The following glossary is arranged alphabetically with each term catalogued by first letter. Select a letter below to begin.
Backdrop
A painting or scenic photograph on the wall behind the layout. It can be as simple as a cloudless sky or it can echo the scenery of the layout and create an illusion of great distance.
Bad order
Defective, out of order.
Ballast
On real railroads, a layer of material - usually crushed rock, cinders, or gravel - on top of the roadbed that holds the ties in position and facilitates drainage. On a model railroad, ballast is simulated by fine gravel spread between the ties and alongside the track.
Balloon track
See Return loop.
Benchwork
Supporting framework for a model railroad layout. L girder and open grid (sometimes called butt joint) are two popular types.
Block
On a real railroad, a section of track defined for the purpose of controlling trains. On a model railroad, a block is an electrically isolated section of track.
Block signal
A signal at the entrance to a block (See Block) indicating whether the block is occupied by a train.
Bolster
The crosswise member of the frame of a car at the truck (body bolster) or the crosswise piece at the center of a truck (truck bolster).
Boomer
An experienced railroad man who moves from railroad to railroad.
Booster
In DCC, the booster takes the low-current signal from the command station and "boosts" it to the high-current signal needed by locomotives to operate DC motors, etc., in conformance with NMRA Standards S-91. Also referred to as power stations or power boosters.
Branch line
Secondary line of a railroad.
Brass (also brass hat, brass collar)
Railroad executives and officials.
Bridge
A structure that supports a track passing over a depression in the terrain or a stream. A through bridge has a floor structure, which supports the track between its side beams or trusses, while a deck bridge has its supporting structure below track level.
Bridge guardrail
A set of steel rails mounted inside the running rails on a bridge or other structure to keep derailed cars in line.
Bridge pier
An intermediate support used between bridge spans.
Bridge shoe
An iron or steel casting which transfers the weight of a bridge to its supports. One end is normally a solid mounting while the opposite end allows for expansion and contraction.
Bright Boy
(brand name) An abrasive rubber block used to clean track.
Bumper
A braced, coupler height blocking device that keeps cars from rolling off the end of a track.
Bunk, camp, or outfit car
A passenger or freight car converted into movable living quarters for track workers.
Bus, or bus wire
A main wire, or trunk wire, running under a model railroad. Shorter branch wires, such as track power feeders, are connected to it.
