The Related Web Page has a list of the Diesel Locomotives operated by the South Australian Railways.
Find the numbers represented by ABCDEFGHIJ.
350 Class, Entered Service 19AB, Total produced C, Axle Load 1D.6 tonnes.
500 Class, Entered Service 1964, Total produced EF, Power output 3G7 kW
900 Class, Entered Service 19H1, Total produced I J
The cache is hidden at: South 34° H G . J I D East 138° E F . B C A