16th Street Bridge (Washington, D.C.)

About

The 16th Street Bridge, also known as the Piney Branch Bridge, is an automobile and pedestrian bridge that carries 16th Street NW over Piney Branch and Piney Branch Parkway in Washington, D.C. It was the first parabolic arch bridge in the United States. Construction on the first span began in 1905 as part of the northward extension of 16th Street, and was finished in 1907 but was never opened to traffic. The second span began construction in 1909 and was completed in 1910. The bridge was renovated in 1990, and again beginning in October 2014. The bridge, which spans the Piney Branch addition to Rock Creek Park, sits at the corner of four Washington, D.C., neighborhoods: Sixteenth Street Heights, Crestwood, Columbia Heights, and Mount Pleasant.

The 16th Street Bridge is 272 feet (83 m) long. Its span is 125 feet (38 m) in length, and has a rise of 45 feet (14 m). The span is a parabolic arch, the first built in the United States and the longest in the world at the time, according to its designer, W.J. Douglas. The abutments and substructure of the bridge are of reinforced concrete; the arch itself is not reinforced with steel. The interior of the bridge is hollow. Square vertical interior columns 2 feet (0.61 m) in length on each side support the road deck. A latticework of horizontal square beams, each 1 square foot (0.093 m2) in size, intersect the columns and are set perpendicular to one another. This system of columns and beams compress the arch and keep it stable as well push outward against the walls. The bridge's abutments are hollow. The abutments are stabilized by soil pressing against them from the outside, and the system of beams and columns on the interior of the bridge. The walls of the bridge and the abutments are 2 feet (0.61 m) thick. A bluish crushed diorite was added to the concrete used to pour the walls of the abutments and the spandrel walls, which were left unfinished, and reflect the texture of the wooden forms used to create them. However, the archivolt, balustrade, and pilasters, whose concrete includes yellow sand and crushed granite, have a much different texture. These elements were removed from their molds before the concrete was fully hardened, then roughened with stiff brushes, helping to expose the granite particles within and make them glitter in the sun. The bridge superstructure rests on walls and columns. The 25-foot (7.6 m) wide spans are of reinforced concrete. Steel beams, their ends resting on the walls of the two bridges, close the gap between the spans. Reinforced concrete slabs lie atop these beams to create a unified deck. Concrete balustrades and newels create a railing on the east and west sides of the bridge. The road is 45 feet (14 m) wide, and 8-foot (2.4 m) sidewalks are on either side of the roadway. Granite curbs define the cement sidewalk. The deck is topped by asphalt. At 65 feet (20 m) in width (roadway and sidewalks), the deck was the widest in the city when built and could support 40 short tons (36 t). The bridge has four ornamental cast iron lampposts. The ends of the bridge are flanked by two bronze reclining tigers on concrete pedestals. The archivolt consists of three arch rings, and is of smoothed concrete. Pilasters flank the arch on the sides of the bridge. Stylistically, the bridge is Neoclassical in design. The bridge cost about $135,000 to build.

On March 30, 1899, the United States Congress authorized the extension of 16th Street NW from Morris Road NW (now Monroe Street NW) to the D.C.-Maryland line. Condemnation proceedings to obtain land began on December 2, 1900, were completed on May 27, 1901, and were approved by the Supreme Court of the District of Columbia on April 19, 1902. By November 1903, work had almost reached the stream known as Piney Branch, which runs through a valley about 60 feet (18 m) below the grade of the street. On December 10, 1903, the Commissioners of the District of Columbia asked Congress for a 300-foot (91 m) bridge to carry one or two lanes of 16th Street NW over Piney Branch. The bridge, whose cost was estimated at $50,000 ($1,791,667 in 2025 dollars), would be long enough to permit a parkway to pass beneath it. In March 1904, the commissioners' request finally saw action. Senator Jacob Gallinger (R-New Hampshire) offered an amendment to the Senate's 1905 District of Columbia appropriations bill which both authorized the city to construct the bridge and appropriated $50,000 ($1,791,667 in 2025 dollars) for this purpose. The House D.C. appropriations bill also contained the same language, but this provision was stricken from the bill on the floor of the house on March 18. Undeterred, the Senate Committee on the District of Columbia included the bridge authorization in the 1905 D.C. appropriations bill just five days later. The legislation, however, authorized a $50,000 concrete bridge but appropriated only $20,000 ($716,667 in 2025 dollars) for its construction. Half the money came from the federal government, and half from the city. A fight erupted on the floor of the Senate over the bridge provision. Both the Senate Appropriations Committee and the Senate Committee on the District of Columbia approved the bridge. But many Senators were unhappy that the federal budget was increasing rapidly. The bill was held up for 10 months, while Senators worked behind the scenes to resolve these differences. The D.C. appropriations bill did not reach the Senate floor for another 10 months. When the bill did reach the chamber floor on February 15, 1905, Senator Stephen B. Elkins (R-West Virginia) demanded that the bridge provision be removed. Senator William B. Allison (R-Iowa) rose to support the expenditure. Their floor fight lasted three full days. Elkins claimed on February 16 that no citizens of the city wanted the bridge, and he demanded a full Senate vote on the bridge amendment. Senator Allison replied on February 17 by bringing in petitions from the Brightwood Citizens Association and the Mt. Pleasant Citizens Association asking for construction of the bridge, and pointing out that these petitions had been delivered to the Senate some months ago. Although Elkins won a vote on the amendment, the Senate overwhelmingly approved its inclusion in the final bill on February 17, ending the three-day floor fight. A conference committee was now appointed by the House and Senate to reconcile the two different D.C appropriations bills. The House voted on February 18 to instruct its conferees to oppose the bridge amendment. The conference began meeting the week of February 20. On Sunday, February 26, the conferees agreed to include the bridge authorization and expenditure in the 1905 D.C. appropriations bill. The conference bill was introduced in the Senate on February 28, and hours later it approved the legislation. The House unanimously approved it on the afternoon of March 1. President Theodore Roosevelt signed the bill into law a few days later.

Adapted from Wikipedia (CC BY-SA). Photography via Wikimedia Commons.