Bonogin Valley have this 2002/3 Heavy tanker. It is an Isuzu FSR500 4x2 with 3000L. There are no set standards or designs for the heavy tanker with decisions made by each brigade.
Bonogin Valley 61 (Heavy Tanker - Isuzu) by coghilla, on Flickr
Bonogin Valley 61 (Heavy Tanker - Isuzu) by coghilla, on Flickr