4636 and 4614 have detached from the down steel train on the right, and are running back towards the station.
In the state of New South Wales, electrification of the main west was extended 83 miles (134km) from Parramatta to Lithgow over the steep Blue Mountains in 1957, extending the wires to 97 miles (156km) from Sydney terminal. 40 electric locomotives were ordered for haulage over the line.
The forecast increase in coal haulage over the Blue Mountains did not eventuate, resulting in a lack of work for the electric locos. And so electrification of the short north line was also extended, 30 miles (48km) from Hornsby to Gosford in 1960, a total distance of just 51 miles (81km) from Sydney terminal.
Most freight trains heading north from Sydney yards were electric hauled to Gosford, where a change of traction took place. The Gosford - Broadmeadow/Newcastle section of the short north was one of the last lines in Australia to be fully dieselised, and in 1970 many freights were still worked north from Gosford by steam - often one or two 60 class garratts. The change between electric and diesel traction at Gosford continued into the 1980s.