Rail transport terms are a form of technical terminology applied to railways. Although many terms are uniform across different nations and companies, they are by no means universal, with differences often originating from parallel development of rail transport systems in different parts of the world, and in the national origins of the engineers and managers who built the inaugural rail infrastructure. An example is the term railroad, used (but not exclusively) in North America, and railway, generally used in English-speaking countries outside North America and by the International Union of Railways. In English-speaking countries outside the United Kingdom, a mixture of US and UK terms may exist.[1]
Various terms, both global and specific to individual countries, are listed here. The abbreviation "UIC" refers to terminology adopted by the International Union of Railways in its official publications and thesaurus.[2]
The condition of locomotives and cars swaying in opposite directions when traversing depressions on the roadbed. A potentially dangerous condition that can cause coupler damage, lading damage, or derailments at slower speeds.[3][4]
Head-End Power
A scheme whereby the locomotive engine or a separate generator provides hotel power to carriages[5]
A transverse structural member located at the extreme end of a rail vehicle's underframe. The headstock supports the coupling at that end of the vehicle, and may also support buffers, in which case it may also be known as a "buffer beam".[7]
A device attached to the track that monitors passing trains for hot axles, and reports results via radio transmission (typical in the US) or a circuit to the signal box (typical in the UK). See defect detector.[5]
A raised section in a rail sorting yard that allows operators to use gravity to move freight railcars into the proper position within the yard when making up trains of cars. This is faster and requires less effort than moving cars with a switching engine.[5]
Swaying motion of a railway vehicle or bogie caused by the coning action on which the directional stability of an adhesion railway depends. The truck or bogie wanders from side to side between the rails, "hunting" for the optimum location based on the forces at play.[5]
I
Independent brake or locomotive brake
The braking system that applies or releases the brakes of a locomotive independently from its train[19][20]
Moving goods by more than one type of vehicle, often achieved using shipping containers that are transferred among railroad flatcars, ships, airplanes, and tractor-trailer trucks[21]
Moving people by more than one type of vehicle[21]
Interoperability
Ability of a transport network to operate trains and infrastructures to provide, accept and use services so exchanged without any substantial change in functionality or performance[27]
A Bogie, or truck (American), shared between two pieces of rolling stock. Cars joined with Jacobs bogies are semi-permanently joined in an articulated configuration. A weight-saving feature used on lightweight passenger trains.
Joint bar or rail joiner
A metal plate that joins the ends of rails in jointed track[28]
A point at which two lines or separate routes diverge from each other[29]
K
Keeper
A padlock or hook securing the lever of a hand-operated switch, thereby preventing the switch points from moving as rolling stock passes over them[33][34]
Kick
To shove a car a short distance and uncouple it in motion, allowing it to roll free under gravity and/or its own inertia onto a track. Commonly practiced in bowl or hump yards to make up or break down trains or classify large numbers of cars in an expedient fashion. Differs from a flying switch in that the locomotive is pushing the car rather than pulling it when the cut is made.[35]
Kicker
A freight car with a defect in its brake valve that causes the entire train's brake system to go into emergency when any application is made[36]
Kinematic envelope (KE)
The outline of the space beside and above the track that must be kept clear of obstructions for the train to pass. This can be larger than the static clearance around an unmoving engine or car.[37] See also: loading gauge and structure gauge
Knuckle
The articulating part of a coupler that locks automatically in its closed position to join rail cars; so named because its movement resembles that of the human finger[38]
L
Script error: No such module "anchor".Lead track
A non-main track from which several others branch within a short distance, such as within a rail yard or engine terminal[39]
A crossing on one level ("at-grade intersection")—without recourse to a bridge or tunnel—generally of a railway line by a road or path. Not to be confused with non-dead-end railways (see Rail crossing)
Light engine
A locomotive travelling on its own, or perhaps with just a caboose (brake van) attached[40]
A city-based rail system based on tram design standards[40] that operates mostly in private rights-of-way separated from other traffic but sometimes, if necessary, mixed with other traffic in city streets.[41] Light rail vehicles (LRVs) generally have a top speed of around Template:Convert though mostly operating at much lower speeds, more akin to road vehicles.
An obsolete method of coupling rail cars, consisting of manually dropping the coupling pin into the drawbar as the cars joined. Extremely hazardous to the brakemen of its day, it was outlawed in the United States by the Railroad Safety Appliance Act of 1893.
Local train
A train that stops at most, if not all, stations along its route[42]
Script error: No such module "anchor".Lunar
An off-white color of railway signal light, like the Moon, achieved by the use of a clear lens of very light blue, to make it distinct from a light that has a broken lens.[43][44]
A system of high speed train transportation that uses two sets of magnets: one set to repel and push the train up off the track, and another set to move the elevated train ahead, taking advantage of the lack of friction.
Main generator
The electric generator in a diesel–electric locomotive that is coupled directly to the prime mover and feeds electrical energy to the traction motors[45]
Main reservoir
The compressed-air tank of a locomotive containing source air for the brakes and other pneumatic appliances[46]Template:Self-published inline
A nose-mounted mechanically oscillated light used to warn traffic of an approaching locomotive. Functionally replaced by ditch lights on modern locomotives.
Mechanical semaphore signal
A signal in which the aspect is conveyed by moving an arm[51][52]
In rail transport operations, a meet occurs when two trains arrive at a location and pass each other on parallel tracks, such as on a siding, usually in opposing directions.[53][54] This is also sometimes referred to as a crossing of two trains.[55]
In the U.S., milk trains ran from the countryside to cities making numerous stops at minor depots to pick up cans of fresh milk, making them a colloquial expression for a very slow train.
In the U. K., an aggregator for transporting milk from farms to dairies, such as British Railways Milk Trains; as these trains invariably ran very early in the morning, "milk train" became a colloquialism for a particularly early train.[57][58][59]
The bottom of the water space surrounding a steam locomotive's firebox that collects solids precipitating from the water supply during the boiling process[64]
Multiple aspect signalling
A system of colour-light signalling in which signals may show three or four aspects[65]
A self-propelled rail vehicle that can be joined with compatible others and controlled from a single driving station. The names of the sub-classes of this type of vehicle, diesel multiple unit (DMU), diesel–electric multiple unit (DEMU) and electric multiple unit (EMU), are more common terms. These may also be termed railcars.
File:WheelArrangement 4-8-4.svgThe Northern wheel arrangementA steam locomotive with a 4-8-4 wheel arrangement, also known in North America as "Pocono", "Niagara", "Confederation", "Greenbrier", and "Potomac"[18][67]
An apparatus mounted on the roof of a rail vehicle to allow the collection of electric current from overhead lines[72][73]
Paperwork
As a reason for delays, written instructions conveyed to a train's engineer in which the train must proceed slower than its normal speed. These instructions are either handed to the crew or recited and read back over radio.[74]
Per diem (pronounced by some U.S. railroaders per die-um, not per dee-um)
A fee paid by a rail company to the owner of a car (or wagon) for the time it spends on the company's property[72][76]
An authorized living expense payment for some workers forced away from their home terminal[72][77]
Permissive signal
A block signal whose most restrictive indication is stop and proceed. A permissive signal is identified by the presence of a number plate affixed to the mast or supporting structure. Proceeding beyond a permissive signal at stop is allowed at restricted speed if operating conditions enable a train operator to stop before reaching any train or obstruction.[78][79][80]
Pilot
A deflective shield affixed to the front of a locomotive to protect its wheels from on-track debris; archaically called a "cowcatcher"[81] See also: Pilot (locomotive attachment)
An employee qualified on the operating rules and physical characteristics of a certain section of the railroad, assisting a crew member who is not so qualified[82][83] See also: Railroad engineer
Where it is necessary to temporarily work a section of line as single track (for instance if the other track of a double-track line is out of use), a person (the pilot man) acts as the single track token.
A specified distance that a brake piston may move from its cylinder to the brake rigging. If the travel exceeds or falls short of this distance, the equipment must be set out for repair.[88]
An employee who performs or performed (the role has now largely become obsolete) various physical duties, chiefly but not exclusively involving lifting. Various types of porter include:
A baggage porter assisting with luggage
An operating porter assisting with safeworking duties
A station porter assisting with general station duties
The practice of coupling two or more passenger trains together over common sections of their respective routes, but otherwise operating the trains separately[91][92]
An American system of functional requirements for monitoring and controlling train movements with the aim of increasing operational safety
Possession
In Britain, a period of time when one or more tracks are closed for maintenance. For the duration of the work, a person in charge of possession (PICOP) has control of the line. When work is complete the possession is relinquished and control of the line handed back to the signaller.[93]Template:Self-published inline
The weight (and thus the cross section) of a length of rail. A heavier rail can carry heavier loads with less distortion and less damage to the rails themselves and the roadbed.
Power
A locomotive or group of connected (MU'd) locomotives serving as the motive power for a train[72]
Power braking
Pulling against the train brakes at the higher end of the locomotive's power output (e.g. notches five through eight on a conventional throttle). This is considered wasteful of fuel and brake shoes, and is therefore discouraged by most operating departments.[94][95]
The internal combustion engine of a diesel locomotive
Pull apart
A rail broken from cold-related contraction[97][98]
Push pole
File:PushPoleSRM.jpgA push poleA pole about Template:Convert long and having a diameter of Template:Convert and used in the United States between 1870 and the mid-1960s to push a freight car onto or off a siding or onto another track by being placed between a locomotive (on an adjacent track) and the freight car. The two ends of the poles were placed in receptacles called push pole pockets.[99] The practice of using a push pole for switching was called "poling".[100]
A configuration for locomotive-hauled trains, allowing them to be driven from either end of the train, whether having a locomotive at each end or not. See also: Auto train. See Top and tail for train with locomotives at both front and back.[72]
R
Rack railway, rack-and-pinion railway, or cog railway
A steep-grade railway with a toothed rack rail (usually between the running rails), used when adhesion is insufficient
A passenger rail vehicle (typically non-articulated or rigid frame) that derived from bus propulsion and construction technology, but may evolve into larger dimensions, performance, and characteristics similar in appearance to a light DMU railcar
The opposite of a dead-end rail, i.e. a line connecting locations accessed by other railways, often associated with the overcoming of natural obstacles, such as mountain ranges.[101] Not to be confused with a railway crossing a road (see Level crossing).
File:Flat-bottom and bullhead rail profiles.pngRail profiles of flat-bottom and bullhead railsThe cross-sectional shape of a rail. There are many rail profiles, often specific to individual railroads. Rails must be periodically scanned electronically, their data inspected and analysed, then re-profiled with rail grinding machines to maintain the correct profile. Rails that cannot be restored are condemned and replaced.
A colour generally associated with stop, when shown by signals or flags
Red zone
The area between, under, or within a few feet of cars and locomotives. To enter the zone, a ground employee must obtain protection from the locomotive engineer (if a locomotive is coupled) or a blue signal (if no locomotive is coupled).[109][110][111]Template:Self-published inline
A siding used as a passing place on a main line, where slow trains may be held whilst an express passes—a simpler, but less convenient, form of the passing loop
File:RerailFrog-SRM.jpgA rerail frog or rerailer stored (on its side) on a locomotive. The slot is placed over the rail and the derailed wheel is pushed or pulled until it runs up the rerailer and back on to the track.
A metal casting incorporating a slot that allows the casting to fit over the rail near the wheel of a derailed car. The locomotive then pushes or pulls the car so that the derailed wheel runs up the rerailer and back on to the track.[116]
A box or panel adjacent to a rail line at an interlocking, with several buttons for train operators to select a desired route, which is then either communicated to a signal tower where an operator fulfills the request, or switched automatically[123][124]
The longest or steepest grade on a division, thus setting the standard for track speeds, locomotive tonnage ratings, and train handling instructions[125]
Run
The action verb for the train's movement. The train runs across the track.
Runaway
A heavy train that has lost speed control while descending a steep grade, due to either brake failure or poor preparation by the crew[126]
Running track
An other-than-main track, typically providing access to a yard or industry and governed by the requirements of restricted speed[127]
The practice of detaching a locomotive from its train, driving it to the other end of the train and re-attaching it, to allow the train to proceed in the direction it has just come from (e.g. when it reaches its destination and forms a service in the other direction).[113][128]
Run-through power
Locomotives that remain attached to a manifest or unit train from their home rails over the tracks of a receiving railroad until the train reaches its final destination[129]
A tank locomotive with the water tank mounted on top of the boiler like a saddle[130]
Safe place
An area within the network of an operator where evacuation of passengers can be performed, depending on current operational conditions, with a minimum of risk to the passengers (e.g. stations, refuges on the line)[131]Script error: No such module "Unsubst".
Safeworking
In Australia, the system of rules and equipment designed to ensure the safe operation of trains[132]
A container on locomotives and self-propelled multiple units, or trams, that run on tramways and adhesion railways. The container holds sand, which a crew can drop onto the rail to improve rail adhesion under wet, steep, or slippery rail conditions. The sandbox and operating mechanism are collectively known as sanding gear.
A steam locomotive not equipped with a superheater; the steam thus remains at the same temperature as the water in the boiler[135]
Scale
Solid debris distilled from boiling water in a steam locomotive. To prevent corrosion damage from scale build-up, the locomotive must undergo a boiler wash once each operating month.[136]
A specialized type of freight car for extra heavy and oversized loads where the car is loaded in such a way that the load forms part of the car superstructure[137]
File:Rail-semaphore-signal-Dave-F.jpgA British lower-quadrant semaphore signal with subsidiary arm belowA type of signal that has a moving arm to change the indication
A type of geared steam locomotive built to the patents of Ephraim Shay[130]
Shunt
In UK and Australian parlance, to make up and divide trains in sidings, to move trains to or from sidings, or to move trains between platforms in a station[143]Template:Self-published inline
Shoofly
Temporary track used to avoid an obstacle that blocks movement on the normal track section
A train, usually a passenger service, that runs back and forth, usually over a relatively short distance, such as between a junction station and a branch-line terminus.
A section of track off the main line. Sidings are often used for storing rolling stock or freight. A siding is also used as a form of rail access for warehouses and other businesses, where the siding often meets up with loading docks at rail car height. In the U.S. the term also covers the British term loop. Also, a passing track in the U.S.
File:CSX Cum-Sub 145-MAGNOLIA-CPL-brackets-winter.jpgA two-head color position signal on a CSXT mainline where the left head displays "Stop" and the right, "Clear"A device that indicates the condition of the line ahead to the driver of a train
The condition of fallen leaves or other debris lying on and clinging to a railroad track that could cause train wheel slippage, resulting in premature wheel wear and train delays
A local speed restriction below the track's normal speed limit often designated by yellow and green flags. Slow orders can be imposed on a temporary basis to protect, for example, maintenance of way employees while sections of track are under repair. Widely used in areas where track is substandard and in need of repair.
A locomotive that contains traction motors yet lacks the diesel engine to create its own power, which is instead supplied by a connected mother locomotive[130]
An enclosed (normally cylindrical) space attached to the end of the boiler opposite the firebox on a steam locomotive (normally the front). Supports the stack; steam pipes to and from the cylinders pass through here; contains the blastpipe where the exhaust steam is used to provide draft for the fire. In superheated locomotives, also contains the superheater header and (optionally) a front-end throttle.
A long shelter erected over a railroad track on the side of a mountain to protect the line from avalanches and drifting[146]Template:Self-published inline
File:Railroad spikes.JPGTwo unused and one heavily corroded spikes, with an inch ruler shown for scaleA bolt, pin, or nail used to hold rails, or plates connected to the rails (known as tie plates), to sleepers (ties)
A device generally used in passenger trains to create steam for heating. The steam generator is usually in the locomotive but may also be located in other cars.[130]
A mechanical device that boosts the pressure of engine intake air to above atmospheric level, causing an increase in power. Not to be confused with the blower used to scavenge the cylinders of a naturally aspirated two-stroke Diesel engine.
Superelevation
Areas on curves where the outside rail is elevated higher than the inside rail, creating a banked curve, generally allowing higher speeds and more comfort for passengers (on passenger trains).
A device in a steam locomotive that raises the temperature of saturated steam substantially beyond the boiling point of water, increasing power and efficiency[130]
To determine the position of constructed objects, including rail infrastructure, in relation to the earth's surface. This is accomplished by measuring angles and distances based on the principles of triangulation.
A method of climbing and descending steep gradients, where shallow-gradient track reverses direction for a while, and then reverses again to continue in the original direction
A company in the United States that owns no cars of its own and transports only the railroad cars of other companies around a specific terminal station[150]
A passenger coach that is disconnected from one train and attached to another before continuing on with its journey, thus avoiding the need for passengers themselves to switch trains[151]
Through platform
The standard platform and track arrangement at a station. The train pulls alongside the platform, arriving from one end of the station, and may pass out the other end of the station by continuing along the same track[152]Template:Self-published inline
In North America, a form used by railroad employees that shows the locations of slow orders, maintenance of way work locations, and other conditions affecting the track and movement of trainsScript error: No such module "Unsubst".
An electrical circuit that detects the presence of locomotives or cars (as their wheelsets electrically bond the rails) in a block of track, and provides real-time input to signaling logic
The gradual application of superelevation and tighter curve radius, calculated with reference to the anticipated line speed and the final curve radius, on the approach to a bend. Also known as the transition spiral and spiral easement.
The mechanical interface that links vehicles so a driver can operate them together. The coupler can be a purely mechanical device such as a screw coupler or bar coupler. Alternatively the coupler can also incorporate electrical or pneumatic connections.[153]
The warning horn in a locomotive or in a control car
Trainman
In North America, an employee assigned to train service, such as a conductor, brakeman, or switchman
Train inauguration
The automated process of train bus configuration that includes detecting all bus nodes and their orientation, assigning the numbers to particular bus nodes and collecting their properties.[154]Script error: No such module "Unsubst".
Train operation and management
In Europe, the procedures and related equipment enabling a coherent operation of the different structural subsystem, both during normal and degraded operation, including in particular train driving, traffic planning and management[155]Script error: No such module "Unsubst".
The process whereby signallers or dispatchers can change the order or timing of trains to maximise overall train service performance in real timeScript error: No such module "Unsubst".
A group of rolling stock that is permanently or semi-permanently coupled together to form a unified set of equipment. Trainsets are most often used in passenger train configurations.Script error: No such module "Unsubst".
Trams that are designed to run both on the tracks of a city-based rail system and on the existing railway networks. Tram-trains' dual-voltage capability makes it possible to operate at lower speeds on city streets and at over Template:Convert on main line tracks allowing travel in an extended geographical area without changing the method of transport.
A mechanical or electrical device for detecting the presence of a rail vehicle with pin-point accuracy, unlike a track circuit, which provides detection over an arbitrary distances
A train in which all cars (wagons) carry the same commodity and are shipped from the same origin to the same destination, without being split up or stored en route[158]
Underbridge
In the parlance of rail transport in the United Kingdom, an 'underbridge' is a bridge that allows a roadway to cross Template:Em the course of a railway line, in contrast to an overbridge, or overpass, that crosses Template:Em the railway.
A continuous train brake that is fail-safe in operation. It is powered by a vacuum from the locomotive but the application is actually by atmospheric pressure when the vacuum is released. Primarily used historically in Britain and in countries influenced by British practice. Now largely superseded by the air brake.
The linkage mechanism that operates the valve for a driving cylinder, to alternately admit steam to the cylinder and then exhaust it when the piston's stroke is nearly complete[160]
Canadian National Railways: Linguistic Services. Freight Car Inspection & Maintenance: English-French Vocabulary = Surveillance et entretien des wagons: vocabulaire anglais-français. Montréal: Canadian National Railways, 1973. Without ISBN or SBN
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