Plans for a second crossing of the Baltimore Harbor that would become the Fort McHenry Tunnel began in the late 1960s. Early plans called for an 8-lane
double-deck bridge to carry I-95 over the harbor just south of Fort McHenry. In 1975, plans were changed to a tunnel after it was determined that a bridge would hurt Fort McHenry's status as a national monument. The state of
Maryland originally intended to build the tunnel with a
reinforced concrete box design, but plans were changed in February 1976 to use a steel tubular design after a dispute with the
Federal Highway Administration. The tunnel was to be constructed using the
immersed tube method, with prefabricated tubes sunken into the harbor. Construction began in May 1980 by K-R-T (a
joint venture between
Peter Kiewit Sons Company, Raymond International Builders, and Tidewater Construction Corporation), and was completed in November 1985. Ninety percent of construction costs were covered by federal funding, while 10 percent came from state funding. The tunnel consists of 32 tube sections, each wide and tall. The east and west approaches are and long, respectively. Opened on time and under budget, the tunnel closed a gap in I-95 through Maryland. Soon after the Fort McHenry Tunnel opened, the nearby
Baltimore Harbor Tunnel, which had opened to traffic in 1957, was extensively rehabilitated. The Fort McHenry Tunnel continues to be a vital transportation link in the Mid-Atlantic region. After the
Francis Scott Key Bridge collapsed on March 26, 2024, the tunnel became one of the primary alternate routes for drivers and trucks containing non-hazardous loads. ==See also==