The North fork bridge is a reinforced concreat 3 arch bridge, as per page 141 of MRs Bridges and trestels. prototype is 1011 long and 200 ft high.
Looking at the plans I not only have the room for it, but would correct a foo-paaa of relocating three of my lower tracks of which are my widest curves. Have 24 x 18 hi area.behing the curve and 6 in from the wall.
I think building a foam mold for the arches and uprights and then pouring somthing like Flex-All would work. Then the foam would be easy to remove between the risers. Leaving it cast in place on a wood base, it then could be mounted to the layout without the hassel of it cracking.
Main reason for using a foam mold is that it would be easy to cut the open supporting area with a table saw and shape the curves under the bridge. O well theres my two cents of another hairbrained idea i will doooo.
Open to any and all suggestions other then not doing it LOL, thanks in advance.