sub-station

From sub- +‎ station.

sub-station (plural sub-stations)

1. (electricity) Alternative form of substation.
   • 1951 January, R. A. H. Weight, “A Railway Recorder in Essex and Hertfordshire”, in Railway Magazine, page 44:

     They form part of the vast electrification and reconstruction schemes which have been in hand for a number of years at Liverpool Street, and in suburban Essex, and include the rearrangement of tracks, of which the Ilford flyover forms part; the modern signal boxes, now needed only at key points; the electric control or sub-stations; and a large electric car shed.

   • 2012, Andrew Martin, Underground Overground: A passenger's history of the Tube, Profile Books, →ISBN, pages 118–119:

     The stations, lifts and trains were all brightly lit with electricity, and there was no question of voltage drop from being too far from the source of the power because the Central was the first line long enough to justify the building of sub-stations along the route.

• bus station