In the restoration of historic metal structures engineers and preservationists are often confronted with the decision to repair or replace historic metals. The lack of knowledge of historic metals, combined with the tendency to use today’s standard materials of known characteristics and properties, often results in the replacement or destruction of historic metals. In the decision making process regarding restoration of a historic metal structure, three groups of people figure prominently: those who want to restore the structure, the engineers who develop the restoration plans, and the craftsmen who do the restoration work. It is the engineer who often has the most impact on the restoration process. Engineers make many of the decisions that determine the type of restoration that will be performed and the percentage of original material to be saved.
There are few opportunities within the engineering community for engineers to see restoration processes demonstrated and to gain personal experience through hands-on activities. The Preservation of Historic Iron and Steel in Bridges and Other Metal Structures project created this much needed opportunity, important in providing engineers different options to the replacement of historic metals and to better comply with The Secretary of the Interior’s Standards for Rehabilitation. These standards state, in part, that “deteriorated architectural features shall be repaired rather than replaced, wherever possible” and “removing or radically changing architectural metal features which are important in defining the overall historic character of the building so that, as a result, the character is diminished” is discouraged. Engineers (and the historic preservationists who work with them) may not become experts in the specific restoration processes, but it is important that they gain enough understanding of how the processes work to be able to recommend them within the scope of work of a preservation project and to communicate more knowledgeably with contractors and craftsmen.
The project also created the opportunity for the contractors and craftsmen who do the restoration work to learn and share their knowledge in an environment that includes engineers and preservationists. In addition, the project addressed the need for greater knowledge among those who want to undertake the restoration of a historic metal structure, including preservationists, transportation officials and various public and civic entities. The project’s three components (a three-day workshop including hands-on demonstrations, six informational web-based videos, and two courses for ongoing training) contributed to the goal of increased knowledge and expertise necessary for good communication and sound decision making among the various groups responsible for the preservation of historic metal structures and the historic record they represent.