On 20th February 1970, the construction of the Bosphorus Bridge began. It was the first of three suspension bridges spanning the Bosphorus Strait in Istanbul, Turkey. The Bosphorus strait is a historically contested body of water bisecting Turkey, dividing the European and Asian side of the country. So, the Bosphorus Bridge not only serves as an important transport route – it literally connects two continents.

The Bridge united the two banks of Istanbul, at Ortaköy (Europe) and Beylerbeyi (Asia). It was the first road crossing the Strait and upon completion in 1973, it was the longest suspension bridge outside the U.S. Bridge-making not only requires effective collaboration between those involved in its construction; collaboration and camaraderie is also needed on cultural and political fronts, gradually fostering stronger ties for the future.



The idea to bridge the gap between the two land masses dates back to around 400 BC when a floating pontoon bridge was built under the rule of Darius I in an attempt to expand the Persian Empire further into the Balkans. The decision to build a permanent, modern bridge was taken in 1957 by the Turkish government. The design of the Bridge was the work of renowned British civil engineers Sir Gilbert Roberts and William Brown, who also designed the Humber Bridge, the Severn Bridge and the Auckland Harbour Bridge. By 1968 a contract had been signed with the British firm Freeman Fox & Partners for the steel engineering work, who teamed up with Turkish construction cooperation Enka. With 35 engineers and 400 construction workers on the project, the Bridge was completed in 3 years and now has daily traffic of about 200,000 vehicles.

Bosphorus Bridge on the 1000 lira banknote (1978 – 1986)

Suspension bridges can withstand a surprising amount of weight but they are known to be swayed by environmental change. They can move subtly from side to side in strong winds and the Bosphorous Bridge is said to sag about 90cm in the middle of its span when at its traffic capacity. The Bridge was built with this in mind and has an aerodynamic deck – enabling it to withstand weather changes.



Since the Bosphorous Bridge opened, two more bridges have been constructed to cross the Strait and plans for a second underground ‘Eurasia’ tunnel are underway. The bridges have eased trade and commute routes but they also help strengthen intercontinental relations between the two sides of the country – connecting people and cultures, despite terrestrial separation!

The Construct Series is here to explore the industry in a wider, cross-disciplinary sense, to champion the creativity of the past, as we drive the future of construction. We’ll be foregrounding innovation which is at the heart of BaseStone’s technology.


Image attributions

Bosphorus Bridge aerial view

Bosphorus Bridge on 1000 lira banknote

View of Istanbul

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