The track plan is a fair amount of double track so that local trains will not cause the main line to be tied up during their work. The operational concept for this part of the railroad is CSX's RF&P Subdivision. In the era that I am modeling (1994), the RF&P has only been an integrated part of CSX for 3 years. There were not (and still isn't) many on line customers between Acca and Fredericksburg in this era. (Most of my research seems to indicate that the only industries were at Doswell and closed before the merger)
A look at the corner where the helix and upper level will join.
A longer shot looking toward that corner from closer to the shelf.
This is another shot, from the YM's normal position at the middle of Acca.
The upper helix is only 1 track, so this will be a chokepoint for the dispatcher to work around. Operational design will take this into effect.
Here's where the helix subroadbed will meet the upper level shelf. In this picture, the shelf support to the far left has yet to be removed.