Facts About Tacoma Narrows Bridge: A Tale of Failure And Success

Regarded as the quintessential example of the suspension bridge model, the Tacoma Narrows Bridge is located across Puget Sound's narrows and connects mainland Washington state with the Olympic Peninsula.

The bridge is remembered as a landmark failure in the history of bridge engineering in the world because of its defective structural integrity. The drive to create a narrow, slender, and eye-catching structure was chosen as the identity of the bridge.

However, the components used in the structure were anything but safe. Building the bridge was seen as a massive expense, and funds were taken from various sources by the Tacoma Chamber of Commerce.

In the end, these financial problems became the main issue, as cost-cutting was the leading cause of the collapse of the bridge in 1940, just four months after it opened.

Today, the remains of the original bridge are exactly where they fell, and the wreckage has resulted in the formation of an artificial reef that is protected by the National Register of Historic Places.

History And Location Of Tacoma Narrows Bridge

The earliest Tacoma Narrows Bridge allowed traffic in 1940. The suspension bridge model was designed and was situated in Washington.

The bridge was built over the famous Tacoma Strait of Puget Sound (a more petite water body connected to a larger sea or ocean) to connect the Kitsap Peninsula and Tacoma.

At the time of its opening, the Tacoma Narrows Bridge ranked third among the most extended suspension bridges in terms of main span length. The only bridges larger than the Tacoma Narrows Bridge were the George Washington and the Golden Gate bridges.

The construction of the Tacoma bridge was launched in September of 1938. After the deck of the bridge was finished, the wind caused the bridge to move perpendicularly. Due to this movement, the bridge workers labeled it as 'Galloping Gertie.' This movement was even present when the bridge was in public use.

There were various attempts to stop the vibration or movement of the bridge, including tactics such as adding cable stays that connected the main cables of the bridge to the wires to the bridge deck. Hydraulic buffers were placed between the floor system of the deck and the towers.

However, it was not useful as it caused damage to the bridge.

When the bridge collapsed in 1940, it could not be built back or repaired because of the events of the Second World War, which left the country with little steel to use in the reinforcing of the bridge.

The cables and towers of the collapsed bridge lay where they were, and the rest of the bridge was taken apart and ended as waste metal. The updated Tacoma Narrows Bridge was constructed in the same place and made use of the cable anchorages and tower pedestals of the first bridge.

An artificial reef was formed from the fallen bridge parts.

The failure of the bridge had a perpetual effect on engineering and science, with many physics books using the collapse as an instance of resonance. The collapse also saw an increase in research in aerodynamics and aeroelastics in the field of bridge creation. The event has affected all the architectural ideas of the world's long bridges built after 1940.

The Tacoma Narrows Bridge eventually began with the demand for a connection spanning the Kitsap Peninsula and Tacoma in the last years of the 1800s. In 1923, the Tacoma Chamber of Commerce (now Tacoma-Pierce County Chamber) started laboring towards generating enough revenue to create a bridge.

Many renowned engineers, such as David B. Steinman and Joseph B. Strauss (Golden Gate Bridge), were consulted about the bridge.

The plan was created by Steinman in 1929. However, by 1931, it was decided that Steinman's plan would be ignored because they thought he was not paying enough attention towards raising funds for the bridge.

The Washington State Toll Bridge Authority, founded by the Washington State legislature, provided $5,000 in funds to Pierce County and Tacoma for the construction of a bridge.

Clark Eldridge, a state engineer, created the suspension bridge design, and the drafts were similar to the designs of the many existing suspension bridges of the time.

The Washington Toll Bridge Authority, managed by the U.S. Federal government, put in a request to the PWA (Public Works Administration) for around $11 million in funds. The early plans showed a draft of a set consisting of 25 ft (7.6 m) deep lateral girders that sat under the roadway.

This would help in making the roadway stiffer to avoid any chances of the central deck moving.

Leon Moisseiff, a renowned bridge engineer, had different ideas for the construction of the bridge. Moisseiff is known for his work as a consultant engineer and developer of the Golden Gate Bridge in San Francisco.

Moisseiff communicated with the government corporation RFC (Reconstruction Finance Corporation) and the PWA about building the bridge for a lower amount than expected. His idea of using shallower girders would result in the creation of a slimmer bridge that would lower the expected construction costs.

The design was chosen, stating that the other designs were too expensive.

The PWS approved an estimated $6 million for the creation of the Tacoma Narrows Bridge. The total cost of the bridge was estimated to come in under $8 million, with the inclusion of an additional $1.6 million from the tolls.

The bridge construction was officially started in September 1938 and took a mere $6.4 million and a period of one year and seven months. The bridge had a primary length of 2800 ft (853.4 m) and became the world's third lengthiest suspension bridge.

The bridge was built with only two lanes because it was supposed to have light traffic. The lanes were 39 ft (11.8 m) wide and were narrow compared to the length of the bridge. With only 8 ft (2.4 m) deep girders to give it depth, the roadway was dangerously shallow.

The Collapse Of Galloping Gertie

The destruction of the Galloping Gertie occurred on November 7, 1940, at around 11:00 a.m. (Pacific time). Aeroelastic flutter was believed to be the main cause of the collapse.

It has been stated that the breakdown of the bridge had much to do with the narrow and shallow girders. The roadways of the bridge lacked rigidity due to the use of such small girders, which caused them to move easily in the winds. Even a small wind could cause movements of several feet in the bridge's center span.

Another stated reason for the destruction of the bridge was the solid sides of the bridge, which prohibited wind from making its way through the deck, that is, the pathways serving as the roadway of the bridge.

This fault in the design caused the bridge to sway on each occasion a wind passed by, and ultimately, this was what caused the bridge to collapse.

After the collapse, investigations into the cause were held, and it was announced that the section formed by the roadway and the hardening girder plates were unable to absorb the disturbance caused by wind gusts. This mixture caused the bridge to become vulnerable to the forces of aerodynamics, which was sparsely known.

The event promoted aerodynamics research, which eventually led to important advances in modern construction techniques.

Thankfully, no lives were lost in the fall of the structure. However, Tubby, a cocker spaniel, was the only known victim of the Tacoma Narrows Bridge disaster.

Replacement Bridge 1950

After the fall of the bridge in 1940, efforts to save the bridge continued until May 1943. It was concluded that the bridge was beyond repair and that the entire bridge would have to be taken down and replaced with a new bridge.

However, the creation of a new bridge came after 10 years. The delay was caused by the shortage of labor and materials generated by World War II, which even saw the melting down of the old bridge cables for trade. The sale came at a larger loss than profit and cost the government an estimated sum of $350,000.

The replacement bridge was opened to traffic on October 14, 1950, and it was located on State Route 16 between Gig Harbor and Tacoma. The new bridge is 5,979 ft (1822.3 m) long and consists of a greater number of lanes compared to the original bridge.

The engineers developed the bridge to carry over 60,000 cars a day, but today it handles more than 90,000 vehicles daily!

Fifty years later, the new bridge's footfall was more than it could handle, which resulted in the creation of a second parallel suspension bridge to ease the eastbound traffic. The 1950 bridge was used only to carry westbound traffic. The new bridge opened in July 2007.

2007 Tacoma Narrows Bridge

A survey in 1998 queried the local population about the modification and creation of a parallel bridge, and the result of the study was an astonishing yes. The work on the bridge began with Tacoma Narrows Constructors and the Washington State Department of Transportation (WSDOT).

The collaboration saw the creation of an eastbound Tacoma Narrows Bridge, a toll plaza, a new maintenance facility, and 3.5 mi (5.6 km) of improvements.

The ceremony for the project was held on October 5, 2000, and the construction began in the days leading up to January 20, 2003. WSDOT and TNC worked to build the massive project over the next four and a half years.

The newest Tacoma Bridge was opened to the public on July 16, 2007. The previous day, WSDOT and the officials were joined by around 60,000 visitors to celebrate the completion of the bridge. This was the first time a parallel suspension bridge was built close to an already existing suspension bridge.

Other Miscellaneous Facts

The budget restriction for the construction of the Tacoma bridge was settled through the proposal of imposing tolls on the bridge. Regardless, after the survey, it was believed that the toll money would not balance the investments.

The economic and political agenda prohibited any further alteration of the design. This resulted in the use of 8 ft (2.4 m) plate girders instead of the proposed 25 ft (7.6 m) truss girders, with solidity taking a hit.

Leonard Coatsworth is known as the last person to walk on the Tacoma bridge before it collapsed. Coatsworth managed to escape, but his dog, Tubby, became the only victim of the bridge disaster.

The sunken remains of the Galloping Gertie are kept safe on the National Register of Historic Places.

It takes an estimated 10 years to repaint the bridge! The bridge workers usually start repainting only in the summer months.

The Bronx Whitestone Bridge has a similar resemblance to the 1940 Tacoma Narrows Bridge. As a result of the incident, the Whitestone Bridge was fortified on both sides in 1943. In 2003, the trusses on the side of the bridge were removed, and aerodynamic fiberglass was added to the road deck.

FAQs

How many died in the Tacoma Narrows Bridge collapse?

There were no deaths when the Tacoma bridge collapsed. The only casualty of the collapse was a cocker-spaniel dog named Tubby.

How old is the Tacoma Narrows Bridge?

The Tacoma Narrows Bridge is 72 years old.

What is the Tacoma Narrows Bridge known for?

The Tacoma Bridge is known for its infamous collapse just four months after its opening to the public.

When was the Tacoma Narrows Bridge built?

The construction of the Tacoma Bridge began in 1938.

Who funded the Tacoma Narrows Bridge?

The PWA grant and an RFC loan funded the Tacoma Bridge construction.

Why did the Tacoma Narrows Bridge fail?

Aeroelastic fluttering is believed to be the reason behind the Tacoma Bridge failure.

When did the Tacoma Narrows Bridge fall?

The Tacoma Narrows Bridge fell on November 7, 1940, just four months after its opening.

What is under the Tacoma Narrows Bridge?

Rumours suggest that a giant octopus lives under the bridge! However, these sightings are exaggerated and are simply the giant pacific octopus species found in the waters.

How was the Tacoma Narrows Bridge built?

The Tacoma Narrows Bridge was designed based on the model of the suspension bridge. The original iteration of the bridge was built with carbon steel girders anchored in blocks of concrete. The bridge paved the way for similar future structures to utilize plate girders to prop up the road.

When was the second Narrows bridge built?

Construction of the second bridge began in 1957, and it was officially opened in 1960. The remains of the first bridge were used as the basis of the second bridge.

How much did the new Tacoma Narrows Bridge cost to build?

The original Tacoma Narrows Bridge, also known as Galloping Gertie, cost approximately $6.4 million. The rates at the toll plaza initially began at 55 cents before the minimum rate was cut to 50 cents.

How did the Tacoma Narrows Bridge collapse?

The Tacoma Narrows Bridge collapsed due to the wind causing movement in the bridge. The poor structural integrity of the bridge also played an important role.