The 600/700 class railcars were a class of diesel multiple unit built by the New South Wales Government Railways. They were built to operate on branch lines from 1949 with low traffic volumes later being transferred to Newcastle and Wollongong to operate suburban services until withdrawn in 1994. However, one 600 class railcar was converted to solar operation for use on the Byron Bay Train service. The upgraded train entered service on 16 December 2017 and is believed to be the world's first solar-powered train.