Forge welds, punch marks, and many other signs of fabrication work made by craftsmen who fabricated historic iron and steel truss bridges are physical signs that can lead to the discovery of how these craftsmen fabricated iron and steel truss members. I’ve found few written documentations that give a detailed description of the tools, fixtures, or the oral transfer of knowledge from elder craftsmen. Over the years my wife and I have inspected many historic riveted truss bridges, photographing details with cameras, reaching with camera sticks, climbing verticals, standing on hub guards, and climbing over and under abutments to get a photograph of an interesting connection to document the historic craftsman’s skills. A drone seems to be a tool that could uncover those difficult-to-reach areas on historic bridges. With the purchase of a Mavic Air 2 drone, I began practicing and developing skills to manipulate the drone around historic bridge truss members. With permission from Nels Raynor, proprietor of Bach Steel in Saint Johns, Michigan, I spent time with the Mavic Air 2 around his yard area flying and photographing bridge parts. Of special interest was the Hidden Lake Forest Preserve Bridge which arrived recently at Bach Steel for restoration. For more about this bridge check out Bach’s Facebook page, https://www.facebook.com/bachsteel, and Hidden Lake Historic Bridge Blog, https://www.dupageforest.org/…/hidden-lake-historic-bridge.
Vern Mesler 2022