Vasco da Gama Bridge
The Vasco da Gama Bridge is a cable-stayed bridge flanked by viaducts that spans the Tagus River in Parque das Nações in Lisbon, the capital of Portugal.
It is the second longest bridge in Europe, after the Crimean Bridge, and was the longest bridge for a while. It is also the longest one in the European Union. It was built to alleviate the congestion on Lisbon's 25 de Abril Bridge, and eliminate the need for traffic between the country's northern and southern regions to pass through the capital city.
Construction began in February 1995; the bridge was opened to traffic on 29 March 1998, just in time for Expo 98, the World's Fair that celebrated the 500th anniversary of the discovery by Vasco da Gama of the sea route from Europe to India.
Along with the 25 de Abril Bridge, the Vasco da Gama is one of two bridges that span the Tagus River in Lisbon.
Description
The bridge carries six road lanes, with a speed limit of, the same as that on motorways, except on one section which is limited to. On windy, rainy, and foggy days, the speed limit is reduced to. The number of road lanes will be enlarged to eight when traffic reaches a daily average of 52,000.;Bridge and access road sections
- North access roads:
- North viaduct:
- Expo viaduct: ; 12 sections
- Main bridge: main span: ; side spans: each ; cement pillars: -high; free height for navigation in high tides: ;
- Central viaduct: ; 80 pre-fabricated sections -long; 81 pillars up to -deep; height from to
- South viaduct: ; sections; 84 sections; 85 pillars
- South access roads: ; includes the toll plaza and two service areas
Construction and cost
The $1.1 billion project was split into four parts, each built by a different company, and supervised by an independent consortium. There were up to 3,300 workers simultaneously on the project, which took 18 months of preparation and 18 months of construction. The financing is via a build-operate-transfer system by Lusoponte, a private consortium that receives the first 40 years of tolls for both Lisbon bridges. Lusoponte's capital is 50.4% from Portuguese companies, 24.8% from French, and 24.8% from British.The bridge has a life expectancy of 120 years, having been designed to withstand wind speeds of and hold up to an earthquake 4.5 times greater than the standards of building resistance in Lisbon. The deepest foundation piles, up to in diameter, were driven down to under mean sea level. Environmental pressure throughout the project resulted in the left-bank viaducts being extended inland to preserve the marshes underneath, as well as the lamp posts throughout the bridge being tilted inwards so as not to cast light on the river below.