I'm not quite sure on what the problem is but i'd defenatly use steel supports for the risers, be there forever. and for the transitions id get a roll pipe bender and rachet away, a little expensive but for a perfict curve evry time, I'll take the cost, and you can bend almost evrything (including fingers)
I havent decided what I'm going to do for subgrade support, it will NOT be the OSB board in the pics, I considered it but it wouldnt last a year even if drowned in preservative before being put down. Maybe i could use something like TREX or similar, or concrete or a mix of both depending on the location. Of course since I'm planning to use stone wall supports I could concievably build up my stone 'faces' with a platform for the track and just float the track on that.
I will be using the OSB boards like in the pics as a template to guide the stone wall construction. I can set the grades and ROWs and then build all the mountains and cliffs around it.
Have fun with your trains
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