Tunnel-i Bahriden Marmaraya: In the 1902 year, where new bridge projects were on the agenda, new projects were being prepared in the form of a tube gate. The steel tunnel to be built under the throat would be double-stranded.
Istanbul's transportation issue, which connects the two continents, was prepared in order to cross the Bosphorus and the Golden Horn, which had an important place in history. One of the oldest of these was the bridge projects which were prepared for the Golden Horn and the Bosphorus by Leonardo da Vinci and presented to Sultan II.Beyazıd but impossible to take place under the conditions of that day. One of these projects for Haliç will be realized in a different way in 19.yy and the two sides of the Golden Horn would be connected by bridge.
The projects for the Istanbul Strait came up during these periods when engineering was developed. The first work to connect Anatolia and Rumelia under the Bosphorus was projected by French Jaggues Preault during the reign of Sultan Abdulmecid in 1860 under the name of Tunel-i Bahri. However, this project, which will connect two continents by train, did not take place upon the death of Sultan Abdülmecid.
In the 19.yy, where the transportation for the integrity, security and economic development of the country has gained importance day by day, the Ottoman state initiated important railway projects in Rumelia and Anatolia. Great efforts have been made to build the railway lines that will connect the Balkans, Anatolia and Arab lands. Despite the economic problems in the state, Baghdad carried out projects such as railway, Hejaz railway. In parallel with the success in the construction of railways, the projects in the form of bridges or tube passages to the Bosphorus started to come up again.
The first project proposal for Tunel-i Bahri was made by Euqene Henri Gavand, engineer of the tunnel between Galata and Pera during the reign of Sultan Abdulhamid II in 1876. This tube passage project would be between Sarayburnu and Üsküdar. However, this project was shelved by the influence of the 93 Ottoman-Russian war known as the war. The second project for the connection between Sarayburnu and Üsküdar by tube passage was presented by French S.Preault in 1878.
In the year of 1900, new projects were brought up to connect the two sides of the Bosphorus with bridges or tube gates. This time the project was prepared by the Germans. The Germans, who undertook the project of Baghdad Railway, projected to connect the Bosphorus with a bridge. The bridge, which was planned to be built between Rumeli Fortress and Anadolu Hisarı, was then connected to the Baghdad railway line with the name of Cisr-i Hamidi.
The second one of the bridge projects that were brought up during the reign of Abdulhamid II was the planned project between Sarayburnu and Uskudar. According to the project drawn by the French construction engineer F.Arnodi, the bridge would be rested on five legs and would be at the height of 50 meters from the sea. With the construction of these bridges, uninterrupted transport from Vienna to Medina could be provided.
In the year of 1902 which is on the agenda of the bridge projects in the Bosphorus, new projects were being prepared in the form of a tube gate. 3 was an American engineer, and the project was designed to build a steel tunnel under the Bosphorus. The tube walkway with the name tı Tünel-i Bahrî geliş was going to be double-stranded.
However, none of these projects could be realized due to the economic difficulties and political turmoil of the period. II.Abdülhamid'in dethronement of the country and then because of the difficulties of the country for many years fell from the agenda.
Source : www.dunyabulteni.net