In 2007, a contractor worked itself into a pickle while building a Midwestern wind farm. There, a Demag CC2600 was being walked from one turbine pad to another. As the 500-ton crawler crane moved down a slight hill, it suddenly tipped forward. The counterweight overcame the upperworks, causing the boom to jackknife and crash to the ground. Photo: WHECO Corp. A crawler crane that tipped over on a wind farm in 2007 was repaired in about five months. It is shown from the scene of the accident Photo: WHECO Corp. Its arrival in the shop Related Links: Crane Owners Step
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.