[1] 4501 had a one-hour power rating of 2,700 horsepower (2,000 kW) with a total weight of 108 long tons (110 t).

Its maximum speed was 70 miles per hour (110 km/h) It had a driving compartment at each end of its very box-shaped body.

Once the electrification project had reached Penrith in October 1955, 4501 had its first opportunity to haul passenger trains.

In October 1967, it received a major overhaul where several tonnes of additional ballast was added.

Main-line safeworking equipment was provided to allow it to haul coal trains over the newly electrified Main South from Glenlee to Rozelle.