The York YVWA Water-Cooled Screw Chiller features a variable-speed drive that allows for more efficient energy usage. It uses HFC-124A refrigerant, which has zero ozone depletion potential and no phase-out date. The screw chiller is able to handle a higher pressure lift than a centrifugal chiller, allowing it to be used in both thermal storage and heat-pump applications. Johnson Controls; 800-537-9675; www.johnsoncontrols.com The Liebherr 65 K Fast-Erecting Crane has a lifting capacity of 1.4 metric tons at 40 meters, with a maximum lifting capacity of 4.5 metric tons. Loads are moved using a pure two-fall operation with no re-reeving. The
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.