Istanbul (1930s-1940s) / Prost Metro Proposal
Henri Prost drafted a detailed report addressing inter-city public transportation, in which he proposed a metro system to alleviate traffic congestion at the heart of the city. Hence, the main spine created with two main motorways between the historic peninsula and the new development area, would be supplemented by an underground metro line as well.
Prost proposed a subway line running from Yedikule (The historical peninsula), to the Karaköy. The line consists of three section, 1) between Yedikule and Eminönü, 2) the Golden Horn crossing, 3) between Taksim and Karaköy.
It was costly building a metro line in Istanbul due to its rugged topography. Prost studied on the possible metro lines and the locations of metro station in relation to his plans. There were two main challenges in the metro project, the Golden Horn crossing and the session between Galata and Beyoglu.
Possibilities at the Golden Horn crossing
The greatest challenge of the metro project was the Golden Horn crossing. Prost developed two alternatives, the bridge and the tunnel. In the first alternative of crossing the Godern Horn through a tunnel, the metro line would run from Eminönü, follow the new road to be opened in the continuation of Tahmis Caddesi and Mahmut Paşa Yokuşu, and finally reach Çakmakcılar Station. The merits of this alternative was that the Eminönü Station was then located near the new bridge, providing easy access for metro passengers to reach the boats without obstructing the silhouette of the Historic Peninsula.
In the second alternative of crossing the Golden Horn through a bridge, both Eminönü and Çakmakçılar Stations were to be built on 10 and 8 m-high viaducts, respectively. The merits of this alternative was preserving the aesthetic views of Süleymaniye, Rüstem Paşa Mosque and Yeni Cami (Mosque).
Possibilities at the session between Galata and Beyoglu
The other challenge was the session between Galata and Beyoğlu. The slope at Beyoğlu was too steep for metro cars to ascend. Two alternatives was developed. The first alternative was a tunnel ascending the slope in a helicoid curve. The merits of this alternative was the possibility to construct two stations near Şişhane and in Beyoğlu, thereby serving more people.
The second alternative was a tunnel parallel to the historic tunnel. The metro line would first run from Tünel Squareand to Tepebaşı, and reached Taksim by passing behind the British Embassy. It then followed Tarlabaşı Caddesi, the new avenue that paralleled to İstiklâl Caddesi. The merits of this alternative was that it was more economical since it was shorter.
Bilsel,C. (2011).“Les Transformations d’Istanbul”: Henri Prost’s planning of Istanbul (1936-1951). ITU AIZ, 8(1), 100-116