The Midland Railway of Western Australia, founded in 1890, received its first major order from Hawthorn, Leslie & Co. in England. There were nine 4-4-0 steam locomotives with a gauge of 3 ft 6 in. They were given the numbers B2 to B10 and with a driver diameter of 4 ft 4 in, the small railway could use them in front of any type of train. Decommissioning began in 1929, but stopped after four engines. The remaining five continued to be used as shunting locomotives and remained in service until the 1950s.

One of the last engines to be retired was the B6, which was exhibited in Geraldton in the park not far from its previous route after its end of service in 1956. It is the only MRWA steam locomotive still in existence today. It changed hands in 1995 and ended up unseen in a locomotive shed. After renewed interest in railroad history among Geraldton residents, it was retrieved in 2010 and placed in the Walkaway Railway Station Museum, where plans have been made for its restoration ever since.