Caption: Typical lowly yard power on CP back in the 2000's was often a rebuilt GP9u-slug set. In the 90's CP had a bunch of surplus low horsepower GMD switchers, both aging and underpowered. Converting some into yard slugs was an economical way to reuse old power and give the GP9u's some extra "oompf" around the yard (where low-speed lugging ability was more important than speed or horsepower). Having one less engine between the pair also saved on fuel, and later when some were equipped for beltpack operation (note the antenna planes on 1598's cab and beacons), it saved on manpower as well.

Sitting next to the yard office near the Runnymede Road underpass, CP GP9u 1598 and former SW8u slug 1012 lounge about the afternoon at the split West Toronto/Lambton Yard awaiting their next assignment. There was usually a set here for flat-switching the yard, with local power (typically multiple pairs of GP9u and/or GP38-2 units) parked on another track near Runnymede Park.

The slug conversion was pretty basic: the units would be modified so their traction motors would receive power from the GP9 "mother" unit. The engine block was either left in, or removed and the space filled with a concrete block. Cab windows and radiator openings would be plated over or left intact, and painting usually amounted to just a patch job and renumbering. This late in the game, CP wasn't putting any money in the slugs aside from keeping them running, so most wore their old action red colours until retirement (the next year, 1598 got an overhaul and brand new coat of paint, but not a drop was forthcoming for 1012). When this set was retired in 2013, 1598 was traded in on the GP20C-ECO program and scrapped, and 1012 was sold for scrap to SLM Recycling in Welland.