Rio Tinto subsidiary Hamersley Iron bought 29 General Electric Dash 9-44CW locomotives in 1994 rather than continue with similar Alco rebuilding programs that BHP and Rober River were undertaking at the time. The units would radically change to look of Hamersley Iron's locomotive roster. With a new silver colour scheme with red and blue stripes, yellow along the frame and a big red HI logo on the cab nose, they contrasted with the existing fleet livery of brunswick green and yellow.

They allowed Hamersley Iron to retire the existing fleet of Alco, GE and EMD units.

Subsequent orders saw the class swell to 72 units, with the last 10 being delivered in 2006. Three units were ordered in 2001 following the formation of 'Pilbara Rail' the merger of HI and Robe assets. These wore a distinctive 'Pilbara Rail' livery with ROBE reporting marks and numbered in the Robe fleet at 9470 - 9472, these were later renumbered to fit into the Dash 9 fleet being 9401 - 9403. The following orders, 4, 5 and 6 had this livery. A similar livery was applied to new units from orders 7, 8, 9 and 10, but named as 'Pilbara Iron'. The difference between owners was either the HI red dot or ROBE logos.

One loco is named, 7097 'Ken Onley'.

Loco 9406 wears an all over silver livery with Rio Tinto lettering following collision repairs.

Road no: 7043-7050, 7053-7098, 9401-9409, 9428-9436.

In 2006 Fortescue Metals Group ordered 15 units for it's new Pilbara mining venture. Delivered in late 2007 to Port Hedland and wearing FMG's blue and white livery, they were also fitted with ECP (electric) brakes from New York Air Brake.

One unit has been named, 012 - 'Peter Tapine'

Road no: 001 - 015.