Four companies bid for 3-level Istanbul tunnel

After successfully completing mega projects like the Eurasia Tunnel, Yavuz Sultan Selim Bridge, Osman Gazi Bridge, and the Ilgaz Tunnel, Turkey now plans to build the world's first 3-level tunnel, aptly called the "Grand Istanbul Tunnel," which will be another milestone in the country's "Vision 2023."

Four companies submitted financial proposal tender bids for the survey, project and engineering of the 3-Level Grand Istanbul Tunnel Project, yesterday. The project aims to ease traffic congestion in Istanbul.

Speaking at the opening of the tender bids, General Director of the Directorate of the Infrastructure Investments of the Ministry of Transportation, Maritime Affairs and Communication Erol Çıtak said the bids would be announced once a competence evaluation of the bidding firms was completed.

Previously, six firms were invited to bid for the tender, with four submitting proposal, including Tecnimont Civil Construction SPA, Italfer SPA-Sintagma Consortium and Arcadis-Prota Mühendislik Proje Danışmanlık and Yüksel Proje Uluslararası AŞ.

The tunnel will offer both rail and highway connectivity

The tunnel, to be built under the Bosporus seabed, will have both a rail and a highway in a singl

e tube. The mid-section of the tunnel will have two-way railway tracks, while the other two floors will feature 2x2 lanes for motor vehicles.

A total amount of TL 7.5 million was allocated earlier this year for survey, project and engineering services for the project, which is estimated to cost TL 30 million ($8.13 million).

As part of these studies, a deep-drilling survey will be carried out on land and in the sea. The results of the survey will help determine ground data.

The first phase of the project will involve a high-capacity, rapid metro system that will start in İncirli on the European side, run along the E-5 highway and pass under the Bosporus to reach Söğütlüçeşme on the Anatolian side.

The second phase will consist of a four-lane highway system, starting at the Hasdal intersection on the European side of the TEM Highway, then pass through the Bosporus to end in Ümraniye's Çamlık intersection on the Anatolian side.

The tunnel will be integrated into Istanbul's major highways, including the TEM and the E-5, the North Marmara highway and nine metro lines.

The metro line that will pass through the tunnel is expected to be finished within five years and will be constructed using the build-operate-transfer model. It will feature 14 stops on the 31-kilometer fast metro track between İncirli and Söğütlüçeşme and will decrease travel time to 40 minutes. In addition, cars will be able to travel between Hasdal and Çamlık in just 14 minutes.

The tunnel will enable faster and cheaper transportation between the two sides of Istanbul. It will integrate nine different urban train systems to a fast metro track, which is used by approximately 6.5 million passengers on a daily basis. It will also enable easier and faster connections to ring roads, thus connecting all the main arterial roads.