Metro Tunnel
The Metro Tunnel (sometimes also known as the Melbourne Metro Rail Project or the Metro Rail Capacity Project) is a metropolitan rail infrastructure project currently under construction in Melbourne, Australia. It includes the construction of twin 9-kilometre rail tunnels between South Kensington station (north west of the Melbourne City Centre) and South Yarra (in the south east) with five new underground stations. The southern portal for the tunnel is to be located to the south of South Yarra station. As a result, the tunnel will connect the Pakenham and Cranbourne lines with the Sunbury line, and allow these lines to bypass Flinders Street station and the City Loop while still stopping in the Melbourne central business district.
Great Istanbul Tunnel
The project was officially announced by Prime minister Ahmet Davutoğlu on 27 February 2015. The tunnel, in length and in diameter, will consist of three levels, two levels for road traffic and one level for rail system. It will be under the sea level. Situated between Gayrettepe on the European side and Küçüksu on the Asian side, it will integrate the highways between the three airports of the city, Istanbul Atatürk Airport, Sabiha Gökçen Airport, Istanbul New Airport, and the nine rail lines of the Istanbul Metro. The three bridges over the Bosphorus, 15 July Martyrs Bridge, Fatih Sultan Mehmet Bridge and Yavuz Sultan Selim Bridge, will be linked together through the tunnel. The cost of the project will amount to US$3.5 billion. The financing of the construction will be on the build–operate–transfer basis.