No, its not laying new track, it resleepering an existing track. The existing rails are reused, only the sleepers are replaced.
Machines in use include a TLM, Track Laying Machine in the early part, Undercutter/BCM (Ballast Cleaning Machine) about half way through, and a Tamper towards the end. I see the latter 2 quite often in my job.
If you watch it, its fairly easy to understand. The clips are removed, the rails are spread to either side of the machine, held out by rollers 1.00 minute, the old sleepers are lifted 1.10, stacked and removed to the rear of the consist 0.20-0.40, a new stack is brought forward on the return journey and placed in position for use 0.00 - 0.15, simultainous lifting and stacking to the rear (bottom) of old sleepers as new sleepers come forward (top) 1.00 - 1.25. New sleepers spaced and aligned 1.25 - 1.55, rail realigned onto new sleepers 1.55 - 2.15, new pads and spring clips in place 2.15 - 2.40, and clips installed under tension 2.40-2.49, Undercutter and Ballast cleaning 2.57 - 3.30 with spoil ejected out to side at 3.11-3.12, (Undercutter/ Ballast cleaning machine does what it says, lifts entire rail/sleeper combo excavates the formation from under it then cleans the ballast and relays it) Extra ballast is brought in and roughly layed 3.40-4.03, formation is then tamped 4.03-4.51 (Tamping machine lifts rail/sleeper combo and forces ballast under the sleepers, packing it in to hold track in place, the fingers being pushed into the ground spread out when underground) more ballast brought in 4.51- 5.17 and final formation shaping of ballast is then done- not shown but similar to 3.40-4.03. A lot off this operation is only possible due to CWR (Continuous Welded Rail) instead of the old clickety clack jointed rails.
Bugger me you are correct.
I only watched it in a small screen before so I didn't notice the writing.
The machines up in CQ are the same colour.
I didn't even notice the houses even though I used to live there.
Well, its definately not Qld, and probably not Australia. Yes, QR uses track machines built by Plasser/Thuerer, and the colour would be pretty much standard across the board, but the give away is the locos hauling the ballast train in the last minute. My guess would be europe somewhere. They seem to use that style of cab on their locos.