Reader Please Note:
The following definitions are collected from various railroad books I have read, mostly dealing with the technical aspects of operating and maintaining railroads and rolling stock. These terms are not original with me, but have originated elsewhere. When you steal one person's work, that is called plagiarism. When you steal work from more than one person, that is called research. This list is by no means complete, and contains only a small fraction of terms used in the industry. I selected these definitions because I felt that they would be the terms most commonly encountered by the average rail fan. Some of the books that I have read are quite old. As a consequence, some of the terms listed herein may be obsolete, and thus be of historical value only. Enjoy!
AB Valve
The operating device used on freight cars for charging, applying, and
releasing the brakes. Also called a triple valve
ABD Valve
An improvement of the AB Valve that features a quick release.
ABDW Valve
An improvement of the ABD Valve. Modifies the Emergency Portion and
provides for accelerated buildup of brake cylinder pressure during
quick service applications.
Absolute Block
A length of track in which no train or engine is permitted to enter
while it is occupied by another train or engine.
Absolute Permissive Block (APB)
A designated section of track or tracks within which the movement of
trains will be governed by block signals, whose indications supersede
the superiority of trains. The block signals may be controlled manually
or automatically.
Absolute Signal
A block or interlocking signal designated by an "A" market or the
absence of a number plate.
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.
Alley
A clear track in a switching yard.
Angle Cock
An appliance used for the purpose of opening or closing brake pipe on
ends of cars, rear ends of tenders, and front ends of switch engines so
equipped. Provision is made for supporting hose at proper angle.
Application
Consists of all of the operations from the time the brake pipe
reduction is started until the brake is released.
Approach Signal
A signal that governs the approach to another signal.
Automatic Block Signal System (ABS)
A series of consecutive blocks governed by block signals, cab signals
or both, actuated by a train, engine or by certain conditions affecting
the use of a block.
Automatic Cab Signal System (ACS)
A system which provides for the automatic operation of the cab signals
and cab warning whistle.
Automatic Train Stop System (ATS)
A system actuated by wayside inductors, so arranged that its operation
will automatically result in the application of the brakes until the
train has been brought to a stop.
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Bad Order
A piece of rolling stock that needs repair.
Block
A length of track between consecutive block signals or from a block
signal to the end of block system limits, governed by block signals,
cab signals or both.
Block Occupancy Indicator
An indicator used to convey information regarding block occupancy.
Block Signal
A fixed signal at the entrance of a block to govern trains and engines
entering and using that block.
Block System
A block or series of consecutive blocks within APB, ABS, ACS, CTC or
interlocking limits.
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 the person who put it
there in the first place.
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.
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.
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.
Brake Rigging
A term commonly used instead of foundation brake gear.
Branch
A portion of a division designated by a timetable. Rules and
instructions pertaining to subdivisions apply on branches.
Branch Line
A secondary line of a railroad, not the main line.
Bridge Line Haul Road
See overhead line haul road.
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Cab Signal
A signal located in engineer's compartment or cab, indicating a
condition affecting the movement of a train or engine and used in
conjunction with interlocking signals and in conjunction with or in
lieu of block signals.
Caboose Valve
A rotary valve type of device providing means for making a controlled
rate of brake pipe reduction for making a service or emergency
application from the caboose.
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.
Clear Block
A block not occupied. Sometimes used to denote a clear signal
indication.
COFC
Container on flat car. Referred to in intermodal traffic.
Color Light Signal
A fixed signal in which the indications are given by the color of a
light only.
Color-Position Light Signal
A fixed signal in which the indications are given by color and position
of two or more lights.
Conductor
Brakeman, with or without brains, displaying pencils.
Controlled Point
A location designated by number where signals and /or switches of a CTC
system are controlled by a control operator.
Controlled Siding
A siding within CTC or interlocking limits, the authorization for use
of which is governed by signal indication or control operator.
Controlled Signal
An absolute signal, the aspect of which, is controlled by a control
operator.
COT&S
Clean, Oil, Test & Stencil. Applies to air brake rework.
Covered Wagon
A nickname that is generally attached to EMD E and F units.
Crossing
A length of track that carries one track across another.
Crossover
A track connection between two adjacent tracks.
Current of Traffic
The movement of trains on a main track, in one direction, specified by
the rules.
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Dead Head
A railroad employee traveling on a pass.
Distant Signal
A fixed signal outside of a block system, used to govern the approach
to a block signal, interlocking signal or switch point indicator. It
will not convey information as to conditions affecting the use of the
track between the distant signal and block signal, interlocking signal
or switch point indicator to which approach is governed. It will be
identified by a "D" marker.
Division
A portion of the railroad designated by timetable.
Drawbar Horsepower
The total horsepower of a locomotive less the amount of horsepower that
it takes to move the locomotive itself, the balance being available to
pull the load.
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.
Drill Track
A track connecting with the ladder track, over which locomotives and
cars move back and forth in switching.
Dual Control Switch
A power-operated switch, also equipped for hand operation.
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.
Dynamite
Initiation of an emergency application.
Dynamiter
A term commonly given to an brake operating valve that goes into
quick-action emergency when it should not. Also called a Kicker.
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Electric Switch Lock
An electrically controlled lock device affixed to a hand operated
switch or derail to control it's use.
Electric Switch Lock
An electrically controlled lock device affixed to a hand operated
switch or derail to control it's use.
Emergency Application
An application resulting from an emergency rate of brake pipe reduction
which causes the brakes to apply quickly and with maximum braking force
for the shortest practical stopping distance.
Engine
A unit propelled by any form of energy, or a combination of such units
operated from a single control, used in train or yard service.
Extra Train
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.
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Facing Point Lock
A locking device which automatically locks the switch points of a
spring switch in normal position.
Fixed Signal
A signal of fixed location indicating a condition affecting the
movement of a train.
Full Service Application
Reducing the brake pipe pressure at a service rate until the reservoir
and cylinder pressures equalize.
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Gandy Dancer
A railroad track worker. Name came from the Gandy Mfg Co. in the 19th
century that made a lot of track tools.
Gateway
See Interchange Point
Gauge
Broad gauge (Spain): 1674 mm 5'5 9/10th"
Broad gauge (Portugal): 1665 mm 5'5 11/20th"
Broad gauge (Ireland): 1600 mm 5'3"
Broad gauge (Finland): 1524 mm 5' exactly
Broad gauge (former USSR): 1520 mm 5'
Standard gauge: 1435 mm 4'8 1/2"
Narrow gauge (Cape gauge): 1067 mm 3'6"
Narrow gauge (meter gauge): 1000 mm 3'3 37/100"
Grade Resistance
Resistance that results from the energy you must put into a train to
lift it vertically. The energy is returned without loss when the train
comes back down again.
Green Eye
A slang term for a clear signal.
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Highball
A signal given to proceed at maximum permissible speed.
Horsepower per Trailing Ton.
The total horsepower of all working locomotives divided by the total
trailing weight of the train in tons.
Hostler
A person who operates engines in engine house territory and works under
the direction of the engine house foreman
Hostler's Controls
A simple throttle to allow independent movement of locomotives not
equipped with engineers controls.
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.
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Initial Station
The first station on each subdivision from which a train is authorized
to occupy the main track.
Interchange Point
The point at which two or more railroads join. Traffic is passed from
one road to another at interchange points.
Interlocking
An arrangement of signal appliances so interconnected that their
movements must succeed each other in proper sequence. It may be
operated manually or automatically.
Interlocking Limits
The tracks between the outer opposing absolute signals of an
interlocking.
Interlocking Signals
The fixed signals of an interlocking, governing trains using
interlocking limits.
Intermodal
Freight traffic that refers to containerization of freight for easy
transloading to different modes of transportation. See TOFC,COFC,
Piggyback.
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Joint Facilities
Any facilities owned by two or more railroads.
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Kicker
A common expression for an emergency brake application which occurs
when a service brake application is intended or when no application is
intended.
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Ladder Track
A series of turnouts providing access to any of several parallel yard
tracks.
Line Haul Road
A railroad that handles freight over a medium to long distance.
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Main Track
A track extending through yards and between stations which must not be
occupied without authority or protection.
Manual Block System
A series of consecutive blocks, governed by block signals operated
manually, upon information by telegraph, telephone or other means of
communication.
Marker
A train signal that is used to indicate the end of the train.
Multiple Main Tracks
Two or more main tracks, the use of which is designated in the
timetable.
MU
Multiple Unit. A lead locomotive followed by one or more locomotives.
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Originating Line Haul Road
The railroad where any freight shipment starts.
Originating Station
The first station on each subdivision from which a train is authorized
to occupy the main track.
Overhead Line Haul Road
Any railroad or railroads between the originating line haul road and
the terminating line haul road. Also known as a bridge line haul road.
Overlap Sign
A sign marking the limit of control of a block signal.
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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.
Partial Service Application
Reducing the brake pipe pressure at a service rate but not enough to
cause the reservoir and cylinder pressure to equalize.
Piggyback
TOFC or trailer on a flat car. Originally used when truck trailers were
loaded onto flat cars for shipment by rail.
Pilot
An employee assigned to a train when the engineer or conductor is not
acquainted with the rules or portion of a railroad over which the train
is to be moved.
Position Light Signal
A fixed signal in which the indications are given by the position of
two or more lights.
Prime Mover
A V-type diesel with 8 to 20 cylinders rated at about 125 hp per
cylinder if normally aspirated or 250 hp per cylinder if turbocharged.
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Rail Weight
The number of pounds per yard that rail weighs. Currently rail is being
rolled at 112 to 145 pounds per yard.
Register Station
A station at which a train register is located.
Regular Train
A train authorized by a timetable schedule.
Restricted Speed
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.
Rip Track
A small car repair facility, often a single track in a small yard. Name
derived from "Repair, Inspect and Paint."
Rolling Resistance
Resistance that is made up of wheel friction, journal friction, and
wind resistance. It is non recoverable.
Ruling Grade
The particular point on the run at which the combination of grade and
curve resistance makes the train pull hardest and , therefore, "rules"
how heavy a load can be given to the locomotive.
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Schedule
That part of a timetable which prescribes class, direction, number and
movement for a regular train.
Section
One of two or more trains running on the same schedule, displaying
signals or for which signals are displayed.
Semaphore Signal
A signal in which the day indications are given by the position of a
semaphore arm.
Shock
The effect of a sudden change in speed of a car, locomotive or train,
or part of a train.
Side Track
A track auxiliary to the main track.
Siding
A track auxiliary to the main track for meeting or passing trains. The
timetable will indicate stations at which sidings are located.
Signal Aspect
The appearance of a fixed signal conveying an indication as viewed from
the direction of an approaching train; or the appearance of a cab
signal conveying an indication as viewed by an observer in the cab.
Signal Indication
The information conveyed by the signal aspect.
Single Track
A main track upon which trains are operated in both directions.
Slack
The motion, forward or back, that one or more cars, locomotives, or
parts of a train has without moving other coupled cars, locomotives, or
parts of the train. Loose slack is the free movement or lost motion
between parts of a train. Spring slack is the movement beyond the free
or lost motion brought about through compressing the draft gear
springs. Slack is necessary so as to start one car at a time and so
that the train may be operated around curves and over high and low
places.
Slack Action
Movement of part of a coupled train at a different speed than another
part of the same train.
Slug
A small, ballasted, four or six axle unit, semipermanently coupled to a
locomotive that does not have a prime mover, but does have traction
motors. Generally used in yard duty where the switcher has enough
horsepower, but not enough tractive force to push long strings of cars
up a hump.
Spring Switch
A switch equipped with a spring mechanism to restore the switch points
to original position after having been trailed through.
Station
A place designated in the timetable station column by name.
Stub Track
A form of side track connected to a running track at one only and
protected at the other end by a bumping post or other obstruction.
Subdivision
A portion of a division designated by timetable.
Superior Train
A train having precedence over another train.
Switch Point Indicator
A light type indicator used in connection with facing point movement
over certain switches to indicate switch points fit properly.
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Tangent Track
Straight track.
Tare Weight
The weight of an empty car.
Team Track
A track on which rail cars are placed for the use of the public in
loading or unloading freight.
Terminating line haul road
The last railroad over which any shipment travels.
Terminating Station
The last station on each subdivision to which a train is authorized to
occupy the main track.
Timetable
The authority for the movement of regular trains subject to the rules.
It may contain classified schedules and includes special instructions.
TOFC
Trailer on a flat car. Refers to intermodal shipments.
Tons per Operative Brake
Gross trailing tonnage of the train divided by the total number of cars
having operative brakes. (not including locomotives)
Track Bulletin
A notice containing information as to track conditions or other
conditions, necessary for the safe operation of trains or engines.
Track Circuit
An electrical circuit of which the rails of the track form a part. The
track circuit is the basis of signaling systems.
Track Gauge
The distance between the inner faces of the track heads. Nominally, 4'
8.5".
Track Head
The top of the track on which the wheels roll.
Track Permit
A form used to authorize occupancy of main track where designated by
special instructions.
Track Side Warning Detector
Wayside detectors which are provided at various locations as shown in
the timetable which detect such conditions as overheated journals,
dragging equipment, excess dimensions, shifted loads, high water and
slides.
Track Warrant Control (TWC)
A method of authorizing movements of trains or engines or protecting
men or machines on a main track within specified limits in territory
designated by special instructions or general order.
Track Web
The thin section of track between the base and the head.
Trackage Rights
An agreement between two railroads according to which, one railroad
buys the right to run its trains on the tracks of the other, and
usually pays a toll for the privilege. That toll is called a "wheelage"
charge.
Tractive Force
The amount of force at the driving wheel rims to start and move tonnage
up various grades.
Train
An engine or more than one engine coupled, with or without cars,
displaying a marker and authorized to operate on a main track.
Train Brake
The combined brakes on locomotive and cars that provides the means of
controlling the speed and stopping of the entire train.
Train Line
See Brake Pipe
Train of Superior Right
A train given precedence by train order.
Train of Superior Class
A train given precedence by time table.
Train of Superior Direction
A train given precedence in the direction specified in the time table
as between opposing trains of the same class.
Train Order
A message changing the meeting point between two trains.
Train Register
A book or form used at designated stations for registering time of
arrival and departure of trains, and such other information as may be
prescribed.
Triple Valve
An operating valve for charging the reservoir, applying the brake, and
releasing the brake.
Truck Hunting
Rapid oscillation of an empty car truck at high speeds where the
flanges tend to ride up on the head of the rail.
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.
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Variable Switch
A switch, designated by letter "V" or bowl painted yellow, when trailed
through the switch points remain lined in the position to which forced.
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Wheel Pull
Caused by the friction between the brake shoe and the wheel and
transmitted to the rail.
Wheel Rolling
The wheel rotating on its axle theoretically without motion existing
between the wheel and the rail at the area of contact.
Wheel Slipping
The wheel rotating on its axle with motion existing between the wheel
and rail at the area of contact.
Wheel Sliding
The wheel not rotating on its axle and motion existing between the
wheel and rail at the area of contact.
Wye
A track shaped like the letter "Y", but with a connector between the
two arms of the "Y".
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Yard
A system of tracks, other than main tracks and sidings, used for making
up trains, storing of cars and for other purposes.
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.
Yard Engine
An engine assigned to yard service.
Yellow Eye
A slang term for a yellow signal.
