page_title: Key Bridge (Washington, D.C.)
section_title: Construction
hierarchical_section_title: Key Bridge (Washington, D.C.) / History / Construction
caption_attribution_description: English: Title: Key Bridge Abstract/medium: 1 negative&#160;: glass&#160;; 8 x 6 in.
context_page_description: The Francis Scott Key Bridge, more commonly known as the Key Bridge, is a six-lane reinforced concrete arch bridge conveying U.S. Route 29 traffic across the Potomac River between the Rosslyn neighborhood of Arlington County, Virginia, and the Georgetown neighborhood of Washington, D.C. Completed in 1923, it is Washington's oldest surviving road bridge across the Potomac River.
  Key Bridge was added to the National Register of Historic Places in 1996.
context_section_description: On June 1, 1916, the Army Corps of Engineers named the new bridge "Francis Scott Key Bridge," in honor of the man who had written the lyrics to the Star Spangled Banner whose home was just a few blocks from the bridge's abutment. Plans began to be drawn up at that time.
  The Classical Revival bridge was designed by Nathan C. Wyeth, an architect in private practice in the city, and Major Max C. Tyler, an engineer with the Army Corps of Engineers. The legislation authorizing the bridge's construction required that the United States Department of War consult with the United States Commission of Fine Arts (CFA) in the design of the bridge. Subsequently, the Chief of Engineers of the Army Corps of Engineers asked the CFA for a list of architects whom the CFA believed would be competent to design an aesthetically pleasing bridge. The CFA swiftly provided a list, and in July 1916 Tyler met with the CFA to discuss a short list of potential architects. The CFA and Tyler also conferred on the bridge's orientation, design, and approaches. Tyler selected Wyeth. The plans were nearly complete by September. Wyeth and Tyler's initial design for the bridge was a double-deck structure with a single, high span. But with World War I erupting in Europe, inflation made this structure too costly. Wyeth then submitted a design for a single-deck, single-span bridge on January 12, 1917. The CFA asked Wyeth to design a multi-span bridge, or, failing that, to construct non-structural decorative elements that would make it look as if the bridge had multiple spans. Wyeth agreed, and the CFA approved the bridge design.
  In January 1917, the Corps of Engineers found that inflation in the price of construction materials made it necessary to ask for $300,000 more in funding from Congress. Congress balked at paying. But citizen pressure and the danger of Aqueduct Bridge's collapse due to ice flows in the spring convinced Congress to pay the money.
  Construction contracts were drawn up in late February, and excavation work on the D.C. abutments began in March. The first coffer dam for construction of the piers was sunk in May 1918, and the old Aqueduct Bridge formally closed on July 9.  Immense amounts of concrete were needed to construct the bridge. One concrete mixing plant was constructed on the D.C. shore, and concrete was delivered to the worksite in the river by ropeway conveyor. A second mixing plant was constructed in mid-river: The plant was floated into position, and then allowed to sink down to the riverbed. Steel for the reinforced concrete structure and for the steel arches within its spans was assembled on the D.C. shoreline, then floated by barge to the worksite. Progress was slow, as reinforced concrete was a relatively new type of construction. The project ran out of money, and Tyler requested and won an additional $1.1 million from Congress in 1920 to finish the work.
  The new $2.35 million Key Bridge opened on January 17, 1923. The federal government turned title to the bridge over to the District of Columbia on November 15, 1924.
  The old Aqueduct Bridge was razed beginning in December 1933. The Aqueduct Bridge's superstructure and most of the above-water portions of its piers were removed in 1933. The bases of the piers were retained to protect the Key Bridge's piers from ice floe damage.
caption: Key Bridge under construction, c. 1920
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