 The smaller diameter cylinders of the 58 class (21.1/2") compared to the earlier 57 class (23.1/4") demanded a later cut-off and thus used more steam.This could cause the locomotives to be uneconomical in the use of coal and water when compared with the 57 class, but the 58's longer valve travel ameliorated this objection if driven as designed to be so.Despite the design being made to enable use on the Main Northern line from Sydney to Broadmeadow, few journeys were ever made on this route.