Related Links: Cardno Entrix Contract Raises Conflict-of-Interest Questions Editorial: Build the Keystone XL Pipeline, a Necessary Evil New York Times Story on Pipeline Contract Conflict Issues TransCanada's Keystone XL oil pipeline will be manufactured from high-strength, epoxy-coated steel able to withstand high pressure. The 36-in.-dia pipeline will be up to 0.748-in. thick in places and will be monitored constantly for leaks by a computerized system. A physical inspection of the 1,387 miles of line in the U.S. will be required every two weeks. Coatings on the pipes must be inspected before they are joined by double submerged-arc welding, and welds
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.