>>1150061At least some of it came from this guy, who basically rebuilt part of the railway network to American standards.
https://en.wikipedia.org/wiki/South_Australian_RailwaysBut really if you think about it, the requirements of Australian railways have way more in common with America than Britain, with longer distances and less plentiful water/resources. So although they got their start and much of their guidance/supplies from Britain, sometimes it was a better idea to incorporate American ideas and designs.
