Glossary of layout design terms


Index by Arguments (Category)

Table of contents 

At the link below is an Index organized by Category, rather than alphabetical. It can be useful to find words related to each other.



American Association of Railroads. Industry group that determines interchange standards among other thing. Succesor to the ARA.

American Railway Association. Industry group that determined interchange standards among other things. Predeccesor to the AAR.

A foundation designed to hold back the pressure of solid ground, such as an end pier of a bridge.


A local passenger train which makes all stops.Serve all or most stations on a route. Serve as collectors

AEI Tag:
An electronic transponder located on the side of rail cars that identifies them to trackside readers.

Small spray tool for fine-spray application of paints and stains with compressed air.

Air Brake System:
All of the devices and parts included in making an air brake for controlling the speed and stopping a locomotive or train. It is made up of the operating devices, the pipes, fittings and foundation brake gear.

Air Test:
The act of operating the brake valve to determine that the air brake system was operating correctly and could stop the train if necessary. (see also Initial Terminal Air Brake test)


A clear track in a switching yard


The track which passenger trains arrive at a terminal; or freight trains arrive in or near a yard

Articulated (Mallet):
  1. A locomotive that has one or more sets of drivers on a hinged or articulated frame to enable the locomotive to negoiate tighter curves.
  2. A Mallet locomotive. A simple articulated is a mallet which had a large enough boiler to supply all four cylinders with high pressure steam direct from the boiler. A compound mallet is a mallet which had a boiler too small to supply high pressure steam to all four cylinders at once, and used steam twice, once to the rear high pressure cylinders and the "partially used" steam would then supply the front cylinders. The best known example of a compound mallet is the N&W Y6b mallet, which "shifted" to compound operation at higher speed. Some well known simple articulated's are the UP BIG Boy, the UP Challenger, the N&W Class A, the B&O EM-1 type, and the SP AC class.

Automatic Block Signal System:
A series of consecutive blocks governed by block signals, cab signals or both, actuated by train, engine or by certain conditions affecting the track. Those conditions may include broken rails or main track turnouts not being lined for the main track.



Bad Order-Track:

A track on which cars are set to wait for repairs

Fireman (because his head was near the door of firebox when shoveling coal)

Ball (of a Rail):
The head of the rail on which the wheels run.

The bottom surface of a a rail that sits on the tie or tie plate.

A frame which is the foundation of a model railroad layout. L girder and open grid (sometimes called butt-joint) are two popular types.

Back Saw:
Fine toothed saw with reinforcing strap along top (back) of blade. Also called razor saw.

A background mural of scenery or sky either on a wall behind the layout or on a freestanding dividers that gives the illusion of depth to the scene or obstructs the view of tracks or other itmes. A backdrop can be painted, a printed background, large photograph or a combination of media.

Usually gravel, cinders, or crushed rock placed between ties and around track and roadbed to help prevent the track from moving, spread load, provide bearing for ties and track, and to drain water and help control weed growth.


Technical term for a reverse loop.

Belt Line:
A connecting railroad between two or more railroads, so-called because it encircles a city like a belt.

Bend the Rails:
To throw or change the alignment of a turnout, change position of turnout.

Big Hook:
The wrecking crane.

A walk way between two passenger cars covered with either canvas or leather in an accordion shape. From the outside of the blinds to the outer edge of the cars there was a space about 24 inches wide. There was a ladder running up to the top of the car in this space and the bums would grap hold of the ladder and hold on to it. That was riding the blinds


  1. A section of track that is electrically isolated from the adjoining sections for multiple-train operation or to prevent short circuits.
  2. A section of track that is isolated for electrical control or indication.
  3. A section of track that is controlled by signals.
  4. A group of cars that are handled together from a yard, interchange or industry to another yard interchange or industry without intermediate switching. See also this TIP : [Blocks ]
  5. To switch cars into blocks.

Blue Flag:
A blue flag or signal that is placed on a car or locomotive when workers are around or under it. When a car or locomotive is blue-flagged, then it must not be coupled to or moved in any manner. The only person allowed to remove a blue flag is a person of the same craft as the one who placed the blue flag.

Board and Batten Siding:
Vertical wooden planking with small wooden strips (battens) nailed over the seams between planks.


An enclosed car used for general service and especially for lading which must be protected from weather.


A member of a freight or passenger train crew. His duties are to assist the conductor in any way. Brakemen (on trains) or switchmen (on yard engines) do the work on a train or yard job. They couple and uncouple cars, throw turnouts and pass signals. Brakemen get promoted to conductor. Switchmen get promoted to foremen.

A portion of a division designated by a timetable. Rules and instructions pertaining to subdivisions apply on branches.


  1. Brake Beam : A cross-piece in the foundation brake gear for a pair of wheels to which the leverage delivers its force to be transmitted through the attached brake head and brake shoes to the tread of the wheels.
  2. Brake Cylinder : A cast metal cylinder with a piston that is forced outward by compressed air in applying the brakes and returned by a release spring in releasing the brakes.
  3. Brake Pipe : Commonly called a train line, it is the pipe, hose, connections, angle cocks, cut-out cocks, fittings, etc., connecting the locomotive and all cars from one end of the train to the other for the passage of air to charge and control the brakes.
  4. Brake Rigging : A term commonly used instead of foundation brake gear.
  5. Brakes, Automatic : Automatic brakes are the brake controls in the locomotive that regulate the pressure of the brake pipe and apply or release the brakes for the entire train including the locomotives
  6. Brakes, Independent :Independent brakes are the brake controls in the locomotive that apply the brakes on the locomotives only. The air hose marked ACT or BR CYL enables the lead unit to control the trailing units brakes

Bumper or Bumping Post:

  1. Device that stops cars at end of a stub track.
  2. The device a loaded car crushes when it rolls off the end of a track.

Slang for a railroad special agent, railroad police officer or railroad detective. A "cinder dick".

Butt Joint:
Wood joint where the end of one board is butted or glued directly to the second board.



Cab Control:
A means of operating and controlling one or more trains singly or simultaneously . (trains operating independent of one another.)


  1. The control compartment of a locomotive.
  2. A caboose.
  3. Forward A steam locomotive with the engineers cab placed ahead of the boiler instead of behind it.

End of train non revenue car. The rolling office and living quarters for the crew of a freight train. Sometimes called crummy, bobber or way car.


Tracks used to hold cabooses between trains, where they can be cleaned and serviced (fuel, ice, water, supplies, etc)

Precision measuring tool for determining small dimensions between two jaws.

A steam locomotive with the cab astride the boiler, the fireman riding under a hood at the rear

Amount by which one rail of a curved track is raised above the other. Cant is ‘positive’ when the outer rail is higher than the inner rail and ‘negative’ when the inner rail is higher than the outer.


Carmen inspect and maintain the rolling stock in the yard. They inspect inbound trains for defects and bleed off the air brakes, that is, release the air from the air brake cylinders on the cars so they will roll free when switched. Any defective cars are tagged "bad order" by stapling or attaching a brightly colored tag to one of the tackboards on the car, and sent to the repair track, known as the rip track (Repair In Place). When the outbound train is set they "lace the air" or couple all the air hoses. The carmen then perform the Federally required brake test to make sure all the brakes on the train are working properly. Carmen are responsible for oiling the journal boxes when friction bearings are used. Once again any defective cars are tagged bad order, switched out and sent to the rip track. The carmen work for the mechanical department directly, but are given work priorities by the yardmaster. A car or mechanical foreman will be in charge in larger facilities. The foreman works for the Master Mechanic.


  1. An overhead wire system for transmitting power to a train for propulsion. It is characterized by a contact wire suspended from a "messenger" wire as opposed to a single wire typical of trolley systems. Normally catenary is used for high speed heavy duty systems
  2. Overhead trolley wires, usually used by prototype interurbans (electric-powered locomotives and self-propelled cars) with diamond-shaped current pick up devices on the roofs called pantographs.

Centipede Tender:
A high capacity tender applied to some large steam locomotives, and multiple axles attached to the frame of the tender, with the front two axles contained in a track casting and capable of swiveling. Major users of centipede tenders include New York Central and Union Pacific railroads.

A specified frequency for communication between train and dispatcher or 2 trains. The channel numbers (07 thru 97) are shorthand methods of designating assigned radio frequencies for transmission. For example, channel 96 means to transmit on an assigned radio frequency of 161.550 mHz

Cherry Picking:

  1. Yard: Pulling only selected car from a makeup track rather than the whole track.
  2. Industries: Pulling before spotting always or handling most convenient first. Prototype had protocol for specific industries like early morning, after 5pm, and between 12-1. Customer serviced ruled here.

Chief Dispatcher:
Officer in charge of a dispatching office. Asst. chief dispatchers, dispatchers and operators report to the Chief Dispatcher. Was responsible for the safe and efficient train movements, managing the balance and flows of crews, locomotives and pool cabooses over the system. In a traditional railroad structure, they and the superintendents were the two most powerful operating officers on a railroad for day to day operations.

Cinder Dick:
(slang)A railroad special agent, policeman or detective, a "Bull".

The path of an electrical current.

Circuit Breaker:
A switch or fuse that automatically opens the circuit in the event of a current overload.

Class 1 Railroad:
A railroad line with annual revenues in excess of a figure set by the Interstate Commerce Commission, adjusted annually for inflation.

Classification Yard:

A freight yard where trains are broken up and made up by shifting cars with a switcher locomotive or by a hump. See also this TIP : [Classification yards].

Coaling Station:
Any building where coal for steam locomotives is stored and shovelled or dumped through chutes into the locomotives' tenders When the storage bins are elevated and the coal hoisted by conveyor belts or buckets, the structure is usually called a coaling tower When the elevated storage bins are reached by a trestle so the coal can be dumped from the cars or shovelled right into the storage bins the structure is usually called a coaling trestle.

Code (of rails):
Height of model rail as measured by thousandths of an inch. Code 83 is .083" tall, code 70 is .070", and code 55 is .055".


Passenger train whose primary purpose to carry people to and from work. They generally link core of large city to its suburbs


A crew member on a freight or passenger train in charge of the train. The conductor (on trains) or foreman (on a yard engine) is the person in charge of the crew. He is the leader of the team; the "captain" of the train. He decides what moves are to be made, when moves are to be made and how the job is to be done. The conductor is responsible for the paperwork of the train. Both the train crew (brakemen/switchmen) and engine crew (engineers/firemen) report to him. The conductor is responsible for the rules observance of all members of his crew

The cars which make up a train; also a list of those cars. Locomotive consist is a group of engines put together to pull a train.

The device used to connect and disconnect locomotives and cars.

Craftsman Kits:
Are designed for the experienced modeller. These kits consist of unpainted wood, metal or plastic parts often accompanied by decals. Instruction sheets usually include assembly drawings or templates.

Oily liquid from coal tars used to waterproof wooden beams and piers. Simulated with black and gray paints.

The men and women who run a train.


When two tracks cross each other, as in the center of a one-level figure-eight-style model railroad.Normal crossing angles are 90°, 45° and 30° but other angles were used when required by the situation.

Crossing, Grade:
An intersection between a highway and railroad tracks on the same level.

The pair of turnouts on parallel tracks that allow trains to travel from one track to an adjacent one.

Slang for caboose; also called a doghouse.

Central Control Room, a facility from which rail system operation will be monitored and controlled.

Centralized Traffic Control (CTC):
A remotely controlled block signal system under which train movements are authorized by block signals whose indicators supersede the superiority of trains

A passage way under tracks for drainage of water.

Small cabin atop the caboose.

Rate of flow of electricity within an electrical circuit.

Classified as:

  1. 1. Simple – one radius throughout.
  2. 2. Compound – two or more simple curves of similar radius.
  3. 3. Reverse – A compound curve of opposite directions.


  1. A number of cars, coupled together.
  2. An excavated section through a hill allowing the tracks to remain level. When the railroad has to dig or blast through a hill or mountain to maintain a level roadbed.



Date Nail:
A small nail used by railroads from late 1800's to present used to mark the year a tie was placed in roadbed. Nails are distinctive in that each has the last two digits of placement year stamped in head. Usually found within six inches of tie end, but some are located mid tie to allow easier inspection. Rarer nails value in 100's of dollar range to collectors.


  1. A track or route that terminates with no outlet.
  2. Short section running line terminating at buffer stops.


  1. Movement of equipment (usually passenger cars or engines) or crews in order to position them for future use. Crews are paid, but not working while deadheading. Equipment is not being used or occupied by revenue passengers while deadheading.
  2. An empty car; a passenger riding on a pass; a locomotive travelling without cars.

Digital Command Control

Departure Yard:

An arrangement of yard tracks in which outbound trains or cuts are placed or assembled.

Charges applied to the customer due to delays in loading or unloading a car after being placed at industry.


  1. To leave the rails.
  2. A device placed short of clearing point on a track to prevent a car or engine from fouling main track, derailing said car or engine if not removed to permit safe passage.


  1. To operate a train on an alternate route; to reroute.
  2. To operate a train on another railroad to bypass an obstruction or interuption on its normal route.

A special track work item that allows two railroad tracks to cross each other at grade. (see also Crossing)

Die Cast:
Casting process where molten metal or other liquid is forced into a mould.


A railroad employee who coordinates all train movements; he may issue specific orders to keep traffic moving. The dispatcher monitors and co-ordinates the movement of trains over main lines and sidings. He may directly control block signal, CTC or interlocking systems or may direct operators that control those systems.

A portion of a railroad considered as an operational and administrative unit, typically under the supervision of a superintendent.

Dog bone:
Model railroad arrangement consisting of two reversing loops connected together. Also known as" Dumb Bell".

Double Hung Window:
Window with two sliding sashes that move vertically next to each other.

Double Ended Siding:

A length of track with switches at each end. See also: (Passing Siding)

Double Slip Switch:
Used only where space is limited, combines the functions of a crossing and turnouts to allow any one of four routings.

Double Track (DT):
Two main tracks, on one of which the current of traffic is in a specified direction, and on the other in the opposite direction.

DPDT (Double pole-double throw):

  1. An electrical switch that has two connections or poles, with two position or capable of completing one of two alternative circuits.
  2. An electrical slide or toggle-type switch that is used for reversing the flow of current to the tracks by wiring across the back of the switch. Some types have an "off" position midway in their throw and these "Center-off DPDT" switches are often used for wiring model railroads to allow two-train and two-throttle operation.
    See also SPDT SPST (Single pole swithes)

To switch cars in a yard.(see also Drill Track)

Drill Track:

A track connecting with the ladder track, over which locomotives and cars move back and forth in switching.

Dry Brushing:
Process of rubbing paint only on the surface of a material without any flowing of the paint. A brush is dipped in just a little paint the excess wiped off, and the nearly "dry brush" is used to rub pigment on an object. Used for weathering.

Switch a car behind the engine onto an adjacent track when the engine can't run around the car. The engine speeds up, uncouples from the car and pulls past the switch, the switch is lined for the other route and the cars roll past the engine.

Dual Gauge:
Track able to accommodate trains of two different wheel gauges. Usually achieved by the laying of a third length of rail, one being common to both gauges. Very common in Europe, and in model railroading in the U.S. such as HO and HON3.

A passage underneath layout benchwork requiring ducking or crawling ( bend down and go under ) to gain access to another part of the layout.

A small auxiliary signal used to control unusual movements such as a set back into a yard from a main line. Implies a complete stop and wait for a manual operation from the panel. Usually ground mounted lens: two whites for proceed and red/white for stop. Also known as dolly or dwarf.

Dynamic Braking:
A method of train braking where the kinetic energy from the train movement generates current at the locomotive traction motors, and is dissipated in a resistor grid on the locomotive.


Electrical connection to complete a circuit; Also called Ground.

A portion of track on a spiral curve that connects a curve of constant radius to a section straight track, or Tangent track. Also known as a Transition Curve. It changes the radius from that of the curve to that of the tangent track, and the rate of change in radius is constant along the easement.


  1. 1) Drawing showing one side only of a structure.
  2. 2) Vertical distance above an established level or grade.

A crew member who controls the locomotive. He is in charge of the train in the conductor's abscence. The engineer is responsible for safely operating the train over the railroad. He is second in command of the train. He must know the territory and the rules, plus the operation of the engine and the air brake system. He is responsible for handling the train to minimize slack action in the train (the banging back and forth in the train due to cushioning devices and slop in the couplers) and to minimize fuel usage

A building in which locomotives are serviced and/or stored

Engine Yard:
The yard in which engines are stored and serviced.

End-of-train device (EOT):
A telemetry device, required by federal law, that is installed at the rear of a train to relay information to the locomotive engineer.

Model layout consisting of a length of track with a terminal at each end. Point-to-Point.


A train not authorized by timetable schedule. It may be designated:

  • Extra - For any extra train except work extra, the movement of which is authorized in a specified direction.
  • Work Extra - For any extra train authorized by Form H train order, the movement of which may be in either direction within specified limits.
  • Passenger Extra -- for passenger train extra. (not in all rulebooks)


Facing (Turnout):
A turnout with the points facing traffic or the direction of movement.

Board nailed vertically to the end of roof rafters; sometimes used for gutter support.

Power connection from the power pack to track and elsewhere on model railroad; Also a short branch road feeding traffic to a mainline.

Ferro- meaning iron plus equine- meaning horse give one who studies iron horses, i.e., a railfan

Fiddle Yard:

See Staging yard. A hidden track or series of tracks used by modellers to make up or break down trains, lifting the equipment by hand.


  1. to add cars to a train, to pick up a block of cars.
  2. An earthworks to raise the level of the tracks above the surrounding terrain.

Crew member whose job it is to keep the fire and steam up in a locomotive; on a diesel he services the motor. Firemen in the steam era were responsible for the mechanical care of the boiler and it's appliances. The engineer was responsible for the running gear. The engineer is responsible for the fireman's actions. They fuel and water the engine outside of terminals oiled steam engines and inspect engines for wear and defects. Once diesels came into widespread usage, fireman became 'engineers in training'. Firemen get promoted to engineers

Protection of a train or location against movements towards that train or location. Traditionally governed by Rule 99. Typical instructions would require that when a train stopped a flagman would provide protection by walking away from the train the distance required by the rules (flagging distance, typically 1-2 miles), placing two torpedoes on the rail and then returning half the flagging distance to the train. The flagman would remain at that position prepared to stop an approaching train with a red flag or a fusee. The flagman would continue to flag until recalled to the train or relieved.


The rear brakeman. The great country music singer Jimmie Rodgers used to brag about being a flagman. Reason? Because flagmen had to know how to read so they could understand train orders.

The portion of any railroad wheel that guides that wheel down the rails. The flange extends around the circumference of each railroad wheel as its largest diameter.


An open car without sides or roof.

Flexible sections of track used on a layout. In "HO" it usually comes in straight, three-foot long sections which can be bent as needed. Larger Flex Track such as large scale "G" need to be bent with a rail bender before it is assembled. Other kinds of track are sectional (rigid pieces of straight and curved track that come with train sets) and hand laid (built with handmade ties, rail, and spikes).

Used to describe the different varieties of wording and purposes for train orders:

  • Form A: Meets.
  • Form E: Time orders
  • Form F: Sections
  • Form G: Extra trains.
  • Form H: Work extra trains.
  • Form L: Annuling an order.

Various forms could be combined together in one train order.
Form D (modern): A form used in receiving written permission to occupy track in DCS sections of railroad lines. Permission is given by Train Dispatcher or Operator.

Flashing Rear End Device -- end of train telemetry device

Modeling that does not closely follow a specific prototype railroad, location or type of operation.

Freight Agent:

The station freight agent accepts requests from customers and prepares waybills, bills of lading as well as pull/spot lists.

Freight Yard:

A group of tracks used for switching, classification or storage of freight cars.

The number of times per second an alternating current reverses its direction.


The X shaped rail assembly where rails cross in a turnout or crossing.

A small flare that burns for a set amount of time, typically 10 minutes. It is used to warn trains that there is a train ahead of them and to pass hand signals. A train which slows to a speed at which it may be overtaken or less than one half the track speed (depending on the rule book) will drop a fusee behind it at regular intervals as a warning to following trains. A train which is moving at a restricted speed must stop before passing a fusee and must remain stopped until the fusee burns out or wait 10 minutes (depending on the rulebook). A train that is moving that encounters a lit fusee must stop and wait until the fusee burns out if it can be seen or wait 10 minutes if it can't be seen.


A break in the rails to electrically isolate some portion of the track from another to prevent short circuits or to allow for multiple-train operation on the same stretch of track.

Gandy Dancer:
A railroad track worker. Name came from the Gandy Mfg Co. in the 19th century that made a lot of track tools.

The spacing of the rails as measured from the inside of one rail head to the next. The "standard gauge" for most American railroads is 4 feet 8-1/2 inches; this distance was also once the standard center-to-center spacing for wagon wheels. Narrow gauge is any track spacing less than standard. Common examples are 3 ft., 2 ft., and 1 meter gauges. Wide gauge is a track spacing larger than standard. Some common examples are 5 ft gauge and 6 ft gauge. Gauge and scale may be combined in a shorthand notation. On3 means 0 scale (1/4" = 1'0") with a 3'0" space between the rails. H0n2-1/2 means an HO scale model (3.5mm=1'0") but the rails are spaced 2'6" apart.

General Code of Operating Rules. Rulebook adopted by most of the railroads west of the Mississippi in 1985.

Slang expression for a locomotive, usually a small yard switcher.


A freight car with sides but without a roof.

The angled rise or fall of the track so it can pass over another track or so it can follow the rising or falling contour of the land. In N. America is is expressed as a percentage which is the ratio of the ride over distance (1 ft rise in 100 feet of distance = 1% grade)

The direction and arrangement of fibres in wood, card stock or stratified stone.

Grade Crossing:
Where a street or highway crosses the railroad. Also where two tracks cross each other.

Gravity Yard:

A yard where gravity assists in the spotting and classifying of cars whereby they move along under their own momentum. Also called a Hump Yard.

Ground foam:
Synthetic foam rubber ground up and dyed for use as a texture element in scenery.

Ground Throw:
A mechanical device (usually done manually) which will change the position of a turnout, and simultaneously change the position of the signal mounted on top of the ground through.

An additional rail used on the inside of rails to help wheel flange follow the proper route (as in a turnout or crossing), or to keep derailed cars on the track structure (as on a bridge).



A scenery base made by dipping paper towels in plaster and laying them over a light support structure.

Haul, Short:
The act of routing freight such that the haul takes maximum advantage of the originating railroad, at the disadvantage of another railroad which had to be used to carry the freight part of the way to its destination. The railroad which suffered the disadvantage was said to be "short hauled."

Head-end Cars:
The front of the train. The cars that are normally coupled to the front of a passenger train, including express refrigerator, baggage and mail cars.

A head shunt, or shunting neck, is a track running parallel with the main line, facing the yards. It is arranged so that shunting can take place without interfering with the main line. In N. america it is a lead or drill track.

The time interval between trains running in the same line.

A climbing or descending curve which turns around an axis like a corkscrew. Used on multilevel layouts to allow trains to go from one level to another in a relatively small space.

The locomotive that is added to a train to supply extra power that may be needed to surmount a steep grade.


  1. A signal given to proceed at maximum permissible speed.
  2. To not perform a work event.

A pressed paperboard often used for roadbed.


An open-top car with pockets, or hoppers, opening on the underside of the car for unloading bulk commodities.


Men who service and sometimes move locomotives from one servicing facility to another to prepare the locomotive for the engineer. Hostlers are the craft that handles light engines in the yards. Hostlers (named for the people that took care of horses at an inn) may take the power off inbound trains to the engine service tracks. They supply the engines with fuel, sand and water. Hostlers move engines around inside the engine service and repair facilities. They may take the engines back out to the outbound train. There may also be helpers or herders with hostlers. Hostlers typically come from the ranks of fireman or engineers. Hostler helpers are engine service employees who handle the switches for hostlers. Herders are switchmen who handle switches for hostlers. Most hostling crews cannot handle any cars, except maybe cars of supplies for the roundhouse or service track. Inside hostlers may only work within the limits of a roundhouse or shop area; building consists of engines, fueling, watering and sanding locomotives. Outside hostlers may work both inside and outside the mechanical areas in the terminal area. Outside hostlers are used to move power within a terminal area. Outbound and inbound road train crews may move their power between the roundhouse and their train or hostlers may do this. Not all terminals have outside hostlers. All hostlers work for the roundhouse foreman while in the mechanical facilities and the outside hostlers work for the yardmaster when outside the mechanical areas. These people come under the Federal Hours of Service Act and are considered train service employees.

Hot Box:
On friction bearings, an overheated journal bearing.

House Track:

A track entering, or along side a freight house. Cars are spotted here for loading or unloading.

An elevated section of track down which freight cars can be coasted for classification in the yards below.

Hump Yard:
  1. A yard where cars are switched by shoving them over a small hill or hump and allowing gravity to roll them into the appropriate track.
  2. A yard where gravity and powered switches sort incoming trains onto correct tracks. DO NOT HUMP signs are placed on cars that must not use a hump yard because of cargo restrictions or car age. Marshalling yard with artificial mound or hump over which cars are propelled and gravitate to correct siding and position in the yard.

Trade name of U.S. Gypsum Corporation for a very hard dense plaster. Much stronger than plaster of Paris or patching plaster.



Incline or Inclined Plane:
A method of moving railway equipment up steep grades using a cable hoist. The cable can be winch driven or assisted by the weight of a car traveling downhill (also called a funicular system).

Initial Terminal Air Brake Test:
Air test required on all trains before they depart their initial terminal. The trainline must be charged to the required air pressure. A brake reduction is made. The train line is checked for leakage. Every car in the train is checked to ensure the brakes have set on every car. The brakes are released and every car is inspected to ensure the brakes have released on every car.


  1. A section of track or several tracks where one railroad connects with another so trains or individual cars can move from one railroad to the next.
  2. The act of exchanging cars between railroads.

A system of mechanical or electrical controls so only one train can move through a junction of two or more tracks like a crossing or yard throat.

Freight traffic that refers to containerization of freight for easy transloading to different modes of transportation.





Kicking or kicking a cut:

  1. To accelerate a cut of cars and then uncouple one or more of those cars, allowing them to roll into a track on thier own momentum.
  2. switching cars "on the fly" without going into the track, stopping, uncoupling, and then reversing the locomotive back onto the lead for the next move. The purpose of kicking was to allow a string of cars being sorted or classified to be sent in ones, twos, threes down a series of classifications tracks on the same lead without the need to stop, back up, and then go forward again.

To combine parts from two or more kits to produce a model different from both. Sometimes called cross-kitting, customizing or converting.

Taking one or more model railroad kits (often structure kits) and changing the construction process or combining parts to make a unique model.

The movable portion of the drawbar coupler.



L-Girder Benchwork:
Benchwork made of two or more L girders, angle with the flange horizontal and on top. Joists are attached to the top of the girders and the roadbed is either attached to the top of the joists or on risers above the joists.


A series of sidings parallel to each other with a set of linked switches for access. Term for marshalling yard or siding layout where series of points on switches follow each other giving leads off a straight line to one side.

Ladder Track:
A track connecting a number of parallel sidings or stubs in a yard or terminal.

Less-than-carload lot; freight shipments that are too small to require an entire car. Small shipments were accumuated into a single car.

Lead Track:

Trackage connecting a yard with the main line.


Passenger train. Only main stations are serviced. Emphasis is on comfort, speed and convenience (see also : Accomodation, Commuter)


Continuous circular connection between up and down lines at terminal station or yard enabling trains to reverse direction without releasing locomotive.



Mile Post:
A post or sign on pole each mile along the track that shows the distance from a predefined location such as a major rail terminal.

Main Line:
(slang) The most heavily trafficked routes of the railroad. (also Main Iron, Main Stem, Main Track, etc.) – Through trackage; restricted by rules to travel only by scheduled trains or those trains with train orders or on a schedule.


The track extending through yards and between stations upon which trains are operated by time table or train order or both, or the use of which is governed by block signals.


Pronounced "Malley" (rhymes with "alley"). See "Articulated".

Maintenance-of-way (MOW):
The employees, rolling stock or structures that are directly associated with maintaining the railroad, structures or bridges.

Marshalling Yard:

Area where cars are sorted, assembled and marshalled into trains. A switching or classification yard.

Small sections of model railroads designed for portability, that have a standard end configuration so they can be interconnected with other sections built to the same standard. Can be joined with other modules to form operating layouts.

Maintenance Of Way

Multilevel car:

A long flatcar designed with one or more deck levels in addition to the car's main deck; used to haul new automobiles and trucks.



National Model Railroad Association.

Normal position:
The position or route of a switch when lined for the main track or primary route. Typically the tangent route through the switch.



Official Railway Equipment Register:

Official Railway Guide:
Document that lists public schedules of passenger and freight trains, stages, rail ferries and packet boats. Also may include maps, lists of connections and offices.

On the Fly:

  1. Switching cars without having the locomotive come to a complete stop after each move. This was done to speed the process. A good crew could switch a "cut" of 10 to 12 cars along a multi-track lead without the locomotive ever coming to a complete stop.
  2. To perform an action without stopping, as in a crew picking up orders on the fly or changing crews on the fly.

Open Grid Benchwork:
Benchwork made of rectangular frames that are attached together to form a layout. The road bed may be attached to the top of of the grid itself or raised above the grid on risers. The grids may be of a uniform size (length, width or both) or may vary according to the design.

Running trains on a layout in a way that stimulates real railroad activity.

ORER, Official Railway Equipment Register:
Quarterly publication that list equipment in service on N. American railroads, their number series, initials, ownership and dimensions. Also contains clearance diagrams, interchange rules and descriptions of car types.

Originating Station:
The first station on each subdivision from which a train is authorized to occupy the main track.



Panel Desk:
Or board on which operating switches for points and signals are mounted. In N. America, a control panel.

Paired Track:
When two railroads own single track lines, they may reach an agreement whereby one railroads track services both roads in one direction, while the other railroads track services both roads in the other direction.

Passing Siding:

A siding specifically for passing of trains in the same or opposite direction; may be several miles long so that neither train is required to stop. See also "Double Ended Siding".

Pick-Up Freight:
Train which stops at intermediate points to pick up and drop off freight cars on an as required basis.

TOFC or Trailer On a Flat Car. Originally used when truck trailers were loaded onto flat cars for shipment by rail.

Portion of track within a terminal on which a train may stand for a period of time

The portions of a turnout that move to change the track's route from the main line to a siding. The point where the rails actually cross is called the "frog" part of the switch.

Private Car/Business Car:
Coaches owned by private individuals/railroad (for use of corporate officials or supervisors). Cars were positioned at end of trains and train crew were to remain off these cars except in performance of duties. Crew was also to see that occupants of these cars were not disturbed at all costs

Describes a layout concept that combines prototype ("real-life") scenes and elements with freelanced (fictional) elements. This includes extending a prototype railraod into territory it did not actually serve, but could have; creating an alternative history that extends the life of a "fallen flag" railroad; and many other combinations.

The term used to describe the full version that any model is supposed to duplicate.



Quill Drive:
A drive system common on electric engines where a motor drives a circular ring with "fingers" that fit between the spokes of the drivers. A quill system was used on the noted class GG-1 electric engines of the PRR.



Radio Control:
A method of operating and controlling locomotives by means of radio signals transmitted through the air or by means of a carrier control basis through the track.

Rail Weight:
The number of pounds per yard that rail weighs. Currently rail is being rolled at 112 to 145 pounds per yard

Rail Joiner:
The pieces of metal that join two lengths of rail together. They slide onto the ends of the rail on a model railroad; they are bolted to the rails on the prototype.

Red Eye:
(slang) A red signal or horizontal semaphore arm requiring the train to stop and proceed with caution.

A common slang term for a refrigerator car

A heavy metal casting which was designed to be placed near a derailed wheelset of a locomotive or car, for the purpose of guiding the wheelset back onto the rail. Steam locomotives and early diesels usually carried rerailers on hooks on the tender trucks or frame (steam locomotive) or on the frame of a diesel.
Also known as a "rerail frog". There were several different designs of rerail frogs, some were designed to be used "outside" where the flange of the wheel had to pass over the top of the rail be rerailed, some were designed to be used "inside" where the tread of the wheel just had to reach the ball of the rail amd some were designed to be used either inside or outside. A notable design looked like a large wide V that straddled the rail and could be used either inside or outside. It was commonly called a "bat wing frog."

Restricted Speed:

  1. (older version)A speed that will permit stopping short of train, engine, railroad car, stop signal, derail or switch not properly lined.
  2. (modern version)A speed that will permit stopping within one half the range of vision; short of train, engine, railroad car, stop signal, derail or switch not properly lined, looking out for broken rail, not exceeding 20 MPH.

Some older versions include "looking out for broken rail". Some versions may not have a speed associated with them or a different speed.

Restricted Track:
A track section where train speeds are reduced.

A station where train reverses direction of travel . May be at normal dead end or terminal station.

Reverse movement:
A movement in the direction opposite the train was previously authorized to move.

Reverse position:
The position or route of a turnout when lined for other than the main track or primary route. Typically the diverging route through the turnout.

Right of Way:
The property and the track owned by the railroad The land on which a railroad is built; also precedence given to one train to proceed before another.

  1. An area of the maintenance yard where equipment is stored while waiting for repairs. In model railroading a few sections of track by a freight yard or on a shelf above the workbench.
  2. The track on which rolling stock is repaired.

Road Bed:
A layer of earth or gravel which provides a foundation for ties and rail. In model railroading wood, cork, plywood, Homosote and other materials are used.

Road Foreman of Engines:
A railroad official responsible for training and rules compliance, particularly of engineers and fireman. They teach and evaluate engineers for rules compliance, train handling and fuel efficiency. Some railroads now call them "managers of operating practices".


A pair of turnouts arranged on parallel tracks in yard ladder that let engine get by train it just pulled in.

Run Through:
An agreement between two or more railroads that allow the locomotives and caboose of one railroad to continue through intact on the route of another. The railroad owning the engines is compensated for their use with "horsepower hours" which is the horsepower of the unit multiplied by the number of hours it is on the second road.



Sanborn Map:
Founded in 1867 by D. A. Sanborn, the Sanborn Map Company was the primary American publisher of fire insurance maps for nearly 100 years.Sanborn fire insurance maps are the most frequently consulted maps in both public and academic libraries. See also this page: [Sanborn Map].


  1. Operating Rules: One of two or more trains running on the same schedule, displaying signals or for which signals are displayed.
  2. M of W: A portion of a railroad maintained by a gang.

Section Gang:

The section gang maintained the ballast, ties and rails (ie. the infrastructure) of the railway. Heavy locomotives in movement cause a lot of shifting and it was the section gang's responsibility that tracks stayed in gauge and could safely handle the traffic. They were often called "gandy dancers", from the rhythm of their work.

Service Yard:
A yard whose main function is to service engines, repair cars and provide heavy maintenance and rebuild functions. Normally located at division points or central point of smaller railroad

A type of steam locomotive using a gear drive in place of a side rod drive, designed by Ephraim Shay in the late 1800's, and produced by what became the Lima Locomotive Works. This locomotive was designed for logging and other operations where heavy grades and sharp curves existed and prevented the use of side rod type locomotives

A track auxiliary to the main track for meeting or passing trains.

Slippery Track:
A highly greased track near the roundhouse or back shop where a newly rebuilt locomotive could be run in without going anywhere, and without calling an engine crew or pilot.

Special Agent:
A railroad ploice officer or detective, (slang) a "Bull" or "Cinder Dick".


An electrical slide or toggle-type electric switch. Classified as :

  1. Single throw (ST). Used to interrupt / close a circuit
  2. Double throw (DT). Used to "switch" between two "path"

Some DT types have an "off" position midway in their throw. See also DPDT (Double pole switch)


  1. A mechanical device used for drawing curves.
  2. A key on a drive shaft.
  3. A mathematical function used for Interpolation between points.
  4. A type of railroad car used in intermodal service consisting of a central spline and crossbeams for the wheels and the front. Minimal construction provided a very lightweight car.
  5. A thin vertical piece of wood, masonite or homasote, typically 8 to 12 feet long used to build elevated roadbed. See also this TIP : [Easyspline-masonite-roadbed ]


  1. The act of placing a car in a specific location on a track.
  2. Placing a car at industry.


  1. A single ended track.
  2. An industry track.
Staging tracks:

Tracks used to represent the rest of the railway system. A staging yard is regarded as off-scene; it may hold multiple complete trains, and may also be subject to direct human intervention (fiddling, see Fiddle yard ) to re-arrange trains.

Storage Yard:
A yard whose main function is to store cars, sometimes with cleaning and maintenance facilities

Stub Track:
A form of side track connected to a running track at one only. It may be protected at the other end by a bumping post or other obstruction.

A track is said to be superelevated when one rail is higher than the other through a curve. Raising one rail tilts the train as it passes over, banking it into the turn much like an airplane. This allows the train to transit the curve at higher speeds and greater comfort. Prototype railroads compute the amount of superelevation for a given curve from the speed the will be used through the curve.


  1. To sort railcars in a yard.
  2. To place or remove cars from industry.
  3. European term for Turnout.
  4. Electric command device (see : SPDT SPST, DPDT )

Switching lead:
Track dedicated for use by the switch engine while classifying cars. Gives the switcher tail room (room to pull back)while switching.



Team Track:
A public spur or siding used by industries that do not have their own siding

Terminating Station:
The last station on each subdivision to which a train is authorized to occupy the main track.


  1. Employeee - a listing of the stations and train schedules (times trains are authorized to depart those stations), with additional information that affects the movement of trains. An employee timetable schedule conveys authority to occupy the main track.
  2. Public - a listing of passenger trains operating and the times they are scheduled to depart stations. A public timetable does not convey authority to occupy the main track.
  3. The original method of train control was through a published timetable of scheduled meeting places for trains where priority was through class (1st, 2nd, extra etc.) then by direction

(also "sleeper") A rectangular object used as a base for railroad tracks. Ties are members laid transverse to the rails, on which the rails are supported and fixed, to transfer the loads from rails to the ballast and sub grade below, and to hold the rails to the correct gauge. Traditionally, ties have been made of timbers, but concrete is now widely used, steel has been used, and plastic has been tried.

Timetable and Train Orders:
A system of authorizing trains to occupy the main track using a timetable or modified by train orders.

A small explosive charge that is placed on the rails that expodes when the wheels of a car or engine passes over it that serves as an alert to the train crew that there is a train or obstruction ahead. If was used to comply with flagging instructions.

Trackage Rights:
An agreement between two railroads which allows trains of one railroad to operate over a portion of the other railroad.

Track Pan:
A water filled trough placed between the rails at certain locations on a railroad's main line, each trough having a length of up to 2500 feet, for the purpose of adding water to the tender of a steam locomotive via an air activated scoop which was located on the underside of a locomotive tender. The use of a track pan arrangement prevented a need to stop to obtain water. Users of track pans included the New York Central, the Pennsylvania, and the Baltimore and Ohio Railroads in the US.

A cargo-carrying highway vehicle without automotive power.

Train Order:

  1. A system of structured messages that direct the movement of trains other than those movement authorized by timetable.
  2. A message changing the meeting point between two trains. For movement of trains not provided by timetable train orders will be authorized by, and over the signature of the director of train dispatching or chief dispatcher.

Train Order Signal:

  1. (US) A fixed signal that indicates whether a train has to obtain a clearance at that station. Train order signals may have 2 or 3 indications, may be a semaphore position arm, solid or flashing light.
  2. Fixed signal near the entrance to a river tube, bridge or at stations with moving platforms. Two lunar white mean Proceed without orders according to rules, two red mean Stop, stay and call for orders. Also: a signal at a station that indicates by its position or by its color, that train orders are to be delivered to a train, or that no orders are to be delivered

An operating officer responsible for managing train operations in a terminal or over a portion of a division. He reports to the superintendent. Train crews and engineers report to him. Clerical forces and agents report to him regarding railroad operating issues. He is the line officer that investigates accidents and derailments, coordinates the operations at and accident scene and conducts disciplinary investigations.

Transportation Plan or T-Plan:
A plan or listing which describes the train schedules, blocking plans, connections, connection cut-offs, locomotive requirements, service requirements and other operational parameters of a railroad. It is used to design the train service of the railroad.

A rotating steel or wooden bridge to turn locomotives or cars and/or to position them to align with the tracks in the engine house or round house.


  1. Where two diverging tracks join.
  2. A piece of track that allows a train to go from one track to another.

Referred to by number. See above: Turnout Number

Turnout Number:
The ratio of the length of the tangent track to an equal unit of space between the tangent track and a point on the branch track. For example, a no. 6 turnout spreads one foot for each six feet of forward travel measured from the frog.



Uniform Code of Operating Rules. There are at least two UCOR rulebooks, one developed by Canadian roads and one by Midwestern US roads (MP, TP, CEI, CRIP, MKT, FWD, et al).

United States Railway Administration. The USRA took over and operated American Railroads during World War I; was responsible for certain long lasting and "standard" locomotive designs.



Term used to refer to passenger trains, dating back to the late 19th century and the varnished passenger coaches of the luxury trains such as those employed on the LV's Black Diamond and the C&O's Sportsman



Walk Around:
A layout designed for physically following a train around the layout while operating.

Process of painting, staining or colouring to show aging, use or effects of weather on a model.

Way Car:

  1. A freight car carrying local shipments.
  2. A caboose.
Way Freight:

A freight train that switches cars at most towns along its route from terminal to terminal. Also called a peddler freight.

The vertical portion of a rail between the head or ball and the base.

Wing Rail:
A continuous running rail that forms the obtuse angle of a diamond crossing. Also a running rail from switch heel towards nose which is then set to form check rail past nose of common crossing.


  1. A turnout where both routes diverge from the centerline of the track. (see also "Y turnout").
  2. Also, the triangular shaped track (in plan view) where trains can be reversed.

Whistle Signals (Engine): (* means a short blast of the whistle or horn) (- means one long blast)

  • * apply brakes, stop
  • * * answer to any signal not otherwise provided for
  • * * * when standing, back
  • * * * * call for signals
  • - test train brakes
  • - - release train brakes
  • - - - when running, stop at next passenger station
  • - - - when standing, train parted
  • - - - - recall flagman from south or west
  • - - - - - recall flagman from north or east
  • - * * calling attention to another train that signals are displayed for a following section
  • - * * * flagman protect the rear of train
  • * * * - flagman protect the front of train
  • - - * approaching meeting or waiting points
  • - - * - approaching crossing at grade
  • - * * - answer to yellow temporary reduced speed flag placed 1 1/2 miles in advance of restricted tracks





"Y (Turnout)":
A equilateral switch. A switch whose routes each diverge from the track centerline at equal angles.

A group of tracks where switching chores are performed for storage, classification, making and breaking up of trains, etc.

Yard Clerks:

Clerks process the inbound trains, making a list of the train and filing the waybills. A waybill is more or less the ticket for a car to ride a train. They would keep track of the switching and make lists of the classified tracks. When an outbound train was finally assembled or "set", they would make the train list and gather the waybills. Clerks called "Weighmasters" weighed cars and recorded the information on the waybills. The clerks that worked out in the yards checking for car/track positions were called mudhops. Clerks (Cashiers) also handled the money and financial affairs for the railroad. There were several types of offices: passenger (handled tickets, baggage, express and mail), freight (billing, car orders, switch orders, customer car delay fees or demurrage and diversions) and yard (weighing, interchanging with other RR's, preparing train and switch lists) in major locations. These functions may be combined in small towns, down to a combination depot with only an agent performing all of these tasks. Clerks also are the ones who "call" or notify the crews that they are to report for duty for a train. Clerks work for a chief clerk on their shift. The Agent is in charge of clerical operations and works for the Trainmaster.

Yard Lead:
The portion of track before the yard ladder used to assemble the train. In theory the yard lead should be as long as the longest train but if shorter, it provides interesting work for the yard engine

Yard Limits:
A portion of main track designated by yard limit signs and by timetable, train order Form T or track bulletin, which trains and engines may use as prescribed by Rule 93.


Railroad employee in charge of a yard operation. Yardmasters are in charge of the overall operation of a yard. They decide which cut will be switched and what cars will be switched into each track. The switch crews work directly for them. They also direct traffic in the yard tracks and on the main track in yard limits. They give trains movement instructions for their area of responsibility. In some smaller yards a switch foreman will be given the title of "footboard yardmaster" and he will have the responsibility to direct the overall yard operation, while still being a yard engine foreman. Complex terminals may have multiple yardmasters (hump, trim, east, west, etc.) and when there are multiple yardmasters a General Yardmaster is in charge. If the yardmasters are agreement employees, seniority in craft determines who gets the assignment. General Yardmaster or yardmasters might be non-agreement on some roads. The yardmasters work for Trainmasters and the General Yardmasters



Revised by Enzo Fortuna 10:24, 3 April 2007 (PDT)

Last revised by Dave Husman