The RL class are a class of diesel locomotives built by Rail Technical Support Group (RTS) for the National Railway Equipment Company at Islington Railway Workshops in Australia.

The concept of the RL class dates back to 1994 when Morrison Knudsen Australia purchased some 442 class locomotives from the State Rail Authority with the aim of rebuilding them with EMD 16 645F3B engines.

Following National Railway Equipment Company purchasing Morrison Knudsen, the project was revitalised albeit using new locomotive frames.

Nine were built by RTS at Islington Railway Workshops, Adelaide between 2005 and 2010 with bogies and compressors from the 442s and reconditioned parts from the United States.

Seven were originally built and initially owned by [1][2][3] One was included in the sale of the South Spur Rail Services business to Qube Logistics in May 2010 who later took delivery of a further two.