ASME-Landmark:Interborough Rapid Transit System, Original Line

Plans to build a rapid transit system in New York were first made in 1831. By 1868, the first elevated railway was erected. As the "El" became crowded, construction of an underground railway was proposed.

The Interborough Rapid Transit Company (IRT) was awarded the rights to build the railway line, and ground was broken on March 24, 1900. The original subway, which opened October 27, 1904, ran 9.1 miles from City Hall in downtown Manhattan to 145th Street and Broadway in Harlem. The fare was a nickel. Extensions to the Bronx opened in 1905 and to Brooklyn in 1908, completing the first subway.

In building such a system, unusual engineering challenges had to be overcome: above the streets were towering buildings and heavy railway and vehicular traffic; under the streets was a complicated network of subsurface structures: sewers, water and gas mains, conduits for electric cables, electric surface railway systems, telegraph and power lines, and numerous basement vaults.

Other contributions included innovative practices in cut-and-cover excavations, subaqueous shields, rock tunneling, steel bent construction, and so forth.

The IRT's properties and operations were acquired by the City of New York in 1940. Today, the IRT lines are operated as the A Division—the lines designated by numbers (1, 2, 3, 4, 5, 6, 7) and the 42nd Street Shuttle—of the New York City Subway, one of the largest rapid transit systems in the world, with 469 stations in operation, 233 miles of routes, and, in 2014, over 1.75 billion rides delivered. See ASME website for more information