Courtesy of Old Time Trains
Canadian Pacific Railway

MLW 660 hp yard units with multiple unit controls.

The only low horsepower diesels built new with m.u. were Dominion Atlantic 6560 and 6561. These two units fit in the CPR numbering for MLW 660 hp units. Other than DAR RDC's 9058 and 9059 no other diesels were lettered for any subsidiary.

DAR 6560_6561 were fully equipped as road units including combination pilot, chime horn and classification lights.
Note the slab along walkway for added weight. 212,000 lbs. (Normally 196,000) S-2/4 230,000 lbs.

These units were used on gypsum trains from Dimocks to Hantsport, NS until 1959 when heavier power was required and they were replaced by 8100's (GMD SW1200RS).
They were transferred to Lambton Yard in Toronto where they worked singly on yard and local jobs. After the new hump yard in Agincourt opened they worked as a pair on the Pulldown until 1974 when they were replaced by 7107 and 7108 (MLW S-4) and sent to Sutherland, Saskatchewan.

26 S-3 and S-10 units were modified (including extra weight on S-3's) 1965-1971 to operate in m.u. when increased tonnage required more tractive effort at main terminals including Thunder Bay.

6561_6560 working in m.u. Lethbridge 7/1978 Bob Heathorn collection