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Tales From the Life and Rebirth of William Howard Taft Bridge
After six decades of neglect, gravity had overtaken grace. William Howard Taft Bridge, a colossus built to symbolize the strength of American civilization, had lapsed into eerily allegorical decay.
Before Taft Bridge’s reconstruction began in August 1993, the concrete surfaces high above the treetops of Rock Creek Park were splitting along the vast intrados, or undersides, of its seven soaring Roman arches. Pounding wind and rain, and freezing and thawing had taken their toll on the structure’s finer details: The ring stones lining the arches were crumbling, and the rhythmic quoining that climbs its tremendous piers was grossly fractured.
The bridge’s demise was symmetrical to its organic creation: All of the decorative outer facings, which conceal 55,000 cubic yards of Portland cement, were fashioned from diorite rock extracted from the ground beneath the bridge itself. After 86 years, they were more or less returning to it.
Conceived in 1897 at the height of the City Beautiful movement in America, Taft Bridge is the august patriarch of a family of concrete arch bridges tucked into Rock Creek Park. It is the most audacious and triumphant of the city’s bridges, classical in design and fearless in form.
When Taft Bridge was completed in 1907, it was dubbed “The Largest Concrete Bridge in the World.” In fact, it was the largest structure in the world ever built of unreinforced concrete—that is, concrete without the benefit of structural steel guts. The Engineering News of 1905 called it an “exceedingly rare” species of bridge. Even today it remains a singular specimen, a virtuous marriage of tectonic form and substance.
The bridge was the brainchild of engineer George S. Morison, a prominent railroad bridge designer, and architect Edward Pearce Casey, who cut his teeth building the Library of Congress in 1892. At $675,000, the Morison-Casey plan was not the cheapest or simplest of five competing designs, three of which contained structural steel. But the selection jury, led by D.C.’s chief bridge engineer, Walter J. Douglas, was intrigued by the all-concrete structure of Morison’s design, in particular the spandrel arches (the six subordinate arches resting atop each major arch), the emptiness of which lightens the bridge’s structural load.
Succeeding generations of engineers were captivated by Taft Bridge’s symphony of structure and materials. Morison struck a relationship between the physical behavior of Roman arches and the singular properties of high-class concrete that can only be called auto-poetic, possessing an integrity unto itself.
Most built structures gain their strength from a checked interplay between two forces: compression (pushing, as in floors stacked atop one another) and tension (pulling, as in the horizontal bracing for the floor of a suspension bridge). Roman arches, however—perfect semicircles, like those holding up Taft Bridge—attain a structural equilibrium that cancels out all tension. They support themselves by compression only; every piece pushes against all the others.
The compression of an arch suits concrete very well. Though concrete has very poor tensile strength, which is why it usually needs steel support, it has amazing compressive properties. Usually, compressive strength alone is not enough to hold up a bridge. The Francis Scott Key Bridge leading into Georgetown, for example, is filled with tons of structural steel because its arches are not perfectly semicircular—they create tension within themselves. “Morison designed the Taft Bridge arches to be purely compressive, concrete structures,” explains Eric Delony, a National Park Service engineer.
Each of Taft Bridge’s arches is a series of gigantic concrete blocks. They were cast on the ground, allowed to cure for about a month, then raised into place by several spindly derricks parked upon the unfinished piers. Once the blocks were in place, the builders poured fresh concrete around them to lock them together and built the mass up to the bridge’s deck supports. Most of the bridge deck, however, is not concrete; the roadway sits on 4 feet of earth fill, which is both cheaper than concrete and a lighter load.
The original construction drawings are as beautiful as Taft Bridge itself, detailing stresses and strengths across the structure in a ballet of arcs and rays. Other drawings and photos show a fascinating system of wood falsework erected to hold up the concrete blocks until the span was complete. Absent steel bars, the arch segments could not be braced and cantilevered out to where two halves of each arch meet, as they would likely be today. Rather, the superstructure of the bridge rested upon an elaborate geodesic complex built from 1.5 million board feet of pine, which tended to dry out and turn quite combustible in the long summers. Because a fire would have destroyed the entire project, the city ran a high-pressure water main to the site to keep the pine framing soaked.
The erection process took a full decade, with construction suspended in the summer of 1902, when Congress temporarily cut off funding. Engineering records show that Taft’s structural experts held their breath until the keystones were set and the final load was applied to the footings of the bridge. Because such a structure had never been built before, there was no telling if their calculations would prove correct. The denouement depended on how much the bridge settled after final keying and loading of the arches. The safe maximum was 3 inches. As it turned out, none of the piers sank more than 2.
Sixty-odd years hence, last September, Marilyn Monroe hovered miragelike above Calvert Street as I made my way gingerly down a naked wooden ladder into a plywood box stapled to the side of Taft Bridge. In spite of terrific vertigo, I inched my way down the rungs until I stood neck- high in the box with my escort, Luke DiPapa, the District’s chief bridge engineer, and two masons turning a fresh batch of mortar to perfection with their shovels, as if it were a fragile roux.
They seemed oblivious to the 150-foot drop to the ground, a one-way trip taken by the two to five people who kill themselves by jumping off Taft Bridge each year. An unfortunate horse named Homer joined the list of bridge victims in 1965, when someone threw a sewer lid over the side. It nailed poor Homer in the left foreleg, and he had to be destroyed.
As we hung in the box off the side of the bridge, DiPapa explained that everything above Taft’s smaller spandrel arches will look new when the restoration is completed in May. The bridge has gotten what looks like a huge orthodontic overhaul, with the pilasters and stone pylons replaced by granitelike molded blocks of concrete. The sidewalks will be 2 feet wider. Twenty-eight triumphal, cast-iron Nernst lamps will return, with detailed foliage and translucent globes. New alloy railings will run the entire 1,341-foot length of the bridge. And for the first time since 1965, conservators are recasting the concrete lion sentinels at each end (see “Artifacts,” 3/4/94). Each day, 34,000 cars will pass between Kalorama and Woodley Park—and, incidentally, across the continental fall line between the Coastal Plain and the Piedmont Plateau.
DiPapa pointed out the exposed joints, half an inch wide, where the masons would put the mortar when replacing the large stone cartridges that form the cornice. When you view a pattern too closely, it’s hard to discern. But soon I realized what we were looking at, and it gave me a start. It was the moulding of an outsized dentil, one of those toothlike details along the top of the bridge, about a foot thick. Looking to the left and the right, it came into focus as one element in Taft Bridge’s enormous entablature, probably the biggest I will ever see.
The grand profile of the bridge represents both a lost aesthetic and a historic juncture in the development of American architecture. The City Beautiful movement, which spread forth from Daniel Burnham’s Beaux Arts master plan for the 1893 Columbian Exposition in Chicago, exalted projects like Taft Bridge as works of public art. (Burnham’s mark on Washington is most evident at Union Station, which he designed.) Progressive urban design in Taft Bridge’s time had a clear sense of human spatial order that was manifested in radial streets and climactic, monumental vistas in the metropolis.
Thus, the city’s overriding reasons for choosing Morison’s design, according to an account compiled by the National Park Service: “[T]he proposed bridge, being so conspicuously located on a fine residence avenue and in full view of a large area [including] the National Zoological Park, should be of a monumental character, and the masonry type [should rate] above all others….” Metal construction, the selection jury concluded, would cost more in maintenance and ultimately not hold up as well as dressed blocks.
“Great effort was taken to have [the bridge] comport in proportions, type and style with the dignity of the thoroughfare,” wrote the Engineering News in 1908. After Taft Bridge was finished, the city began to militate against potentially debasing development in its vicinity. In his annual report of 1908, D.C. bridge engineer Douglas called for “permanent protection against the unsightly construction of buildings near the bridge.” In particular, Douglas derided two new houses near the northern approach, and he warned that “the entire esthetic value of the bridge will be lost, and the large sum of money expended will fail to beautify this section of the city.” Douglas must have foreseen the apartment slab that eventually became the Embassy of the People’s Republic of China, at the south end, in his worst dreams.
Of course, there was an investment to protect. The final cost of the bridge was $846,331, an unheard-of sum that earned the span the dubious title of “Million Dollar Bridge.” (Who would have thought reconstruction in the ’90s would cost $10 million, or about a dozen times as much?) The bridge retained that nickname until 1931, when it was renamed to honor the late president and chief justice at the suggestion of the Women’s City Club. Taft himself “watched its construction closely and when it was completed he used it frequently,” according to the Washington Star.
During the time Taft Bridge was being built, there was increasing worry among contemporary critics and academics that advancements in technology were sacrificing beauty for functionality in civic structures. The visionary master builder—he who gave Europe the high Gothic cathedral—was virtually extinct. The combined role of engineer and architect had split, and modern engineers were growing increasingly estranged from architects as their professions developed a diverging set of codes and values. “[F]or the first time in human history a broad line has been drawn between scientific construction and artistic construction,” wrote the influential critic Montgomery Schuyler in 1901. “[T]he designers of one class of construction do not hold themselves responsible, nor does any one, for the looks of their work.”
Schuyler is not on record regarding Morison’s design for Taft Bridge; regardless, it was a fortunate pairing of architect and engineer. Taft Bridge was Morison’s last work, and his only one in Washington. Since that time, however, Schuyler’s prophecy has materialized locally: As the century wore on, Washington’s bridges became increasingly dull, indifferent structures bereft of art or embellishment.
The early 1900s were good to Rock Creek Park, structurally speaking. Boulder Bridge on Beach Drive, from 1902, is a Melan arch, which means it has two curved steel rails set inside concrete; it is voluptuously clad in boulders. The surprisingly modern, open-spandrel Ross Drive Bridge, which sails across a cool ravine in the park, dates to 1907. Q Street’s Dumbarton Bridge over Rock Creek, with its belt of enigmatic Chief Kicking Bear masks and anatomically correct bronze he-bison up top, was finished in 1914. Taft Bridge’s closest rival, the smooth, straightforward Duke Ellington Bridge serving Calvert Street, opened in 1935.
The city’s major portals, on the other hand, didn’t come out so well. The blunt edges of Key Bridge, finished in 1923, show the resourceful use of a wartime budget. Memorial Bridge, albeit off-axis, is what one might have hoped for more of around the city; after a protracted competition, it finally opened in 1932. But then along came the John Philip Sousa Bridge in 1940, the Frederick Douglass Memorial Bridge in 1949, the East Capitol Street Bridge in 1951, and the 11th Street (SE) Bridge by 1968—all variations of a drab steel platform set atop faceless concrete piers.
Particularly galling is the story behind the Theodore Roosevelt Memorial Bridge, completed in 1960, which need not have been built at all. According to Donald B. Meyer’s book Bridges and the City of Washington, experts told the National Capital Planning Commission in 1955 that it would cost no more to build a tunnel under the Potomac (not unlike the one Metrorail has nearby) than it would to put up the Roosevelt Bridge. But their advice was ignored, and the Highway Department forged ahead, leaving Washington not only with a homely battleship of a bridge connecting its banks on the Mall to Virginia, but a mess of interchanges on all that open space.
Such a travesty would have been unthinkable in an era when civic capital improvements could generally be relied upon to enhance the built environment. In Taft Bridge’s case, the city banked as much on its heroic form as its function: For Connecticut Avenue, the road to the president’s house, another version of the iron-and-steel trestles that dotted Washington at the time would never do.
Just as in some sense the Empire State Building will always be the tallest building in the world, Taft Bridge retains a permanent superlative status, estimable for its placement relative to its setting, which makes it many events at once. Approached southbound in the evening, the bridge consumes the skyline, with pastel light shining through its spandrels. From underneath, the gigantic arches fill one’s entire field of vision, exposing the broad soffits of the bridge’s underbelly. And from the west at dusk, the bridge is a glowing, gargantuan arcade reaching across the valley, its sepia walls creating a chiaroscuro effect against the deep shadows under its arches.
On certain gloomy days just before dawn, Taft Bridge looks like one of Piranesi’s sublime engravings of disintegrating Roman antiquities. The mist frequently rising from the watershed exaggerates the bridge’s epic scale, giving it the aspect of being large yet farther away—thus even larger, more fantastical, seemingly unbuildable.
Art accompanying story in the printed newspaper is not available in this archive: Darrow Montgomery.