Last fall, Manitowoc Inc. was flying high. The 107-year-old fabricator had just wrapped up two years of factory upgrades worth roughly $70 million and was popping out construction cranes for record sales and backlogs worth more than $3 billion. It also had started building its biggest crane ever—the Model 31000—a massive, 2,500-ton rig with a $30-million price tag. Photo: Tudor Van Hampton / ENR The giant crane’s lowerworks are powered by two 600-hp Cummins diesels and stand firm on four trunnion-mounted tracks. Tellock says Manitiwoc may apply its patented designs to other rigs. Related Links: Heavy Lifter: Manitowoc Builds Its
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.