The 1905 shaft-driven Burlington Northern Santa Fe Railway swing bridge over Bayou Boeuf near Morgan City, La., has begun a new life after an intensive four-day project that converted it into a computerized, hydraulically operated crossing with opening times cut from 17 minutes to seven. Photo: Angelle Bergeron / ENR Crane operator holds span over pivot assembly while workers install collar. Photo: Angelle Bergeron / ENR Alignment and balance were critical as crews maneuvered center span into place. Related Links: Quick Change Artists: BNSF Railway Bridge Span Replacement During a 96-hour window that ended at midnight on Sept. 24, OCCI
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.