Preservation and Restoration of 19th Century Cast and Wrought Iron Bridges

Restoration of cast and wrought iron bridges is not covered in civil engineering curriculum and engineers have been called upon, or volunteered, to restore these structures with little or no methodology in print to guide them in their work. The writer has restored many of these bridges as pedestrian bridges, published his work in ASCE journals and made presentations at local, regional, national, and international meetings describing methods he used. A brief history of the development of cast and wrought iron bridges in the United States from 1840 to 1890 is presented. The paper discusses properties of cast and wrought iron, methods of replacing in kind or rehabilitating bridge members using casting/riveting/bolting/welding methods, dismantling or removal intact, transportation and rebuilding the structures on new sites. It concludes with images of several bridges restored by the writer.