It's because the main Depot is Inverness and they need to do a big clean of each set. So they do half a train and the other half is split to the Outstations and Aberdeen is a bigger market than Fort William like Oil Rigs etc... That's the reason for Inverness being half a train and Aberdeen being 6 load
I've been following the sets for sometime and they don't seem to quite follow that pattern
Quite often I have seen the same set operate between Glasgow and London for several days, and then a few weeks later between Aberdeen and London
In effect this is what should happen with a set...
Inverness - London
London - Glasgow
Glasgow - London
London - Edinburgh
Edinburgh - London
London - Aberdeen / Fort William
Aberdeen / Fort William - London
London - Inverness
However, it does appear that there is great flexibility between whether a set goes to Glasgow, Edinburgh, or Aberdeen / Fort William
Presumably this takes into account time keeping, layover at Wembley, and so on
Also interesting to note that one of the sleepers I was on a few weeks ago between Inverness and London was not in use yet it was in the set
There was a fault with the air conditioning and Inverness had been unable to fix it
Seems a complete waste to send it back out, rather than take the sleeper out of the set and reinsert it either the following day or next, and then rematch it back into a set
Unless Wembley can also repair sleepers?