noun
track number; platform number
Used at train stations to indicate a specific track or platform, e.g., 1番線, 2番線.
東京行きの新幹線は14番線から発車します。
The Shinkansen bound for Tokyo departs from track 14.
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.
noun
Refers to the thickness of wire, often expressed as a number (e.g., 12番線). Common in electrical and construction contexts.
この工事には12番線の電線を使います。
We use 12-gauge wire for this construction.