The two earlier built locomotives (Nos. 44 & 46) were fitted out with well tanks instead of side tanks, while the other M class locomotives (Nos. 43, 45 and 47) did have side tanks.
On their journey to South Australia, the ship which was carrying the M Class (as well as other locomotives destined for the country) got wrecked off New Zealand. All the locomotives on board were eventually salvaged, and the M Class entered service on the Port line and its branch lines. They also occasionally worked on the privately operated Glanville to Largs Bay railway line. Their duties included shunting on the wharves, and later on in their life they worked trains to Henley Beach, Outer Harbour, Semaphore and on mixed traffic trains on the Northern railway line. The class was extinct by 1922.[2]
^FLUCK, R. E.; SAMPSON, R.; BIRD, K. J. (1986). STEAM LOCOMOTIVES AND RAILCARS OF THE SOUTH AUSTRALIAN RAILWAYS. South Australia: Mile End Railway Museum (S.A.) Inc. p. 58. ISBN0959-5073-37.