Wednesday last week I was in Bordertown with little to do so decided to drive over to Wolseley and Serviceton. Sitting in the Bordertown loop was an eastbound SCT train headed by SCT007 and two CSR locos. Parked on the side of the road near the locos were two service vehicles but all loco engines were apparently running and there was no sign of activity. When I returned to Bordertown about an hour later SCT007 was sitting about 50m ahead of CSR010, and the other CSR was very slowly (ie walking pace) propelling the train back beyond the west end of the loop (pissing off quite a few car drivers at the Creecoona Tce level crossing). It then pulled forward until it was adjacent to CSR010 on the other track. SCT007 then headed east past the end of the loop and reversed back onto the front of the train and eventually recommenced towards Melbourne.
So, at least several hours lost for this train that I know of. Presumably if three locos were thought necessary then performance for the rest of the journey would also be affected. I did wonder where the service vehicles came from. Maybe the crew knew of the problem early and was able to arrange a rendezvous ahead of time, but otherwise I would expect to take some time to get appropriate mechanics on site. At least one of the vehicles seemed to have Penske markings - I'm not sure where their nearest location would be.
I'm surmising that whatever was wrong with CSR010 made it unmovable for some reason, as I would have thought it quickest to just pull it off the front of the train with the SCT the 100m or so past the loop, set it back on the other loop track, detach and then the SCT could rejoin the front and be off.
Several hours later CSR010 was still being worked on (and engine still running). Thursday morning as I headed home it was still in the loop, shut down and with no one around.
Consider that while CSR010 sat there the loop was unavailable for use. Next loop for 1800m trains to the east is Diapur, and Keith to the west. Easy then for other trains to be affected by an operator's problems.
I learned long ago that the MTP for my purposes as an enthusiast is a guide only.