In days of yore the down track used to cross Lady Ruthen Drive twice.
The first crossing was at the north end of the short northern straight before the bend to head towards the harbour and be parallel with LR Drive.
The down track to the pax platform then turned north and cross LR Drive again. Look closely at the Google map and you can see a reservation just south of LR Drive
There was a facing junction about where South Australia One Drive is located for tracks leading to the wharf. Boat trains used these tracks and later stock trains. The junction was protected by an Outlying Switch Lock and a two arm, one light absolute semaphore. There was a country privy type phone hut which probably had the selector for releasing the signal.
The junction disappeared with the redevelopment of Outer Harbour access some years before the marina development when the down track was shifted north of LR Drive.
The up track had a trailing siding running into what is now the golf course to serve what I think was a concrete pipe plant. There were other trailing connections including that returning from the wharf. Each had a disk starter type signal controlling movements from the siding and an OSL locking the points. All mainline signals except at the junction I mentioned were permissive.
I remember the track being on the south of Lady Ruthen Drive (although the road name was different back then). There was also a connection from the northern end of the wharves that crossed Victoria Road near the Yacht Squadron that connected back onto the loop line.
The siding you mention would have gone into the property just east of the golf course where a business called "SteelMains" was located. I believe they made large steel pipes (maybe for the then E&WS for the mid north pipelines - Morgan to Whyalla)
I can remember seeing a few the stock trains on the wharf in the very late 70's when I worked for a company that did repair work on the sheep carriers. Yes the sheep for live export were bought in via train! However I only saw this on maybe two occassions before the sheep were bought in via semis.
I can also remember at least one stock train at Berth 11 (inner harbour) as the smaller sheep carriers would use Berth 11/12
Damn! that was only 35 years ago!!!