Ever heard of the Car Strangled Banner? It is a common joke from the song Americans should all know very well, the Star Spangled Banner. It is the national anthem from a poem by Francis Scott Key. And the Car Strangled Banner was created because of the traffic on the Francis Scott Key Bridge. And yes, the bridge across the Potomac River was very well named after him. The bridge is a Span Steel Truss Bridge, and the bridge itself is 8,636 feet long; about 1.6 miles. Its main span consists of a continuous steel truss with 185 feet of vertical navigational clearance. And then the bridge ends with a span length of 1,200 feet. Also, it is the 2nd longest continuous truss in the United States; so far.

The Francis Scott Key Bridge was designed by Nathan C. Wyeth. He created a design made of steel truss cantilever arch main spans and plate girder approach spans. And it was built by the United States Army Corps of Engineers between 1917 and 1923. It is built across the Potomac River between the Rosslyn section of Arlington Country, Virginia, and the Georgetown section of Washington, D.C. And the bridge was finally opened to traffic on March 23, 1977.

Francis Scott Key Bridge was built to replace the Aqueduct Bridge, which was originally built to carry the Chesapeake and Ohio Canal across the river; to connect with the Alexandria Canal. But it was converted into a roadway after the Alexandria Canal was abandoned. One major breakthrough on this bridge was listed in the Engineering News Record magazine. “Heavy-lift floating and traveling derricks team to erect truss bridge” was an article on January 15, 1976; which said that the structure was the longest continuous truss bridge in the country. Until Astoria-Megler Bridge was built and removed on December 24, 1993.

The society in which the bridge was created was that everyone passes through the river. It was first built to support the Alexandra Canal. But because the Alexandria Canal didn’t work as well and was eventually abandoned, people go pass the Francis Scott Key Bridge even more often. Soon it became a bridge with traffic jam so people eventually named it the Car Strangled Banner.

Composed of numerous scalene and isosceles triangles together to form both sides of the bridge, Francis Scott Key Bridge is supported by parallel wires in the middle of the bridge. The wires are used to connect the bridge and the road together. The top of the bridge forms a arch and overlaps the road. Aside from the scalene and isosceles triangles, parallel lines of metal were also formed on all sides of the bridge. Then, they are composed of smaller triangles in the parallel metal.

At the bottom of the bridge, each side is concluded with two points of the bridge, which helps the bridge stand. As the bridge narrows, triangles began to decrease in size as well. All the triangles are acute triangles and none of them are perpendicular or have a transversal line. Between the points on each side, even smaller triangles are connected from the point to the middle of each point. Supposedly, it helps support the bridge better, and it does.

Inside the bridge, tiny triangles are formed, and each one is congruent to the other. The road form a huge rectangle from one end to the other, and two parallels are formed. Also, many perpendicular lines are formed created smaller rectangles to form a giant one on the road. This concludes that the country’s second longest truss bridge is support by numerous shapes and sizes to support such a huge weight. Which created the bridge, we now call, the Francis Scott Key Bridge.

For truss bridges, they include forces such as compression, tension, torsion, and shear. Compression “is the act of being compressed”. Being pulled down by the earth’s gravitational pull and its own weight, the bridge would collapse without a good design. For toothpick bridges, the gravitational pull doesn’t show it as much, so a test is to put items such as books, on the middle of the bridge to test its strength. Tension “is the act of stretching or straining”. For some bridges, such as an arch bridge, they are being bended and stretched from one end to another. If the bridge isn’t bent properly with the same amount on each side or if it was bent too less or too much, then the bridge would collapse as well. Torsion is “the act of twisting”; or in mathematics, “the degree of departure of a curve from a plane”. It twists the bridge like how tension does and creates two equal and opposite torques. Without exact measurement, the bridge would not be known to be safe. Shear is “to be removed by or as if cutting or clipping with a sharp instrument”. Truss bridges create triangles with different shapes and types of triangles. Workers would have to cut different sizes of hard structures in order to create the bridge. For a toothpick bridge, testers would cut different sizes of toothpicks. And each would need to make sure both sides are even.

The most important thing about the history of the bridge is why and how it’s made. Without knowing why it was made, why would anyone bother to make something that’ll just waste money and take up space in the society? And without knowing how it’s made and its designs and structure, it might be crushed or washed away on a stormy night if it’s not strong enough. If no one knows the design it was build in, maybe it happen to be stronger than other bridge designs. Then people would miss out on a good architecture design to help better the future. Difficulties on testing the bridge strength is that there’s a possibility that it’ll collapse and the bridge would have to be remade again.