historic context of maryland highway bridges built between 1948 ...

3. Section 1 ONE Methodolog ySECTIONTWOMethodology3.1 BACKGROUNDThe Historic Highway Bridges in Maryland: 1631 – 1960, Historic Context Report providedbackground and preliminary evaluation of post-World War II bridges, but did not fully addressthe important contextual issues that architectural historians, industrial historians, and engineershave examined during the past decade concerning the post-World War II road building era inMaryland. Therefore, SHA sought an update of its historic context that would provide the basisfor evaluation of historic bridges and begin a new phase of identification and evaluation with asample of 21 highway bridges built in Maryland between 1948 and 1960. In addition, the newcontext report would contain information about previous documentation efforts and build on thework contained in the Historic Highway Bridges in Maryland. The end product would includewell-developed information about technological innovations in bridge design and manufacturing,bridge manufacturing companies and designers, and important transportation advances or eventsfrom 1948 through 1960 in Maryland specifically and the United States generally.3.2 FIELDWORKTwenty-one highway bridges, representing the 1948 – 1960 period and 12 different bridge types,were chosen by the SHA, in consultation with MHT and FHWA, to be surveyed as part of theexpanded inventory of historic bridges. Hardlines architectural historians visited each bridge anddocumented the bridge and its appurtenances on Maryland Inventory of Historic Properties(MIHP) forms. In addition to completing each MIHP form, a MHT Determination of Eligibility(DOE) form with a detailed National Register eligibility evaluation was also completed for eachof the surveyed bridges. Each bridge was recorded on the appropriate USGS quadrangle map at1:24,000 scale and photographs were taken using 5 x7-inch, 35-millimeter black-and-white film,and 35-millimeter color slide film. Hardlines also obtained the MIHP inventory numbers foreach bridge from the MHT Inventory Registrar.3.3 RESEARCH AND CONTEXT UPDATEURS updated the historic context written in 1995 to include information regarding technologicalinnovations in bridge design and manufacturing, bridge manufacturing companies and designers,and important transportation advances or events from 1948 through 1960 in Marylandspecifically and the United States generally, as these themes correspond to National RegisterCriteria A, B, C and D. In order to develop a historic context update for the post-World War IIor mid-century-era bridges, historians from URS and Hardlines also conducted general andspecific research at a number of local, regional, and university repositories. In addition, thesehistorians researched county and/or SHA bridge maintenance records and construction plans, aswell as secondary sources of information, including the Office of Bridge Development‘s 2003Bridge Inventory and the most current list of county-owned bridges in Maryland. The historiansalso had access to the most current SHA Historic Bridge Inventory (1995 – 2001). Inspection ofprevious cultural resource survey reports, site forms, and other references was conducted eitherat MHT or at SHA. Other repositories of information used in the research effort include, but arenot limited to, the Enoch Pratt Free Library‘s Maryland Room, the Maryland State Archives, theHistorical Society of Maryland Library, New Jersey State Library, New York Public Library, and\15-SEP-11\\ 3-1