Bridges are structures that, in most cases, allow an individual to get somewhere that they may have been unable to get to because of an obstacle, be it a body of water, a ravine, or some other natural barrier. There are more than seventeen thousand entries for “bridge” in the Records of the National Register of Historic Places (NAID 20812721). When the records were processed by the Electronic Records Division of the National Archives, we determined that bridges were a theme in the records and we included it in our Reference Report for these records, and noted that bridges were further refined by Covered Bridges, Highway Bridges, “Historic” Bridges, Railroad Bridges, and Truss Bridges to name a few.
Within the entry for the Vehicular Bridges in Arizona file (NAID 75609247), it reads, “Bridges, as integral elements of a developing transportation network, have played a pivotal part in the spanning of America. Generally the most sophisticated components of any overland transportation system, from the early primitive territorial roads to transcontinental highways, they are also the most prominent . . . This is particularly true for Arizona, a state in which overland transportation forms a central historical theme.” The entry continues “After formation in 1863, the Arizona Territorial Assembly immediately recognized the need for transportation routes to connect the widely scattered settlements and foster economic growth. Money for road construction was scarce, however. In 1864, the First Territorial Assembly did what government bodies have traditionally done when short of funds themselves: it authorized others to build roads.” One of the more prominent structures built in Arizona, was “without question, the most spectacular, expensive and important of the territorial bridges was the multi-span concrete structure over the Salt River in Tempe.”
Among the many bridges in Washington, DC, two are both historic and essential to navigating one’s way into and around the Capital City. The Arlington Memorial Bridge (NAID 117691943), which crosses the Potomac River and links the District with Virginia, is “widely regarded as Washington’s most beautiful bridge. Memorial Bridge symbolically links North and South in its alignment between the Lincoln Memorial and Arlington House, The Robert E. Lee Memorial . . . The entire composition was designed by the prominent architectural firm of McKim, Mead and White during the 1920s . . . Construction took place between 1926 and 1932, although some details were left for later years and the monumental equestrian statuary of Fraser and Friedlander at the east end of the bridge and the parkway terminus was not installed until 1951 . . . Design and construction of the project was overseen by a commission specially authorized for the purpose in 1913. The work of the Arlington Memorial Bridge Commission, whose five members included the President, got underway after Congress appropriated planning funds in 1922.”
In Upper Northwest Washington DC, the Connecticut Avenue Bridge (NAID 117692067) towers over Rock Creek. “The William Howard Taft Bridge, constructed from 1898 to 1907, represents the culmination of 19th century bridge design, exemplifying the transition from utilitarian structures to artistic monuments. Originally known as the Connecticut Avenue Bridge since it carries Connecticut Avenue over the Rock Creek valley, the bridge was renamed in memory of William Howard Taft after his death in 1930. The only masonry bridge designed by noted engineer George S. Morison, the Taft Bridge was the largest monolithic concrete bridge of its time . . . The bridge incorporates innovative concrete sculpture by Roland Hinton Perry, designer of the Neptune Fountain at the Library of congress, and cast iron lampposts designed by Ernest C. Bairstow.”
There are over one thousand entries in the NRHP records for Railroad Bridges, including both a functional railroad bridge and a covered bridge, the Fisher Covered Railroad Bridge (NAID 84285459). “The Fisher Covered Railroad Bridge consisted originally of a single span supported by two flanking timber Town—double lattice trusses. In 1968 the timber deck structure was removed and replaced with a two-span steel deck truss structure independent of the wood superstructure. The southerly span is supported by two plate girders and the northerly span by four steel I-beams.”
“The Fisher Covered Railroad Bridge is unique in Vermont, being the only covered wood railroad bridge in the state which still carries an active railroad. (Two other covered railroad bridges–at Swanton and East Shoreham–remain in the state but the railroad lines which they carried have been abandoned and their tracks removed.) Nationally, the covered railroad bridge has nearly disappeared; according to Richard Sanders Allen (1974), there are only twelve examples of the bridge type left in the United States.”
There are more than fifteen hundred entries for “Covered Bridges” in the NRHP records, and not just in Madison County, Iowa. There is the Office Bridge in Oregon (NAID 77848097) which “spans a mill pond created by a dam on the North Fork of the Middle Fork of the Willamette River at the town of Westfir. The wooden span connects the mill and office of the Edward Hines Lumber Company—hence it derived its name. At 180 feet in length, it is Oregon’s longest covered bridge. The present structure is a replacement of the original bridge at this location which washed out in 1942. The Westfir Lumber Company, which built the bridge, was purchased by Edward Hines Lumber Company of Chicago in 1945. A distinctive feature of the span is the covered walkway, separate from the roadway. Built for carrying loaded log trucks, the truss members are of herculean proportions. The bridge is in the basic design of covered bridges built for railroad use, with multiple steel tension rods and compound chord members. Cross bracing on both the bottom and top chords adds rigidity to the structure.”
You can cross Campbell’s Covered Bridge in Greenville County, South Carolina, “built in 1909 . . . and crosses Beaver Dam Creek on Campbell Covered Bridge Road. This wooden bridge with a metal roof is 35’ long by 12’ wide. It sits on a rock foundation with a concrete cap, as masons supplemented existing rock formations on each side of Beaver Dam creek as load-bearing abutments and partial foundations . . . Campbell’s Covered Bridge is a four-span Howe truss bridge with counter braces. The two outer spans are 9’ long and the two inner spans are 8’ long. Each truss is 4” x 8”, and each counter brace is made from 2” x 8” pine boards nailed together in an interlocking pattern. Vertical tie rods called kingposts, made from 1” diameter iron rods, are in between each span, tying the top and bottom chords together. This method of truss construction absorbs and transfers a passing vehicle’s weight to the rock abutments on each end of the bridge.”
Campbell’s Covered Bridge “was one of four covered bridges built in this part of northern Greenville County in the first decade of the twentieth century; before that time, the only safe crossing over Beaverdam Creek was a narrow rock shoal. Morrow’s Covered Bridge and McClain’s Covered Bridge spanned the Middle Tyger River on Pleasant Hill Road and S.C. Highway 14, respectively, and a third unnamed covered bridge spanned the South Tyger River between S.C. Highways 101 and 253. Campbell’s Covered Bridge was the largest and most sophisticated of the four.”
There are also many entries for “Historic Bridges” in the NRHP records, including the Lenape Bridge in Chester County, “a seven arch stone bridge constructed in the 20th century in the style of Pennsylvania’s nineteenth century stone bridges. It was built in 1911-12 of random rubble construction and with conically shaped piers and a continuous parapet, features typical of some nineteenth century turnpike bridges.”
No discussion about bridges is complete without mentioning the work of the master bridge builder, John A. Roebling, a German-born American civil engineer who designed and built wire rope suspension bridges, in particular the Brooklyn Bridge, which has been designated as a National Historic Landmark and a National Historic Civil Engineering Landmark. There are nearly 200 entries in the NRHP records specific to “Roebling,” including the Pennsylvania SP Roebling, John, House (NAID 71998045) and the Brooklyn Bridge (NAID 75315928), seen above, and as noted, a National Historic Landmark.
“The John Roebling House was built sometime between 1832 and 1835 . . . a 2-story frame and brick structure covered with aluminum siding . . . The Roebling Shop (1841) is a one story, gable roof, frame structure covered with clapboard and topped with a tin roof . . . John Augustus Roebling . . . noted civil engineer, was born in Germany in 1806. He was schooled in architecture and engineering. He organized a group of family members to emigrate to America and consequently settled in Butler County, Pennsylvania. After forsaking farming as a profession, Roebling sought employment on state canal projects. While working on these projects, Roebling developed the method of stranding wires to form a stronger and thinner cable to replace hemp that had been used on canals and railroads . . . Roebling applied his cable to suspension bridges and related industrial uses . . . Roebling died (1869) due to complications of an industrial accident incurred while supervising construction of the Brooklyn Bridge.”
As to the Brooklyn Bridge, “Specifications alone reveal the impressive scale of the Brooklyn Bridge. Measuring 5,989’ in length, it has a central, or river, span of 1,595’6″ and two land spans of 930’ each; the approach from the Brooklyn side is 971’ while that from the New York side is 1,562’6″. The bridge deck is suspended from four steel cables, each measuring 15 3/4″ in diameter and 3,578’6″ in length. Each cable consists of 5,434 individual wires with a total length of 3,515 miles, and is protected by 243 miles 943’ of wire wrapping. The cables weigh 1,732,086 pounds apiece. The structure’s two massive masonry towers stand 276’6″ above high water, measuring 140’ in length and 59’ in width at the high water line and 136’ x 53’ at the top. There are, in all, 38,214 cubic yards of masonry in the Brooklyn tower and 46,945 cubic yards in the New York tower. The anchorages at either end of the bridge, in which are buried iron bars to which the cables are attached, each measure 129’ x 119’ at the base and 117’ x 104’ at the top and weigh 60,000 tons, or 120,000,000 pounds, apiece.”
“A national symbol and a world-renowned landmark, the Brooklyn Bridge” was “Designed by John A. Roebling . . . and built under the careful scrutiny of his son and successor, Colonel Washington A. Roebling, the bridge was for twenty years the largest suspension bridge in the world. In addition, the building of the bridge required a variety of new and unusual construction techniques, among them, the use of pneumatic caissons and the use of steel — instead of iron — cable. A majestic and impressive structure, little altered from its original form, the bridge stands today as a testament to the vision and determination of both its designers and its builders.”
So, get out there on the open road and cross a bridge and learn some history about the building of bridges across the country.