Second Bosphorus Bridge, Turkey

Sector: Pell Frischmann Brown Beech

Cost: Confidential

Client: Turkish Highways Authority (KGM)

Location: Turkey

Project Details

Increasing volumes of traffic over the first Bosphorus Bridge resulted a in a decision to construct a new suspension structure 5KM from the original bridge. It is a toll bridge, and a toll plaza with toll booths is situated before the bridge on the European side. Toll is paid for one way passing from the European side to the Asian side.

The bridge is situated between Hisarüstü (European side) and Kavacık (Asian side). It is a gravity-anchored suspension bridge with steel pylons and inclined hangers. The aerodynamic deck is hanging on double vertical steel cables. It is 1,510 m long with a deck width of 39 m. The distance between the towers (main span) is 1,090 m (World rank: 12th) and their height over road level is 105 m. The clearance of the bridge from sea level is 64 m. It was the 6th longest suspension bridge in the world when completed in 1988.

A key challenge for this scheme included calculations to counter extensive tectonic and seismic risk in the region. Turkey's North Anatolian fault runs east-west nearly 1,000 km and since 1939 earthquakes have ruptured successive segments of the fault close to Istanbul.