After each of the single track lines leave the junction they will enter staging through a helix. I have a length of about 11 feet for the staging yards and turn around loop. To properly simulate the prototype operation I want each single track line to have it's own staging and loop back to itself. After playing around with several ideas, this is the design I came up with to accomplish this.
It's hard to visualize from this one drawing but what happens is that at the west end of the layout the two lines will leave the layout disappearing behind some hills or buildings of Winnemucca to enter the double track helix down to this staging yard. At the bottom of the helix the WP line will leave the helix first at one turn above the bottom and enter the staging yard on a level at the back half that is higher than the SP yard. The WP return loop will pass over the SP return loop and then over the SP staging tracks to re-enter the higher level WP staging yard.
I'm ready to start building this and today picked up a nice sheet of 1/2 inch birch plywood at Home Depot.