It’s not quite 10am on a blustery November morning in 1940. Like many other motorists that day, newspaperman Leonard Coatsworth makes his way toward Washington’s Tacoma Narrows suspension bridge. Carrying his daughter’s black cocker spaniel in the back of the car, Coatsworth cruises onto the stretching span completely unaware that it is about to collapse. As his car hits the roadway, the crossing begins to violently convulse. Horrified onlookers can only watch as he approaches what looks like certain death.
Coatsworth was news editor of the local Tacoma News Tribune. That morning, he was on his way to the family vacation home on the other side of what locals call The Narrows, part of Washington state’s Puget Sound coastline. As we mentioned, travelling with him was his daughter’s dog, Tubby. And as the newspaperman approached the crossing, nothing appeared out of the ordinary.
The bridge itself was essentially brand new, having been opened in July 1940. Once completed, the crossing became very popular almost immediately. And that’s despite the 75 cent toll for vehicles and 10 cent charge for pedestrians. Why? Well, it seems that before its construction, the only way to get from Tacoma to the Kitsap Peninsula on the other side of Puget Sound was to take a long drive.
And by a long drive, we mean a good two-plus hours to navigate from one side of The Narrows to the other. The construction of the bridge cut an enormous amount of time off that journey. Indeed, for the measly sum of only 75 cents, you could be on the peninsula in just 17 minutes. But it wasn’t simply the convenience that made it popular.
On its completion, the Tacoma bridge was the third-longest suspension bridge on the planet. It was designed by Leon Moisseiff, a consulting engineer of San Francisco’s Golden Gate Bridge, the world’s longest at the time. It was something of a coup for Washington, a modern, cost-effective, lucrative and — above all — useful state-funded project. The crossing, however, was far from perfect.
The bridge’s construction had left it with one or two idiosyncrasies. And by idiosyncrasies we mean panic-inducing movements that would give even the most ardent roller-coaster fan a panic attack. Or at least, that’s what you’d think. For locals, however, the crossing’s convenience appeared to far outweigh the fear factor. So what, exactly, was the issue?
Well, high winds caused the bridge to behave in a very unusual way. The roadway would visibly undulate, sending waves up and down the deck. Locals became so used to the rippling that they even gave the crossing a nickname. Inspired by the ribbon-like motion, it became known as “Galloping Gertie.” Nevertheless, drivers continued to use the span.
Constructed using light-weight steel girders and a thin concrete skin, the bridge’s design was hailed as a modern masterpiece. Low-cost and easy on the eye, Tacoma was the proud home of a ground-breaking project. But the problems began during the building process, when workmen first noticed the undulations. In May 1940, those laying the roadway noted the deck’s wave-like motion or “bounce.”
So noticeable, in fact, were the bridge’s undulations that engineers were forced to reassure the public. Talking to local media, they said the movement was entirely normal and that the crossing would be perfectly safe when it opened. But just to err on the side of caution, the state installed some hydraulic dampeners in an attempt to stabilize the deck. They didn’t work.
At a loss as to why the bridge was still rippling, authorities called in Frederick Burt Farquharson. A professor in engineering at the University of Washington, they hoped he would be able to solve the problem. In May 1940, Farquharson set about building scale models of the span and testing them in wind tunnels, looking for answers. The research, however, would take months to complete.
In the meantime, the new bridge opened in July that year, and drivers just got used to Gertie’s weird behavior. Authorities, though, continued to try and solved the undulation problem. In October, they installed several heavy-duty cables in an attempt to stabilize the span. Unfortunately, one of them broke on November 1. The next day, however, Farquharson completed his research and submitted two recommendations.
Farquharson’s recommendations: either install wind deflectors or drill holes in the girders to allow gusts to blow through. Authorities settled on the wind deflectors and plans were made to install them swiftly. Engineers believed stability could be significantly improved within ten days and completely safeguarded in under a couple of months. Those plans, however, never came to fruition.
Just five days later, on November 7, 1940, Gertie’s idiosyncrasies went from weird to deadly in a matter of hours. At 7.30am winds of 38 miles per hour were gusting across The Narrows. This increased the bridge’s rippling, with the surrounding waves reaching as high as five feet. Despite this, the bridge remained open to traffic.
Around 9.30am, Farquharson arrived at the bridge. The last cars to safely cross the span did so only 20 minutes later. But around 10am, Gertie began doing something unbelievable. The bridge began to twist. At which point, the authorities finally made the decision to close it to all traffic.
This dramatic turn of events didn’t go unnoticed by locals. Crowds began to gather, watching the bridge writhe in horrified silence. Eyewitnesses later described the cacophony of noise coming from the stricken span. The sounds of screeching metal and rumbling concrete joined the gusting wind, adding to the sense of impending doom. And among the spectators, two men set up their 16mm cameras, ready to capture the events as they unfolded.
The bridge continued to twist, reaching ever-higher with each swing. But while the crossing was closed to traffic, it certainly wasn’t empty. At around the same time that Leonard Coatsworth was unwittingly making his way onto the bridge, a single pedestrian also began to cross. But this walker was doing so for a very different reason.
Winfield Brown, a 25-year-old college student decided the twisting bridge was an opportunity not to be missed. He later said he crossed the bridge, not once, but twice, because he “wanted to get a little fun out of it.” It was a decision, though, that he soon came to regret.
After deciding to make a third journey across the bridge, Brown found himself in some trouble. He later told the Washington Department for Transportation about the experience. “About the time I got to the center, the wind seemed to start blowing harder, all of a sudden. I was thrown flat. Time after time I was thrown completely over the railing. When I tried to get up, I was knocked flat again. Chunks of concrete were breaking up and rolling around. The knees were torn out of my pants, and my knees were cut and torn.”
The student went on, “During the worst parts, the bridge turned so far that I could see the Coast Guard boat in the water beneath.” Eventually, though, he made it to safety. “I don’t know how long it took to get back. It seemed like a lifetime. As soon as I got off the bridge, I became sick.”
During Brown’s ordeal he noticed someone else on the bridge. As the student was making his third trip, he said, “A car came up. The driver got out, walking and crawling on the other side. We didn’t have time for any conversation.” The vehicle belonged to Leonard Coatsworth. He had just drove past the East Tower when he lost control of his vehicle.
After driving through the toll plaza, Coatsworth continued his journey, despite Gertie’s violent swaying. When the bridge tilted hard, his car slammed into the curb. Swaying as high as 28 feet, it was clear that the bridge was in trouble. Unsure of what to do, the newspaperman made a quick decision.
Coatsworth hit the brakes hard and made his escape through the car window. For his efforts, he was thrown face-down on the ground as the bridge convulsed once more. Holding onto the curb for dear life, the newspaperman tried to reach Tubby — who was still in the car — but another twist landed him too far away to reach the dog.
At that point, amid all the chaos and sure that the bridge was going to collapse, Coatsworth made a heart-wrenching decision. With Tubby too far away to reach safely, the newspaperman began to crawl the 500 yards back towards the toll plaza. His daughter’s cocker spaniel remained in the abandoned car.
Making progress on his hands and knees, Coatsworth crawled over 500 yards towards the safety of the toll plaza. All the while, the bridge was twisting further and further with each turn, the sound of cracking concrete and whining steel must have been terrifying. The span continued to writhe as the newspaperman inched up the roadway.
Somehow, Coatsworth made it back to the toll plaza. Despite the cuts and bruises to his body, the newspaperman’s training then kicked in. After informing the authorities that Tubby was still out there, Coatsworth then called his office. They immediately sent out a photographer to capture the incredible events as they were unfolding.
Tacoma News Tribune photographer Harry Clifford arrived moments later. By 10.30am, a section of the central span cracked and plummeted in to the water below. At that point, both Clifford and Farquharson mounted their own, separate, attempts to rescue Tubby. Both, however, failed due the violent twisting of the bridge.
Then, at 11am, all hell broke loose. The bridge, which had been twisting and swaying in the high winds for over an hour by now, finally began to fail. Both Clifford and Farquharson were still on the span as it began to break up. The photographer later described hearing “rumblings and explosive sounds which scared the daylights out of me.” As the men scrambled to safety, cables broke and concrete cracked.
Farquharson later told the Washington Department for Transportation what he experienced that morning. “At least six lamp posts were snapped off while I watched. A few minutes later, I saw a side girder bulge out. “I saw the suspenders [vertical cables] snap off and a whole section caved in. The bridge dropped from under me.”
Fighting undulations of up to 30 feet, Farquharson also miraculously made it to safety. But the worst was yet to come. Hundreds of people had gathered to watch the stricken bridge and the attempts of those stranded to escape the inevitable collapse. As the professor reached the East Tower, pieces of the span began to fall into the water. Bolts flew threw the air and the cables snapped with the sudden crack of gunshots. The din grew louder as steel girders twisted and wailed.
At 11.02am that morning, as the suspension cables failed, a 600-foot-long section of the bridge twisted and fell into the waters below. Creating a thunderous roar, it’s wrenching-free was followed by a cloud of concrete dust and water plumes as it hit the ocean. Foam shot up over 100 feet in the air and ripped electrical wires sparked and spat as they shorted.
From there, successive sections of the roadway split and fell straight into the water. Along with them went Coatsworth’s car and the stricken Tubby. As he later told the Washington Department for Transportation, that was perhaps the hardest part of the day. “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.” All in all, the collapse had taken only eight minutes. But that wasn’t the end of the story.
Once the dust had settled on the collapse in which, miraculously, Tubby was the only casualty, the search for answers began in earnest. Among others, authorities turned to Farquharson. His wind tunnel experiments had, in fact, recreated the bridge’s twisting motion seen that day. Sadly, though, two things meant his research wasn’t massively helpful.
Firstly, the state had brought the professor in far too late for his work to really be of any help with the events of November 7. The fact that the swaying had been noticed during construction and not dealt with certainly contributed to the disaster. And secondly, although Farquharson had been able to reproduce the twisting, no one could explain exactly why it occurred.
A new bridge was eventually built, using a much sturdier design as well as the wind-dampening deflectors and holes Farquharson had recommended for the original. Around the time the new crossing opened, the professor finally found an answer to the twisting riddle — and the lessons learned have informed suspension bridge building ever since. But, it seems, the correct explanation never really caught on.
In fact, thanks to the spectacular footage taken on the morning of the collapse, as well as some questionable physics, many experts have attributed the incident to the wrong phenomena. You may well have seen the film yourself in science class and it really does look horrific. The swinging swaying and rippling on show led many physicists to conclude that harmonic resonance caused the bridge to fail. But that’s not the case.
For the non-scientists among us, harmonic resonance is best described as the phenomena that causes a glass to break when a singer hits a particular note. At that point, both the voice and the glass are vibrating at the same rate. When the glass can no longer dissipate the energy it’s accumulating, it shatters. And for many experts, the Tacoma Bridge is the glass and the wind the voice, leading to catastrophe. That conclusion, though, is far from the truth.
In essence, Farquharson’s explanation, backed up by several other engineers puts the collapse down to a phenomenon known as “flutter.” This basically means that while the high wind caused the bridge to sway, the span’s construction meant that its reaction to the wind set up a vibration of its own. This interaction created a feedback loop of rippling, growing exponentially worse with each circuit. And it’s this effect that caused the catastrophic failure of the bridge. So how do we not know that? The answer, it seems, is in the video.
The two cameramen responsible for the footage of the bridge collapse shot the action at different frame rates. One shot at the standard 24 frames per second [fps] while the other was 16 fps. As a result, when the film was transferred to video or DVD, footage was stretched so that it would all run at the same speed. The result of this process is that the treated film appears sped up, leading many to a false conclusion based on the rate of rise and fall on the roadway. Thankfully, though, some engineers listened.
In fact, the work done after the Tacoma collapse led to a new field of research — bridge flutter. Its findings and principles have since guided the construction of several huge suspension spans, including Japan’s Akashi Kaikyo crossing. As for the remains of Galloping Gertie, they’ve been given a new lease of life.
While some of the twisted steel from the bridge is now on display in the local harbor museum, much of it remains on the ocean floor. And there, it has been transformed into an artificial reef, a magnet for marine life and divers alike. There’s even a rumor that the world’s biggest octopus lives there. Even 80 years after its collapse, the bridge still serves the local community, just in a very different way.