New product announcements: 03/18/2009 Rotary Hammer: Lower Vibration Bosch rotary hammers now include the new Vibration Control system for reducing operator vibration. The system employs a slightly larger air cushion between the piston and pin to reduce vibration during impact and a redesigned handle with rubber built into the top and bottom to absorb the shock. The new pin design also contributes to faster drilling in concrete. Bosch Power Tools and Accessories; 877-267-2499; www.boschtools.com Hydraulic Power Packs: Portable Portable Hydraulic Power Packs from Chicago Pneumatic are available in four compact models. The largest pack is less than 30 in. to a
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.