A History Of The Tacoma Narrows Bridge Collapse

The 1940 Tacoma Narrows Bridge

Bridges are a physical, concrete representation of our desire as human beings to connect with one another across geographic and cultural lines. The Tacoma Narrows Bridge is a bridge that holds so much history for the people of Tacoma. The bridge, at the time of construction, was the third longest suspension bridge in the world, coming after the Golden Gate Bridge and the George Washington Bridge. 

Many physicists and structural engineers have wondered and theorized about what could have caused the collapse of this bridge unexpectedly barely four months after it was opened up for traffic. Eight decades later, the question of why the bridge collapsed has not been answered definitely, and the story of the bridge continues to serve as a cautionary tale for engineers and scientists all over the world. 

The Tacoma Narrows Bridge was first constructed in 1940 in the State of Washington.

The bridge was a suspension bridge spanning the Tacoma Narrows Strait of Puget Sound between Tacoma and the Kitsap Peninsula. The dramatic collapse of the bridge in a 40mph wind was a defining moment in the history of Tacoma and in construction science. 

Proposals for the construction of the bridge first came about in 1889 with the Trestle Proposal. However, concerted efforts on the construction of the bridge started sometime in the 1920s. After an increase in public interest in the possibilities that the bridge could bring about to people on both ends of the proposed bridge, the calls for designs and sourcing for funds for the project intensified. 

Notable bridge engineers, including Joseph B. Strauss and David B Steinman were consulted on the project. David Steinmann, whose preliminary proposal was initially accepted in 1921, had his agreement with the State of Washington canceled purportedly because he was not doing enough to secure funding for the project by 1931. 

As part of the build-up towards the execution of the bridge project, the Washington State Legislature established the Washington State Toll Authority and appropriated some funds to the committee to study the request by Tacoma and Pierce County over the Narrows. Financing was always an issue with the project; even the proposed toll fees were shown insufficient to cover the cost of constructing the bridge. However, that did not deter those who were pushing for the project. By 1938, Washington State engineer, Clark Eldridge produced a preliminary design, but it was petitioned by Lean Moisseiff, who proposed a slimmer, more elegant, and cheaper design. Of course, Moisseiff won the petition with the cheaper design, and construction of the bridge eventually commenced in September 1938, taking about nineteen months. 

Moisseiff’s design was made to suit light traffic volumes, but this proved to be the bridge’s undoing. From the time the deck was built, it began to move vertically in windy conditions in spite of several damping measures earning it the nickname of Galloping Gertie.

Unfortunately, on Nov. 7, 1940, the bridge came to a rather premature end.

Leonard Coatsworth,  a news editor for the Tacoma News Tribune, was the last person to drive the bridge. Coatsworth was injured while trying to escape the bridge as the bridge started to collapse around him. Tubby, his Cocker Spaniel, who was in the car from which Leonard escaped, could not be saved. Tubby was the only fatality from the bridge collapse. Coatsworth was compensated for the loss of his car and the possessions in it. 

Also, funds recovered from the insurance policies on the bridge to some extent, provided a hedge against the losses that would have been incurred from the collapse. The only unrecovered insurance policy was due to an insurance fraud committed by an official who did not pay the premiums as required. 

The collapse of the bridge boosted research into aerodynamics and aeronautics which has influenced the designs of subsequent long-span bridges. 

The Replacement Bridge And The Span (1950 And 2007)  

Following the bridge's collapse, portions of the bridge that were still intact, particularly the cables and towers, were dismantled and sold as scrap metal. Since steel was a scarce commodity while the second world war was ongoing, it seemed like a good way to make some revenue for the government. 

This, however, turned out to be a bad move as the money that was used to recover the materials was more than the money made from the sales of the materials. Shortage of materials and labor as a result of the war caused the project to be put on hold for about ten years. A review of the situation showed that a repair of the bridge would be impossible and what was needed was a full reconstruction. 

Eventually, the 1950 replacement bridge was constructed. The 1950 Tacoma bridge is a suspension bridge that carries the Westbound lanes of Washington State Route 16 across the Tacoma Narrows Strait between Tacoma and the Kitsap Peninsula. The bridge was constructed from the 1940 bridge’s original tower pedestals and cable anchorages. 

The replacement bridge was longer than the original bridge and had more traffic lanes and shoulders on both sides. The bridge opened to the public on October 14, 1950. It is the older of the two Tacoma Narrows Bridges, and it carried traffic in both directions of traffic until 2001, when the second span of the bridge was constructed. 

The bridge was designed with a wider deck and taller and wider towers and addressed the wind issues that led to the collapse of the original bridge. The replacement bridge carried traffic in both directions of traffic for over forty years. Development and population growth on the Kitsap Peninsula caused an increase in vehicular traffic on the bridge, causing it to exceed its design capacity. 

In 2002, following a series of proposals, protests, and even court battles, the second span of the Tacoma Narrows replacement bridge was constructed. The second span opened in July 2007 to carry eastbound traffic, and the 1950 bridge was reconfigured to carry westbound traffic. The Tacoma bridges continue to carry the traffic on the Narrows, retaining their status as a part of Tacoma’s history.