motive power

Noun

motive power (usually uncountable, plural motive powers)

1. (figuratively, sometimes, usually) The power that enables something to move.
   • Using electricity as motive power for railroads will do away with fuel trains, tenders, coal handling, water, and all that.

   Synonyms:

   locomotion, motivity

2. (collective, usually) The locomotives or other powered units that operate on a railway.
   • While at first in the U.S.A. it may have been a matter of high-pressure salesmanship—and it has undoubtely been the irresistible enterprise of the General Motors Corporation, through its Electro-Motive subsidiary, that has set in motion this amazingly rapid transformation of American railway motive...1950 January, Cecil J. Allen, “British Locomotive Practice and Performance”, in Railway Magazine, pages 12–13
   • In the United States, where the railways are 90 per cent. dieselised today, diesel-electric power is the unvarying rule for independent locomotive units, and the only motive power exceptions are the highly successful 600-h.p. diesel-hydraulic railcars of the Budd "RDC" type, of which between 300...1958 April, Cecil J. Allen, “British Locomotive Practice and Performance”, in Railway Magazine, page 268