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

5. Section 3 THR EE Post W orld W ar II T echnolog ical Dev elopment s Asso ciated W ith Maryland Bridge Con structionSECTIONFOURPost World War II Technological Developments5.1 DEVELOPMENTS IN DESIGNThe most important technological development in bridge design and construction after WorldWar II was bridge design standardization. This phenomenon occurred years before the postwarperiod but design standardization paved the way for the rapid-fire, postwar technologicaldevelopments that increased the economy, quality, and quantity of bridge construction.In the late nineteenth century railroad bridge designers began to standardize their plans in theinterest of efficiency. Roadway bridge designers followed suit in the early twentieth century. Theroadway bridge standardization movement began as a component of the Good Roads movementin the early twentieth century. State and municipal roadway bridge design systems becamehighly standardized between 1900 and 1960. Bridge standardization increased constructioneconomy. Lower construction costs and rapid construction rates enabled bridge constructors tokeep better pace with the demands of increased road usage.Consultant engineers did continue to be hired by states and municipalities when the realities of aconstruction plan required uniquely intensive study and design planning efforts. In these casesconsultants were hired to do the work that states and municipalities could not balance alongsideregular workloads. A notable example of the type of contribution that consultants added tounique bridge design and construction in Maryland is the Chesapeake Bay Bridge project (1949-1952) (Spero and Berger & Associates 1995: 29-30).After World War II, technological innovations had an immense impact on bridge projectplanning. Advances included the introduction of the computer, the tellurometer, andphotogrammetry. An electronic computer was installed in the Road Design Division in 1957.The computer could make calculations 10 times faster than the engineers could and the newtechnology assisted with design problems; its effectiveness led to the expansion of itsapplications and its adoption by other divisions. A tellurometer used microwaves to measuredistances. In 1958, the Bureau of Public Roads chose Maryland as one of three highwaydepartments to test the tellurometer‘s usefulness in plotting new highways. The State RoadsCommission found the tellurometer to be extremely accurate. The new tool was proven to befaster and less expensive than conventional triangulation or traverse methods (LeViness1958:200).Aerial photography and photogrammetry were applied to the preparation of new highway plansbeginning in the 1950s. Photogrammetry allowed engineers to survey alternate routes withoutsending out survey parties. The first use of photogrammetry in Maryland was applied to theplanning of the Rising Sun Bypass, a three-mile relocation of US 1, opened in 1957 (LeViness1958: 200, 195 – 198).5.2 MATERIALS AND TECHNIQUE DEVELOPMENTSDuring the postwar period, advances in bridge building materials and building techniquesassisted in the improvement, development and construction of many types of bridges. Theseadvancements are in evidence along roadways throughout Maryland.The development and availability of high-strength and corrosion-resistant steel to bridge buildersincreased both bridge capacity and lifespan. Fabrication was further empowered by the adoptionsof welding technology and the introduction of the high-strength bolt (Burroughs 1975: 463-464).\15-SEP-11\\ 5-1