The following glossary is arranged alphabetically with each term catalogued by first letter. Select a letter below to begin.
A maneuver by which two trains can meet at a siding thats too short to hold either one of them. (If neither train fits, its a double saw-by.)
The size of things on a model railroad relative to things on a real railroad. For example, in the most popular scale, HO, models are 1/87th full size. More Information.
That portion of a timetable that lists the class, direction, number, and timings of regular trains.
Two crossovers interlaced with a crossing in the middle which allow trains to pass from one parallel track to the other in either direction.
Making a model from raw materials and parts, not using kits.
General Motors designation for its six-axle "special duty" diesel locomotives.
Track in short, rigid pieces (fixed length and curve radii) that are easily joined to each other.
A type of geared steam locomotive used extensively in logging, mining, and industrial railroading. It had three cylinders mounted vertically on the right side of the boiler driving a crankshaft geared to all the axles.
A small railroad, generally Class II. See Class I railroad.
A side track with a turnout at each end. Passing sidings are long enough to let trains meet each other.
Single slip switch
A special condensed track component that combines the functions of two turnouts in a short distance. Allows only three possible routings, not the four of a double-slip.
A weighted locomotive unit with traction motors but no diesel engine or generator. Used in conjunction with a diesel locomotive for additional tractive force.
A chimney on a car or building.
A structure built over the track in mountainous areas to protect the tracks from snow and avalanches.
Single-pole, double-throw. A type of electrical switch used in model railroading. See DPDT.
In DCC, table of parameters specifying the motor voltage in response to a speed and direction command. Individual speed tables can be programmed for each locomotive, allowing locomotives from different manufacturers to work together in a consist.
On a prototype railroad, a forged steel fastener with an offset head thats driven into the ties to secure the rails.
Spiral curve or easement
A curve of gradually increasing radius that makes the transition between a tangent or straight track and a fixed-radius curve.
Spot a car
To place a car in its designated position, as at an industry or on a station track.
A turnout held in one position by a spring so that facing point traffic always takes the same route but trailing point traffic can run through the turnout from either track.
Spur or spur track
A dead end track, one with a turnout at only one end.
In North America, the standard gauge between rails is 4' 8½".
A pointless turnout that changes its route by gently bending the approach or "fly" rails sideways (image).
Short for polystyrene, a versatile plastic commonly used for modeling. Comes in sheets, blocks, and rods of many different thicknesses and sizes.
The bottom or foundation layer of model track, usually made from plywood.
Raising the outside rail of curved track to help trains negotiate curves more easily and at higher speeds.
General Motors designation for its diesel switchers.
Electrical switches are usually called toggles. In a turnout, the "switch" is the assembly of moving points that select one route or the other.
A padlock or an interlocking device that secures a switch so it cannot be moved.
A single- or double-coil electromagnetic mechanism for directing trains to one track or another at a turnout. A remote-control device that moves the switch points to select a route through a turnout.
A motorized point-moving machine.
A metal rod that connects switch points to each other and to a switch stand or switch machine.
Manual device that allows a turnout to be lined (changed) from one route to the other.
A track layout that requires a change of direction.