Following the collapse of the Tacoma Narrows Bridge, the replacement bridge was planned (based on lessons gained) and completed in 1950. (Fig. 4). It is a continuous truss design that includes vertical panels inside the main girders to increase its strength. The new bridge has three traffic lanes and two sidewalks. It also has a large central plaza with space for public gatherings and displays.
The original bridge had only two traffic lanes and no center median. It collapsed on April 51, 1940, after which it was determined that it was too dangerous to continue crossing the river by vehicle. The new bridge was opened to vehicles and pedestrians on November 17, 1950. It took six years and $13 million to rebuild the bridge. At the time of its completion, it was considered one of the most expensive public works projects in U.S. history.
In 2007, the American Society of Civil Engineers gave the new bridge's overall rating of "good" and its condition rating of "fair".
During the summer of 2009, a band-aid style repair was made to the bridge when temporary supports were installed in the river to hold up the eastern half of the bridge while the western half was being repaired. The temporary supports were added after tests showed that the bridge was bending under its own weight during heavy rains.
Tacoma Narrows Bridge, a suspension bridge in the United States state of Washington, broke in 1940 due to poor aerodynamic design. This caused aeroelastic flutter, which nearly destroyed the bridge. Collapse was even filmed, and all big bridges have since been constructed in wind tunnels. The film can be viewed today in historical documentary films about the Tacoma Narrows Bridge collapse.
This disaster killed 46 people and injured another 7. It is one of the worst transportation disasters in U.S. history.
The bridge was built between 1936 and 1940 by the American Bridge Company. At the time of its opening it was the longest continuous truss span in the world. The main span was 1,980 feet long with approach spans of 405 feet and 105 feet. The total length of the bridge was 2630 feet.
The bridge crossed the narrow part of Puget Sound between Seattle and Tacoma. It connected both cities and provided access to the ports there. The bridge was part of the United States National Highway System, which at the time included only highways that were designated as US Highways. Today it is known as SR 903.
The cause of the bridge collapse has never been fully determined but may have been triggered by an abrupt change in wind direction. Witnesses reported seeing something dark pass over the bridge before it fell. This may have been one of the vehicles crossing it.
Bridge across the Tacoma Narrows The Tacoma Narrows Bridge is the historical name for the twin suspension bridges that crossed the Tacoma Narrows strait in 1940. Four months later, it crashed due to aeroelastic flutter. It was the first major U.S. highway bridge to be destroyed by its user.
The disaster led to improvements in the design of large bridges. It also inspired writers and artists to create stories about other doomed bridges. These include:
King's Row (Thomas King) - a street of shops and houses built on both sides of the B&O Railroad line between Baltimore and Washington, D.C., where one house had bars across the windows to prevent people from seeing the wrecked condition of the Tacoma Narrows Bridge after its collapse in April 1955.
The Doom Line (Jack Finney) - a border between Maryland and Pennsylvania where the two states' road networks meet where all the bridges are gone or will be by the time the car gets there. There's also a gas station with a haunted cashier who won't take money.
The Bellamy Road Bridge (Pat Conroy) - a fictional bridge in Prince Regent Island where Captain Vere lives with his family. Their house is at one end of the island, and the bridge is at the other.
On July 1, 1940, the first Tacoma Narrows Bridge opened to traffic. Four months later, on November 7, 1940, at 11:00 a.m. (Pacific time), its main span fell into the Tacoma Narrows due to aeroelastic flutter triggered by a 42 mph (68 km/h) wind. The bridge collapse has long-term consequences for science and engineering. Before the incident, engineers had only experienced wind loads on suspension bridges. This disaster showed that even a small amount of additional load, such as a vehicle crossing the bridge, can be fatal to a structure already in tension due to its own weight plus any other load it is carrying.
The accident resulted in the death of 49 people and injured another 73. It also destroyed much of the surrounding urban area, including 15 houses and 3 businesses.
After the incident, a federal investigation concluded that the cause of the collapse was excessive vibration caused by wind loading when combined with other factors such as heavy traffic and shallow piers. Engineers have since developed methods to prevent aeroelastic flutter on bridges and other structures using the principles revealed by the Tacoma Narrows Bridge disaster.
Additionally, the disaster led to improvements in both bridge design and construction techniques. Future bridges are now designed with more rigid connections between their components to reduce vibration and risk of failure under similar conditions.
Finally, the experience has been used by engineers to develop methods for predicting the stability of bridges under dynamic loading conditions not previously experienced.