OR are you asking about a section of line which was Up at one point in time and then changed and became a DOWN section later in life (or vice versa)?
Hmm. I can't argue with that. Every direction from Peterborough was down except that to Terowie. However I am looking for a section of track, between two adjacent stations, where a train heading from A to B was down one day, and up the next.
Thinking about it, Snowtown to Brinkworth? Before the BG from Snowtown to Adelaide closed (prior to SG) the direction of Snowtown to Brinkworth would have been DOWN as it pointed in the direction ultimately to Gladstone. The next day, it would have become the UP line for the BG from Wallaroo to Adelaide with the turning of the loco and brake at Brinkworth and Balaklava as well?
That's not the section I have in mind, and I cannot verify that the direction of the section between Brinkworth and Snowtown would have changed. In any case, your answer does not meet my hint that we are looking for "a section of . You track, between two adjacent stations" as Condowie existed between the two stations you are suggesting.
Not around Osborne, Mt Gambier/Wandilo, or the Lochiel line. This was a section of line where a train travelling from A to B was a down train from opening up until a particular point in time, from whence a train travelling that same route from A to B was now designated as an up train.
The line between two adjoining stations had up and down reversed, but no other sections adjacent to this one had the direction reversed.
That extra clue rules out Yunta-Peterborough/ Wolseley-Serviceton might qualify - I don't recall loco changeovers being swapped, but there's lots I don't recall these days! -- but it's not the section I was thinking of.
Take another clue: the line is/was narrow gauge.
I'm sure I've asked this before but some years ago.
I'll make it a double barreled question: (a) what was the most westerly station of the SAR? and (b) what was the most easterly point of the Commonwealth Railways?
Older participants should know this; it may stump younger members.