Portimao is the biggest town in the western Algarve. It is situated on the bank of the Arade River. If you have got a chance to visit the Algarve, you might have crossed the Portimao Bridge. It is an iron road bridge. The bridge was built by the well known French Structural engineer, Gustave Eiffel. The bridge has been cited as the ‘Algarve’s answer to the Eiffel tower’.
The bridge was built in 1876. The bridge was constructed using the techniques that were later implemented by Gustave Eiffel for developing other structures including the Eiffel Tower. Gustave thought that there is a demand for bridges that could be constructed in a short period of time and have prefabricated models from wrought iron.
The bridge is a three-span cable stay bridge made from prestressed reinforced concrete. The central span of the bridge is 256 meters long and the two lateral spans are 107 meters long. There are also two 107 meters reinforced cement towers in the shape of an upside down ‘Y’ between the three spans. The bridge has a road deck so that the vehicles can pass over the bridge. The road deck is supported by beams and safety parapets made from iron. The upper deck which makes the actual road for the traffic is 12-17 meters wide and has two lanes running in each direction.
The most important feature of the bridge is that there is a total lack of any form of rigid connection along the suspended road surface. The bridge also has a series of oscillation dampers because the area is prone to seismic activity and this property makes the bridge protected against the seismic destruction.
If you get a chance to drive over Portimao Bridge, you will notice that the metal structures supporting the bridge consist of vertical, horizontal, and diagonal elements that are secured tightly to end posts. The foundation of the bridge was set deep under the water by using a series of hydraulic presses and in curving the edges of the supporting piers. The base created for the bridge was so strong that it could stand for more than a hundred years.
Gustave Eiffel’s passion did not stop and he built many more structures such as the Maria Pia Bridge. It is more commonly called Ponte Dona Maria and was built in 1877. It is known as the world’s longest arched bridge. It is 352 meters in length and with a railway track that is 62 meters long and ran over the river.
Eiffel believed that the bridge should be supported by a curved truss of open metalwork. It not only enabled the wind to flow through the bridge but was less expensive to build. It is truly a pleasurable experience to wander through the rich fertile soil, wooded hills, vineyards, and farms of Portugal and enjoy the natural beauty. The town has something for everyone to enjoy.
Make sure that if you plan a vacation to Portugal, you get a chance to view the two wonderful constructions that helped Gustave Eiffel to become a world-renowned person.