May 24, 1987 – Golden Gate Bridge Flattens at the 50th Anniversary Celebration

On this date in 1987 San Francisco held a celebration for the approximate fiftieth anniversary of the Golden Gate Bridge. (The actual anniversary was on May 27, but May 24 was a Sunday and therefore more suitable for a ceremony.)

The official website of the Golden Gate Bridge tells us that in 1846, Captain John Fremont declared California’s independence from Mexico and named the entrance to the San Francisco Bay “Chrysopylae,” which means Golden Gate in Greek.

More gold became associated with the city after its discovery in Northern California in 1849. San Francisco exploded into a city of 35,000.

In 1919, the San Francisco Board of Supervisors launched a study of the feasibility of a bridge across the Golden Gate Strait. The study was completed in May, 1920, and the prominent engineer Joseph B. Strauss in Chicago was selected to head up the project. It wasn’t until December, 1928 however that the Golden Gate Bridge and Highway District was incorporated as the entity to finance, design, and construct the bridge. A year later, two dedication ceremonies were held to mark the start of borings for the tower piers at each end.

San Francisco’s Joseph Strauss Memorial, in March 2010.

In the summer of 1930, Strauss hired a local architect, Irving Morrow, to design how the bridge would look. Morrow was later recognized for his aesthetic contributions – the Golden Gate Bridge’s distinctive Art Deco lines, burnt red-orange hue, and the structure’s dramatic lighting. Still, it wouldn’t be until January 5, 1933 that the bridge construction officially began.

On April 27, 1937 the “Last Rivet Ceremony” was held at midspan. On May 27, 1937 Golden Gate Bridge opened to pedestrian traffic and on May 28, it opened to vehicular traffic at twelve o’clock noon, when President Franklin D. Roosevelt pressed a telegraph key in the White House to announce the event to the world. Simultaneously, every fire siren in San Francisco and Marin was sounded, every church bell rang, ships sounded their whistles, and every fog horn blew. The bridge opened ahead of schedule and under budget.

On the timeline of the official website for May 24, 1987, the entry only reads: “Golden Gate Bridge celebrates its 50th Anniversary.” But it was actually a much more exciting event, and the website does describe what happened on its page “Golden Gate Bridge Anniversaries:”

The day began as “Bridgewalk ‘87” reenacted “Pedestrian Day ‘37” and an estimated 300,000 people surged onto the roadway. The Bridge roadway was closed to traffic at 5 am and from 6 am to 10 am pedestrians were allowed onto the roadway. While up to 200,000 people participated in the 12-hour Pedestrian Day ‘37, fewer people were expected to participate in the Bridgewalk ‘87 as it was held over a four-hour period. However, it is estimated that 300,000 people surged onto the span that morning, with another 400,000 to 500,000 gathered anywhere they could on all areas surrounding the span.

With the very large crowd gathered on the roadway that morning, the Bridge’s profile shifted and its normal convex shape was flattened.”

According to “The Mercury News” newspaper published in San Jose, California:

On May 24, 1987, 300,000 people were stuck in human gridlock for hours while getting a rare chance to cross the 1.7-mile bridge en masse on foot to celebrate the bridge’s golden anniversary. Officials quickly closed the bridge, so a half-million other people waiting to cross never got the chance. Still, the enormous, unprecedented weight caused the middle of the bridge to sag 7 feet.”

Engineers maintained afterward that the bridge was never in danger of collapsing. (. . . . just like the Titanic was never in danger of sinking. . . .)

An estimated 350,000 people turned out for the bridge walk, which kicked off the Golden Gate Bridge 50th anniversary celebration. (AP Photo/Doug Atkins)

The article furthermore contended:

On fully loaded suspension bridges the size of the Golden Gate, it’s normal to have ‘deflections’ of up to 10 feet, said Greg Deierlein, a Stanford University professor of civil and environmental engineering.”

The bridge had originally been engineered to hold 4,000 pounds for every foot of bridge. During the mid-1980s, concrete was replaced with a lighter steel framework, boosting that capacity to 5,700 pounds per foot. Ewa Bauer, chief engineer of the bridge district, said that the designers of the Golden Gate over-engineered the bridge to accommodate at least an additional 150 percent weight.

Stephen Tung, the author of the article in the “Mercury News,” writes:

No one knows the exact weight of the pedestrians on the bridge on that May day. But assuming the average person weighs about 150 pounds and occupies about 2.5 square feet in a crowd, there would have been about 5,400 pounds for every foot in length. That’s more than double the weight of cars in bumper-to-bumper traffic.”

For the sixtieth anniversary in 1997, a different celebration was planned: The world was able to explore the famed landmark virtually via an interactive web site. On the 75th anniversary in 2012, the main activities were held at Fort Point, Crissy Field, The Presidio and Marina Green.