A joint venture of two Spanish contractors, Obrascon Huarte Lain S.A. (OHL) and Dimetronic S.A., emerged May 17 as the low bidder for the Marmaray suburban rail upgrade project in Istanbul with a $1.5-billion bid. Related Links: Byzantine Port, Botched Buildings Put A Brake On Bosporus Link Japanese Team Goes Deep To Link Istanbul's Two Parts The project to upgrade the city’s 140-year-old suburban train lines will create an uninterrupted high-capacity commuter rail system of 76.3 kilometers between the suburbs of Gebze on the Asian side and Halkalı on the European side. It will include a line running through an
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.