In 1927, class leader N 110 was equipped with a two-cylinder Franklin booster engine which drove the trailing truck axle. Based on the success of this device, VR built all but two of the much larger X class 2-8-2s with booster engines. VR also modified the design of the Delta trailing truck on the second (1930-31 built) batch of N class locomotives to enable easy retrofitting of booster engines. Despite this, no further boosters were ever fitted, and in 1945, N 110's booster was removed and fitted to one of the two non-booster equipped X class locomotives.