 Failure to observe these periodic checks and corrections, if necessary, would result in less than exact valve events.Were these checks to be neglected, in the worst case, this was not a great forfeit in itself, as the 460 members of the closely related other two sub-divisions of the Standard Goods engines normally had markedly indifferent valve events.Averagely, in fact, the D55 class had much better valve events than any other Standard Goods engines, especially notched up

The first of the class, then classified as K1353, entered traffic on 29 November, 1918, but the NSWGR wanted to extensively test the first locomotive, so the next member did not appear for a further two years.