Dom Luís I Bridge
The Luiz I Bridge, commonly known as Dom Luís I Bridge, is a double-deck metal arch bridge that spans the river Douro between the cities of Porto and Vila Nova de Gaia in Portugal. At its construction, its 172 metres (564 ft) span was the longest of its type in the world. It can be confused with the nearby Maria Pia Bridge, a railway bridge that was built 9 years earlier, which is similar in aspect to the Luiz I bridge.
Imagem: duncan cumming · BY-NC · Openverse
Inception and construction
In 1879, Gustave Eiffel presented a project to construct a new bridge over the Douro, with a high single deck in order to facilitate ship navigation. This project was rejected due to dramatic growth of the urban population, which required a rethinking of the limits of a single-deck platform. A competition was initiated in November 1880, in order to construct a double-deck metal bridge, which included projects by Compagnie de Fives-Lille, Cail & C., Schneider & Co., Gustave Eiffel, Lecoq & Co., Société de Braine-le-Comte, Société des Batignolles (which submitted two ideas), Andrew Handyside & Co., Société de Construction de Willebroek (also two projects), and John Dixon. It was in January of the following year that deliberations by the committee supported the project of Société de Willebroek. This design cost 369,000$00[clarification needed] réis and provided better carrying capacity. On 21 November 1881, the public work was awarded to the Belgian Société de Willebroek, from Brussels, for 402 contos. It was to be administered by Théophile Seyrig, the former partner of Gustave Eiffel and author of the project. Seyrig had also designed the Maria Pia bridge that was constructed by Eiffel & cie, hence the resemblance of his new bridge to the Maria Pia bridge. Construction began on the Luiz I bridge alongside the towers of an earlier suspension bridge, the Ponte Pênsil [de; es; pt], which was disassembled.
20th and 21st centuries
By the turn of the century (1908) electric carriages were installed in the city centre, extending to the bridge. On 1 January 1944, the toll system was discontinued, and the bridge began to function as a free infrastructure of the municipal authority of Porto. Originally and for more than a century, the bridge carried road traffic on both decks. Along with other vehicles, electric trams crossed the upper deck from 1908 until May 1959, and trolleybuses crossed both decks from May 1959 until 1993. By 1954, public works were initiated on the bridge under the direction of engineer Edgar Cardoso, who extended the decks and removed the electrification of the deck.
Imagem: Gwenaël Piaser · BY-NC-SA · Openverse
The bridge is situated in an isolated, urban area over the River Douro between the granite banks, where the Cathedral of Porto and the escarpment of the Serra do Pilar form a box valley. It is 1 kilometre (0.62 mi) from the bridge of D. Maria Pia and, farther along, the Arrábida Bridge. On the Porto side, the lower deck connects the Cais da Ribeira and the upper Avenida Vímara Peres, while the bank of Vila Nova de Gaia to the Avenida Diogo Leite and Avenida da República, respectively. Access to the Porto side is located along the Pillars of Ponte Pênsil. At the same time, the Guindais Funicular, the Church and Shelter of Ferro, the Fernandina Walls, and the Monastery of Serra do Pilar. The iron bridge has two decks, of differing heights and widths, between which develops a large 172.5 metres (566 ft) diameter, central arch supporting these upper and lower decks. Both decks are moored to the riverbanks by means of masonry piers. Those in the upper deck are rectangular with a trimmed cornice finish, consisting of two staggered registers separated by cornice and interlacing struts. The lower deck is based on large foundations supporting molded cornices and wedges linked together by a felled arch, and framed by interlacing beams. At the base of the arches, facing the riverbanks, are large marble plaques with inscriptions "PONTE LUIZ I", and on the upstream face are stones representing royal coat-of-arms, with a shield framed by garlands. At the base of the lower deck, are iron-pillared, pyramidal-truncated pillars, erected in three sections, that attach to the upper deck.
