Are they Australian design? They were built in Canada (except for 4) no?
They were designed in the USA and built in Canada.
Even those assembled in Australia only had Australian built frames, the rest being built in Canada and shipped out.
But they were the first main line locomotives with an end cab and long hood which was followed by the NR class, the Q class and most other locomotives built in Australia subsequently.
They did most of the really heavy coal haulage for ten years from 1994, and the Aurizon 5000 class were clearly influenced by them. They will probably remain in coal traffic for some time to come, even if they cost more to maintain because of the cost of traction motor maintenance.