The PSS was telling only a half truth. Yes they were running a trial, but
the trial was for train order working from Orange to Dubbo. That is why 2006
was back on the train.
The reason for only 1 engine is as you guessed it, short of power cars.
Countrylink has 19 power cars and require 16 to run the rains every day.
Today they only had 15 working so as the Dubbo is the only set that returns
home every day, and is the lightest consist, it quite often goes out with 1
unit or with the patched up ones that can be repaired that night. They are
hoping to have 2 of the 4 sick units back in service tomorrow. So hopefully
they will have one spare, provided no more die today. Out of interest 2001
probably won't be back on the road for about 6 months. It is more or less
being rebuilt.
Cheers
Rex