The K class 2-8-0 built by VR in 1922-23 was a success, but with a firebox mounted between frames engineered for broad gauge operation only, it was not readily gauge-convertible. Thus when additional branch line locomotives were required, the VR produced a 2-8-2 'Mikado' variant of the K, the first 2-8-2 tender engine in Australia. It retained the same wheels, cylinders, motion, and much of the frame of the K, but featured a longer boiler with a wider, larger grate, mounted above the frames and supported by a trailing truck. This enabled possible gauge conversion without radical re-engineering of the frames and grate.