Golden Gate Bridge

The Golden Gate Bridge is a suspension bridge spanning the Golden Gate Strait, the one-mile-wide channel connecting San Francisco Bay and the Pacific Ocean in northern California. The structure links San Francisco—the northern tip of the San Francisco Peninsula—to Marin County, carrying both U.S. Route 101 and California State Route 1 across the strait. Recognized by the American Society of Civil Engineers as one of the Wonders of the Modern World, the bridge is one of the most internationally recognized symbols of San Francisco and California. At the time of its opening in 1937, it was both the longest and the tallest suspension bridge in the world, titles it held until 1964 and 1998 respectively. Today it remains one of the most photographed structures on Earth and a defining landmark of the American West Coast.

Background and Naming

The area known as the Golden Gate is the narrow channel formed at the mouth of San Francisco Bay, where a gap in the line of low mountains opens to meet the Pacific Ocean. Topographical engineer John C. Frémont first named these rocky straits the "Chrysopylae or Golden Gate" in his report to Congress in 1848. Frémont's designation, which also appeared on his accompanying map of the region, caught the popular imagination when gold was discovered in California soon after.

Before the bridge was built, the only practical short route between San Francisco and what is now Marin County was by boat across a section of San Francisco Bay. A ferry service began as early as 1820, with a regularly scheduled service beginning in the 1840s. In the 1930s, San Francisco was the largest American city still being served primarily by ferries and was experiencing stunted growth from its lack of connection to the rest of the state. The city was in dire need of a solution.

Many experts said that a bridge could not be built across the 6,700-foot strait, which had strong, swirling tides and currents, with water 372 feet deep at the center of the channel, and frequent strong winds. Experts warned that ferocious winds and blinding fogs would prevent construction and operation.

Planning and Design

The idea of bridging the mile-wide Golden Gate channel was proposed as early as the 1870s, but it was not until the San Francisco Call and Post began an editorial campaign in 1916 that the plan received popular backing. James Wilkins, editor of the San Francisco Call Bulletin, began an editorial campaign for a bridge that caught the eye of San Francisco City Engineer Michael O'Shaughnessy. Although many said it could not be built, engineer Joseph Strauss said it could be done.

The initial plan's price tag was exorbitant—$100 million—so San Francisco's city engineer, Michael M. O'Shaughnessy, put out a call to engineers to see if they could do it for less. An engineer from Chicago, Joseph Strauss, jumped at the call. Already skilled at constructing drawbridges, he concluded after collaboration with O'Shaughnessy that a bridge across the Golden Gate Strait could be built for only $30 million.

After submitting his sketches for a cantilever-suspension hybrid span in June 1921, Strauss set about convincing communities on the northern end of the strait that the bridge would be to their benefit. The project gained momentum in May 1923 when the state legislature passed the Golden Gate Bridge and Highway District Act of California for the purpose of planning, designing, and financing construction.

The final design represented a significant evolution from Strauss's original proposal. Leon S. Moisseiff submitted a plan that scrapped the original hybrid design in favor of a suspension span capable of moving more than two feet laterally to withstand strong winds. Irving F. Morrow conceptualized the Art Deco towers, and later decided on a paint color he dubbed "International Orange." Charles Ellis worked out the complex engineering equations as the primary structural designer, though he was fired before construction began and did not receive proper credit until many years later.

The original plan had actually been to paint the bridge black and yellow. The Navy proposed this color scheme to help make the bridge easily visible for passing ships, especially in San Francisco's famous fog. Designer Irving Morrow chose "International Orange" instead because it fits better with the bridge's surroundings while still offering excellent visibility.

The Golden Gate Bridge and Highway District, authorized by an act of the California Legislature, was incorporated in 1928 as the official entity to design, construct, and finance the Golden Gate Bridge. The bridge was constructed using a $35 million bond, well below early construction estimates of up to $100 million, due to ingenuity on the part of chief engineer Joseph Strauss and his team.

Construction

Construction commenced on January 5, 1933, and the bridge was opened to vehicular traffic on May 29, 1937. Carried out by multiple prime contractors and subcontractors, the massive undertaking of constructing the Golden Gate Bridge would take four years to complete, finishing on April 19, 1937. To build a bridge capable of supporting motorists, the first step was to construct huge concrete piers in the bay at each end of the bridge. Then the towers were built, and the cables drawn between them. Finally, sections of roadway were lifted into position and connected to the Marin and San Francisco approach roads.

The attempt to build what would be the first bridge support in the open ocean proved an immense challenge. As a 1,100-foot trestle extended off the San Francisco side, divers plunged to depths of 90 feet through strong currents to blast away rock and remove detonation debris. The trestle was damaged when it was struck by a ship in August 1933 and again amid a powerful storm late in the year, setting construction back five months.

When the towers were completed in June 1935, the New Jersey-based John A. Roebling's Sons Company was tapped to handle the on-site construction of the suspension cables. The Roebling engineers, who had also worked on the Brooklyn Bridge, had mastered a technique in which individual steel wires were banded together in spools and carried across the length of the bridge on spinning wheels.

Construction claimed a significant human toll. Despite efforts to encourage safety, the work was often treacherous. The bridge claimed its first fatality when Kermit Moore was killed by a falling piece of equipment. The following winter, on February 17, 1937, ten more men died when a scaffold they were working on fell through a safety net. Owing to incomplete employment records, the names of many of the workers who labored on this project are lost to history.

Even though construction began during the Great Depression, it still finished under budget and ahead of schedule. The bridge was completed $1.3 million under budget.

Opening and Milestones

On May 27, 1937, San Francisco's Golden Gate Bridge was opened to the public for the first time for "Pedestrian Day," marking the start of the week-long "Golden Gate Bridge Fiesta" held to celebrate its completion. More than 200,000 people paid twenty-five cents each to walk the bridge. The following day at noon, President Franklin Roosevelt, from across the continent at the White House, pressed a telegraph key and the Golden Gate Bridge was officially opened for vehicular use.

In May 1987, to celebrate the bridge's fiftieth anniversary, some 300,000 individuals walked the bridge in an event dubbed "Bridgewalk '87." The weight of bridge walkers that day caused the roadway to sag in the middle by 7 feet, but bridge engineers said the structure always remained safe.

By 2015, more than 2 billion motor vehicles had passed over the Golden Gate Bridge. The bridge has only been closed three times due to weather since it was built, all three times due to high winds gusting close to or over 70 miles per hour. The bridge has also been closed for visits from dignitaries President Franklin D. Roosevelt and President Charles de Gaulle of France, and on its 50th and 75th anniversaries.

Architecture and Engineering

The main span, 1,280 metres (4,200 feet) long, is suspended from two cables hung from towers 227 metres (746 feet) high; at midpoint the roadway is 81 metres (265 feet) above mean high water. The Golden Gate Bridge measures 8,981 feet in total length, which equates to 1.7 miles (or 2.7 kilometers).

To support the suspended roadway, two cables—each more than 7,000 feet in length and containing 80,000 miles of wire—stretch over the top of the towers and are rooted in concrete anchorages on shore. The bridge weighs 887,700 tons, after shedding 12,300 tons when the roadway was replaced in the 1980s.

The bridge's iconic appearance owes much to the deliberate choices of its designers. The aesthetic origins of the Golden Gate Bridge can be credited to architectural designer Irving Morrow, who also chose the structure's signature color. Known officially as International Orange, Morrow felt the shade would stand out against the surrounding land, sea, and ever-present fog. Meanwhile, the trio of Joseph Strauss, Charles Ellis, and Leon Moisseiff collaborated on the bridge's engineering design.

The Golden Gate Bridge came to be recognized as a symbol of the power and progress of the United States, and it set a precedent for suspension-bridge design around the world. Until the completion of the Verrazzano-Narrows Bridge in New York City in 1964, it had the longest main span in the world. The Golden Gate Bridge was the longest suspension bridge in the world until 1964. It is now the ninth-longest.

The bridge carries pedestrian and bicycle traffic in addition to motor vehicles. It is 1.7 miles long and takes approximately 45–60 minutes to walk across. The sidewalk is open to visitors seven days a week during the hours between sunrise and sunset. The bridge is open to autos and cyclists 24 hours a day.

In more recent years, the bridge itself has generated unusual attention for a new phenomenon. In June 2020, residents across San Francisco and Marin Counties began to notice a humming noise described as "eerie" and "a shrill screeching sound." The Golden Gate Bridge Highway and Transportation District determined that the sound is produced by new railing slats when a strong wind blows. The new slats were installed starting in 2019 on the west side of the bridge and were selected to improve the bridge's aerodynamic tolerance of high wind to 100 mph.

Cultural Significance and Legacy

Although other bridges have since surpassed it in size, the Golden Gate Bridge remains incomparable in the magnificence of its setting and is said to be the most photographed bridge in the world. Since it opened in 1937, this 1.7-mile suspension span between San Francisco and Marin counties has become one of the most beloved bridges in the world—a work of art, an engineering marvel, and an American icon, flanked on both ends by the natural beauty of the Golden Gate National Recreation Area.

Like New York Harbor's Statue of Liberty, San Francisco's Golden Gate Bridge has become an icon for its setting and its city. The Golden Gate Bridge is a historical landmark and has carried well over two billion vehicles since opening to traffic. In 1994, the American Society of Civil Engineers declared the Golden Gate Bridge one of the "Seven Wonders of the Modern World."

The land upon which the Golden Gate Bridge now sits was and is part of the traditional territory of the Yelamu, a local tribe of the Ramaytush Ohlone peoples. This heritage is acknowledged in ongoing preservation and educational efforts connected to the broader Presidio landscape surrounding the bridge.

Starting from the Golden Gate Bridge, visitors find connections to the California Coastal Trail, the Bay Area Ridge Trail, the SF Bay Trail/Golden Gate Promenade, and the Presidio Promenade, collectively linking San Francisco's iconic landmark with the rest of the Presidio's abundant offerings.