The class were ordered from Baldwin-Lima-Hamilton (the former Baldwin Locomotive Works) to relieve motive power shortages.

The most immediately apparent difference is the rather stubby short tender that was specially built to allow the 59 class to be turned on a standard 60-foot (18.29 m) turntable.

[1][2] The class was the first 'new build' (as opposed to conversions) of oil-fired engines to be introduced by the New South Wales Government Railways and were the first locomotives to be built for NSW by Baldwin since 1905.

They were soon placed in service on both the Main Western and Main South lines and, although their light axle load made them available to a large proportion of the state, their sphere of operation was limited by the location of oil fueling facilities.

Seventeen were converted using an ashpan based on the 38 class engine arrangement, together with modifications to the smokebox, fitting of brick arches, grates, firehole doors, etc.