Back in the early 70's when I was young fit and bloody stupid, I worked first on the old Ghan Line from Adelaide to Alice springs, and then the Indian Pacific Sydney to Perth line doing exactly that, but back then we had to dig the old hard wood sleepers out with a pick, then a small track mounted crane type machine would pull the concrete sleeper into place, then we checked the spacing and fitted the spring clips with a blunt pick hammer.
it was all bloody hard work in some tremendous heat, and there were gangs of around 20 blokes living in converted railway wagons and no mod cons like air conditioning, on a spur all the way across the line
the only track machines we had back then was the ballast machine similar to the one in the vid, and the Electromatic, which both levelled and straightened the line , but it was nowhere near as flash at the one in the vid.
god i'd love to be doing it today,
cheers John