Solder in the form of a hollow wire containing flux.

c

coupling

1386
Views
device for connecting vehicles into train.

C

Coupling Rod

838
Views
A metal rod connecting the large driving wheels of a locamotive.

Coupling Rods

1017
Views
Large metal rods that connect the driving wheels of a steam locomotive.  Their purpose is to distribute the tractive force to each of the driving wheels.

CR Caledonian Railway

1072
Views
This Glasgow based firm formed the northern leg of the West Coast Main Line, from Carlisle to its home city.  It also owned important routes from Glasgow to Edinburgh, Perth and Aberdeen.

Cramptons

955
Views
The name given to a design of early express locomotives in which a single axle with two large diameter driving wheels was located at the rear of the locomotive, thus allowing a low slung boiler. Read more

Crosshead

843
Views
The two parallel pieces of metal connecting the piston rod that slide in the side bar and transmit power to the connecting rod.

Crossing

876
Views
The diamond formed by two tracks where they cross.

Crossing keeper

1030
Views
A railwayman that operates a remote level crossing and who often resides in an adjacent crossing keeper's cottage.

c

crossover

1537
Views
pointwork allowing a train to divert to a parallel line.

crosstie

1161
Views
longer than standard sleeper (tie) beneath point ect.

C

Culvert

1029
Views
A small bridge or short tunnel provided to take a stream or ditch under the railway trackbed. 

Current

1528
Views
The flow of electricity in a circuit.

Current draw

998
Views
The amount of electrical flow required by an operating device.

Current limiter

1013
Views
See cut-out.

Cut-out

1050
Views
A device for breaking a circuit, should the current flow become excessive.  See fuse.

c

cutting

1510
Views
excavated channel through rise of ground.

C

CV

847
Views
Configuration Variables: information stored in decoders that controls characteristics such as sound volume and performance.

D

DC

1545
Views
Direct current.

DCC

2558
Views
Digital Command Control is one of several methods of controlling and/or operating a model railroad layout.  The control information is provided in the form of a digital signal instead of a standa... Read more

DCC

1618
Views
Digital Command Control is the application of computer technology to contol the movements of locomotives and operation of accessories.  Each locomotrive is fitted with a decoder that is uniquely ... Read more

Dead frog

1055
Views
An insulated crossing in the track.

d

decal

1102
Views
printed lettering or design which can be transferred to vehicle.

D

Decoder

1130
Views
A device that receives and acts on digital packets created by the command station.  See also "Accessory decoder", "Locomotive decoder", "Mobile decoder", "Stati... Read more

Departmental

833
Views
An umbrella term for non-revenue earning vehicles used for engineering, infrastructure or test duties.  Covers everything from ballast hoppers to sophisticated experimental vehicles.

Detcector

1003
Views
A device for sensing the presence of a train.

Diamond

828
Views
The centre portion of an acute angled crossing.

d

diaphragm gangway

1152
Views
another term for bellows or concertina connection.

D

Diesel Electric

1087
Views
A locomotive powered by a diesel engine which uses an electric transmission system to transfer the power from the engine to the locomotive wheels.  Essentially the engine is linked to an alternat... Read more

Diesel Hydraulic

966
Views
A locomotive powered by a diesel engine which uses a hydraulic transmission system (See Torque Converter).

Diesel Mechanical

977
Views
A locomotive powered by a diesel engine uses a mechanical system of transmission.  Essentially the engine is linked to the driving wheels through a conventional gear box.

Dieselisation

974
Views
Referring to the replacement of steam locomotives by diesel locomotives and other modern forms of diesel traction.

Digital Command Control

1160
Views
See "DCC".

Digital Packets

1027
Views
A digital packet is a defined sequence of bits that instruct the decoder how to respond.  See also bit and byte.

Diode

1000
Views
An electronic device which only permits current to flow in one direction.

Direct Current/DC

786
Views
The opposite of Alternating Current/AC.  DC is a current that flows in one direction.  Most moidel railway locomotives work on a Direct Current of 12V.

Distant signal

1026
Views
A signal which gives an advanced indication of the setting of the next home signal.  Semaphore distants have fishtail ends and since the 1920s have been painted in the familiar yellow colour.&nbs... Read more

DMU

1047
Views
See Multiple Unit.

Doll

989
Views
The name for each of the signal posts fitted to a bracket or gantry signal.

d

dome

1031
Views
fitting on top of boiler from which steam is led to cylinders.

D

Double Crossover

817
Views
Two crossovers superimposed on one another, i.e. in a facing and trailing direction.

Double slip

1079
Views
A track formation which permits trains to travel over a crossing in more than one direction; a complicated device.

d

double-acting

1039
Views
steam engine where steam is applied alternately to either side of piston(s).

double-decker

1044
Views
coach etc. with accommodation on two levels.

double-heading

1058
Views
connection of two locomotives to one train.

double-slip point

1321
Views
complex point allowing crossing other lines with additional rail allowing train to move on to one of several tracks.

D

DPDT

1040
Views
Double pole, double throw (switch).

DPST

1009
Views
Double pole, single throw (switch).

d

dribbler

1043
Views
early trackless steam locomotive model.

D

Driving wheels

1055
Views
The main wheels of a locomotive which provide the tractive force to move the train.  Non-driving wheels are called bogie and pony wheels

Drybrushing

835
Views
A painting and weathering technique.  Fistly, dip a paint-brush into the paint, then remove most of it by dragging the brush on a paper tissue.  The "dry" brush can then be moved b... Read more

d

dump wagon

1029
Views
type of wagon body which can be tilted to discharge load.

E

Eastern Region (ER)

1032
Views
The southern half of the English lines of the former LNER.  The Eastern and North Eastern Regions were combined into one in the 1970s.

ECML

1012
Views
Abbreviation for the East Coast Main line.  Used to describe the line from Kings Cross through York and New castle to Edinburgh and Aberdeen.

EEPROM

1000
Views
Electrically-Erasable Programmable Read-Only Memory.  These computer memory devices are used to storedata in a manner that is easily read, but that changes infrequently.  Most decoders use E... Read more

Electric locomotive

1055
Views
A locomotive powered by electric current which can be picked up from either a 3rd rail or overhead wire.  The current is used to drive conventional electric traction motors linked to the driving ... Read more

e

electric pencil

1101
Views
conductive rod used for quick closing of electric circuits.

E

Electronic

1042
Views
Electrical circuits involving either the obsolescent thermionic valve or, more commonly, devices including transistors (qv) and microchips (qv).

Electrostatic grass tool

888
Views
This useful tool provides an electrostic charge to static grass fibres, making them stand up like real grasses.  The tools are either battery or mains powered.

EM gauge

1709
Views
18.2 mm gauge, 4 mm to the ft, 1:76 scale.

e

embankment

1130
Views
built - up track base over dip in ground.

E

EMU

1013
Views
See Multiple Unit.

e

end-swing

1128
Views
overhang of long vehicle ends on sharp curve.

engineer

1740
Views
U.S. term for engine - driver.

E

Epoxy

800
Views
A two-part adhesive or putty.  Equal parts of hardener and resin must be mixed before use.  Glue is ideal for all materials and also acts as an electrical insulator.  Putty, such as mil... Read more

EPROM

1057
Views
Erasable Programmable Read-Only Memory.  These computer memory devices are used to store data in a manner that is easily read, but can only be erased and reprogrammed with special tools.

Etched

813
Views
An etching or chemical engraving process is used to manufacture model parts from flat metal sheet.  Images of components are printed photographically onto a sheet of metal and the unprinted areas... Read more

ETH/ETS

845
Views
Electric Train Heating (or Latterly Electric Train Supply) is a system of generating and transmitting an electric supply from a locamotive to coaching stock for heating, lighting air-conditioning and ... Read more

F

Facing Point

888
Views
A turnout or point which faces oncoming trains.

Farad

1019
Views
The unit of measurement of capacity; very large, hence microfarads are more commonly employed.

Feather

1000
Views
A term often used to describe a specific type of route indicator fitted to colour light starting signals.  Feathers are rows of small white lamps enclosed in a casing and are fitted to signals wh... Read more

Feed

1260
Views
The electrical input to the controlled rail on a layout.

Feedback

1186
Views
In DCC: The ability of a device to transmit information regarding its status back to the command station.

f

fiddle-yard

1176
Views
area of layout, often concealed, where trains can be made up manually etc.

F

Finescale

859
Views
A more precise interpretation of wheel, rail and track dimensions,nearer to the true proportiopns of the proportions of the prototype. For example 4mm: 1ft finescale incl;udes 18.2mm "EM&quo... Read more

Fireman

1073
Views
In railway terminology, the person responsible for stoking the fire, regulating water levels and maintaining boiler pressure on a steam locomotive.

Fishkind

833
Views
Using the names of fish and marine mammals to identify departmental wagons.  Wellknown examples of this practice include "Sealion" and "Dogfish" ballast hoppers and "Merm... Read more

f

fishplate

1044
Views
connector between ends of length of rail holding ends firmly in alignment; sometimes erroneously relied on for electrical connection.

F

Fitted (goods)

824
Views
A train fitted with continuos brakes - that is braking on all wagons, controlled from the locomative.  Could be air or vacum operated brakes depending on the railway company, era or region. ... Read more

f

flash

1243
Views
extraneous material on moulding where dies were not sufficiently tight together.

flatcar

1070
Views
platform wagon for self-supporting loads.

F

Flexible track

860
Views
Prefabricated section of flexible track that can be used to create both curves and straights on a model railway layout.

Flip-flop

1028
Views
An electronic circuit which will take up one of two states, and remain so until triggered.

Flux

1140
Views
A paste or fluid employed in soldering.

f

footplate

1061
Views
locomotive platform for driver and fireman.

F

Formers

806
Views
Sections of strong cardboard or timber that form the top and sides of the slope of a model landscape.  They may be shaped to provide the land contours.

Four foot

1160
Views
A railway term used to describe the track, meaning the space in between the running rails, derived from the standard gauge of 4ft 8½ins. 

Four-Aspect Signal

818
Views
A colour light signal that uses four lights.  From top to bottom in order, the lights are yellow, green, yellow, red.

Fowler's Ghost

1098
Views
An early attempt at building a "fireless" steam locomotive with the objective of ridding the underground sections of London's Metropolitan Railway of smoke.

FPL

924
Views
Facing Point Lock.  A safety feature required on all facing points used by passenger trains,which locks the point blades in position to prevent derailments.

f

freight car

1053
Views
U.S. term for goods van (also boxcar)

frog

1031
Views
break in rail permitting wheels to cross (in pointwork).

F

Function mapping

1063
Views
The ability to specify (ie map) which function buttons on a cab activate which specific decoder function outputs.  This defines which decoder wires are active for each user input.

Function output

1014
Views
In DCC  A decoder controlled switch that can be turned on and off by a user's cab action.

Fuse

983
Views
A device, generally a thin wire, which ruptures should the current flow in a circuit be excessive.  See also cut-out.

G

G gauge

1248
Views
45 mm (1) gauge, scale chosen to suit modelled prototype.

Ganger

1082
Views
A railwayman who works and maintains the track and the associated permanent way.

Gangway

1059
Views
Normally used to describe the flexible corridor connectors between carriages that allows passengers to move from one to the other.

g

gauge

1863
Views
the actual width, centre width, centre to centre between rails.

G

Gauge Commission

1024
Views
A committee set up in 1845 to deliberate over the merits of Brunel's "broad" gauge against Stephenson's "standard" gauge.

GCR Great Central Railway

1033
Views
Formed out of the Long Established MSLR (Manchester, Sheffield & Lincolnshire Railway), it renamed itself upon completion of its main line through to London, via Rugby and the Chilterns.

Gears

804
Views
Large and small toothed or cog wheels which mesh with each other to give an increase or decrease in speed.

GER Great Eastern Railway

1105
Views
This famous railway served most of East Anglia, almost having a monopoly of lines heading east out of London.  With its HQ at Stratford in the East End, its principal line was from London (Liverp... Read more

GNR Great Northern Railway

1073
Views
Serving from the north eastern home counties, through Lincolnshire and Nottinghamshire to Leeds.  This railway formed the southern half of the East Coast Main Line.

GNSR

1037
Views
Great North of Scotland Railway.  Serving the northern part of Aberdeenshire, as well as Banff and Moray, this small concern had its main route from Aberdeen to Elgin.  It also served much o... Read more

g

gondola

1020
Views
U.S. platform wagon fitted with low sides.

goods train

1114
Views
train carrying materials, produce etc. (U.S. freight train).

gradient

1048
Views
slope or incline, usually expressed as a ratio, e.g. 1: 120.

G

Gradient post

980
Views
Small marker boards used to indicate the rate at which the track is inclined up or down.

Grass Mats

808
Views
Various sized mats with grass fibres embedded onto one side of them.  They come in different colours and hues.  Some of the best quality grass mats may feature different lengths of grasses. Read more

Great Western Railway

811
Views
Formed in 1835, the GWR was originally the London-Bristol route.  It swallowed up numerous other railway companies in Wales and the West of England.  The only major company to retain its ide... Read more

Ground foam

823
Views
A synthetic foam material that has been ground up and dyed for use as a scenery-making product.  It is offered in various colours and sizes of particles and is ideal for adding texture to a scene... Read more

Ground Frame

796
Views
A small signalbox or open lever frame often seen in shunting yards.  It does not usually control signals or points for a main line but for sidings and yards.

Ground signal

1006
Views
As the name implies these are signals placed at ground level.  They can be discs, miniature semaphore arms, or small electric lamps.  They are used mainly to signal shunting manoeuvres. Read more

Grouping

993
Views
The 1923 amalgamation of the vast majority of independent UK railway companies into four regional conglomerates.  Namely the LMS, LNER, GWR, and SR.

GSWR Glasgow & South Western Railway

1103
Views
This company's lines ran from Glasgow down the Ayrshire coast south to Stranraer and also via Kilmarnock to Carlisle.

g

guard

1113
Views
official responsible for train, other than driving.

G

GUV

852
Views
General Utility Van.  Rolling stock able to run at express passenger speed but for carrying general merchandise, parcels or even road vehicles.

GWR

1017
Views
Great Western Railway.  Unlike other companies, the great Western Railway, which had been incorporated in 1835, merely absorbed the independent Welsh railway companies.  Due to their relativ... Read more

GWR Great Western Railway

1055
Views
Unlike other group companies, the Great Western Railway, which had been incorporated in 1835, merely absorbed the independent Welsh railway companies.  Due to their relatively small size this gro... Read more

H

Hairspray

818
Views
A cheap and useful adhesive for fixing scatter and foliage on layouts.  The best choice for use with scenery is the extra-hold unscented version of the cheapest supermarket product because it has... Read more

Half-O gauge

1079
Views
16mm, 16.5 mm, 5/8  in gauge, scale nondescript (thankfully obsolete).

h

half-wave rectification

1105
Views
electronic means of controlling current supply allowing very precise control and full power irrespective of speed.

H

Handheld (cab)

1054
Views
In DCC  A portable cab used by the model railroad engineer (operator) to control one or more locomotives.  Simple handhelds may have speed and direction controls only.  Specialized cabs... Read more

Handrail

831
Views
A rod or tube along the boiler of a locomotive to act as a handgrip for the crews.  They can also be found on cab sides and brake vans to assist the staff or passengers in getting on and off the ... Read more

h

head shunt

1278
Views
trackwork allowing a locomotive to move away after pulling a train into a terminal platform.

H

Headcode

782
Views
A means of identifying a train by a configuration of white discs, lamps, or later illuminated displays of numbers or letters carried on the front of the locomotive.  Precise definitions varied fr... Read more

Headstock

996
Views
The load bearing end cross member of a rail vehicle.  Also known as the buffer beam.

HO gauge

1042
Views
16.5 mm gauge, 3.5 mm to the ft, 1:87 scale.

HOe gauge

988
Views
9 mm gauge, 1:87 scale.

Hold section

1078
Views
An isolated section used to hold trains in hidden loops, etc. Hertz, the measurement of frequency; in practice, the number of cycles per second.

HOm gauge

1037
Views
12 mm gauge, 1:87 scale.

Home signal

962
Views
This refers to the first stop signal that a train encounters when it enters a block section controlled by a signal box.  There may also be "outer" home signals in a block section too. Read more

HOn3 gauge

1099
Views
10.5 mm gauge, 3.5 mm scale.

Hoppers

1112
Views
Colloquial name for hopper wagons.  An open or enclosed wagon in which the body tapers at its base and is provided with a bottom door through which the load is discharged.

h

hornhook

1027
Views
a type of non-scale coupling, reasonably simple to operate.

H

HR Highland Railway

1136
Views
With headquarters in Inverness, this company operated some of the most scenic routes in the UK.  Its lines included those to Perth, Keith, Wick and of course the charismatic line to the Kyle of L... Read more

Hydrocal

833
Views
A quick-setting plaster commonly used for making scenery such as rocks and embankments.  It needs to be mixed with water in precisely the right quantities for rhe best results.  There are lo... Read more

Hz

1005
Views
Hertz, the measurement of frequency; in practice, the number of cycles per second.

I

Impedance

1045
Views
A quality of a coil of wire which carries an ac or fluctuating current.  Its effect is similar in action to a resistance.

Indicator lamp

1026
Views
A lamp mounted on a panel to provide an indication of the state of a circuit, or a length of track.

Inner Home Signal

1178
Views
A home signal within station limits where an outer home signal is positioned. The inner home signal is in advance of the outer home and usually to the rear of the signalbox.

Inoperable Signal

811
Views
A lineside signal that is permanently set at stop or caution, usually called "fixed".

Insulated fishplate

1105
Views
A fishplate made from plastic material to provide an insulated joint in the track.

Insulated joint

1004
Views
A break in the track, which is insulated to provide isolation.

i

interlocking tower

1027
Views
U.S. term for signal box.

I

Island platform

821
Views
A station platform with track on either side (pictured above).

i

island site

894
Views
layout area allowing operator to walk round all sides.

I

Isolation section

1041
Views
A section of track that can be isolated by means of a switch or similar device.

J

Jinty

833
Views
One of several nicknames for the LMS general purpose 0-6-0T designed by Sir Henry Fowler for shunting and light freight duties.

j

jumper cables

938
Views
free-ended multi-strand electrical cables plugged in when portable sectionalised tracks are reassembled.

J

Junction Signal

781
Views
Any signal that has more than one route and is a capable of displaying an indication of which route has been selected.  A junction indicator will also be fitted to a junction signal to inform the... Read more

K

Kb/s

918
Views
In DCC  Kilobits per second (alsoKbps) refers to the speed of data transmission on various buses.  For example 2.2Kbps transmission passes data at 2200 bits per second.  See also bus an... Read more

Kettle

786
Views
This is a lineside boiler for filling locomotive boilers directly with hot water.

Key switch

894
Views
A type of switch formerly used in telephone exchanges, frequently provided with a large number of contacts.

King Lever

869
Views
A lever in a signalbox which cuts out the box's control and allows its signals and points to be controlled remotely from another box or automatically via track circuits.

Kip

951
Views
A hunp at the top of a rope-hauled railway to prevent wagons or carriages accidentally running back down the incline; an incline on which wagons are built to be run off by gravity as required, usually... Read more

Kitbashing

746
Views
A method for creating locomotives, rolling stock or structures using one or more different kiis (cardboard, plastic, timber or metal) and changing the building process or combining the parts in a diff... Read more

L

L & MR

944
Views
The Liverpool and Manchester Railway, opened in 1830, this is accredited as being the first public, steam powered passenger carrying railway in the UK.

L&YR Lancashire and Yorkshire Railway

1044
Views
Based in Manchester, it had a busy trans-Pennine network, linking Lancashire and the industrial areas of Yorkshire.

l

ladder

1158
Views
arrangement of parallel rows of siding.

L

LAN

959
Views
In DCC  Local Area Network is a computer term referring to the interconnections by which various computers and devices communicate with each other in a geographically small location.

Laser cut

868
Views
A relatively new, but increasingly popular technique for making precision cut components in cards, metal or wood.  Most frequently used for kits of buildings (pictured below) and structures such ... Read more

Latching relay

934
Views
A relay which remains held even when its operating current no longer flows.

l

leading wheels

937
Views
carrying wheels ahead of driving wheels on locomotive.

L

LED

1158
Views
Light-emitting diode, an electronic device which emits a small amount of light when current passes through it.

Lever Frame

1016
Views
The assembly that holds the signal and point levers in a signal box or ground frame.  A lever frame is made up of slots for the levers to operate in and allows for them to be locked togethe. Read more

Lichen

775
Views
One of the traditional natural products that is still used to make trees and bushes.  It is sold in various colours.  Often seen at gardenj centres and in model shops.  It does need to ... Read more

Lineside

923
Views
Area of land immediately surrounding and adjacent to a railway line.

Live Steam

930
Views
A novel method of powering a model; locomotive, as opposed to electric current.  Hornby was the first manufacturer to commercially produce a Live Steam locomotive, powered entirely by steam, in &... Read more

l

livery

889
Views
consistent colour scheme employed by railway to identify/pubblicise their locomotives and other rolling stock, vehicles etc.

L

LMR

894
Views
London Midland Region. This was basically the English routes of the LMS combined with the ex - LNER lines west of the Pennines.  Later (in 1964) expanded to include ex - GWR lines north of Banbur... Read more

LMS (London, Midland & Scottish Railway)

781
Views
One of the "BigFour" train companies formed on January 11923, encompassing the London & North Western Railway (LNWR), Midland, North Staffordshire (NSR), Furness Railway (FR), Caledonian... Read more

LMSR London Midland and Scottish Railway

1106
Views
Normally tagged the LMS this was the largest of the largest of the Big Four.  Its territory, mainly centred to the north and west of London, stretched from the far north of Scotland and north wes... Read more

LNER London AND North Eastern Railway

1050
Views
Second largest of the groups, this railway covered the eastern side of country, north of the Thames, through to Edinburgh, and Aberdeen.  It also had lines to Manchester and Glasgow and included ... Read more

LNER London and North Eastern Railway

1055
Views
Second largest of the groups, this railway covered the eastern side of country, north of the Thames, through to Edinburgh, and Aberdeen.  It also had lines to Manchester and Glasgow and included ... Read more

LNWR London and North Western Railway

1001
Views
Centred on Crewe, its main lines ran from London, out to Birmingham, Holyhead, Liverpool, Manchester and Carlisle.  The LNWRs main line from Euston to Carlisle is now West Coast Main Line.

l

loading gauge

1120
Views
the physical dimensions which will pass safely through tunnels, past other trains etc. of a specific railway, also the light metal frame suspended from an arm which checks dimensions.

L

Locomotive decoder

877
Views
A decoder intended for controlling a locomotive (or other similar device).  See also decoder, and mobile decoder.

Louvres

749
Views
Horizontal slots cut into the sides of diesel and electric locomotives and certain goods vans to give ventilation.

Low Melt Solder

875
Views
Grade of solder specifically formulated for bonding materials with a low melting point, such as whitemetal, commonly melting at 70-100'C.

Low voltage

1144
Views
Any voltage below 50V, more commonly between 3 V and 24 V.

Lower Quaddrant Signal

761
Views
A semaphore signal on which the arm drops from horizontal to indicate the line ahead is clear.  Most commonly used by the Great Western Railway.

LSWR

1275
Views
London and South Western Railway.  This company's main line ran from Waterloo to Portsmouth, Southampton and Exeter.  It also owned an extensive suburban network to the west of London and a ... Read more

M

Macro

894
Views
In DCC  A sequence of user - definable commands, that is accomplished with a single button press.

Main Frame

743
Views
The strong metal sides of the chassis of a locomotive in which holes are cut for axles.  They also carry the spacing pieces and fixings for the locomotive's motor.

Manufacturer

912
Views
A company that produces models, kits scenery or accessories for modellers.

MAS

932
Views
Abbreviation for Multiple Aspect Signalling: The correct term for modern electrically operated colour light signals which can show Red, Amber, Double Amber and Green aspects.

Meter

837
Views
A measuring device; in electrical circles, a means of measuring the voltage or current in a circuit.

Microchip

948
Views
An ingenious device which contains a mass of specialized electronic circuits; more correctly termed an integrated circuit.

m

microchips

887
Views
minute integrated electronic circuits.

M

Microcontroller

845
Views
A miniaturized, self-contained, computer on a single chip.  The computer's operating instructions are also stored in this self-contained chip.

Microprocessor

865
Views
A specialized microchip which forms the heart of a computer and can also be used in control circuits.  Fiendishly complicated but frequently very cheap.

Microswitch

1068
Views
A switch which makes contact with a very small movement of the operating mechanism.

Mighty Wurlitzer

924
Views
The irreverent term for a complicated control panel.

Milliamperes

876
Views
In DCC  One thousandth of an ampere.  One thousand milliamperes (mA) equals one ampere.  See also ampere.

Millisecond

898
Views
In DCC  One thousandth of a second.  One thousand milliseconds (mS) occur every second.

Mobile decoder

878
Views
In DCC  A decoder that is designed be able to properly work if installed in a device that moves around the layout using rotating wheels on tracks.  See also decoder.

Modernisation Plan

1020
Views
Published in 1955.  This was a grand plan outlining how the country's railway network was to be re-equipped and revamped to meet the challenges of post-war Britian.  Chief amongst its propos... Read more

m

monitor roof

930
Views
raised central roof extension like a clerastory but without windows.

motive power depot

944
Views
complex for servicing and readying locomotives.

M

Motor

870
Views
A device for turning electrical energy into rotary (or occasionally,reciprocating) motion.

Motorman

1080
Views
An early term used for drivers of diesel or electric propelled locomotives or units and trams.

MR Midland Railway

1000
Views
Centred on Derby, this company's lines radiated from there to London, Carlisle, Manchester and Bristol.

MUing

914
Views
In DCC  See "Consist".

Multi

863
Views
Wire containing a large number of separate cores, each identified by colour coding.

Multi-pin plug

910
Views
A plug with a number of pins, handed so that it can only be inserted one way; used to connect cables to baseboards, ect.

Multi-selector switch

860
Views
A series of rotary switches advanced step by step by means of a solenoid-actuated ratchet mechanism.

Multimeter

905
Views
A test meter provided with probes and a means of switching between various ranges to measures volts, amperes and ohms.

m

multiple aspect signals

892
Views
electric light signals (red, amber, green).

M

Multiple unit

1008
Views
Passenger carriages, some with underfloor engines and Driving cabs, which are designed to couple together with others of similar type and be under the control of one driver.  A separate locomotiv... Read more

N

N gauge

1870
Views
9 mm gauge, :160 scale (2 1/16 mm scale, 1:148 British N scale).

Nationalisation

1017
Views
The merging of all UK railways into one state owned company.  This occurred on the 1st January 1948 with the birth of British Railways.

NBR

931
Views
North British Raileay.  Like the Caledonian, based in Glasgow.  It had an extensive network in Scotland, owning the Berwick to Edinburgh and Aberdeen lines.  Further N.B. routes include... Read more

NBR North British Railway

1046
Views
Like the Caledonian, based in Glasgow.  It had an extensive network in Scotland, owning the Berwick to Edinburgh and Aberdeen lines.  Further NB routes included the West Highland line to For... Read more

Neon

862
Views
Strictly, neon tube, a specialized detector lamp, generally used in mains voltages.

NER

994
Views
North Eastern Railway.  This company had a near monopoly of the lines in the North East with its main line forming the central part of the East Coast Main Line north of Doncaster to Berwick. Read more

NMRA

987
Views
The National Model Railroad Association is an Organization of volunteers that, among other things, created the NMRA/DCC Standards and Recommended Practices.  For membership information, call +1-4... Read more

North Eastern Region (NER)

824
Views
As well as the lines of the ex - NER, this region included some routes of the former LMS, plus the more northerly ex - GNR lines transferred into the ER during the 1960s.

O

O Gauge

1941
Views
32 mm gauge, 7mm to the ft, 1:42.5 scale.

O-16.5

980
Views
16.5 mm (OO/HO) gauge, 7 mm scale.

o

observation car

909
Views
passenger coach with extra facilities for viewing scenery.

O

Occupancy detector

919
Views
In DCC: A device that senses the presence of a train on a section of track.  Also known as a block occupancy detector.

Occupation crossing or bridge.

886
Views
A small ungated level crossing, or bridge, provided to maintain access for farmers whose land was bisected when the railway was built.  They are not public rights of way.

Ohm

855
Views
The unit of electrical resistance.

OO gauge

1878
Views
16.5 mm gauge, 4 mm to the ft, 1:76 scale.

OO9

1158
Views
9 mm gauge, 4mm scale.

OOn3

1415
Views
12 mm gauge, 4 mm scale.

o

open platform end

1035
Views
from a passenger car with railed balcony at rear.

O

Operations mode programming

1006
Views
The process of changing the decoder's CV's while the decoders are operating on the layout, instead of on the programming track.  This method of programming decoders does not interfere with the op... Read more

Over Head Line Equipment

1138
Views
The term used to describe the system of masts, insulators and contact wires used on railways using electric power delivered by an over head conductor wires.  Also known as catenary.

Overhead wiring

857
Views
The system of current collection used for most prototype electrified railways.  Can be modelled using commercial or home-made equipment, but involves considerable additional work.

P

P4 gauge

1016
Views
18.83 mm gauge, 4 mm to the ft, 1:76.2 scale.

Packet

882
Views
See digital packet.

Paged programming

876
Views
One method used for programming of decoder CVs.  It is a method of accessing the configuration variables four variables at a time.  Each set of four variables is called a page.  Se... Read more

p

pannier tank

885
Views
tank locamotive carrying water supply in side tanks.

P

Pantograph

1024
Views
Insulated frame fitted to the roof of an electric locomotive or unit and used to collect current from the overhead contact wire.

Parliamentaries

1120
Views
A nickname given to the 19th century trains that the railway companies were, by law, obliged to run to cater for the less affluent.  They stopped at all stations and were consequently slow. The f... Read more

Permissive Block

750
Views
Method of controlling block section in which more than one train can be allowed in one block section.  Mostly used on goods lines, it can sometimes be used in the platform lines of large stations... Read more

p

pilot engine

780
Views
locomotive used (usually) at terminal station for handling empty coaches and so on.

pilot truck

759
Views
U.S. term for leading bogie (truck) on locomotive.

P

Plateway

810
Views
The ancestor of the railway track.  A system of fixed wooden "rails" which were used to guide truck with wooden wheels which were either horse drawn or manually propelled.

p

points

1629
Views
(U.S. turn-outs or switches) trackwork allowing a train to change from one set of lines to another or proceed in either of two directions.

P

Potentiometer

727
Views
A variable resistance (qv), generally used in electronic circuits.

Power district

722
Views
The portion of a layout that is powered by a single power station.

Power pack

743
Views
A source of electrical power.  Commercial power packs might also have controls for conventional analog (NMRA S-9) operation.  See also tranformer.

Power rating

753
Views
The measure of power of an electrical device, expressed in va (qv) or watts (qv).

Power Station

951
Views
A device intended to amplify the low current DCC electrical signals transmitted by the command station for the purpose of providing high current DCC signals with sufficient power to operate model trai... Read more

Power unit

1012
Views
A box containing transformer(s) plus rectifiers & controllers; the interface between 240V mains and the layout low voltage supplies.

Pre-grouping

745
Views
The generic term used to describe the era of railways prior to grouping of 1923.

Privatisation

747
Views
The dissolution of the nationalised railway system, breaking it up into individual privatisation was the 1st April 1994.

Probes

726
Views
Insulated prods on the end of flexible leads which are plugged into a multimeter to connect it to  the circuits being tested (probed).

Programming track

874
Views
A special section of track isolated from the main portion of the layout and used for checking instasllation and for setting the values of the decoder's configuration variables.

PROM

1001
Views
Programmable Read-Only Memory.  Also OTPROM: One-Time PROM.  These computer memory devices are used to store data in a manner that is easily read, but can only be written at the factory befo... Read more

Protocol

763
Views
The definition of the "language" used between two devices.  The agreed upon definitions of the packetis format and intended meaning is known as a protocol.  The DCC protocol. ... Read more

Prototype

1094
Views
The full - sized railway system on which the model is based.

Puffing Billy

1016
Views
One of the earliest successful steam locomotives.  Designed by William Hedley a mentor of George Stephenson, it operated at Wylam colliery in the early 19th Century.

Pullman

744
Views
passenger coach with dining facilities and comfortable seats.

Pulse Width Modulation

718
Views
The technique of controlling motor speed with voltage pulses of varying time duration (pulse width).  The wider the pulse, the more power is provided to the motor, the faster the motor rotates.&n... Read more

Push-pull

698
Views
Method of working where a locomotive is coupled to a coach which has driving controls at the rear end, allowing the driver to drive the train from both ends, obviating the need to run round at terminu... Read more

PWM

731
Views
See pulse width modulation.

q

queen-post

859
Views
vertical strut supporting wagon/coach substructure.

Q

Queuing

692
Views
The sequencing of items to be processed.  A programming technique intended to insure that command stations transmit important digital packets first and less important packets later would be a pri... Read more

R

Rail break

800
Views
An insulated gap in a rail, used to separate one section from another.

r

railbus

749
Views
type of (usually) two-car train running regular local services.

railcar

775
Views
as railbus in countries other than Britain.

R

Railtrack

696
Views
The post - privatisation company charged with maintaining and running the UK railway network infrastructure.

Railway bill

920
Views
The name of the legislation required before any railway can be built.  The sponsors have to prove it's financial soundness and benefits to Parliament to receive approval.

Railway Mania

944
Views
Refers to the great rush and craze to sponsor and build railways which occurred during the mid 19th century in Britian.  Many fanciful schemes were promoted through Parliament during the period a... Read more

Railway time

903
Views
Prior to the building of the railway network, many different "time zones" existed across the UK.  This however, proved to be unworkable to the railways and so a "standard" was... Read more

Rainhill trials

795
Views
A famous competition held at Rainhill, near Liverpool, in 1829 to test various designs of steam locomotive.  Stephenson's Rocket proved the superiority of the simple expansion steam locomotive ov... Read more

r

rake

958
Views
set of coaches made up into a train or part of one.

R

RAM

797
Views
This form of computer memory is used to store data in a manner that is easily read and written.  Used in command stations and decoders to store information that frequently changes.

r

rating plan

779
Views
scale drawing of an area of railway including all building, basically for calculation of rates (local taxes) payable.

R

Rationalisation

775
Views
A term that describes the cutting back or loss of railway services.  The term has been in recognised use since the mid 1930s.

r

reception road

905
Views
track for goods trains leading into (but stopping at) station for handling parcels, mails and so on.

R

Recommended Practices

727
Views
A set of specifications that are only less mandatory than NMRA Standards by virtue of their slightly less critical subject matter.  While the inclusion of features described by NMRA DCC Recommend... Read more

Rectifier

748
Views
A device for converting ac supplies to dc.

Reed switch

776
Views
A magnetically - operated switch, enclosed in a glass envelope.

Register programming

760
Views
A basic method for accessing the eight most basic decoder CVs.  See also paged programming, direct CV programming and operations mode programming.

Relay

762
Views
A series of switches operated by means of a coil magnet.

r

release crossover

721
Views
pointwork near end of rails in terminus to allow locomotive to depart leaving train at platform.

R

Repeaters (power)

787
Views
This device cleans up the DCC signal timing and provides power to drive additional power stations.

Resistance

745
Views
A device which has the effect of limiting the flow of electricity in a circuit.  Also used to describe the quality of such a device.

RETB

859
Views
Radio controlled Electronic Tokenless Block.  Introduced during the 1980s on lightly trafficked lines, RETB uses radio communication combined with a computer based interlocking system to control ... Read more

Return

1012
Views
The electrical output from the non - controlled rail on a layout.

Reverse feed

763
Views
The feed, via a DPDT reversing switch, to a reverse loop or triangular junction.

r

reverse loop

873
Views
loop of track returning locomotive to original line in opposite direction, requiring current polarity to be reversed.

R

ROD Railway Operating Division

1472
Views
The division, During WW1, of the Ministry of Defence charged with operating military railways overseas.  The acronym became the nickname of the ex-military owned, Great Central Railway designed, ... Read more

r

rolling resistance

909
Views
the drag of a vehicle or train opposing tractive effort.

R

Rolling Stock Leasing

901
Views
These were set up during privatisation as owners of locomotives and carriages who in turn hired and leased the equipment to the new Train Operating Companies.

ROM

778
Views
Read-Only Memory.  Also Mask Programmed ROM.  These computer memory devices are used to store data in a manner that is easily read, but can only be written at the time the silicon chip is ma... Read more

Rope worked incline

946
Views
Because early steam locomotives were low powered, pioneering engineers used rope or cable winches powered by stationary steam engines to haul trains up steep inclines.  Similarly, the ropes would... Read more

Routing control

813
Views
The act of specifying the desired route for a train and programming the DCC system to properly actuate all turnouts (track switches) automatically when the route is chosen.  See also Macros. Read more

RR

882
Views
Rhymney Railway.  A great rival to the TVR, covering much the same area in South Wales.

RR Rhymney Railway

917
Views
A great rival to the TVR, covering much the same area in South Wales.

Rule 17

730
Views
A rule on many prototype railroads that specifies conditions for lighting and dimming the headlight.

Running in board

742
Views
The Large station name boards placed at the ends of platforms.

S

S gauge

808
Views
7/8 in gauge, 3/16 in to the ft, 1:64 scale.

S&DR

710
Views
The Stockton & Darlington Railway.  This scheme is accepted as the first public steam operated railway, although initially, it only carried goods traffic.

s

saddle tank

693
Views
a tank engine carrying water supply in tank fitted and curved over the top of the boiler.

S

Sandwich frames

799
Views
Describes a method of building locomotive frames in which iron plates are bolted around a wooden beam, usually oak, for rigidity. 

s

scale

1824
Views
the relationship between any dimension of a model and that of its full - size counterpart.

S

Schematic

724
Views
A wiring diagram where the components and wires are laid out in symbols without regard for their actual appearance or location in the unit.

Scottish Region (Sc R)

768
Views
This consisted of all the former LMS and LNER lines north of the Border.

SCR

765
Views
Silicon - controlled rectifier, an electronic device that is the heart of "chopper" control.

Secondman

716
Views
Official title given to a trainee or assistant driver of a diesel or electric locomotives.

SECR

924
Views
South Eastern and Chatham Railway.  A joint company formed from the London, Chatham and Dover Railway and the South Eastern Railway.  This concern had a near monopoly of lines in the country... Read more

Section switch

841
Views
A switch used to energize or isolate a section of track.

s

semaphore signal

750
Views
the older type of signal employing a counterbalanced arm, the position of which instructs a driver.

S

Semaphore signal

728
Views
One which uses a pivoted arm or board to indicate either a clear road or danger.

Service mode programming

803
Views
This method is used when programming decoders on the programming track.  It is characterized by using broadcast packets and a safe power level.

Short

1290
Views
See short circuit.

Short circuit

715
Views
A direct connection across a power supply of negligible  resistance, creating overload conditions.  Only serious if cut-out or fuse is not provided in circuit.

Shunt ahead signal

850
Views
Similar to a calling on arm, these allow a train to draw forward to proceed with shunting operations.

s

shunting

979
Views
(U.S. switching) the arrangement of vehicles into a train.

shunting engine

727
Views
locomotive used to manoeuvre coaches, wagons and so on, to make up a train in the correct sequence.

shunting neck

1482
Views
track(s) leading into a marshalling area in which they debouch into a number of sidings.

side tanks

743
Views
water containers mounted on either side of a tank engine boiler.

sidings

1891
Views
tracks of limited length adjacent to main lines, used for shunting, loading/unloading or temporary vehicle storage.

signal box

1053
Views
a control centre for all signals affecting a particular stretch of line (U.S interlocking tower).                &n... Read more

S

Signal Gantry

769
Views
A bridge spanning multiple tracks and fitted with several signal dolls, each controlling a specific route.

s

single-slip

933
Views
type of point allowing crossing or travel on alternative track.

six-foot way

728
Views
the area between pairs of main lines.

S

Slave decoder

927
Views
A special type of decoder that is intended to increase the power available from one conventional locomotive decoder.  Slave decoders are quite inexpensive and are very useful in the larger scales... Read more

s

sleeper

1137
Views
heavy wood, sometimes concrete, cross-member supporting track (U.S. tie).  Also passenger car with sleeping accommodation.

S

Slugged relay

1412
Views
A relay provided with a device, generally a capacior (qv), to delay iits release.

SM 32

842
Views
32 mm (O) gauge, 16 mm scale.

Solder tag

740
Views
A small banjo - shaped tag that is placed under a nut to allow a wire to be soldered to the terminal.  See tag strip.

Solebar

755
Views
The longitudinal load bearing beam of a vehicle's underframe.

Solenoid

696
Views
A coil of wire around a hallow core; when energized, forms a magnetic frield and draws in an iron or steel core.

Southern Region (SR)

715
Views
Originally consisting of all the ex - Southern Railway routes.  Those lines located to the west of Salisbury were transferred into the controlof the Western Region in 1964.

SPDP

737
Views
Single pole, double throw (switch).

Special Interest Group (NMRA DCC SIG)

690
Views
The DCC SIG was established as a communications vehicle for exchanging DCC information amongst users.  Membership is open to the public.

s

spectacle plate

750
Views
front of locomotive driving cab with small windows.

S

Speed steps

721
Views
Cab-controllable voltage increments which are used to control motor speed.  With some decoders, the output power can be set for each speed step.

s

splasher

736
Views
casing concealing upper part of locomotive driving wheels.

spline

745
Views
flexible strip of wood or metal used to draw curves.

S

Sprinter

662
Views
The official name given to second generation DMUs built during late 1980s.  So named due to their rapid acceleration.

SPST

686
Views
Single pole, single throw (switch).

SR

1159
Views
Southern Railway.  Smallest of big four and based in an area with little heavy industry.  This concern was often thought of as a passenger line, but freight was still impotant, especially ar... Read more

Stall current

803
Views
When a motor is prevented from rotating and its maximum rated voltage is applied, the current draw of the motor is known as its stall current.  Typically, it is safest to insure that the stall cu... Read more

Standard gauge

955
Views
American gauge of 2¼in used in 1906, now obsolete.

Standards (NMRA DCC S-9.x)

739
Views
NMRA Standards provide the primary basis upon which interchange beween equipment and various North American scale model railroads is founded.  Under this requirement NMRA Standards include only t... Read more

Starting signal

731
Views
This is the last signal in a block section to be encountered before leaving that particular section.

s

station throat

985
Views
point from which main lines spread into several platforms.

S

Stationary decoder

740
Views
See accessory decoder.

Stop packet

720
Views
A digital packet that commands a locomotive decoder to stop.

s

strapping

729
Views
metal strip reinforcement on wagon or van body.

stretcher

696
Views
cross - member between locomotive or bogie frames.

S

Strowger switch

746
Views
See multi - selector switch.

s

stud

1081
Views
metal connection in centre of each sleeper contacting a wiper beneath locomotive for electrical pick - up, now rarely seen.  Also a collection of locomotives.

superelevation

903
Views
banking of track in tight curves by raising outside rail.

T

Tag strip

664
Views
A series of solder tags mounted on an insulated strip, used to make connections between units and connecting cables.

t

tank locomotive

759
Views
one carrying water and coal supplies on one chassis.

tender locomotive

685
Views
one drawing a separate vehicle (the tender) carrying coal and water supplies in greater quantities.

T

Third rail.

758
Views
An electrical conductor rail fixed parallel to the side of the running rails.  This being used on networks electrified using the "third rail" system in which EMUs and locomotives collec... Read more

Three rails

734
Views
System of current collection on model railways (now obsolete) where the running rails form the return and the feed is through a third rail mounted either in the centre or to one side of the track.&nbs... Read more

Throttle

716
Views
US term for controller (qv).

t

tie

1040
Views
U.S. see sleeper.

T

Tie-bar

726
Views
This is a bar or rod fitted between the "W" irons and used to stabilise the chassis against brake forces. 

Tipplers

707
Views
A wagon designed to be unloaded by either rotating it completely upside down, or by lifting it up at one end.  Some modern tippler wagons have special couplings which allow the train to remain co... Read more

Toe

901
Views
The front end of a point, where the blades and tiebar are situated.

Torque converter

706
Views
Transmission system notably used in the Western Region's diesel hydraulic locomotives..  Torque converters are a successful part of the "gearless" transmissions used in modern diesel mu... Read more

t

towerman

751
Views
U.S. term for signalman manning signal box (interlocking tower).

T

Track power bus

879
Views
The bus used for connecting power stations to track feeder wires.

Traction motor

654
Views
Of locomotives with electric transmission systems.  They may be direct acting or linked through spur gears.

Tractive force/effort.

703
Views
The amount of power that a locomotive can exert "at the rail". i.e.  A measure of how powerful the locomotive is.

t

trailer coach

714
Views
unpowered second part of a railcar or railbus.

T

Train Operating Company

759
Views
A post - privatisation railway company that is franchised to run passenger train services over a given area or set of rail routes within the UK.

t

trammel

778
Views
instrument for describing large - radius curves.

transfers

711
Views
original English term for decals (q.v.).

T

Transformer

675
Views
A device consisting of a number of coils wound around a laminated core which alters (transforms) the voltage of an ac supply.

Transistor

705
Views
A semi - conducting device, the heart of modern electronics.  Extremely small and deceptively simple, but almost incomprehensible to the layman.

t

tread

767
Views
the horizontal (actually very slightly coned) face of a locomotive tyre.

truss rod

702
Views
diagonal brace in underframe of a wagon for example.

T

TT gauge

810
Views
12 mm gauge, 2.5 mm to the ft (USA), 3 mm to the ft (GB), 1:120  (Continental Europe).

t

turn-out

941
Views
see point.

turret

703
Views
similar to dome, a fitting on the top of a boiler for steam feed.

T

TVR

700
Views
Taff Vale Railway.  The largest of the South Wales companies, this line served from Cardiff through to Llantrisant, Cowbridge and Aberdare.  Its main trade was the carriage of coal and miner... Read more

TVR Taff Vale Railway

849
Views
The largest of the South Wales companies, this line served from Cerdiff through to Liantrisant, served from Cardiff through to Llantrisant, Cowbridge and Aberdare.  Its maintrade was the carriage... Read more

Two rails

757
Views
The near universal system of current collection on model railways.  The two rails are insulated one from another, as are the wheels on locomotives and rolling stock.

U

Underframe

709
Views
The name given to the chassis of a railway vehicle upon which a vehicle body is fitted.  It includes the buffer beams and fittings, the solebars, wheels, suspension and brake gear.

V

V hanger

714
Views
The "V" shaped brackets on the vehicle under frame used to suspend brake linkages.

VA

710
Views
The measure of power output of an ac supply (volts x amps).

Valve gear

738
Views
Set of rods and levers which operate the valves controlling the steam flow into a steam locomotives's cylinders, allowing it to vary its direction, speed, and power output.  Common types used on ... Read more

v

van

1180
Views
closed goods vehicle (U.S. boxcar).

V

Variable resistance

714
Views
A resistance which can be varied in value, usually by turning a knob.

v

ventilation tower

722
Views
brick structure for ventilating tunnel beneath.

viaduct

988
Views
elevated structure carrying road and/or railway across valley.

V

Volt

793
Views
The measure of electromotive force.  Loosely, the higher the voltage, the bigger the kick.

Voltmeter

751
Views
A meter for measuring volts.

W

W iron

797
Views
The "W" shaped plate connected to the solebar of a wagon in which the axleboxes are suspended.

Wall socket

739
Views
The three - pin socket, connected to the mains and, ideally, provided with a switch, used to connect high voltage electrical equipment to the mains supply.

Watt

780
Views
The measure of power output of a dc device (volts x amps).  Note that due to quirks in ac supply, va and watts are not exactly identical, even though they are calculated in exactly the same way.&... Read more

WCML

673
Views
Abbreviatiion for the West Coast Main Line.  Refers to the main line route from Euston to Glasgow via Rugby, Preston and Carlisle.

WD

745
Views
War Department.  In WW2 the War Department instigated the production of cheap to build, austerity locomotives to aid the war effort.  These heavy freight locomotives were suitable tagged &qu... Read more

w

weathering

753
Views
technique of painting simulating normal wear and tear.

W

Western Region (WR)

752
Views
Basically all the ex - GWR lines, although it later lost some of its more notherly routes to the LONDON Midland Region.

w

wheel arrangement

818
Views
disposition of driving and carrying wheels on a locomotive.

W

Wheelbase

952
Views
The distance between the centres of the axles on a wagon, bogie or locomotive chassis.

Whyte notation

1077
Views
widely used description of wheel arrangement using numbers of carrying, driving and carrying wheels listed front to rear.  Certain common arrangements are referred to by names, e.g. Atlantic 4-4-... Read more

Working Group (NMRA DCC)

658
Views
A group of DCC manufacturers and NMRA members who volunteer their time and expertise to create the many Standards and Recommended Practices that constitute the defining documents of digital packet com... Read more

Z

Z gauge

764
Views
6.5 mm gauge, 1:220 scale.