We know there are questions around travel amid the coronavirus (COVID-19) outbreak. Read our note here.
The Golden Gate Bridge is easily San Francisco’s most recognizable landmark. This world-famous suspension bridge spans nearly two miles across the San Francisco Bay, linking the city to Marin County to the north. In an average year, as many as 10 million visitors come to admire this magnificent feat of engineering. But here are eight surprising facts they might not know about the Golden Gate Bridge.
It Was Once the Longest Suspension Bridge in the World
Initially, there was plenty of opposition to the planned construction of the bridge. The press derided the first design as “ugly,” and ferry operators resisted a new threat to their business. But after four years of construction, the Golden Gate Bridge was finally completed in 1937. The total length of the suspension span — main and side suspensions combined — was 6,450 feet (1.2 miles) wide, making it the longest such bridge in the world at that time. Incidentally, it was also the tallest — the height of the towers above the water was 746 feet (500 feet above the road level).
It wasn’t until 1964 that the Verrazano-Narrows Bridge (which links the New York City boroughs of Staten Island and Brooklyn) would beat the Golden Gate Bridge for length, though its towers weren’t quite as high. The record holder today for the world's longest suspension bridge is Japan's Akashi Kaikyo Bridge, which carries traffic from the city of Kobe to Awaji Island. Its central span alone is 6,532 feet, compared to the Golden Gate Bridge’s main span measurement of 4,199 feet.
The Name Refers to the Strait of Water It Crosses, Not the Color
Almost a century before the bridge was constructed, the strait it spans was named the Golden Gate. Though you might assume the name refers to the Gold Rush, it actually predates that era by a couple of years. Europeans were relatively late in exploring the Bay Area, probably due to the persistent fog which plagues the region in summer. In 1775, Juan de Ayala, a Spanish naval officer in charge of a ship called the San Carlos, was first to pass through the strait, which he called the Boca del Puerto de San Francisco (“Mouth of the Port of San Francisco”). But in July 1846, U.S. Army Captain John C. Fremont renamed the strait Chyrsopylae, meaning Golden Gate. His choice was a nod to the Chrysoceras, or Golden Horn, a waterway of the ancient city of Byzantium, located in modern-day Istanbul. However, the Greek name of Chyrsopylae was soon dropped, and it’s been simply called the Golden Gate Bridge ever since.
The Color Was Only Supposed to Be Temporary
The Golden Gate Bridge’s distinctive reddish-orange paint color came about by accident. Architect Irving Morrow noticed that some of the steel that arrived for construction of the bridge was coated in a dark red primer, which inspired him to write a 29-page report advocating for a similar color to be used in the bridge’s final design. Although most bridges at the time were painted gray, silver, or black, he suggested using paint in a shade like orange vermillion or burnt sienna, as these luminous tones would emphasize the grand scale of the bridge and provide a contrast to the grey and blue color of the water beneath.
Not everyone agreed, but in the end, Morrow won over his critics. The bridge was painted a shade unimaginatively called “International Orange,” and it’s been the same ever since. Those wishing to replicate it should note its CMYK coordinates: cyan: 0%, magenta: 69%, yellow: 100%, black: 6%.
In Summer, the Massive Structure Can Disappear From Sight
The prevalence of fog hanging over the bridge in summer leads locals to refer to those months as June Gloom and Fogust. The area’s original settlers, the Ohlone Native Americans, were said to believe that when the fog rolled into the bay, it signaled the time for spirits to rise and walk among the living. Today, scientists know it as advection fog, formed when warmer humid air from the ocean meets the colder, drier air over the land. As they collide, the air is cooled from below and condenses to form fog — which can completely obscure the 746-foot-tall, 8,981-foot-long bridge.
It Has Foghorns to Keep Marine Traffic Safe
Because of the dangers caused by poor visibility, the Golden Gate Bridge is fitted with five foghorns, two at the south tower pier and the other three in the middle of its span. Each has a different tone and length of time it sounds, depending on weather conditions and the season. To avoid a collision, vessels entering San Francisco Bay are required to keep to the left of the south tower foghorns and steer right of the mid-span horns. Ships traveling in the opposite direction keep to the right of the mid-span horn. Red beacons also help to ensure ship traffic is safe.
Its Busiest Day Ever Coincided with a Giant Earthquake
On October 17, 1989, the Loma Prieta fault line sprang to life, shaking San Francisco and the bridges which crossed its bay. It was a powerful 7.1-magnitude earthquake, the largest since the infamous 1906 quake that devastated the city. The Golden Gate Bridge absorbed the quake’s energy, but the Bay Bridge, built to different design specifications, sustained significant damage, diverting as many as 40,000 drivers. Many of them had to cross the Golden Gate instead. Ten days later came the peak flow of the rerouted traffic: 162,414 vehicles crossed the Golden Gate Bridge in a single day, a record that has never been surpassed.
After the 1989 earthquake, seismic engineers were aware that the city could still be hit by what they call the "Big One," so they began to retrofit the bridge with measures aimed at strengthening the structure. Base isolators were fitted that enable the bridge to slide instead of rock, and much of the structure was braced or anchored more effectively to the bedrock. If a stronger, shallower, or closer earthquake ever hits the area, engineers anticipate that the bridge will be able to withstand its impact.
Closures Are Extremely Rare
The Golden Gate has fully closed only three times due to high winds: in 1951, 1982, and 1983. The longest of these weather-related closures – 3 hours and 27 minutes – coincided with exceptionally strong wind gusts up to 75 mph that buffeted the bridge on December 3, 1983. The bridge has also closed a handful of times for structural upgrades and visiting dignitaries, including President Franklin D. Roosevelt.
Although it didn’t result in a full bridge closure, one of the stranger incidents occurred on September 5, 2014, when a pair of black-tailed deer stopped northbound traffic for a short time. They’d decided to cross from San Francisco to Marin County during the evening commute, so everyone else had to wait to ensure they made it across unharmed.
Over 2 Billion Drivers Have Crossed the Bridge
The one billionth driver to cross the bridge was a dentist named Dr Arthur Molinari, who was presented with a hard hat and a glass of Champagne to commemorate the occasion on February 22, 1985. Less than 40 years later, an incredible 2,241,603,474 vehicles have crossed the Golden Gate Bridge (as of the most recently available 2019 data).
But surprisingly, at the end of the bridge’s opening day, the total number of vehicles was zero. May 27, 1937, was deemed Pedestrian Day — approximately 200,000 people paid a 25-cent fee to walk across the bridge on its first day. It was opened to vehicles the following day. To mark the bridge’s 50th anniversary, the bridge was closed again for a mass walk. An estimated 800,000 people turned up — hundreds of thousands more than organizers had anticipated — and 300,000 of them managed to make the crossing, creating the worst gridlock the bridge had ever seen. Under their combined weight, the towers leaned and the roadway was pushed down seven feet below its normal height, though fortunately the bridge was designed to cope with such stress and was undamaged.