Galloping Gertie

Roman Mars:
This is 99% Invisible. I’m Roman Mars.

Roman Mars:
The thing about being wrong is that before you know you’re wrong, it feels exactly like being right.

Kathryn Schulz:
If we knew that we were wrong, we wouldn’t be wrong. Nobody’s committing intentionally to a false belief about the world. If they are, they’re not wrong. They’re deliberately lying.

Roman Mars:
Even during the construction of the original Tacoma Narrows Bridge, which was to become the third-longest suspension bridge in the world, it seemed like something was wrong. Well, at least in hindsight, it seems like it should have felt that way, but that’s not how being wrong works.

Kathryn Schulz:
If you grew up like I did, watching the Warner Brothers cartoons….

Roman Mars:
This is Kathryn Schulz, author of “Being Wrong: Adventures in the Margin of Error.”

Kathryn Schulz:
The Sunday morning cartoon moment where the roadrunner is dashing off the cliff and the coyote is following him and of course, the roadrunner can fly and the coyote can’t…. And there’s this great moment where he’s run off the cliff, but he has not yet realized that there’s no solid ground underneath him. And the moment when we’re wrong about something but before we realized it is like that moment. We think that our belief is rock solid. We think we have all of the facts in the world bolstering us.

Roman Mars:
We feel like our giant suspension bridge is not going to collapse….

Kathryn Schulz:
We have not yet looked down and realized that. Whoops, that’s not the case.

Roman Mars:
I know that sounds crazy, but even during its construction, the deck of the Tacoma Narrows Bridge would go up and down by several feet with the slightest breeze. Construction workers on the span chewed on lemon wedges to stop motion sickness, but construction continued because the bridge had been designed specifically to withstand winds up to 120 miles per hour. So, everyone thought everything would be fine. Well, almost everyone. The original Tacoma Narrows Bridge designed by Clark Eldridge was pretty conventional for a suspension bridge, but it was later modified by Leon Moisseiff to be slimmer and more elegant. The most notable change was the 25-foot lattice of stiffening trusses underneath the bridge on the original drawings were replaced with an 8-foot solid steel plate girder. The new solid girder along the side that Moisseiff designed made for a much lighter, slimmer, and more flexible bridge. It also caught the wind like a sail, but they didn’t know that. Moisseiff’s design was also 2/3 the price of the original Eldridge design and that fact ultimately won the day. Eldridge and other state engineers were said to have protested but it didn’t matter. The original Tacoma Narrows Bridge opened to the public on July 1, 1940.

John Marr:
From the day it opened, it was prone to having these oscillations, these longitudinal waves of the bridge deck.

Roman Mars:
That’s our master of disaster, John Marr.

John Marr:
I write on various murders and disasters and other sundry topics.

Roman Mars:
He used to publish a ‘zine called “Murder Can be Fun” about these sundry topics. He wrote about the Tacoma Narrows Bridge years ago.

John Marr:
The workers on the bridge had nicknamed it “Galloping Gertie” and that became quickly the bridge’s unofficial name.

Roman Mars:
Even light winds caused the roadway to ripple with longitudinal waves some 5 feet high.

John Marr:
The State of Washington was concerned about this, but not like, intensely. So, they were looking at various things to reduce the motion. They tried some tie-down cables and installing a damper and various other things, none of which had worked.

Roman Mars:
But again the roadbed seemed like it could handle the waves just fine.

John Marr:
They were very confident in the structural integrity of the bridge.

Roman Mars:
The bridge was as solid as the air underneath Wile E. Coyote’s feet. When you watch film of the waves traveling down the bridge, it is stunning. And the fact that the bridge stayed open at all really illustrates how local governments have changed since 1940. That thing would never stay open today! If you were sitting in a car on the bridge when the waves were going, the cars in front of you would bob up and then disappear completely from view.

John Marr:
Almost like a thrill ride, people actually drive specifically for the feeling of riding on this bouncing bridge.

Roman Mars:
The ride ended just four months later.

[REPORTER]
Dawn of a fatal day and the wind begins to speak with a roar that no man can fail to hear.

Roman Mars:
It was clear early on the morning of November 7 that the gale-force winds were having a greater effect on the bridge than ever before.

John Marr:
Previously, these sorts of waves on the bridge had been fairly transitory. You’d bounce up for a couple minutes but this was just going on and on, so they thought this could be problematical. Although they had seen actually deeper waves on the bridge.

Roman Mars:
But then the movement changed.

John Marr:
Things just got worse.

Roman Mars:
The bridge began to twist violently along the centerline.

John Marr:
And that became extremely violent. One end of the bridge deck was up at a 45-degree angle.

[REPORTER]
In a 40 mile an hour gale, the center span weaves like a ribbon on the swinging bridge that you wouldn’t believe possible as the bridge gyrates right like a nightmare high above the river. Twisting, turning, curling!

Roman Mars:
By this time everyone had gotten off. The blunt solid edge of the bridge disrupted the flow of the strong wind causing one part to twist up, while the other section twisted down. And it continued this torsional back and forth for over an hour. So there was plenty of time for spectators to come watch, including the bridge’s original designer, Clark Eldridge. A local camera store owner named Barney Elliot arrived on the scene and took the now-famous color film of the bridge’s relentless gyrations.

[REPORTER]
No structure of steel and concrete can stand such a strain. Steel girders buckle and giant cables snap like puny threads! There it goes! Engineers are divided as to the cause of the disaster. Some claim it was the use of solid girders, others differ. But whatever the reason, Tacoma will rebuild! This time a bridge that will not provide a super thrill in the news.

Roman Mars:
Before the collapse, bridge aerodynamics and structural failure due to torsion had scarcely been considered. Or maybe those lessons have been lost in the rapid evolution of more and more slender and longer bridges. But the failure caused the study of bridge aerodynamics to take off, and any bridges that were on the drawing board in 1940 were redesigned with more conservative, deep open truss deck structures. The lead designer, Leon Moisseiff, and his solid steel I-beams received most of the blame for that disaster. He never designed another bridge again, due in no small part of the fact that he died three years later.

John Marr:
No one was killed on the bridge. A few people were very lucky to get away with their lives because just imagine, you’re on this bridge and it’s twisting it at a 45-degree angle and you’re trying to walk off in a fairly stiff wind. The only casualty was a dog.

Roman Mars:
A local newspaperman named Leonard Coatsworth drove his car just past the east tower when the twisting started.

John Marr:
It got bouncing so hard. He couldn’t control his car anymore.

Roman Mars:
The tilting bridge threw his car into the side curb.

John Marr:
And he had his daughter’s dog, a Cocker Spaniel named Tubby with him.

Roman Mars:
Coatsworth gets out of his wrecked vehicle and gets thrown face down on the curb.

John Marr:
The dog’s completely freaked out. He couldn’t get the dog out.

Roman Mars:
He hears the concrete cracking beneath him.

John Marr:
And he barely makes it to safety.

Roman Mars:
An engineering professor studying the bridge name Farquharson ventured out to get Tubby right when the bridge was about to fall into the sound. But when he reached into the car, Tubby bit him. The dog was just too freaked out to leave the vehicle. There’s an amazing film of Farquharson stumbling back as best he could, sticking to that middle yellow line as the bridge rocked wildly along its center axis.

John Marr:
So, Tubby was the only casualty. And poor guy, he said, “I’m gonna have to tell my daughter this.”

Roman Mars:
Coatsworth was quoted immediately after the collapse saying, “With real tragedy, disaster and blasted dreams all around me, I believe that right at this minute what appalls me most is that within a few hours I must tell my daughter that her dog is dead, when I might have saved him.”

(music)

Roman Mars:
This next bit is a completely unrelated addendum that will serve as a valuable life lesson to any 99% Invisible fan. Here’s John Marr again.

John Marr:
Several years ago, I went to the Portland Zine symposium to do a seminar on research-based ‘zines.

Roman Mars:
Research-based ‘zines, like research-based blogs or podcasts, have always been a bit in the minority. Anyway-

John Marr:
It was held in this building called the Michael Smith Memorial Student Union Building on the Portland State University campus. Very first thing I did is, I got in front of the class and said, “Okay, this panel is being held in the Michael Smith Memorial Student Union Building. Does anyone know who Michael Smith was?” No one did. Michael Smith was the captain of the Portland State University College Bowl team. The College Bowl was a televised trivia competition matching teams from various universities throughout the country. And he led Portland State University to the championship, which is this incredible accomplishment. They’re beating out schools like Harvard and Yale and this is Portland State, this is a state school. This is not the type of school you expect to win something like this. I’m sure the Ivy League people were horribly embarrassed, and it was quite a big deal at the time. He also was suffering from cystic fibrosis and he would die three years after this. So, everyone agreed this was a good story. They asked me, “How’d you find out about this?” There’s a plaque in front of the building. My slogan is, “Always read the plaque.”

Roman Mars:
99% Invisible was produced this week by me, Roman Mars A special thanks to John Marr of “Murder Can be Fun” and Alan Bellows of the website “Damn Interesting.” We are a project of KALW 91.7 Local Public Radio in San Francisco and the American Institute of Architects in San Francisco.

You can find the show and ‘like’ the show on Facebook. I would like it if you would ‘like’ us. I tweet @romanmars. You can always catch up with us online at 99%invisible.org.

  1. Kat

    What is the song that starts playing at 2:15? I can’t place it and it’s driving me mad :)

    1. Damian

      Five years late, almost to the day, but it’s ‘Soft Trees Break The Fall’ by Trent Reznor and Atticus Ross from the Soundtrack to ‘The Social Network’

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