Bosphurus tunnel: engineers voice earthquake concerns
The tunnel under construction
Engineers and urban planners have voiced concern about the safety of the underwater section of the world's deepest underwater railway tunnel, which opened on 29 October.
Almost a mile of the 8.5-mile tunnel between the European and Asian sides of Istanbul, Turkey’s capital, is immersed under 56 metres (184ft) of water. Istanbul is above a seismic hotspot. Tectonic plates meet under the Sea of Marmara, putting the city at risk of a major earthquake within a generation.
Quoting a report by Rıza Behçet, an engineer who has worked on the project for eight years, the Istanbul Chamber of Architects warned the tunnel lacked an electronic warning system and that the flexibly linked parts of the immersed section would be prone to rupture and water leakage in the case of earthquakes.
The country's transport minister, Binali Yildirim, countered such claims, saying the Marmaray tunnel was "the safest place in Istanbul" and that the structure would withstand up to 9-magnitude quakes.
The subway crossing will take four minutes, much faster than the ferries which criss-cross the Bosphorus.