From Rome’s Pons Sublicius over the Tiber River, built in 642 B.C., to China’s Qingdao Haiwan, the longest in the world at 41.6 kilometres, bridges throughout history have been at the frontier of engineering innovation at the service of improving people’s lives.
A bridge’s contribution to social and economic change is undeniable. As recently as 2012, the Federal Reserve Bank of San Francisco published a study showing how for every $1 spent on bridge construction, $2 was generated in economic growth for the area served by the new infrastructure.
If a bridge reduces distances – the span between Hong Kong and Macao will shorten the drive between the two cities from 160 to 30 kilometres when it opens in the coming months –it also contributes to trade and cultural exchange, as is the case with the new Gordie Howe International Bridge that will connect Windsor in Ontario, Canada, with Detroit in Michigan. Its impact on international trade will be greater than any bridge ever built.
Salini Impregilo’s contribuition
Over the past 100 years, Salini Impregilo has made a contribution to this millennial development in civil engineering by building a total of 102 bridges and viaducts, stretching for a combined length of 590 kilometres. Some of these are far-flung examples of majestic infrastructure that play a strategic role in the mobility of goods and people, while others are examples of technological excellence.
From the railway viaduct at Recco that connects northern Italy with the central regions, built in 1914 and rebuilt after the bombing damage of World War II, to the second bridge over the Bosphorus; from the Rosario-Victoria in Argentina to the replacement of the Gerald Desmond Bridge underway in the United States, Salini Impregilo has built bridges for vehicles and trains in more than 20 countries.These include cable-stayed bridges like the Sfalassà viaduct at Favazzina on the Salerno-Reggio Calabria highway in Italy; extremely long bridges like the 977-metre A. Max Brewer in the United States; or complex highway systems like the Anchieta and Immigrantes in Brazil, consisting of nine consecutive bridges and viaducts between 74 and 1,225 metres long. Large projects, built using the most up-to-date techniques, some of which rank among the top feats of civil engineering.
The Skytrain: A curved bridge for a Sydney metro line
Construction work on the Sydney Metro Northwest, a line that will serve areas like Bella Vista and Rouse Hill in the Australian city, is not finished yet but the Skytrain viaduct has already become a landmark for the city. The line that will run along the bridge will cross 23 kilometres of the city, stopping at eight stations. The bridge’s distinctive feature is its curved structure, taking up its entire above-ground portion at a height that varies between 10 and 13 metres, and for a total length of 4.6 kilometres. The structure enables the trains to make a wide curve along their track supported by 130 concrete piers spaced about 39 metres apart.
The Gerald Desmond Bridge: A strategic infrastructure for Long Beach
The new structure will have a tough task to live up to: substitute the historic Gerald Desmond Bridge, which connected the port of Long Beach in California to land transportation – a fundamental artery for trade considering that 15% of cargo at the port must pass through this infrastructure. Work on the new cable-stayed bridge began in 2013. It spans 610 meters in length and stands 62 metres (as high as an 18-story building) above sea level. This great height is necessary to accommodate the to and fro of the massive new post-Panamax ships. Once completed in 2019, as according to plan, the two towers of 157 metres in height will make it the tallest bridge of its type in the country, enabling it to carry three lanes of traffic each way, for a total of 68,000 vehicles a day and 18 million transits each year.
The second bridge on the Bosphorus
An integral part of the Istanbul skyline, the second bridge over the Bosphorus River is a prime example of how a large infrastructure work can change people’s lives and contribute to the economic well-being of the area. The Fatih Sultan Mehmet Bridge is not only a mighty piece of engineering, with a span of 1,090 metres at its widest point, but it also connects a 247-kilometre-long highway that links the city of Kinali in Europe to Kazanci, in Asia.
Built between 1985 and 1994, its construction was a response to the need for commuters and travellers to cross Istanbul without passing through its centre. Something that was extremely useful for the Turkish metropolis, as demonstrated by the traffic flows registered on the bridge and the impact on the adjacent neighborhoods. During the seven years following the bridge’s construction, trade volume between the adjacent areas rose 31.8%, while from 1994 to the present day the urban build-up in the area surrounding the bridge’s access points swelled from 340 to 42,260 hectares.
The Rosario-Victoria: A bridge for South America
Its leap across the valley of the Paranà River is not only spectacular – supported by a main section 608 metres long – but also a triumph for business traffic linking four countries: Chile, Argentina, Uruguay and Brazil. The cable-stayed Rosario-Victoria Bridge is actually part of a 59.4-kilmetre highway link between the cities of Rosario in the province of Santa Fé and Victoria in Entre Rios in the northeastern Argentina. The bridge has cut travel distance for cars and trucks headed north by 120 kilometres, substituting a tunnel that used to pass under the river. The impact on trade is considerable, given that Rosario is the main center for grain production in Argentina, and the bridge creates a transport corridor between the Atlantic and Pacific coasts.