The Negrelli Viaduct, is after the Charles Bridge, the second oldest still existing bridge over the river of Vltava in Prague. Its construction was requested by continuation of North state trunk road from Prague to Dresden. The viaduct spans over the valley of Karlín, a non-regulated flood area at that time, and two branches of Vltava, which are divided by the lower part of the Island of Štvanice.
Ing. Jan Perner (1815-1845), who died tragically, and Alois Negrelli (1799-1858), assistant of Lesseps in construction of the Suez channel, participated in the project. They decided on arch and partially segment structure type. Construction of the viaduct, which was realized by company Bratři Kleinové and company of Vojtěch Lanna, started in the spring 1846 and it was completed in 1850, when the first regular train went on the viaduct on 1st June.
It was the hugest railway construction in Europe at that time; 3000 Czech, German and Italian workers were working there. The material was Czech granite and the pillars had coating of sandstone. Length of the viaduct was 1130 m, original width was 7,60 m, and after removal of the stone parapet it was equal to 9 m. The viaduct had 90 arches. The railway line leading on the viaduct was double-line since the very beginning. As a whole the viaduct had a very stylish and balanced effect, and it was thought out in details as well. Project designers and builders executed a perfect technical work, as the bridge withstood the floods of Vltava and it bears huge weight increase of the present train wagons as well.
In 1952-1953 three arches over Křižíkova Street in Karlín were removed, as they had been a serious road obstruction in the present vehicle traffic. They were replaced with concrete beams. In 1981, the same was repeated above Bubenské embankment due to the same reasons. In spite of these tiny cosmetic modifications the Negrelli Viaduct is still proof of the fact that technical work may be realized at high aesthetic level.
