Beautiful. Graceful. Iconic.
Seemingly hyperbolic — yet, actually wholly accurate — words are often used to describe the Golden Gate Bridge, the landmark that defines the City by the Bay.
The Golden Gate Bridge’s elegant form came at a price, however. In a chapter of its life not often discussed, the Golden Gate Bridge was once briefly shut down for fear that strong gusting westerly winds would tear it asunder.
It had happened before: Those familiar with the tragedy of “Galloping Gertie” may be surprised to learn that before the Tacoma Narrows Bridge collapsed, its lead engineer also played a key role in designing San Francisco’s own famous bridge.
And much like its galloping sister bridge, the Golden Gate would face its own wind-born challenge.
The ugly girders
Ninety years ago, the engineers leading the design of the Golden Gate Bridge had a wholly different view of what shape it would one day take.
But its transformation on the drawing board to a beauty was not guaranteed. When lead engineer Joseph Strauss first presented his design to the San Francisco public in the 1920s, they hated it.
A 1987 United Press International article called the design an “atrocity.” When it was first presented, local press dubbed it “ugly,” according to historical accounts.
Conceptual sketches show a naked, girder-laden double-decked bridge, featuring protruding “cantilevers” that emerged from the towers like a spiderweb of steel rather than the graceful sloping wings of the bridge’s span today.
So it was in 1929 that one engineering consultant on the Golden Gate Bridge, Leon Moisseiff, pushed a new bridge engineering theory — one at the forefront of his industry — that allowed the bridge design to transform.
Moisseiff gave the Golden Gate its beauty.
He did not achieve this alone, but was principal in its inception, according to texts on the subject, and a historian from Duke University who specializes in bridge engineering who spoke to the San Francisco Examiner.
But while Moisseiff’s design principles forever changed the San Francisco region, he died in shame, after those same principles led to tragedy over the water just 786 miles north, near what was in the 1800s called The City of Destiny — Tacoma, Washington.
Before Moisseiff’s bleeding-edge engineering theories led to disaster in the Pacific Northwest, however, he’d test those theories in the Bay Area.
A partnership of necessity
Moisseiff took the long way ‘round to San Francisco.
A native of Latvia and a Columbia University graduate, according to the Washington-state paper, The Olympian, he worked his way up the rungs of the engineering world, from New York City’s Department of Bridges to his role as a consulting engineer. He designed the Manhattan Bridge, an iconic crossing in its own right which opened to the public in 1909.
Come the 1920s, Moisseiff’s reputation towered tall in the bridge building community. Strauss, the Golden Gate Bridge’s chief engineer, whose bulldog personality dragged The City kicking and screaming into funding the project, even as some railed against the construction’s high costs, brought in Moisseiff to be one of his top consultants.
Henry Petroski, a civil engineering professor at Duke University and the author of “Engineers of Dreams: Great bridge builders and the spanning of America,” described Strauss and Moisseiff’s relationship as one of necessity.
“The bridge probably wouldn’t have been built when it was if it weren’t for him,” Petroski said of Strauss. “But he didn’t have experience building bridges of that magnitude.”
Indeed, Strauss’ initial designs were not only monstrous in appearance, but may have been unsound.
“He drew a design for a bridge over the gate,” San Francisco author John van der Zee told United Press International in 1987. Strauss’ design was “a combination of cantilever and suspension. It never would have worked. The wind would have set it vibrating and ripped it apart.”
It is perhaps ironic then that it was Moisseiff’s engineering principles that brought not only beauty but stability to the Golden Gate Bridge, for reasons that would only emerge years later.
As Petroski describes in his book, Engineers of Dreams, Moisseiff wanted to bring the cutting-edge concept of “deflection” design to the Golden Gate.
In Strauss’ design, massive cantilevers — essentially protruding beams — propped up the bridge’s towers. But deflection principles held that making a bridge longer, and more slender, allowed it to become more flexible and resistant to movement.
Moisseiff was far from alone in making this possible. Charles Ellis, another engineer nowadays credited with a profound impact on the design of the Golden Gate Bridge, performed the calculations making this design possible, working in tandem with Moisseiff. But it was Moisseiff who pushed the deflection principle itself in the first place.
“It was an aesthetic goal,” Petroski said.
And as the Golden Gate Bridge website’s own historical account describes, “By 1929,” Moisseiff and another consulting engineer, O.H. Ammann, “had persuaded Strauss to accept the more graceful all-suspension bridge design that we see today.”
The interwoven basket of girders would be dropped from those drawing board sketches, leaving the swooping curves of the Golden Gate Bridge’s suspension cables to solitary towers that would cut through the San Francisco fog for decades to come.
“The celebrated beauty of the Golden Gate Bridge rested upon deflection theory,” wrote Louise Dyble, in the historical account “Paying the Toll: Local Power, Regional Politics, and the Golden Gate Bridge.”
It was also a financial consideration.
“ADOLPH UHL WARNS TAXPAYERS, Watch your step on Golden Gate Bridge!” advised a political advertisement in the Feb. 14, 1930 edition of the San Francisco Examiner, which said that the bridge’s engineers — including Moisseiff — might be overpaid to the tune of $57,000 for his work designing the bridge.
The deflection design decreased construction costs by reducing the amount of needed construction materials.
But it also would lead to destruction up north.
Disaster over the Narrows
Moisseiff’s reputation and career rose with the Golden Gate Bridge. Consequently, when Washingtonians were in need of advice to design a new span over the Puget Sound, to be called the Tacoma Narrows Bridge, they turned to him.
Here again, Moisseiff employed the deflection theory, pushing the Tacoma Narrows Bridge to become longer and slimmer.
“The Tacoma Narrows Bridge took its application even further,” according to “Paying the Toll,” and Moisseiff declared this new Pacific Northwestern span to be “the most beautiful in the world.”
Petroski put it a different way.
“He was instrumental in making or dictating changes that led to its downfall,” he said.
When it debuted in 1940, the Tacoma Narrows Bridge was the longest suspension bridge between its two towers compared to its depth, Petroski explained, which engineers call a “slenderness ratio.” It was “unprecedented,” a ratio to which no other bridge could compare, and “well beyond the experience of engineering” at the time.
The bridge immediately became an attraction for how easily it began to sway and undulate, according to The Olympian, garnering it the nickname “Galloping Gertie.”
“Why did it happen?”
It only took six months for a 42 mph wind to start the Tacoma Narrows Bridge undulating violently enough to crumble. On Nov. 7, 1940, a cable on the bridge snapped, according to Paying the Toll, causing the bridge to twist as the roadway undulated in waves.
A team of engineers came out to assess the problem, but it was too late. The most they could do was catch the event on film, and the Tacoma Narrows Bridge’s rollicking, rolling destruction for decades became a staple of some high school science classes.
The sole fatality was a dog, Tubby, who was trapped in a stranded car, according to The Olympian.
“Why did it happen? The ultimate cause? Physicists often say resonance, that the wind matched the resonance of the structure, like if a singer hits a high note and breaks a wine glass. That’s resonance,” said Petroski.
But, he countered, engineers “don’t think it’s as simple as that.”
That’s because wind occurs in gusts. That’s not so much like holding a high note, but instead, more like buffeting the bridge repeatedly.
That buffeting started the bridge twisting. It would go up on one side and down on that same side, in a see-saw fashion.
“It’s sort of analogous to a kid on a swing,” Petroski said. “If you time your pushes right, you can go higher and higher.”
Moisseiff died three years later, while sitting as chairman of a federal committee to re-evaluate the principles governing suspension bridge design, according to The Olympian.
“The bridge and Moisseiff’s reputation as an engineer were both a total loss,” according to Paying The Toll.
The Golden, Swaying, Gate
The Golden Gate Bridge didn’t fully escape the fallout from Moisseiff’s design.
Galloping Gertie’s demise put the fear of God into San Francisco officials. After all, Moisseiff had designed the Golden Gate Bridge too, hadn’t he?
Bridge district engineer Russell Cone was brought in to inspect the Golden Gate Bridge and the Tacoma Narrows Bridge failure. While he was fired shortly after amidst politicking, according to “Paying the Toll,” his observations about the Golden Gate Bridge’s susceptibility to swaying during windstorms were included in a federal report on the Tacoma Narrows Bridge collapse.
He saw a “wave similar to that made by racking a whip” at vibrations of 20 to 30 a minute.
Bridge directors balked at the cost of any further investigation into the bridge’s soundness.
That is, until Dec. 1, 1951, when a major windstorm sent gusts blasting past 60 mph across the San Francisco Bay.
The results were immediate — our city’s icon became the Galloping Golden Gate.
The bridge was closed. The roadway undulated in 6-foot-tall vertical waves. The Golden Gate twisted like a snake, in exactly the same fashion as the Tacoma Narrows Bridge.
“It would undulate excessively,” Petroski told the Examiner.
At last, the Golden Gate Bridge District yielded. They paid for a study, which led to the installation of a lateral bracing system in 1953, effectively halting the bridge from doing its best Chubby Checker impression.
Petroski said when that steel was added, “it made the roadways so heavy they couldn’t make a second deck on it,” which perhaps coincidentally or not, was the justification in the 1960s for not running BART service underneath the Golden Gate Bridge to Marin.
The Golden Gate Bridge may have been put in peril by Moisseiff’s designs, but without him, it wouldn’t have captured the hearts of a region.