in the early 20th century, nzr sought a means of providing economic services on lowly trafficked services including some suburban routes and to provide a faster alternative to mixed trains on rural lines. it aimed to develop a light and self-contained vehicle that could operate economically even with low passenger levels. the first true railcar, the macewan pratt petrol railcar of 1912, did not pass its tests and never entered revenue service. it was followed by the westinghouse railcar in 1914, which did enter revenue service but proved unreliable. accordingly, in 1916, nzr developed its third railcar, the thomas transmission railcar. it was classified as rm 2; the westinghouse railcar had previously re-used the macewan-pratt railcar's classification of rm 1.