Frank L. Stahl, 91, a Holocaust survivor who became a noted bridge designer and the chief engineer at Ammann & Whitney Consulting Engineers PC, at which he built and rehabbed many landmark U.S. spans and highways, died on April 17 in Sandy Springs, Ga. The New York City firm says his death was due to natural causes. Stahl stands at the record-settingVerrazano-Narrows bridge, which opened in 1964. STAHL Stahl joined A&W in 1946, working directly for its legendary founder, O.H. Ammann. Stahl held key roles in designing Philadelphia's Walt Whitman Bridge and New York's Verrazano-Narrows and Throgs Neck bridges in
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.