So I spent some time fiddling with the concept of two or three sidings. Each time I looked at designing a layout around Spencer Junction, I insisted on having Whyalla, this reduced the running distance from yard to fiddle yard where you would loose the concept of seeing trains moving in the landscape, and the space was sucked up by Whyalla or the fiddle yard.
Here is the link.
How do i get out of this loop of design failure? I started with Spencer Junction yard. This has to be long enough to have decent length trains, as the yard curves in one direction. So I plotted this round the edge of the room, with the thick part of the yard at one end of the room. So, i now have a decent sized Spencer Junction. Whyalla would fit inside the middle space, but I was looking at increasing the mainline run, so i used the pennisula design from Everett - Skykomish. Just plonked it where I thought it should go. The end result is something I could turn into Wirrappa looking curves. Joining the dots, Spencer Junction north to a "Wirrappa" type loop, on a reverse curve, with space for a triangle. On the opposite side of the peninsula, something like the "Wirrappa" curves, at the end of this I put a triangle. One way would lead back into Tassie street, thus satisfy Dougs want for continuous operation. The other lead I thought dead end staging sidings. Thus, traffic could go from the staging into Spencer Junction, shunt as required. Depart Spencer Junction, for a "Wirrappa" type station, around the reverse curves. Then back into the staging sidings. For the line to Whyalla, as it goes upgrade to the bridge I thought of just continuing the grade up and over and into the staging sidings, upper staging.
Now all of the above is great on paper, but I need to incorporate what I have learnt from Alice Springs. Appropriate space for people. Minimum width of 2'4" standard width of 3' lift out section for easy access, I have an idea that will make install and removal easy, without locking and adjustment.
Alice Springs was all about trains terminating and shunting them out. Spencer Junction is about trains going four ways, originating and terminating. And re marshalled. So, full use of things like the motive power sheet, TIMS could be really cool. The Tea and sugar could shunt at "wirrappa" on its way west so that could be fun too.Ultra modern could also be possible as the yard has not changed that much.
Anyhow here if the plan.