track number; platform number
Used at train stations to indicate a specific track or platform, e.g., 1番線, 2番線.
The Shinkansen bound for Tokyo departs from track 14.
Refers to the thickness of wire, often expressed as a number (e.g., 12番線). Common in electrical and construction contexts.
The train will soon be arriving at platform 2.
お客様、3番線に電車がまいります。
Ladies and gentlemen, a train is arriving at platform 3.
We use 12-gauge wire for this construction.
This train departs from platform 3.
This construction work uses gauge-12 wire.
線路 refers to the physical railway track itself, whereas 番線 is the numbered designation of a specific platform or track (e.g., 1番線).
platform 2; track 2
Compound of 番 (number) and 線 (line/track/wire). The railway sense comes from numbering tracks, and the wire gauge sense from numbering wire thicknesses.