Within days of the earthquake and tsunami that severely damaged Japan's Fukushima Daiichi nuclear plant, Tokyo Electric Power Co. and the Japanese government were in talks with equipment manufacturers about how their specialized machines could lend a hand. Cargo planes airlifted huge concrete pumps to water-cool the reactors, and a robotics manufacturer known primarily as a defense contractor stepped forward with an unusual proposal. “We had contacted TEPCO, and after a demonstration of our equipment they chose to deploy it to the site,” says Ed Godere, senior vice president, unmanned systems, QinetiQ North America, Reston, Va. QinetiQ manufactures compact, remotely
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.