- Jack: A dwarf signal (slang, Boston and Maine and New York New Haven and Hartford Railroads)
- Jerk a lung (North America): To break a train in two, usually by shearing the knuckle pin in a coupler, often caused by the application of excessive head end power at startup. Example: "The engineer jerked a lung on the upgrade." Also: Get a knuckle.
- Johnson bar (US): On a locomotive, a long, heavy lever that operates the reversing gear, etymology unknown.
- Joint bar, fishplate (UK): Joins the ends of rails in jointed track. Also referred to in North America as a rail joiner or angle bar.
- Jointed track: Track in which the rails are laid in lengths of around 20 m and bolted to each other end-to-end by means of fishplates (UK) or joint bars (US).
- Journal bearing: a bearing without rolling-elements; a plain bearing
- Journal box, the housing of a journal bearing.
- Jubilee: A steam locomotive with a 4-4-4 wheel arrangement.
- Junction: A point at which two lines or separate routes diverge from each other.
|
|