This may be the group of tankers which I know least about. 

Until April 2008 I only knew of their existence from an old WAGR diagram.  The diagram indicates that there were 3 in service in 1900 and that all had gone out of service  before the wagon record cards began in 1909.

Then the photo at left appeared showing one of them coupled behind a GSR T class 4-4-0 in very early GSR days (before the WAGR takeover).   This at least established where they came from.   The 1900 renumbering list does show some J class tankers amongst the GSR wagons but  these numbers are scattered amongst the other types and there are more than 3 of them. At the moment the WAGR numbers of these 3 tankers remain a mystery and the GSR numbers and classification unknown. 

Great Southern water tanker (A S May Collection)