Originally built with steam heating boilers and for use on passenger services where steam-heated passenger stock remained. When steam-heated began to be phased out, the boilers were isolates and in many cases were removed completely.
When the 47/0 sub-class was first created, several TOPS numbers were allocated but were never used, instead the designated loco for which they were intended for was converted to electric train (ETS) and were renumbered to the 47/4 series.
Class 47's which can rightfully be classed as 47/0's are:
47001 - 47099
47100 - 47199
47200 - 47299