When they entered service in 1960, the 49 class were intended to alleviate the woeful efficiency of the long section of railway to Broken Hill. They quickly found themselves at home on the branch lines in the western regions of NSW, becoming a regular sight on many services west of Lithgow and as far north as Moree and south to Cootamundra.

Although typically most commonly seen on goods and wheat trains across the region, the locomotives also led passenger services across the west, including on the Central West Express to Orange.

In 1989, the whole class were transferred to Delec Locomotive Depot in Sydney. As well as metropolitan work, they were commonly used on coal trains to Tahmoor on the Main South line. However, by 1999, the 49 Class had begun to be sold off to various operators.