New York City-based Structure Tone is banking on a boost to its institutional and base-building capabilities by acquiring L.F. Driscoll Co., a major construction-management-at-risk firm in metropolitan Philadelphia. The deal, announced on Nov. 16, allows Structure Tone to leverage Driscoll’s experience in healthcare, higher education and high-rise base building. Financial details of the deal, which combines two of the nation’s largest privately held CM-at-risk firms, were not disclosed. Structure Tone ranks 21st among ENR Top 400 contractors, with $3.1 billion in 2008 revenue, while Bala Cynwyd, Pa.-based Driscoll is ranked 104th with $646 million in revenue. A Structure Tone spokeswomen
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.