My approach to the restoration of a historic metal truss bridge is
to restore as much of the original material as possible. If a bridge
member cannot be restored, I replicate the original piece. To destroy
the original parts or make no effort to replicate them is to destroy a
valuable historic record. The parts that make up a historic bridge and
the historic bridge itself are the words of a craftsman.
This method of restoring a historic metal truss bridge is based in part
Secretary of the Interior’s Standards for Rehabilitation that state
“deteriorated architectural features shall be repaired rather than
replaced, wherever possible,” and advise against “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.” Yet, there are no standards specific to the
restoration of historic metal truss bridges, and as a result historic
metal truss bridges are often end up altered.
If standards are developed they must include not only the engineer’s
perspective but also the craftsman’s. Standards should also require
steel fabricators to demonstrate proficiency in the use of the tools
they have selected and the procedures they develop. Furthermore, a high
level of inspection must be required to ensure that the standards agreed
upon for the project are met.