Scientist of the Day - Ralph Modjeski

Ralph Modjeski, a Polish-born American engineer, died June 26, 1940, at age 79. There are many notable American bridge builders, including James Eads, Gustav Lindenthal, Othmar Amman, and John and Washington Roebling, but Modjeski is usually considered by historians of technology to be the greatest of them all, perhaps because he built so many bridges and built them so well, even if he doesn't have one of our signature bridges, such as the Golden Gate Bridge or the Brooklyn Bridge, to his credit. He started out building railroad bridges in the 1890s, long ones that could span the Mississippi, which he crossed at least four times, by our count, at New Orleans, St. Louis, and the Quad Cities. He made his name when he took over the construction of the Quebec Bridge, which had collapsed in 1907, due to faulty design. Modjeski's cantilever truss replacement design was completed in 1917, and although it is rather clunky looking (as cantilever trusses usually are), it showed the hand of a master engineer (see first image above). In the 1920s, Modjeski began designing suspension bridges, and these are elegant and attractive, such as the Benjamin Franklin Bridge over the Delaware River at Philadelphia (completed 1926; second image), or the Mid-Hudson Bridge at Poughkeepsie (1930; third image). Most of Modjeski's bridges had very long spans--the Ben Franklin was the longest in the world for some years. Modjeski's best known bridge is probably the San Francisco--Oakland Bay Bridge, completed in 1936, just before the Golden Gate Bridge was finished. The original western span that connects San Franciso to Yerba Buena Island is still in place (fourth image), but the eastern span was replaced in the aftermath of the 1989 Loma Prieta earthquake. The last image shows the Bay Bridge under construction in 1935. As a final note, we might mention that Modjeski was also a classical pianist. Some think it doesn’t hurt to have the sensibilities of an artist when designing bridges. Dr. William B. Ashworth, Jr., Consultant for the History of Science, Linda Hall Library and Associate Professor, Department of History, University of Missouri-Kansas City. Comments or corrections are welcome; please direct to ashworthw@umkc.edu.