line shaft

Wiktionary

1. n. An early power transmission system used extensively during the Industrial Revolution, with a single central power source distributing power to all of the machinery in a building.

GNU Webster's 1913

1. n. (Mach.) a main shaft of considerable length, in a shop or factory, usually bearing a number of pulleys by which machines are driven, commonly by means of countershafts; -- called also line, or main line.