The Legend of Galloping Gertie: Beautiful Bridge Doomed to Failure
I saw the Narrows Bridge die today, and only by the grace of God escaped dying with it. I have been near death many times in my life, but not even in my worst experiences in France did I feel the helpless horror that gripped me when I was trapped on the bridge this morning.— Leonard Coatsworth (copy editor at the Tacoma News Tribune, daily newspaper)
Galloping Into History
The year was 1940. The Axis powers were making favorable gains on fronts in Europe, Africa, and Asia. In fact, between Germany and Italy, most of Western Europe was controlled by them. Only England remained.
Here in America the pain of the Great Depression was finally beginning to ease. Americans were earning more, buying more, and thus refueling the economy. Franklin Delano Roosevelt was elected for a third term as President of the United States, and his New Deal domestic recovery programs were being used to help bolster and stabilize the U.S. economy.
One of those New Deal programs was the construction of a mile-long suspension bridge linking the City of Tacoma to the Kitsap Peninsula. When completed it would be (in the year 1940) the third-longest suspension bridge in the world.
On the 1st day of July, the Tacoma Narrows Bridge was opened. A 17-year campaign for the construction of the bridge had finally been rewarded with the grand opening and a festival that drew 7,000 spectators.
However, before it was even opened to the public, the Tacoma Narrows was nicknamed “Galloping Gertie” by the engineers who were involved in her construction.
The Most Beautiful Bridge in the World
A “tried-and-true” conventional suspension bridge design, with a price tag of $11 million dollars, was proposed by a Washington State engineer. Preliminary construction plans called for a set of 25-foot-deep (7.6 m) trusses to sit beneath and stiffen the roadway.
However, an East coast consulting engineer named Leon Moisseiff suggested and received approval for a more elegant design; its shallower supports would result in a more sleek profile and a much reduced cost—only $8 million of which $1.6 million would be recovered with the collection of bridge tolls.
Mr. Moisseiff was not a novice in the design of suspension bridges. He was the architect and designer of both the Golden Gate and George Washington Bridges. But his plan for the span across the Narrows was doomed from the start.
The Legacy of Bridge Engineer Leon Moisseiff
Thousands of commuters stream across his handiwork today.
San Francisco’s Golden Gate Bridge, New York’s George Washington and Manhattan bridges, and Philadelphia’s Ben Franklin Bridge, among a host of others, bear the stamp of Moisseiff.
And every year civil engineers bestow on their finest the “Moisseiff Award.”
With a Bad Reputation
From the first week of May 1940, as the floor of the bridge was finished, engineers and construction workers noticed the deck's sinuous vertical wave movements, or "bounce." They knew something was wrong. Months before, in the summer of 1939, they had heard rumors of similar small waves in another suspension span, the Bronx-Whitestone Bridge, which opened in April 1939. The Bronx-Whitestone Bridge, like the Tacoma Narrows Bridge, had been designed by consultant Leon Moisseiff of New York. Moisseiff admitted that two of his latest bridges (the Deer Island Bridge and the Bronx-Whitestone Bridge) were experiencing similar movements, though on a much smaller scale.
From construction until after it failed, people noticed how much it swayed in the wind. Former Tacoma Mayor, Bill Baarsma said “My grandparents would tell me that when they crossed the bridge, it undulated so much the car in front of you would disappear.”
The Toll Bridge Authority contacted Professor F. Bert Farquharson at the University of Washington. With the help of some of his students, Farquharson conducted wind tunnel studies using a 1:200 scale model.
"We knew from the night of the bridge opening that something was wrong. On that night the bridge began to gallop."
Farquharson carefully monitored the bridge's movements, noting wind speed and the size and shape of Gertie’s movements. During his studies he noted a “twisting motion” under certain conditions. "We watched it," the professor later told reporters, "and we said that if that sort of motion ever occurred on the real bridge, it would be the end of the bridge."
A Plan to Save the Bridge
On November 7, just five days after Professor Farquharson completed his study of the bridge, State authorities began drafting a contract for the installation of wind deflectors. They knew that they needed to act quickly. Bridge Engineer Clark Eldridge quickly prepared sketches and obtained price quotes for steel and other materials. The plan was that in ten days the bridge would be protected from southerly winds, in 14 days the center span would be protected, and in 45 days the entire bridge would be retrofitted with wind deflectors. Eldridge and Farquharson felt optimistic.
But they were too late.
The undulations were more rapid than I had ever seen before. I drove on the bridge and started across. In the car with me was my daughter’s cocker spaniel, Tubby. Not until I reached the first towers did I realize something was terribly wrong.”— Leonard Coatsworth
A Historic Catastrophe
Eldridge and Farquharson were not the only ones at work on the 7th of November. In the early morning hours Mother Nature began a relentless assault of the bridge. Winds from the west blasted Gertie broadside; the bridge began to gallop. At 7:30 a.m. winds measured 38 miles per hour.
Around 8:30 a.m.Eldridge drove across the bridge and noted the usual up-and-down movements. At 9:30 Professor Farquharson also arrived at the bridge. He began to take photographs of Gertie’s movements for his continued studies. By this time winds were now clocked at 42 miles per hour on the east end; at the west end fishermen reported gusts substantially higher.
At 10:03 a.m. the roadway began a “lateral twisting motion,” tilting up to 28 feet on one side and then the other. At this point highway officials and the State Patrol quickly closed the bridge to vehicle traffic. Only Professor Farquharson and members of the press were allowed onto the span.
Leonard Coatsworth, copy editor for the Tacoma’s daily newspaper was in his car when the road tilted violently. He stopped his car, crawled through an open window, and began the perilous crawl to safety.
The bridge began to sway violently from side to side. Heretofore, the noticeable motion has been up and down and undulating. I jammed on the brakes and got out of the car, only to be thrown onto my face against the curb. I tried to stand and was thrown again. Around me I could hear the concrete cracking.— Leonard Coatworth
At 10:30 a large chunk of concrete fell from the west side of the center span. Farquharson continued to take photographs and was joined by the Tacoma News Tribune photographer Howard Clifford and Barney Elliott, from the Camera Shop, who began to record motion picture footage.
Farquharson loved animals and decided to try to save Tubby, Coatsworth’s cocker spaniel. The frightened dog, stranded in the car, bit him. The professor then retreated, stumbling back to the East Tower. The time was 10:55 a.m.
Five minutes later the extreme twisting motions began to rip the span apart. Large chunks of concrete broke off like popcorn and plunged into the icy waters below. Steel girders twisted like rubber bands, bolts sheared off. Witnesses say that the light poles broke off as though they were match sticks.
Those who stood on the shore and watched the bridge in its death agony still have no conception of the violence of the movement felt by one out beyond the towers. Safely back at the toll plaza, I saw the bridge in its final collapse and saw my car plunge into the Narrows.— Leonard Coatsworth
In her death throes the bridge writhed and shrieked. At 11:02 a 600-foot section of roadway crashed into the icy waters below, sending up a massive geyser of foam and spray. Sparks from the shorting electric wires flew into the air. More deck sections followed; in moments Coatworth’s car and Tubby plunged into the waters below.
By 11:10 a.m. the first Tacoma Narrows Bridge was no more. Icy November waters churned and swirled over what had once been “the most beautiful bridge in the world.”
The heart of Gertie was resting at the bottom of Puget Sound. Silent and at last at peace.
About the Motion Picture Recording
The collapse of the bridge was recorded on film by Barney Elliott, owner of a local camera shop. Elliott’s original films were shot on 16 mm Kodachrome film, but most copies are in black and white because newsreels of the day copied the film onto 35 mm black-and-white. Elliott’s original footage was selected for preservation in the United States Film Registry of the Library of Congress. It is still shown today to engineering, architecture, and physics students as a “cautionary tale.”
Timeline of the First Tacoma Narrows Bridge, aka "Galloping Gertie"
- 1923 - A campaign to bridge the Tacoma Narrows (an extension of Puget Sound) is launched by the Federal Improvement Clubs of Tacoma
- 1928 - David Steinman, a New York Engineer, is hired by the Tacoma Chamber of Commerce to develop a preliminary design. After two years of work Steinman proposes a mile-long suspension bridge with an estimated price tag of $9 million. The idea is abandoned.
- 1932 - Another engineer, hired by the Tacoma Chamber of Commerce, proposes a $3 million bridge. Financing is denied after the project plans are reviewed by experts, including bridge designer Leonard Moisseiff.
- 1936 - The U.S. War Department approves an application from Pierce County to build a $4 million bridge. Half of the funds will come from a New Deal program.
- 1938 - State Engineer Clark Eldridge presents a "tried and true" conventional bridge design that will cost $11 million--much more than the funds available through the New Deal. As a result, a New York engineer, Leonard Moisseiff is hired. Ten days after signing a contract, Moisseiff recommends design changes that will substantially cut the cost of the bridge.
- November 23, 1938 - Groundbreaking for the Narrows Bridge.
- July 1, 1940 - The Tacoma Narrows Bridge opens with a festival that draws 7,000 attendees.
- August 1940 - University of Washington professor F. Burt Farquharson starts recording Galloping Gertie's "potentially dangerous" movements. Wind tunnel models are used to test ways to stabilize the bridge.
- November 2, 1940 - Farquharson presents two plans to stabilize the bridge: one is to cover the solid plate girders with curved steel to deflect the winds, or cut holes in the girders to allow wind to pass through. State officials select the first plan and draft a contract for the $80,000 installation.
- November 7, 1940 - On a morning of steady 40 mile-per-hour winds Galloping Gertie collapses into Puget Sound.
© 2015 Linda Lum