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Railroad Industry Overview Series - Industry Terms - October 2007

LMSB Control Number: LMSB-04-1007-072
Affected IRM: X.XX.X

This document is not an official pronouncement of the law or the position of the Service and cannot be used, or cited or relied upon as such.

Industry Terms

A. Terms Specific to Railroad Industry

These terms were taken from the Railway Age’s Comprehensive Railroad Dictionary, by Simmons-Boardman Books Inc., January 1992 edition.

Industry Term

Definition or Explanation

The Association of American Railroads (AAR)

An industry association whose purposes include the promotion of railroad interests and the standardization and coordination of operating and mechanical activities within the railroad industry.

Abandonment (of Lines)

As distinguished from curtailment, the complete cessation of service, operations, and maintenance of a railroad (usually a branch line), for which discontinuance permission has been granted by appropriate federal or state agency..

Auto Rack Car

A flatcar with fixed steel racks, for transporting setup automobiles.  Racks have either two or three levels, and are equipped with tie-down devices.  Auto rack cars carry an A.A.R. mechanical designation of “FA”.


Material selected for placement on the roadbed for the purpose of holding the track in line and at surface.

Ballast Car

A car for carrying ballast for repair and construction work, usually of either the flat, gondola, or hopper type.

Belt Line

A short line railroad operating within and/or around a city; usually organized to be a pickup, delivery and transfer service facility for trunk lines and industrial plants.


A person who assists with train and yard operations.

Branch Line

A secondary line of a railway, as distinguished from the main line.

Business Car

A term frequently applied to a car used by railway officials while traveling.  Equipped with office and living accommodations for eating and sleeping.


A shipment of not less than five tons of one commodity.

Center Sill

The main longitudinal structural member of a car under frame often constructed as a large box section or hat section.  The center sill receives all of the buff and draft forces created in train handling and switching.

Class I Railroad

A railroad having gross operating revenues of more than $319 million annually.  This designation is by statute under STB regulations and is updated periodically. 

Class II Railroad

As defined in STB regulations, a railroad with gross operating revenue > $23.6million and < $319 million.  See also, Regional Railroad below.

Class III Railroad

As defined by STB regulations, a railroad with gross operating revenue < $23.6 million.  See also Short Line Railroad and Switching & Terminal Companies.


The process by which cars are grouped according to their destinations and made ready for proper train movement.

Classification Track

One of the tracks in a classification yard, or a track used for classification purposes.

Classification Yard

A rail yard consisting of a number of usually parallel tracks, used for making-up trains.

Container On Flat Car (COFC)

A type of rail-freight service involving the movement of closed containers on special flat cars equipped for rapid and positive securement of the containers using special pedestals or bolsters.

Common Carrier

One who holds himself out the general public to transport property and passengers, intrastate, interstate or in foreign commerce, for compensation.  Common carriers must operate from one point to another over routes or in territory prescribed by the Interstate Commerce Commission (interstate) and by a Public Service or Public Utilities Commission (intrastate).  See Contract Carrier.

Company Car

In a general sense, a freight car owned by the carrier over whose line it is being operated as opposed to a foreign car.”  Sometimes called a “system car.”


A large, weatherproof box designed for shipping freight in bulk by rail, truck, or steamship.

Continuous Welded Rail (CWR)

Rail lengths welded together end to end into rail strings providing a track without joints.  Also called welded rail or ribbon rail.


Removal of metal from the end of an ingot bloom or rail during its manufacture.  Also, cutting of the ends of used rails that are battered or damaged.

Cross Tie

The transverse member of the track, See Tie.  The transverse member of the track structure to which the rails are spiked or otherwise fastened to provide proper gage and to cushion, distribute, and transmit the stresses of traffic through the ballast to the roadbed.

Cycle Time

The length of time consumed by a freight car from one loading to the next.

Density of Traffic

The tonnage or volume of traffic over any section or division of a railroad measured in terms of carloads or ton-miles.

Distribution Center


A centrally located warehouse where goods shipped long distances by rail are loaded onto trucks for short-haul delivery to receivers, or vise versa.  Also called a reload center, it combines the economies of rail with the flexibility of truck pickup and delivery.

Double Track

Parallel sets of main line tracks, typically found in areas with high densities of traffic.

Double-stack Container

Containers that can be stacked one atop another on a flatcar.

Federal Railroad Administration

An agency of the U.S. Department of Transportation with jurisdiction over matters of railroad safety and research.

Field Manual

One of two manuals that together form the A.A.R. Code of Interchange Rules governing the condition and repair of railway equipment used in interchange service.  The Field Manual contains technical information concerning mechanical condition, wear limits and repair criteria for interchange cars.

Finance Docket

Interstate Commerce Commission’s dockets on which are listed, for consideration and decision, questions relating to abandonment, extensions, consolidations and financing of common carriers.


An open car without sides or roof.

Foreign Car

Any car not belonging to the particular railway on which it is running.


See Federal Railroad Administration.


A track structure used at the intersection of two running rails to provide support for wheels and passageways for their flanges, thus permitting wheels on either rail to cross the other.

Gage (Track)

See Standard Gage.

Gondola Car

The common gondola car is a freight car with low sides and ends, a solid floor, and no roof.  It is used mainly for transportation of coal, iron and steel products and other lading not requiring protection from the weather.

Grade Crossing

An intersection of a highway with a railroad at the same level.  Also, an intersection of two or more railroad tracks at the same elevation.

Gross Ton-Miles

A measure of transportation, being the movement of the combined weight of cars and lading a distance of one mile.

Haulage Rights

Rights obtained by one railroad to have its cars or trains operated by another railroad over that railroad’s tracks, using the other’s crews and usually its locomotives.

Heavy Repairs

As reported to the Association of American Railroads, repairs to revenue freight cars requiring over 20 man-hours.

Hi-Cube Car

A term used to describe any of a series of boxcars whose inside dimensions are such as to produce a cubic capacity of approximately 10,000 cu. Ft., as opposed to the cube of conventional cars, which is usually in the range of 4,000 to 6,000 cu. Ft.

Hopper Car

A freight car, either open or covered, designed for handling bulk commodities such as coal or grain.  Hopper cars have floor sheets that slope from the car sides and ends to form a series of pockets, or hoppers, which when opened, can discharge the bulk lading by gravity through hopper doors operated from outside the car.

Hump Yard

A railroad classification yard in which the classification of cars is accomplished by pushing them over a summit, known as a “hump,” beyond which they run by gravity.


Abbreviation for Interstate Commerce Commission.

Interline Freight

Tonnage passing over the lines of two or more carriers.  The interchange between the carriers is termed an “interline movement.”

Intermodal Car

A rail car designed specifically for handling piggyback trailers or containers, or both.

Intermodal Traffic

Freight moving via at least two different modes of transport.

Less-Than-Carload (LCL)

A term applicable to a quantity of freight that is less than the amount necessary to constitute a carload.

Light Repairs

As reported to the A.A.R., repairs to revenue freight cars requiring 20 man-hours or less.

Line Capacity

The maximum number of trains that can operate safely and reliably over a given segment of track during a given period of time.

Line-haul Service

The movement over the tracks of a carrier from one city to another, not including the switching service.


A self-propelled, non-revenue rail vehicle designed to convert electrical or mechanical energy into tractive effort to haul railway cars.

Main Line

A term referring to the primary or most heavily used tracks of a railroad. Primary rail line over which trains operate between terminals.  It excludes sidings, and yard and industry tracks.

Narrow Gage

A gage narrower than standard gage.  A gage of 24 inches or less is commonly employed for industrial railways. Metric gage is commonly used in foreign countries.

Net Ton-mile

The movement of a ton of freight one mile.

Office Manual

One of two manuals that together form the A.A.R. Code of Interchange Rules governing the condition and repair of railway equipment used in interchange service.  The Office Manual contains the pricing and billing information used for preparing bills for repair work done on foreign cars.  See Interchange Rules and Field Manual.

Operating Ratio

The percentage of revenues that goes into operating the railroad.  It is calculated by dividing railway-operating expenses by railway operating revenues.

Passing Sidings

Tracks adjacent to main line or secondary tracks for meeting or passing trains.

Passing Track

See “Side Track.”

Per Diem

The amount or rate paid by one carrier to another or to a private car owner for each calendar day (or each hour) it uses a car belonging to the other.


A term referring to the practice of transporting highway trailers on railroad flatcars.  See TOFC.


As used in track, a rolled steel shape, commonly a T-section, designed to be laid end to end in two parallel lines on cross ties or other suitable supports to form a track for railway rolling stock.

Rail Anchor

A device attached to the base of a rail bearing against a crosstie to prevent the rail from moving longitudinally under traffic.

Rail Joint

A fastening designed to unite the abutting ends of contiguous rails.

Rail Lubricator

A device designed to apply grease to gage side of the railhead at the beginning of a curve.  In order to minimize wear of the rail and wheel flange or to eliminate noise.

Railroad Retirement Act

An Act of Congress, August 29, 1935, for the purpose of establishing a retirement system for employees subject to the ICC.

Railroad Retirement Board

A board consisting of three members appointed by the President, by and with the consent of the Senate, to administer the Railroad Retirement Act.

Railroad Tie

The transverse member of the track structure to which the rails are spiked or otherwise fastened to provide proper gage and to cushion, distribute, and transmit the stresses of traffic through the ballast to the roadbed.

Regional Railroad

A line haul freight railroad that has operating revenues > $23.6million and < $319 million, as defined by STB regulations.  Generally operate at least 350 miles of road.  See also Class II Railroads above.

Relay Rails

Rails taken up from tracks where formerly used, which are suitable for relaying in other tracks.

Right of Way

The strip of land on which a railroad truck is built.  The term generally refers to intercity main line tracks, but can also apply to branch lines and sidings.

Rip Track

A small car repair facility, often simply a single track in a classification yard or terminal.  In larger yards, the rip track may be quite extensive with several tracks and shop buildings.  Larger car repair facilities are generally known as “car shops”.  The name “rip track” is derived from the initials RIP, which stand for “repair, inspect and paint.”


The foundation on which the rails and ties of a railroad are placed.

Running Repairs

A term describing minor, itemized standard repairs performed and billed by the railroads in accordance with the Interchange Rules.

Short-line Railroad

As defined by STB regulations, a railroad with gross operating revenue < $23.6 million.  Any freight railroad that cannot be classified as a I or Regional railroad.  Short line railroads may originate or terminate freight traffic on its track, participates in division of revenue and are usually less than 100 miles in length.  See also Class III Railroads above.

Shoulder (Track)

That portion of the ballast between the end of the tie and the toe of the ballast slope.

Side Track

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


The general term used to describe main structural members of a car under frame. See Center Sill, Side Sill, End Sill.

Single Track

One main track, on which trains operate in either direction, distinguished from double or multiple tracks.

Single-line Service

Service by a single railroad between two locations.


A cable less locomotive, which has traction motors, but no means of supplying power to them by itself.  Power cables provide power from an adjacent unit.  Slugs are used where low speeds and high tractive effort are needed, such as in hump yards.


A long steel square nail with a cutting edge used to secure rail in place.

Spur Track

As distinguished from a sidetrack, a spur track is of indefinite length, extending out from main line.

Staggers Rail Act of 1980

An act of Congress that fundamentally altered the regulatory environment of the railroad industry by reducing regulations including the elimination of antitrust immunity in certain areas of activity.

Standard Gage

The standard distance between rails of North American railroads, being 4’ 8-1/2” measured between the inside faces of the railheads.


Any material which is spread on the finished sub grade of the roadbed below the top-ballast to provide better drainage, prevent upheaval by frost, and better distribute the load over the roadbed.

Surface (Track)

The condition of the track as to vertical evenness or smoothness.

Switch Tie

The transverse member of the track structure that is longer than, but functions, as does the cross tie, and in addition supports a crossover or turnout.


Switching service consists of moving cars from one track to another track or to different positions on the same track.   It includes the moving of cars in the make-up and break-up of trains; also moving of cars on industrial switching tracks or interchange tracks, and the general movement of cars within terminals or at junctions.

Switching and Terminal Companies

Carriers performing primarily switching service, or terminal service at stations, stockyards, etc.


A power-driven machine for compacting ballast under ties.


Any straight portion of a railway alignment.  Tangent track means straight track with no curves.

Tank Car

A rail car, the body of which consists of a tank for transporting liquids.  Tank cars may be pressure or non-pressure, and are often equipped with special equipment to enhance their usefulness for handling specific commodities.


A railroad facility used for handling of passengers or freight and the receiving, classifying, assembling, and dispatching of trains.


In track construction, the cross members to which the rails are attached.  The majority of ties are made from wood.  Other materials used in manufacture of ties are concrete, steel and new composites.  See also, Railroad Tie.

Tie Plate

A steel plate interposed between a rail or other track structure and a tie.


An acronym for “trailer or flatcar” intermodal service.


A term denoting the transportation of one ton of freight a distance of one mile.


An assembly of rails, ties, and fastenings over which cars, locomotives and trains are moved.

Track Chart

A map-like representation of the grade and alignment of a section of a railroad

Trackage Rights

The right of one carrier to use track owned by another carrier pursuant to an agreement between them.

Traction Motor

A specially designed direct current series-wound motor mounted on the trucks of locomotives and self-propelled cars to drive the axles.


The name given to a computerized car movement system coordinated by the Association of American Railroads for furnishing information to member railroads about movement of their cars throughout the country.


The complete assembly of parts including wheels, axles, bearings, side frames, bolster, brake rigging, springs and all associated connecting components, the function of which is to provide support, mobility and guidance to a railroad car.


A centrifugal blower driven by an exhaust gas turbine used to supercharge an engine.


An arrangement of a switch and a frog with closure rails by means of which rolling stock may be diverted from one track to another.  Another name for “track switch.”


Acronym for Universal Machine Language Equipment Register.  A computerized file maintained by the Operating Transportation Division of the Association of American Railroads.  UMLER contains specific details on internal and external dimensions of equipment as well as special equipment and the general information shown in The Official Railway Equipment Register.

Uniform Systems of Accounts (U.S.O.A.)

A chart of accounts prescribed by the Interstate Commerce Commission for common and contract carriers.  There are separate systems of accounts for the various types of transport under I.C.C. jurisdiction, such as railroads, motor truck and bus lines, freight forwarders, pipe lines, etc.

Unit Train

A freight train that moves carloads of a single product between two points.  By unloading on arrival and returning promptly for another load, such trains cut costs because they eliminate intermediate stops in yards and reduce cycle times.


An erosion of the permanent roadbed by storm or flood to such an extent as would cause delay of trains, or endanger traffic.


The primary written documentation of every freight shipment that forms the basis for railroad freight revenue accounts.

Welded Rail

See Continuous Welded Rail (CWR).


A system of tracks within defined limits provided for the making up of trains, storing of cars and other purposes.  A system of tracks branching from a common track.

B.  Terms Specific to Transportation Industries Generally

Industry Term

Definition or Explanation

Bill of Lading

Shipping documents which transfers title to the goods.

Cargo Handler

Person that loads freight onto dock and into trailers; also known as swampers, lumpers, stevedores, longshoremen.


An ocean vessel, airfreight or common carrier (trucking) in the business of transporting goods or persons.


In trucking, to transport goods between the freight terminal and cargo carrier.

Charge backs

Uncollectible account receivables that reduce the cash received from factored invoices.


Basically long, thin, steel frame on wheels, which attaches to truck tractors to haul containers.


A freight forwarder that consolidates shipments with another freight forwarder.


The company or individual that receives the shipment of freight.


Purchases container space at a volume price for resale to freight forwarders.  Practice of taking several small separate shipments of freight and organizing them into one container.


A large metal box used to store freight on ocean vessels and rail cars.  Once the vessel arrives in port, the container can be loaded onto either a truck chassis or a railroad car.  They usually come in 20 or 40-foot lengths.

Container Freight Station (CFS)

Customs‑bonded warehouse.

Custom Delivery Order

Delivery order prepared by a customs house broker.

Customs House Broker

A licensed agent authorized to pay customs duties and take possession of goods coming through Customs.  No one may act as a Customs House Broker without a Customs House License. 

Because customs duties may range up to 20 percent plus on some products, the consignees, for cash flow purposes, may elect not to clear customs at point of entry, but instead, through the services of a Customs House broker, wait until the goods are shipped inland before clearing customs and paying the duties.

Custom House brokers have to post a $500,000 bond, to insure that if the goods are damaged or stolen during transportation, the duties on the goods will still be paid to Customs.


A fee charged by the shipping companies if the container is not returned timely.


A fee charged by the railroad if the trailer is not returned timely.


In trucking, pickup at the shippers dock (door) and delivery to the ramp of the railroad, ocean ship or airline carrier.


Pulling a trailer or container (cartage), the charges for transfer and cartage between stations, or to and from vessels on carts or trucks.

Free Time

Amount of time (days) the container can be used without any charges.  Varies with the type of container and mileage distances.

Free Zone

The area within a certain radius of the port‑of‑entry or harbor where a for‑hire carrier is not required to be licensed by the ICC to transport freight between states.

Freight Broker

An agent for the independent contractor that arranges jobs for independent contractors.

Freight Forwarder

An agent who makes the arrangements for the transportation of freight from the shipper to consignee.  The freight forwarder issues a through bill of lading from the origin to the destination, and takes full responsibility of the freight while it is in transit.

Land bridge

Port haulers who transport freight from the harbor to the railroad.

Line haul

In trucking, the movement of freight from the point of origination to point of destination.


Ocean carrier cargo handler that loads and unloads freight at the harbor. 


In trucking, cargo handler of agricultural products that is usually paid by cash.


Schedule of freight pickups and deliveries.

Non‑Vessel Operating Carrier (NVOCC)

A consolidator of freight for an ocean carrier that is regulated by the Federal Maritime Commission.


Loading freight at the shipping end, point of origination.


Unloading freight at the receiving end, final destination.


Where the trailer is loaded onto a rail car.

Piggyback Agent

Shipper's agent that books and schedules freight on railroad.

Port hauler

A sub hauler that picks up freight at the harbor and hauls it to the operations terminal or to the consignee.

Ramp to Door

In trucking, pick up at the railroad and delivery to the consignee's door.


In trucking, refrigerated trailer.


The individual or company sending the freight to the consignee.

Shipper's Agent

A transportation broker that arranges movement of freight.


In trucking, hauling empty trailers back to the rail yard or container company.


Cargo handler that loads and unloads freight from vessels at the harbor (longshoreman).


The process of moving freight from ocean containers to domestic containers and vice versa.  Ocean containers belong to the steamship lines and are not designed for transportation by truck or rail.

C.  Abbreviations & Acronyms

Industry textbooks generally include an extensive glossary of terms and phrases unique to the industry.  Below is a partial list of the more common terms to aid the reader in understanding this document.


Association of American Railroads


Authority for Expenditure


American Railway Engineering Association


American Railway Engineering & Mechanical Association


American Shortline & Regional Railroad Association


Bridge & Structures (Department)


Bad Order


Container on Flat Car


Continuous Welded Rail


Department of Transportation


Distributed Power Unit


Federal Railway Administration


Gondola Car


Gross Ton Miles


Gross Weight


Interstate Commerce Commission (now STB)


Interest During Construction


Joint Facility


Less than Car Load


In trucking, less than Truck Load


Million Gross Tons


Maintenance of Way


Mile Post

MW or M/W

Maintenance of Way


North American Free Trade Agreement


Onboard Terminal


Operating Expense


Other Track Material


Personal Liability/Property Damage


Point of entry


Right of Way


Railroad Retirement Board


Retirement Replacement Betterment (accounting method)


Railroad Retirement Tax Act




Staggers Rail Act


Surface Transportation Board


Standard Transportation Commodity System


Trains & Engines


Train and Engine (personnel)


Tie & Surfacing or Timber & Surfacing


Traffic Control System


Trailer on flat car (that is, piggyback)


Transfer Out to Operations


File maintained by AAR with freight car statistics, by RRD


Uniform System of Accounts

Val (Section)

Valuation Section (of track)


Work Order

Chapter 3 | Table of Contents | Chapter 5

Page Last Reviewed or Updated: 05-Mar-2015