Shelf Layout Design: The South Park and Silverton. O gauge using Atlas-O track.

Assembling this design, I am pulling content from two other discussion threads into a single discussion on the SP&S.

Gum Stump & Horseshoe

SP&S Rolling Cassette Construction

The South Park and Silverton Shelf Layout.

Here is how I figure the grades

From the turnout on the left at 0"

• Climb at 6% to the next turnout, 58.5".  At 6% the rise is 3.51".
• Climb from the intermediate level through tunnel, to the top level is 74".  At 6%, the rise is 4.44"
• The total rise over the switchback is 7.95".  Call it 8", or 7.9", either way enough clearance at the double-track tunnel.

The inside tunnel height of the center tunnel on the switchback, needs to be 6" above the track below, which will be about 7" on exiting the tunnel at the left portal.   So that would be 13" to the tunnel ceiling, and maybe 16" to the top of the mountain.

I figure a switcher or short loco, can pull and push three cars up the 6% grades easy.