The first railway tunnel to be crossed by the Bosphorus was prepared as a draft in 1860.
The idea about a railway tunnel under the Istanbul Strait was first proposed in 1860. But where the tunnel planned to pass under the Bosphorus would pass through the deepest parts of the Bosphorus, it would not be possible to build the tunnel above or under the seabed, using old techniques; and so this tunnel was planned as a tunnel over the columns built on the seabed in the design.
Such ideas and ideas were further evaluated over the next 20-30 years, and a similar design was developed in 1902; In this design, a railway tunnel passing under the Bosphorus is envisaged; but in this design, a tunnel placed on the seabed is mentioned. SHE IS zamSince then, many different ideas and ideas have been tried and new technologies have given more freedom to design.
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