Tim Morlok says:

Ryan, first a couple of questions. What size of a layout are you planning and is it going to be multi-level with raisers or flat with just hills and mountains on top of the base? I, my self am in the process building a layout that will be a combination of shelves above a wider flat base level. I am going to use 7/16ths inch plywood (5-ply) as my normal base. It will give me a strong base but is still flexible enough to allow me to make cuts that I can bend to make raisers or dips in the table. Most of the plywood will be covered in 1/4 inch foam core craft board. This can be cut away to form creeks or rivers with a shallow bank. If you want to make deeper banks, you can either cut out the river shape from the base board and lower it or use 2 or 3 inch thick foam insolation board over the base that can be carved to the desire depth or combine both for a deeper ravine. I am going to use 3-ply veneer and the 1/4 inch craft board on a 2×1 frame on shelf brackets for the narrow part of the upper shelf that I can gap to make a high tressel over a lower shelf with a background picture of a ravine. I hope this gives you some ideas to consider. Tim

Kevin says:

Hi Ryan,
I build my bridges from Balsa wood using 1/4″ square as the main runners under the track and 3mm for the ties or sleepers usually hand lay the track onto the sleepers to add realism Look at pictures of different types of bridges and build one that suits the era that you are modeling in, Mine is around 1936 steam