I think Jim Barrett's articles mentioned above should be the basis for anyone starting out with the intent to build a trestle/bridge. What REALLY amazes me about Jim's work is that he built 3 or 4 trestles on a slide-out section of his layout that detaches from the fixed portion of the layout....and then slides right back in and lines up perfectly. Only Barrett would build trestles on wheels! But all joking aside, his movable trestles are a remarkable piece of basement modeling. Some of the final details about hiding the joints are in the 12/2018 issue of OGR.
Sometimes I have to read his stuff twice because it is just so valuable that I want to make sure I remember it.
Don Merz
