1877: This Portuguese Railroad Bridge Was the Longest Single Arch Span in the World

November 4, 1877

The Maria Pia Bridge in northern Portugal made its public debut. (At the time, the country was a constitutional monarchy formally known as the Kingdom of Portugal.) The railway bridge, which spans the River Douro and connects the city of Porto with the municipality of Via Nova de Gaia, resulted from a competition for prospective designers that had been held by the Royal Portuguese Railroad Company. A total of eight entries were submitted for the competition. The winning design was submitted by the French company Eiffel & Cª. de Paris. One of that company’s partners was civil engineer and architect Gustave Eiffel, whose most famous creation is the iconic tower in Paris that bears his name.

It is not clear which person at Eiffel & Cª. de Paris was primarily involved in designing the Maria Pia Bridge, although many have given much of the credit for that work to Eiffel’s business partner Théophile Seyrig. A German-born engineer, Seyrig did present a paper on the development of the bridge to the Société des Ingénieurs Civils in 1878. Moreover, Eiffel’s own account of the bridge (written for a display at the 1878 Paris International Exposition) highlighted both Seyrig and their colleague Henry de Dion for the calculations and drawings that they came up with for the bridge.

The construction of the bridge began in early 1876. The task proved to be a daunting one since the River Douro is fast-flowing and as deep at 66 feet (20.1 meters). In addition, the river bed consists of a deep layer of gravel that ruled out building piers and made a central supporting arch the only viable option.

When completed in October 1877, the wrought-iron structure – with a length of 1,158 feet (353 meters) – was the longest single-arch span in the world. The bridge’s central span of 525 feet (160 meters) narrowly beat out the previous record of 520 feet (159 meters) held by the Eads Bridge over the Mississippi River at St. Louis.

Those on hand for the dedication of the bridge included King Luís of Portugal. He was accompanied by his queen Maria Pia, for whom the bridge was named. The Sunday festivities were reported far and wide. “A railway bridge over the Douro was formally opened today, the even being celebrated with great éclat,” stated the London-based Standard. “When the work had been blessed by the bishop, the members of the Royal family passed over the bridge in a railway carriage and were present afterward at a luncheon at the [Campanhã Railway Station in Porto]. There was a great concourse of people, and the engineers were enthusiastically cheered.”

In 1982, the Maria Pia Bridge was designated a National Monument by the Portuguese federal agency Institute for the Management of Architectural and Archeological Heritage. The bridge is no longer used for rail traffic, having been replaced in that function by the Ponte de São João (St. John’s Bridge) that opened nearby in 1991.

For more information on the Maria Pia Bridge, please check out https://en.wikipedia.org/wiki/Maria_Pia_Bridge.