Hi
I have not had an O scale layout since I was a kid and looking for advice from more experienced people in the hobby. I want to build an 8 x 18 two tier subway layout using MTH subway cars. My idea is to have the underground subway train transition to the top level and become an elevated line. I have no idea what is involved in accomplishing this. I have researched online to find a suggested track plan and cannot find anything.
Once it becomes an elevated line I would like it to transition back down to the first level
I am guessing first step is to have a track plan but not even sure how to do this. Then even if I have a plan not sure how to build it, what kind of graduated trestles to use, what grade is needed to go from one level to the other and back down to underground level
If anyone has a track plan that could be used as a guide it would be appreciated. If special benchwork is required would also like to know this
Thinking of having either a four or six car subway train. Already have the trains. Also would like to have a trolley line run underneath the elevated subway line