Rehabilitation of Two Floating Bridges, Turkey

Two floating bridges were built by German firms: the Galata Bridge and the Unkapani Bridge. The Galata Bridge was constructed over a period of forty months and opened to traffic in 1912; the Unkapani Bridge opened in 1938. The original Galata Bridge was 460 m long and 25 m wide, carried by 26 pontoons. According to Turkish highway technical specifications, a maximum allowable load of 60 kN was prescribed in the replacement bridge design. The design called for a lightweight vehicular traffic lane and a pedestrian lane in each direction. The bridge rehabilitation required a total of 19 months. The 454 m long Unkapani Bridge was originally designed and constructed with a 16 m wide deck slab allowing a lane of vehicle traffic in each direction flanked by two 4.5 m wide pedestrian lane. It was decided to increase the capacity of the bridge by widening the vehicle traffic lane from 16 to 20 m.