Golden Gate Bridge

Constructed at the height of the Great Depression, this iconic suspension bridge spans the Golden Gate strait between the Presidio, a former military fort on the northern tip of the San Francisco Peninsula, and Fort Baker in Marin County. Measuring 1.7 miles long and 90 feet wide, the steel bridge carries six lanes of automobile traffic (on U.S. Route 101) as well as bicyclists and pedestrians. Until 1964, the bridge’s main span (4,200 feet) was the longest suspension bridge in the world. The Art Deco infrastructure’s silhouette is recognized internationally as one of the most beautiful feats of engineering, and the American Society of Civil Engineers has designated it a Wonder of the Modern World.

As early as 1820 and for the next century, those wishing to travel from San Francisco to points north crossed the channel via ferry, such as those owned by the Golden Gate Ferry Company, considered the world’s largest ferry service in the 1920s. In the early twentieth century, San Francisco’s businessmen and civic leaders felt the lack of a vehicular bridge curbed the city’s natural growth into Marin County, yet the ambition to cross the 6,700-foot strait known for its strong currents, high winds, and fog seemed improbable if not impossible. As the idea circulated, journalist James Wilkins published a piece in the 1916 San Francisco Bulletin asking whether a span of 3,000 feet—nearly twice the length of any then-existing bridge—was feasible. San Francisco’s city engineer, Michael M. O'Shaughnessy, estimated such an endeavor would cost $100 million. Despite the exorbitant sum, O'Shaughnessy began making inquiries among bridge engineers. Civil engineer Joseph Strauss (1870–1938) responded with a proposal in which massive, steel-girded cantilevers were linked by a central suspension segment; Strauss estimated the cost of construction at $17 million.

After attaining a degree from the University of Cincinnati in 1892, Strauss had worked for Ralph Modjeski designing bridges. While in that office, he innovated the bascule bridge design. Commonly known as a drawbridge, this design is a moveable bridge with a span balanced by heavy iron counterweights. Strauss proposed using a cheaper and lighter material—concrete—for the counterweights, which would reduce the load. When his innovation was ignored, he left the firm and established his own practice, the Strauss Bascule Bridge Company, in Chicago. By 1916, he had completed over 400 inland drawbridges, including the HX Draw (1911) in Secaucus, New Jersey (the first heel trunnion bascule bridge in the nation), and the HB&T Railway Bridge (1912) over Buffalo Bayou in Houston, Texas, a design that was appropriated by Norwegian engineers to complete the Skansen Bridge (1918) in Trondheim. His major works were designed in the 1920s through the early 1930s and included the Burnside Bridge (1926) in Portland, Oregon; the Lewis and Clark Bridge (1930) over the Columbia River between Oregon and Washington; and Toronto’s Cherry Street Strauss Trunnion Bascule Bridge (1930).

But in 1917, when Strauss’s proposal was accepted, he had not yet designed a bridge of such magnitude. A suspension bridge (as opposed to a bascule bridge) was considered, on the whole, the proper form for such a span, and Strauss’s drawn pylons with cantilevered segment was thought visually unappealing. Strauss cobbled together a team of collaborators, and ultimately his scheme was supplemented with the elegant designs of structural engineer Charles Alton Ellis (1876–1949), along with Leon Moisseiff (1872–1943), architect of New York’s Manhattan Bridge (1909), and local architect Irving F. Morrow (1884–1952). Even with this team and amended designs, it took Strauss and other advocates several years to curry favor for the scheme with Marin County residents, business syndicates, and federal agencies. The Southern Pacific Railroad, which owned the Golden Gate Ferry Company, was the project’s most vehement opponent as a vehicular bridge would compete with its ferry operations. Equally, the U.S. Department of War worried the bridge would interfere with shipping channels or that sabotage of the bridge would hinder the Navy’s access to harbors. Regardless of the opposition, in 1923 the California legislature passed the Golden Gate Bridge and Highway District Act, which financed the project, and in 1924, the Secretary of War transferred the federal lands needed for construction to the Bridging the Golden Gate Association. In November 1930 city and county residents approved a bond for $35 million, but with the onset of the Great Depression the bonds didn’t sell until 1932, when the founder of Bank of America, Amadeo Giannini, purchased all of the issued bonds.

Construction commenced on January 5, 1933. The bridge’s foundations, dug into the hillsides, were laid by the Pacific Bridge Company, while the suspension cables were spun on site by the the John A. Roebling’s Sons Company. The McClintic-Marshall Construction Company, a subsidiary of the Bethlehem Steel Corporation, undertook the construction of the bridge and managed the myriad ironworkers. California’s assistant civil engineer, Alfred Finnila, oversaw the bridge’s ironwork and some of the road construction, which consisted of poured concrete with copper expansion joints every 50 feet. The bridge was completed within four years and under budget, at a total cost of $33.7 million. Strauss invented a transferrable safety netting that was employed at the construction site, saving many lives, although 11 laborers did indeed fall to their deaths; 10 of them were killed in one incident in early 1937, when a disengaged scaffold broke through the safety-net system.

Ellis was the principal manager and collaborated with Moisseiff remotely. While Moisseiff supplied the basic structural design, Ellis, a mathematician and former engineering professor at the University of Illinois, provided the technical and theoretical calculations. Moisseiff employed his own deflection theory, in which the roadway’s weight is supported by two cables that pass through the vertical towers and are anchored on either side by concrete weights. This allowed for the roadbed’s flexibility in high winds, as the cables and towers would disperse the stress. Ellis created the elegant solution in which two massive cables, which gently sweep up and over the towers, are each supported by 27,572 strands of vertical wire connected to the horizontal trestle that bears the road. Ellis’s contributions were unrecognized in his lifetime, as Strauss fired Ellis in November 1931 for wasting money on telegrams to Moisseiff, replacing him with underling Clifford Paine. Ellis, unable to find work in the economic doldrums, continued working on the project’s mathematical calculations pro bono.

The bridge’s aesthetics are due to two consulting architects: John Eberson, who had gained fame from his designs of atmospheric movie palaces in the 1920s, and Morrow, a little-known residential architect in the Bay area. While Eberson has been credited with designing the Art Deco towers, he was replaced by Morrow in 1930, who designed the streetlights, railings, and pedestrian walkways. The 746-foot towers’ simple forms—two upright posts connected by four lintels, creating four archways—feature abstracted geometrical vertical fluting and chevron patterns as well as stepped forms characteristic of the interwar-era style. Morrow’s choice of color, a vermilion shade called International Orange, was a sealant used on the steel members. The bridge’s 1,200,000 exposed rivets not only directly reference the construction technique but add to this Machine-Age aesthetic.

The bridge complex includes a secondary steel arched bridge (also designed by Ellis) at the southern abutment in order to bypass (and thereby save from demolition) the pre-Civil War fortification at Fort Point. Finnila designed the Art Deco Bridge Round House diner (1938) and plaza at the bridge’s southeastern entrance. As the name implies, the small building is cylindrical, and its modernist features include a flat roof and glazed curtain wall.

Since it opened on May 27, 1937, the Golden Gate Bridge has become an icon for the city of San Francisco as well as the state of California, and a recognizable image frequently reproduced in popular culture. Despite its revered status, the bridge is a behemoth steel structure requiring frequent maintenance and continuous painting to forestall corrosion from the bay’s salty fogs. As many as 16 ironworkers and 28 painters, suspended 220 feet over the water, repair and replace the corroded steel members constantly. The bridge also has required a $320 million retrofit in order to better withstand seismic events elicited from the San Andreas Fault.