Haliç Metro Crossing Bridge. A Bridge in the Historical Heart of Istanbul

Abstract

Over the past years, Turkey has made remarkable efforts to modernize its transportation system. The municipality of Istanbul has planned a subway for connecting the heart of the city with the Ataturk Airport. The Haliç Metro Crossing Bridge, designed in 2004 by Hakan Kiran and by prof. Michel Virlogeux, is the key of this development plan. It is a cable-stayed bridge with a central span 180 m long, two lateral spans of 90 m long and a swimming bridge. To this main system, two approaching viaducts are connected at sides defining a total system approximately 1 km long. In 2010, as required by the UNESCO Committee, the municipality of Istanbul appointed a group of independent international experts to assess the historical and visual impact of the bridge in relation to the Outstanding Universal Values of the Istanbul World Heritage areas and in particular on the Süleymaniye Mosque.

The results, contained in the Independent Historical and Visual Impact Assessment Report for the Golden Horn Metro Crossing Bridge, have highlighted the need to review the architectural design of the bridge in order to better insert this infrastructure in the historic city in relation and in the respect of its significance and OUV. The height of the pylons was lowered to 65 m above the sea level, and the length of the central station was reduced. In the end, the study of the colours and the architectural lighting of the bridge have completed the insertion of the bridge in terms of formal coherence with the surrounding landscape.