I have all 3 Great Model Railroad videos and DVD’s of Howard Zane’s Piermont Division. How does he build those viaducts?? They look great. It would seem to me like he uses styrene over some other material but I have no clue what it is. I would like to build something similar. I wish Model Railroader would publish an article on the subject. And while they are at it, it would be nice to know how to scratchbuild some of the concrete and stone bridge abutments. The ones Howard has built are fantastic. I also, love the ones built by Allen McClellen.
Foam can be carved to form the basic structure and styrene used to dress it up to look like a bridge.
Actually if you want, you could ask him yourself, he hangs out here. Just find one of his posts and hit “Start Conversation”.
John