Railroad Property, A Glossary Of Various Types

Last revised: September 9, 2024

By: Adam Burns

Below are several railroad infrastructure and property terms that broadly cover both areas such as various track terms, how a turntable functions, and what is the purpose of a shoofly. 

The terms are listed in alphabetical order and provide thorough but brief descriptions of each topic covered.

Lastly, I do hope that the terms and meanings included here are of help and beneficial use to you, as that is the primary  reason for providing the information presented. 

Please note that you can also find additional meanings at the website of Trains magazine, the leading periodical covering the railroad industry.

Soo Line GP9 #2411, a chop-nose design converted in 1963, lays over in Stevens Point, Wisconsin on April 21, 1974. This unit later became Canadian Pacific #8270. American-Rails.com collection.

Railroad Infrastructure and Property Terms (A)

Abandon: To cease operating all or part of a route or service, especially with the intent of never resuming it again.

Angle bar: Short pieces of steel used to join together standard sections of rail (usually 39 feet in length). Four bolts, fastened through a pair of holes at each end of the angle bar, are used to join the rails together.

Armstrong turntable: Any old-style equipment that relies only on manpower to operate (in this case, a turntable). A steam engine that lacks an automatic stoker is sometimes called an "Armstrong."

Railroad Infrastructure and Property Terms (B)

Backshop: Facility where heavy repair and rebuilding of locomotives takes place.

Ballast: A layer of material, which usually consists of either crushed rock, cinders, or gravel that is placed upon a railroad right-of-way, which holds railroad ties in place and allows for drainage and runoff.

The term is also sometimes used to describe extra weight added to locomotives. (An SD40-2, for example, can weight anywhere from 150 to 200 tons, depending on the amount of ballast added at the buyer's specifications.

The usual method of ballasting is to use thicker sheets of steel to fabricate the frame. Occasionally smaller amounts of weight, usually concrete casting, are added to equalize weight distribution.)

Beanery: A railroad eating house.

Block: Usually refers to a particular section of track that is computer-controlled so that trains can be properly, efficiently, and safely operated.

Bowl: The primary means of building trains in a yard with hump capability, these tracks are located following it.

Boxed joints: Rail joints that are located directly across from joints on the other side of the tracks. These are also known as "opposed" or "square" joints.

Branch line: A secondary railroad line that is not a main line, it also usually receives less maintenance than main lines.

Broad gauge: Any track gauge that is greater than 4 feet 8 1/2 inches.

Railroad Infrastructure and Property Terms (C)

Catenary: A system of overhead trolley wires that carry electrical current. It is suspended directly above the railroad tracks with aid from wires that are strung along line-side poles.

Continuous welded rail (CWR): Rail laid in lengths of 1,500 feet or so (roughly a 1/4-mile), rather than 39-foot pieces bolted together.

Aside from saving railroads millions in maintenance costs and derailments CWR does not buckle, because it resists thermal expansion and contraction. It is also referred to as ribbon rail.

Controlled siding: A siding where switches and signals are remotely controlled by a dispatcher.

Crossing: Commonly known as a diamond, they allow for railroad tracks to intersect each other at any type of angle that does not allow for actually switching on to the other track. It is also the term often referred to the place where highways and railroad tracks meet commonly known as grade crossings.

Crossover: Facilitates the movement of rail equipment onto parallel tracks via back-to-back switches.

Railroad Infrastructure and Property Terms (D)

Diamond: Similar to a crossing, a situation when two railroad lines cross one another without the means of switching onto the other track.

Dual control switch: A track switch that can either be operated manually or remotely (by a dispatcher).

Railroad Infrastructure and Property Terms (E)

Exempt railroad crossing: This notice allows for all vehicles to operate over the grade crossing without the need to stop or watch for oncoming trains.

Railroad Infrastructure and Property Terms (F)

Fill: A railroad right-of-way formed by leveling a low area to keep the ruling grade manageable.

Flying junction: Similar to a flyover (below) except that two or more railroad tracks, on at least one line, operate through the junction.

Flyover: Also known as an overpass/underpass it allows for two intersecting railroad lines to cross one another without the means of a diamond, which would require dispatching and increase transit times.

Frog: The area of the track through a switching point that allows for the wheel flange to pass through it (otherwise the wheel would snag the track and derail).

Switches are numbered according to the angle of their frogs (so the sharper the curve the less speed it can be taken at). For instance, a Number 20 switch separates the rails one foot for every twenty feet traveled.

Railroad Infrastructure and Property Terms (G)

Gauge: The inside width of a railroad track. Here in the U.S. the Standard Gauge is 4 feet 8 1/2 inches.

Grade: The slope or angle of the railroad right-of-way. It is based on percentages so if the ruling grade for a rail line or section of railroad track is 2% than this means that the right-of-way rises roughly two feet per every one-hundred feet traveled.

As an example 2% is a somewhat steep climb and railroads try to keep their ruling grades no great than this (although it does happen with railroads operating lines that reach up to 3% to 4%).

Ground throw: A manual device to operate switches that is roughly the same height as the rail-head.

Guard rail: Usually placed on bridges one or two rails are placed inside the running rails to prevent railroad equipment from tumbling completely off of the right of way when it derails.

Railroad Infrastructure and Property Terms (H)

Helper district: A segment of railroad line with steep grades that must use extra locomotives to negotiate the train over it.

High iron: Slang term for a main line or main track as iron was once the main material used in the construction of rails.

Hot box: An overheated wheel bearing, which if left undetected, can burn off and cause a derailment.

Hot box detector (HBD): A heat sensor that warns of hot boxes and are found along a railroad line.

House track: A siding track running near a station that allows for either passengers or freight to be unloaded (very common in the older days of railroading).

Hump yard: Classification yards where strings of freight cars are slowly pushed over a hump, or small hill, and properly organized according to whatever precedent the railroad has them planned for.

Once the single car reaches the top of the hill, or hump, it coasts under its power into the bowl until it reaches the proper yard track, via a computer-controlled switch, it is designated for.

Railroad Infrastructure and Property Terms (I)

Interchange track: A simple length of track, usually a siding, where two railroads interchange cars.

Railroad Infrastructure and Property Terms (J)

Jointed rail: Rail in standard sections (usually 39 feet) that was bolted together, as opposed to continuously welded rail.

Junction: The area where two or more rail lines meet or intersect.

Railroad Infrastructure and Property Terms (L)

Lead (pronounced "leed"): A track which connects a group of tracks to a main line.

Light rail: A term referring to rail transit, it usually consists of a single powered car or small consist with a single operator that uses overhead catenary (electricity) for power. Normally this type of transit system if sound in cities and towns (usually operating directly on the streets) and is very similar to the trolley systems of old.

Railroad Infrastructure and Property Terms (M)

Main line, or Main track: The principle railroad track that connects two points it usually also includes sidings, spurs, and yards at a number of different locations to serve train meets, customers, and/or hold freight cars.

Maintenance of way: The repair and maintenance of a railroad right-of-way.

Movable-point frog: The "new" frog it allows for the wheel flange to be constantly supported through a switch rather than the opening that occurs in standard frogs to allow flanges to pass through freely (i.e., the gap is eliminated). It also allows for higher speeds through a crossing of at least 70 mph.

MOW: Maintenance-of-Way.

Railroad Infrastructure and Property Terms (N)

Narrow gauge: Any track gauge that is less than the Standard Gauge of 4 feet 8 1/2 inches.

Railroad Infrastructure and Property Terms (O)

Operating rod: The manually or mechanically operated bar at a switch which allows the switching points to be moved into either the main route position or diverging route position.

Railroad Infrastructure and Property Terms (P)

Plant: A shortened version of the "interlocking plant" term, which efficiently controls the movements and operations of all of the switches, signals, and controlling mechanisms at a particular junction of railroad tracks.

Pound (rail): The unit of measure of rail size is weight per yard. For instance, 120-lb rail gets its weight designation because every three feet of rail weighs roughly 120 lbs.

Railroad Infrastructure and Property Terms (R)

Rail: The standard steel-fabricated structure that railroads use to operate over. Today the structure is known as "T"-rail as it is formed in roughly an upside-down "T" shape to provide for maximum support.

Once made from standard 39-foot sections today rails are fabricated in 1/4-mile sections (up to 1,500 feet) and then welded together to form continuous welded rail (CWR) that is much stronger, reliable, and cheaper to maintain than jointed rail.

Rail lubricator: Devices mounted along the rails in areas of high curvature that apply lubricant to the flanges of locomotives and cars of passing trains to reduce both flange- and rail-wear.

Receiving yard: The destination for arriving trains carrying cars to be sorted or classified.

Ribbon rail: Also known as continuous welded rail (CWR), rail laid in lengths of 1,500 feet or so (roughly a 1/4-mile), rather than 39-foot pieces bolted together.

Aside from saving railroads millions in maintenance costs and derailments CWR does not buckle, because it resists thermal expansion and contraction. It is also referred to as ribbon rail.

Railroad Infrastructure and Property Terms (S)

Shoofly: Temporary track constructed to allow trains to pass around an obstacle that blocks movement on the main track, usually as a result of maintenance or an accident/derailment.

Siding: An additional track found to the right or left of the main line that allows for trains to operate more efficiently over a line whereby they can "pull over" to allow another train to pass.

Slip switch: The combination of a diamond crossing of two tracks including a connecting track that allows for the movement between the two through tracks.

Split the switch: The result of a freight car's trucks following opposite rails (i.e., one follows the main line the other the diverging track), the car is said to have split, or "picked" the switch.

Spring switch: A spring-mounted track switch that automatically returns to the normal position when the final car passes over it. This type of switch saves time by not needing to be operated manually.

Spur: A short stretch of track splitting from the main line which is normally used to serve either customers or store equipment.

Standard gauge: The track gauge used throughout North America and most of Europe of 4 feet 8 1/2 inches, which is the measurement between the inside of the two rails.

Stock rail: The rail against which the point of a switch rests.

Stub switch: A track switch in which the rails of the single-track end of track move sideways to meet the two (sometimes three) pairs of rails from the other end. Stub switches are long since obsolete, replaced by the conventional switch with movable tapered rails called points.

Switch: As a noun the term that refers to track equipment that allows for cars to move, or crossover, from one track to another. The verb meaning of this term refers to shuffling or moving rail cars, usually within a yard (also called marshaling).

Switchback: A track setup whereby a reserve move is made to negotiate very steep grades that is usually performed by using back-to-back switches.

Railroad Infrastructure and Property Terms (T)

Tangent: The term for straight track.

Team track: A historical term that carries on today as a rail siding for general use by freight shippers. It was originally named for the teams of horses that once pulled the wagons to pick up and deliver the freight.

Tell-tale: A device that was once placed along the track to warn crew members operating a top freight cars of a moving train that a low structure was eminent down the line. Once crew members no longer operated on top of moving freight trains these were abolished.

Third rail: A rail that runs parallel to the main running tracks whereby locomotives or powered rail cars pick up, via "shoes," electricity for power. Third rails are essentially the same as overhead catenary in that it is a device for locomotives or powered rail cars to pick up needed electricity.

Throwbar: A bar underneath the ties of a turnout to which the points are attached and which moves the points.

Tie: The component of railroad infrastructure that holds the rails in place and supported by the surrounding ballast. Ties are usually made of either wood, concrete, or newer composite materials.

Torpedo: A small explosive charge that can be clamped to the top of the rail, which is used as a warning device to crews as it detonates upon impact with the locomotive wheels.

Track gauge: The distance between the two rails. Here in the U.S. and North America the gauge, known as Standard Gauge, is 4 feet 8 1/2 inches.

Trestle: A structure that spans a short distance (usually a stream or overpass that uses timbers or steel for supports.

Turnout: Another term for a railroad track switch.

Turntable: A rotating structure that swivels in a 360 degree radius that either turns locomotives in the opposite direction or diverts them onto a different track.

Railroad Infrastructure and Property Terms (U)

Union station: A railroad station that was used by multiple railroads which was typically also funded jointly by the railroads which used it.

Railroad Infrastructure and Property Terms (V)

Viaduct: Long bridge structures that span land areas, usually constructed of arches and heavy, reinforced concrete.

Railroad Infrastructure and Property Terms (W)

Wye: A triangular arrangement of tracks forming the letter "Y", typically used for turning railroad cars and locomotives.

Railroad Infrastructure and Property Terms (Y)

Yard: Usually a large series or groupings of tracks that allows for either the storage of railroad cars or to be held for a short time to build future trains.

Yard-limit board: A trackside sign which marks the boundary of yard territory and rules.

Yard ladder: An angled track which connects a grouping of tracks that make up the yard tracks.

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