Seeking to keep an endangered $8.7-billion trans-Hudson River rail tunnel plan alive, U.S. Transportation Secretary Ray LaHood has bought the project a little more time. Proposed route was downriver from existing Amtrak tunnel. New Jersey Gov. Chris Christie [R] had announced Oct. 7 that he was killing the project. But after meeting with LaHood the following day in Trenton, Christie agreed to a two-week study of unspecified project "options". Nevertheless, it remains to be seen whether the results of that study will convince Christie to do an about-face and give the plan a green light. Supporters of the Access to
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.