The work can be divided into three main sections, which were built simultaneously: the bridge itself, over Guanabara Bay, the access roads in Rio de Janeiro and the access roads in Niterói. “The most complex part, of course, was the 9 kilometers built over the sea, which required drilling the ocean floor in search of rocky terrain that would support the structure of the bridge”, says civil engineer Bruno Cantarini, who was director technician in historic construction. In addition to the long stretch over the water, several kilometers of access ramps and viaducts needed to be made to integrate the bridge into the local traffic system. With this, the total extension of the work reached 13 kilometers. The dream of making a direct connection between the cities of Rio and Niterói existed at least since the 19th century.
In 1875, Emperor Dom Pedro II even hired an English engineer to design a tunnel in Guanabara Bay. The idea did not take off and the locals had to wait several decades to see a bridge begin to be built in the place, in 1968. The beginning of the work was tumultuous, with the death of workers drowned in an accident and several interruptions due to bureaucratic problems. When the work was finally completed, in 1974, it immediately became a source of national pride. “The bridge broke some notable records, such as the longest span with a straight beam, 300 meters wide and 72 meters high,” says civil engineer Mario Vilaverde, who also worked on the project as a technical superintendent. Another impressive fact was the volume of material used.
If the work’s cement bags were stacked, they would be 1,500 times higher than that of the Sugarloaf Mountain. But, contrary to what many people think, the Rio-Niterói bridge is not the longest in the world. Its 13 kilometers long are well below the 38 kilometers of a bridge over Lake Pontchartrain, in the state of Louisiana, in the United States, considered the largest in the world by the Guinness Book, the book of records.
Concrete connection
3 – On top of a group formed by about ten of these metal pipes, each of the foundations of the bridge were built, a large solid concrete base 2.5 meters high and 6 tons in weight. Pillars were placed on this base, positioned in pairs to hold the bridge lanes. In the 9 kilometers over the sea, 103 sets of support were used, consisting of pipes, concrete base and pillars.
4 – With the use of cranes – which were supported at the base of the pillars – the precast structures that formed the two lanes of the bridge were erected. These pieces, called staves, which were made of concrete and were 5 meters long and 110 tons in weight each, were fitted together, as if they were large Lego kits.
5 – As the staves were difficult to install in very wide spans, they were not used in the central part of the bridge, which needed to have a greater distance between the pillars for large ships to pass. The way out was to use gigantic metal blocks that, added, reached 850 meters. Once the problem was solved, the bridge was ready to be inaugurated, which occurred on March 4, 1974. It was officially named Ponte Presidente Costa e Silva.
1 – Several proposals for the bridge were studied before the federal government, responsible for the work, hit the hammer. One of the possible routes was shorter (in lilac), but passed close to the airport, forcing the bridge to be a maximum of 50 meters high, which would hinder the flow of large ships. There was also an option that facilitated navigation (blue), but with a longer route than the one finally approved by the government (black).