Use of laser scanning technology to obtain as-built records of historic covered bridges

Covered bridges are part of the fabric of American history. Although much effort is expended to preserve these structures, many are lost forever. The National Park Service's Historic American Engineering Record (HAER) has efforts under way to document historic structures. Their Level I documentation is defined in the Secretary of the Interior's Standards and Guidelines for Architectural and Engineering Documentation and consists of measured and interpretive drawings, large-format photographs, and written historical reports. To assist in this effort, newer technologies need to be explored that can provide as-built records at a faster rate and with more accuracy. The University of Minnesota Duluth's Natural Resources Research Institute (UMD NRRI), in cooperation with the USDA Forest Products Laboratory and Federal Highway Administration, conducted a study to examine the use of laser scanning technologies for providing as-built records for historic covered timber bridges. Additional support for the study was provided by the City of Zumbrota, Minnesota, via funds from the Operational Research Program (OPERA) of the Minnesota Local Road Research Board. This research report summarizes results obtained from that study.