In the 1950s the Victorian Railways were looking for Alternative locomotive power to replace the aging fleet of steam locomotive which were used for shunting duties.^[1] To aid in the replacement of the steam locomotives, in 1959, 2 shunting Locomotives where built by the Victorian Railways at their Newport Workshops.^[2] These locomotives would feature an Ellison TC 500 Diesel-hydraulic transmission powered by an 112 kilowatts (150 hp) EMD power unit. The two engines were given class M and the numbers 231 and 232.^[3] When introduced, both locomotives wore a plain, dark red livery with black under frame, similar to the Victorian Railways V class.^[4] Both locomotives later in their life would be repainted into the traditional Victorian Railways blue and gold livery. The two M class locomotives would almost exclusively operate in the Newport Workshops compound under the ownership of the Victorian railways.^[5]

M231 would be sold to Steamrail Victoria on the 17/12/1981, where it would continue to be operated in the Newport workshop compound.^[6]

M232 would be sold to Brunswick Plaster Mills, a subsidiary of CSR Limited on the 9/2/1981.^[7] M232 would haul gypsum trains from Nowingi, to a gypsum loader on the former Millewa South line.^[8] After the closure of the Nowingi gypsum operation in 1987, M232 would fall under the ownership of Steamrail Victoria and would be transferred back to Newport workshops in 1988.^[9]

As of 2024, M231 is operational as a shunting locomotive for Steamrail Victoria and is currently painted in its original red paint scheme with a black under-frame.^[10] It is notable that M231 has worked its entire life in the Newport Workshops compound. M232 is currently stored in Newport Workshops West block.^[11]

• Peter J. Vincent: M class
• VICSIG M class
• Vicrailways – M class