Tag: Union Arch Bridge (Washington Aqueduct)

Wikipedia says: The Union Arch Bridge, also called the “Cabin John Bridge”, is a historic masonry structure in Cabin John, Maryland. It was designed as part of the Washington Aqueduct. The bridge construction began in 1857 and was completed in 1864. The roadway surface was added later. The bridge was designed by Alfred Landon Rives, and built by the United States Army Corps of Engineers under the direction of Lieutenant Montgomery C. Meigs.

The bridge, with an overall length of 450 ft (140 m) and width of 20 ft (6.1 m), is constructed of Massachusetts granite and red sandstone quarried at the nearby Seneca Quarry, and rises 101 ft (31 m) above Cabin John Creek. The main arch span is 220 ft (67 m) long and rises 57 feet 3 inches (17.45 m). The bridge has an internal spandrel wall structure that contains nine additional smaller arches, which are concealed from view by exterior stone sidewalls. At the time of its construction in 1864, the main span was the longest single-span masonry arch in the world.