That early train looks like pre 20 hard tire Macks?
Try a mile behind it (the Aussie trains) unless you like driving in dust..
Utah and I thnk Nevada has triples.. Between Calgary and Edmonton AB they used triples.
When I was doing work at the Western Star plant they talked of some small rail operators that ran Western Stars on tracks, cheaper than locomotives for small volume hauling..
I built all the fixtures x2, they use for roof drilling and back of cab, etc.. when the Western Star plant left here and production all moved to Portland.. I used to work on those a lot in the plant, many mods and changes as new parts came and went..