V/Line G class

At the same time Australian National had placed an order with Clyde Engineering, Rosewater for 10 BL class locomotives, with an option for a further five. VicRail's chairman Alan Reiher, stepped in and negotiated for the five to be completed for the newly formed V/Line.[2][3] The new diesels had a much higher axle load than the smaller T and Y class diesels used on branch lines, with these lines either being upgraded to carry heavier trains or closed.[2] These were all delivered in late 1984.[4][5]

A second order was placed for ten further units that were more tailored to V/Line's requirements. The first five were built with standard gauge bogies being delivered via Sydney. Over the next few years, members of the second batch would frequently swap gauges as needs dictated. In July 1986, through running without changing locomotives at Albury began with G class locomotives operating through to Sydney.[6] Two further contracts for eleven and seven broad gauge units had brought the fleet up to 33 by November 1989.[5][7] The first 15 were built at Clyde Engineering's, Rosewater factory with the balance built at Somerton.[8]

Although primarily intended for hauling freight services, they were also used on passenger trains such as the Intercapital Daylight and Sydney/Melbourne Express.[9] They rarely hauled broad gauge passenger trains.[10]

When National Rail commenced operating interstate services in the mid-1990s, seven (517–520, 522, 523 & 525) were leased by V/Line pending the delivery of the NR class.[11][12]

The class were also used on the first privately operated train on government tracks in Australia, operated by SCT Logistics with V/Line locomotives and crews between Melbourne and Adelaide on 13 July 1995.[2] This was extended through to Perth from October 2000.[13]

All 33 were included in the sale of V/Line Freight to Freight Victoria in March 1999. On 26 November 1999, G517 and G518 were destroyed in a head-on collision at Ararat when an eastbound grain train collided with a stationary ballast train at 70 km/h.[10][14]

Freight Australia commenced a program of engine upgrades purchasing new, more powerful EMD 16-645F3B engines for some of the G class, with the old engines being used to repower X class locomotives, later recoded the XR class.[15][16] The upgraded G classes were G523, G526, G529, G530, G531, G536, G541 and G543. These locos now have a power output of 3,800 hp (2795 kW).

In the early 2000s, Freight Australia was contracted to move freight between Melbourne and Sydney for CRT Group. The contract contained a clause that if Freight Australia was acquired by a competitor of CRT Group, 10,000 hp (7,500 kW) of locomotive power (calculated by the business CRT Group was offering Freight Australia) was to be transferred to CRT Group.[17] As a result, when Freight Australia was acquired by Pacific National in 2004, G516 & G534 were handed over to QR National (now Aurizon), alongside X class locomotives X53 and X54.

A condition imposed by the Australian Competition & Consumer Commission on Toll Holdings taking control of Pacific National was that nine locomotives be sold to SCT Logistics.[18][19][20] This resulted in nine G class passing to SCT Logistics in February 2007.

By mid 2008, SCT Logistics had received new locomotives, and their G classes were sold to the Australian Wheat Board, CFCLA and Southern Shorthaul Railroad.[5]

Pacific National's fleet operate on both the broad and standard gauges, with the latter often operating in New South Wales.