I said new alignment and not using an old alignment. If a hume higway type alignment could be achieved then 1 hour is easy to remove between campbelltown and goulburn. For sure the track needs fixing between goulburn and canberra but it has no significant need for any re alignment
All the proposed alignments following the Hume Highway have much steeper gradients than could be used by freight trains.
Despite what you have said, such alignments are ONLY suitable for Very High Speed trains owing to the steep gradients.
One of the truly amazing things about the Federal Government VHST survey was that NO gradient profile was ever published. Despite all the money spent it was a completely amateur operation.
The distance between Canberra and Goulburn is substantially shorter (and slower) than the section between Campbelltown and Goulburn. It would be cheaper to reduce the time south of Goulburn than north of Goulburn.
I would be absolutely amazed if a serious realignment of the line around Picton was actually carried out.
When the Hume Highway was realigned, I recall that the deviation around Mittagong cost ten times as much as that around most other towns. That is the sort of country we are discussing. The government is talking about spending 4 billion dollars in the whole state on infrastructure.
The section around Picton to be bypassed is less than one fifth of the distance between Goulburn and Campbelltown. I doubt that an hour cold be saved on that section alone. And that would leave many of the sharp curves on the existing line which limit speeds.
I do not believe they would spend close to a billion on one rail line to reduce the travel time to a destination not in NSW.