Prime Minister Recep Tayyip Erdoğan joined ceremonies in Istanbul on October 13 to mark completion of the immersed-tube tunnel which will carry the Marmaray rail link under the Bosporus. After removing the last seal from the final segment, Erdoğan was able to walk through the tunnel linking Europe and Asia, accompanied by other guests. ‘We have just brought both sides of the city together’, he said, pointing out that the vision of a railway under the Bosporus dated from 1860.

The US$3·5bn Marmaray project includes nearly 10 km of bored tunnel and 2·4 km of cut and cover tunnel, as well as the 1·4 km tube section which lies in a trench at a depth of 58 m, making it the deepest immersed tunnel in the world. The undersea section is formed from 11 concrete segments 60 m long, weighing up to 19 000 tonnes each. These were fabricated in two dry docks at Tuzla and floated to the site using a launching catamaran. The last segment was put in place on September 23. Being led by the General Directorate of Railways, Harbours & Airports at the Ministry of Transport (DLH), the Marmaray project is being financed by loans from Japan Bank for International Co-operation, the European Investment Bank and the Council of Europe Development Bank. DLH has appointed Avrasyaconsult, a joint venture of four consultants led by Pacific Consultants International of Japan as project engineer, in association with Parsons Brinckerhoff.