Two contracts have been awarded in two months for preliminary design on a natural-gas-treatment plant. Calgary, Alberta-based TransCanada Corp. awarded a contract to URS Corp., San Francisco, for a 5-billion-cu-ft-per-day plant in Prudhoe Bay. In February, a BP-ConocoPhillips joint venture tapped Fluor WorleyParsons Arctic Solutions for a similar contract. But only TransCanada has a contract with Alaska to build a North Slope pipeline.
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.