I did once hear that the loop cause some operational problems because it reversed the consists; A end became B end etc. if trains don't reverse with a loop the consist is always the same in any set.
Some like to post on here every now and then saying that this loop or the cutoff line heading past the Old Adelaide Gaol (not a loop as such) should be retained or even rebuilt as they used to be purely because they say having the facility to turn consists is a good thing.
How right are they though? On such a simple system as Adelaide has where wheel wear shouldn't be too uneven, is there ever really a need to do that kind of thing? I can only think of the Jumbos as a reason to do that (a 3100 split from its normal partner can have the back end coupled to a 3000) and with their days as tuna cans or artificial reefs rapidly approaching even that justification looks to be shrinking.
Trains used to turn back at the middle road at Glanville. Is the middle road still serviceable? Note I did not say "in service".
The new timetable featuring the Glanville services extended to Osborne only started four months ago. How much does a line deteriorate in such a short period, apart from a bit of rust on the surface of the rails that is easily dealt with?
Of course, on a real railway there would be an interest in keeping facilities like extra turnbacks (and crossovers) in a condition that they can see emergency use even if they don't need to be used on a regular basis. They are important for building in some level of resilience, so the whole system (not just one line, they are too interlaced at the city line for that) doesn't roll over like a pathetic poodle the instant that real life gets in the way of their nice perfect computer models - see that other thread about the inconvenience of 19 kilometres of wrong direction running on the Gawler line.
I see from Google Earth that it seems there are rails of a second track still in the road at the Osborne Road level crossing so my memory is not completely false.
The level crossing may have been refurbished since the satellite images were captured for that area though, Google no longer purchases new satellite imagery to replace the old as they now prefer to focus on getting aerial photography just for more interesting areas.
For what it's worth, there are still rails to be seen at the site of a long-gone level crossing in the Pedler Creek gorge on the unlamented Willunga line, and at numerous spots in the Mile End and Port Adelaide areas.