Bad Order Car
or Bad Order Track
A railway car which is being taken out of service for repair. Also, the yard track assigned to storage of such cars.

Bakehead
Slang term for a locomotive fireman.

Ballast
Cinders, crushed rock, or gravel placed on the roadbed to hold track ties in place and to promote uniform drainage.

Ballast Tamper
A track installation and maintenance machine used to tamp down the rock ballast used to hold the ties in position on the roadbed.

Balloon Stack
A widely-flared steam locomotive smokestack designed to prevent sparks from escaping; commonly used on 19th Century locomotives.

Balloon Track
Technical term for a reverse loop.

Bascule Bridge
A counter-balanced lift bridge, generally used where relatively low-lying railroad tracks pass over narrow waterway channels which must be used by waterborne traffic.

Belpaire Firebox
A square-topped firebox typically used on Pennsylvania and Great Northern Railroad locomotives.

Belt Line
A connecting rail line between two or more other railroads; so-called because it often encircles a city like a belt.

"Bend the rails"
To re-align or re-set the movable rails on a turnout.

Bent
One section of a model railroad trestle set. On real railroads, the evenly-spaced vertical sections of a trestle.

Big Boy
Common name for the largest steam locomotive: a 4-8-8-4 Union Pacific.

Big Hole
A quick stop.

Big Hook
Slang term for a heavy-duty derrick or crane railcar, often called a wrecking crane.

Big O
Slang term for a conductor.

Big Shot
Slang term for a yardmaster.

Big Wheel
A rotary snowplow; equipped with blades that turn in a wheel-like manner.

Bill-of-Lading
A printed form which describes freight, the charges incurred in shipping, and the freight's point of origin and destination.

Birney A short, single-truck (4-wheel) trolley car designed for use in congested urban areas where tight track curves are required.

Bleed
To drain the air from the brake system of a railcar or string of cars.

Blind Drivers
Driving wheels without flanges which permit locomotives to negotiate sharper curves than the wheel arrangement would normally allow; widely used on narrow gauge locomotives.

Blind Siding
A railroad siding without telephone or telegraph connections to the dispatcher; no order can be received by a train on such a siding.

Block
In prototype railroading, a section of track through which rail traffic is controlled as a unit. In model railroading, commonly the designation for a length of track with an independently controlled power supply, constructed so two or more trains may operate independently on, for example, a simple oval of track.

Block Signals
A signal or series of signals, usually automatic, which control a block.

Board
A fixed signal.

Bobber
A short, four-wheel caboose.

Bobtail Haul
Early slang expression indicating that a locomotive was pulling only a few cars and a bobber caboose; a short train.

Bogie Truck
A four-wheel pilot truck on a steam locomotive. (Also used for some "Road-Railer" units.)

Boiler
That portion of a steam locomotive, usually round, where the steam is generated.

Bolster
The crosswise member of the frame of a railroad car at the truck (body bolster) or the crosswise piece at the center of a truck (truck bolster).

Boom Car
The car next in line to the wrecking crane or derrick, used to support the crane boom in transit.

Boomer
Slang term for an experienced railroad worker who moves from railroad to railroad in search of (usually) temporary employment.

Booster
In prototype railroading, a small secondary steam engine which assists and increases starting power. Some trailing trucks and tender wheels featured boosters which automatically cut off after a certain speed had been reached.

Boss
Slang term for conductor.

Box Cab
Electric or diesel locomotive with a cab shaped like a box.

Brakeman
A member of a freight or passenger train crew. His duties are to assist the conductor in any way necessary.

Branch Line
Secondary line of a railroad.

Brass Hat
Slang term for conductor; also for President or boss of a rail line. In model railroading, an advanced modeler.

Brass Buttons
Slang term for a freight conductor.

Brass Collar
Slang term for a railroad official.

Brownies
In model railroading, demerits given to members of model railroad clubs for various infractions of operating rules; a form of good-natured punishment for making a mistake.

Buggy (also Crummy, Cabin, and Hack)
Common terms for caboose.

Buggy Track
A caboose holding or storage track.

Bull
Slang term for a railroad police officer.

Bumper
A device for stopping railroad cars at the end of a spur track.

Bunker
A bin, usually elevated above track level, used for storing and dispensing coal.

Brill
A type of two-truck, 8-wheel trolley car used primarily in urban areas.

Cab
The section of the locomotive that contains the controls and where the engineer and fireman customarily ride.

Cab Control
A system for switching control of a series of blocks on a model railroad so that two or more throttles are capable of controlling operation in those blocks, depending on which locomotive is to use the blocks at any given time.

Cab-Forward
A type of steam locomotive (most commonly used by the Southern Pacific) built so the cab portion is at the front for added visibility and safety from smoke and fumes in tunnels and snowsheds.

Caboose
Car for the brakeman and other crew; office for the conductor at the rear of a freight train.

Cab Signals
Lights on a control panel in fornt of the engineer which indicate the condition of the track ahead of his train.

Caboose-Way Car
A caboose with a section for tools and equipment for track work, or a caboose with a section for hauling freight.

Call Board
Bulletin board where crew assignments are posted.

Camelback
A steam locomotive with the cab set astride the boiler. The fireman on this type of locomotive rides under a hood at the rear. Also called a "Mother Hubbard."

Cap
A noise-emitting torpedo placed on the track for signaling purposes. The cap is activated when locomotive wheels pass over it.

Car Barn
Storage house for trolley and interurban cars.

Car-catcher
Slang term for brakeman.

Car Knocker
A car inspector; so-called because these individuals tap the wheels of cars to test for soundness.

Carry a flag
To run late or off-schedule.

Carry the mail
To travel at high speed; walk or run swiftly.

Car Toad
Slang term for a railroad car repairer.

Car Whacker
Slang term for a railroad car cleaner.

Catenary
A system of overhead wires suspended over the track to provide power for electric-type locomotives.

Cinder Pit
Same as "Ash Pit."

Circuit Breaker
A device which interrupts an electrical circuit if a short or overload occurs.

Class
Groups into which trains are divided--usually from two to four, depending on the railroad.

Class 1 Railroad
In the United States, a railroad with operating revenue in excess of $5 million per year.

Classification Lamps
Lights (or flags) mounted on the front of a locomotive to indicate the status of the train. White lamps (or flags) indicate an "Extra," while green indicates all sections but the final one of multi-section trains.

Classification Yard
A freight yard (or yards) where complete trains are made-up or broken-up by shifting cars with a switcher locomotive, or by means of a hump.

Clean the clock
To stop suddenly.

Clear Board
A signal indication which authorizes a train to proceed.

Clerestory Roof
Raised center portion along the length of a roof of certain passenger cars featuring "clerestory windows" along the sides to allow natural light into the car.

Climax
A type of geared steam locomotive used primarily by logging railroads. The locomotive's twin cylinders drive a crankshaft aligned parallel with the axles; power is transmitted to the trucks through an arrangement of bevel gears and a driveshaft; rods couple the axles on each truck.

Clinker Boy
Slang term for a locomotive fireman.

Clown Wagon
Caboose.

Coaling Station
A structure for storing coal and transferring it into locomotive tenders.

Coil
In model railroading, a tightly wound "spool" of thin wire which is a component of electrical devices such as solenoids and electromagnets.

Cold Joint
In electrical work, a soldered connection in which the materials being joined were insufficiently heated to melt the solder and cause it to flow and bond.

Common Ground
In model railroading, the use of a single wire to complete a circuit for numerous track sections or accessories. Eliminates the need for a large number of "ground" wires, one for each accessory or track.

Commutator
The rotating part of an electric motor which contacts stationary carbon brushes to complete the electrical circuit.

Conductor
The senior crew member on a freight or passenger train responsible for the safe, prompt movement of the train; for the care of its cargo and equipment; and for the actions and safety of the crew. The conductor is the ranking crew member in charge of train movements and operation. Also, in model railroading and electricity, the term for any material (usually metal) that allows electrical current to flow through it.

Consist
The full set of cars which make up a train, usually used in reference to a freight train.

Contactor
In model railroading, a switch-like device that fits beneath a section of toy train track, and is activated by the weight of a train passing over it.

Continuous Rail
Rails which have been welded together to form a very long single rail, thereby eliminating rail joints which are the weakest part of the track. Also known as Welded Rail or Ribbonrail.

Control Rail
In model railroading, any rail fitted with auxiliary electrical connections that allow it to perform special electrical functions, such as the two extra rails in Lionel remote-control track sections. Also, Insulated Control Rail: wherein one of the outer, or running, rails of a section of three-rail toy train track is isolated electrically and then connected by wire to an accessory. When the metal wheels of a passing train contact this rail, an electric circuit is completed which causes the accessory to operate.

Convertor
Electrical device for changing Direct Current (DC) into Alternating Current (AC).

Cornfield Meet
A head-on collision of two trains.

Counterweight
In the context of a steam locomotive, the solid weights on the drive wheels which offset the weight of the engine's crank pins and drive rods.

Coupler
A device at the ends of a car or locomotive used to connect that car to other cars or locomotives.

Covered Wagon
A diesel unit with a full-width (streamlined-appearing) cab, as opposed to a "Hood Unit."

Cow and Calf
A double diesel engine unit consisting of a regular switch engine and a matching cab-less booster unit which are semi-permanently coupled together--often by a drawbar as is used to couple tenders to steam locomotives. Used mainly for heavy transfer work and yard hump service. The Calf unit itself is also sometimes referred to as a "Mule" unit.

Cowcatcher
Early term for a locomotive's pilot. A pointed device used on the front of a locomotive to shove livestock off the track. Now used to prevent any object from going under the locomotive's wheels.

Cradle
A gondola car.

Crankpin
Pin or screw attached to the driving wheels which holds side rods in place, while still allowing them to turn.

Crossing at Grade (also Grade Crossing)
An intersection between a road or highway and railroad tracks on the same level.

Crossing
An intersection between two tracks on the same level.

Crossover
Combination of track and switches which enable trains to cross from one parallel track to another.

Crummy
See "buggy."

CTC (Centralized Traffic Control)
Train dispatching conducted at one location for several or all of a railroad's designated operating divisions.

Culvert
A passageway under tracks for the drainage of water.

Cupola
A small cabin atop the caboose where the brakeman can scan ahead over the roofs of freight cars in a train.

Current
The movement or flow of electricity.

Cushion Rider
Slang term for a passenger conductor.

Cut
(1) A number of cars, coupled together, or (2) an excavated section through a hill so the tracks can remain as level as possible.

Cycles
In electricity, the alternation of the direction of current flow, generally expressed as cycles per second. In the U.S., most household current alternates at 60 cycles per second. Also known as "hertz."

DC (Direct Current)
Electric current which flows in only one direction. Model railroad power packs for two-rail trains typically input AC (household) current, and convert (rectify) it for output as low-voltage DC current to run the trains.

Dead Man's Control
Automatic control which an engineer must hold in an "on" position against a spring. If the engineer dies or becomes somehow disabled, the Dead Man's Control is automatically released and stops the train.

Deadhead
(1) An empty car, or (2) a passenger (or off-duty crew member) riding free on a pass; or (3) a locomotive traveling without cars.

Departure Yard
An arrangement of yard tracks from which cars are forwarded.

Depot
A station for passengers and freight; term usually applied to a rather small facility in a town or village.

Derail
A device placed over the rail to prevent a car from rolling out of a siding (for example) and onto the main line.

Detainer
Slang term for train dispatcher.

Diamond Pusher
Slang term for locomotive fireman.

Diamond Stack
A diamond-shaped smoke stack, usually associated with 19th Century locomotives. See also, "Balloon Stack."

Dinger
Slang term for yardmaster.

Dinky
Any small, undersized locomotive.

Dispatcher
An employee who coordinates all train movements in his assigned area (usually one division). He is authorized to issue specific orders to keep trains moving.

Division
That portion of a railroad managed by a superintendent.

Doghouse
Used on steam locomotive tenders, it is a small enclosure usually located atop the back of the tender, which provides shelter for the brakeman. Also, a slang term for caboose.

Dome
A round protrusion atop the boiler of a steam locomotive; it houses the steam controls or sand.

Doodlebug
A rail motor car.

Doubling
The process of moving a very heavy train up a hill by splitting it in half and moving one-half at a time.

Double-header
A train pulled by two locomotives, each with its own crew.

Double Stack (or Stacks)
Intermodal service characterized by shipping containers that are stacked two-high on railcars.

Draft Gear
Mechanism that connects the coupler to the frame of the car. In model railroading, the coupler mounting box is often so-named.

Drag
A slow freight.

Drawbar
The bar that connects (couples) a steam engine to its tender.

Drill
To switch cars in a yard. Also, the switch engine itself.

Driving Gear
The arrangement of rods and cranks that are used to transfer piston energy to the driving wheels.

Driving Wheels
The powered wheels of a locomotive.

Drovers' Caboose
A long, eight-wheel caboose which contains a small passenger compartment for hauling and bedding down cattleman who are aboard to care for their cattle en route.

Drum
To switch.

Drumhead
An identification emblem attached to the last car on a railroad's most prestigious, named passenger trains.

Dual Gauge
A mixed track gauge, often seen at interchange points between standard gauge and narrow gauge railroads.

Dynamic Brake
(1) A system on a diesel locomotive which converts its traction motors into electric generators--the resulting resistance provides a braking action to help slow a train, especially when going down a grade. (2) The protrusion on some engines which is often called the dynamic brake is really only a cooling mechanism for the heat produced by the excess energy being generated.

Eagle Eye
Slang term for locomotive engineer.

E-Unit
An electrically-activated mechanical reversing device on some model locomotives, especially those made prior to 1990. Most recent model locomotives are equipped with solid-state electronic reversing units.

Eccentric Crank
A large, forged casting attached to the main drive wheels of a steam engine which allows a rod to rotate in an elliptical path, thereby opening and closing the cylinder slide valves.

Electromagnet
A device made of a core of iron or steel wrapped in a wire coil, which attracts other ferrous metals when current is passed through the wire.

EMD
Electro-Motive Division of General Motors. Manufacturer of diesel-electric and electric-outline locomotives.

Engine
Common term applied to mean "locomotive," but properly only the cylinders and their drivers.

Enginehouse
A building in which locomotives are serviced. See also, "Roundhouse."

Engine Yard
A yard area in which engines are stored and serviced.

Engineer
The crew member responsible for the physical operation of a freight or passenger train and for monitoring the locomotive's running condition.

ETD
End-of-train device. A box-like apparatus equipped with a flashing warning beacon, and often train status detectors, which is mounted on the end of the last car in a freight train. On most contemporary railroads, an ETD replaces the caboose.

Extra
A train not shown or authorized on published schedules; operates on train orders.

Facing Switch
A turnout (switch) situated with the points facing traffic.

Feeder
In model railroading, a power connection from the transformer or power pack to the track, and then on to another portion of the trackwork. Also a short branch road feeding traffic to a main line.

Firebox
The combustion chamber on a steam locomotive for generating heat which is used to convert water into steam in the engine's boiler.

Fireman
The crew member whose job it is to keep the fire and steam up in a steam locomotive, and who is responsible for the operating condition of power units on diesel and electric engines.

Fish Plate
A bar which joins the ends of rails.

Fixed Voltage Post
In model railroading, a terminal post on a transformer or power pack which is permanently configured to provide a set amount of voltage at all times. Generally used to power accessories and lamps.

Flag
(1) To protect the rear of the train by having a brakeman walk back with a flag or lantern while it is halted; or (2) to have any person not part of the train crew to cause the train to stop by waving hands, hat, etc.

Flange
A protruding lip on a grinder or wheel; the inside edge of a railroad car wheel which guides the wheel and keeps the wheelset on the track.

Flexible Track
or
Flex-Track
In model railroading, long (about 3 feet) straight sections of track manufactured so one or more of the rails slide somewhat freely through the spikes or tieplates, thereby allowing the track section to be curved into a customized configuration.

Flimsy
A written train order.

FM
Fairbanks-Morse. Manufacturer of diesel-electric locomotives, especially opposed-piston types.

Foreign Car
A car belonging to a railroad (or shipper thereon) other than the one it is presently on.

Freezer
Slang term for refrigerator car; also known as a "reefer."

Frog
The portion of a turnout which is grooved for the wheel flanges; so-named for its resemblance to a frog.