Suspension Bridges
Manuel Herrera
Mr. Batten
5th Period
27th of April
Suspension Bridges A suspension bridge is a bridge with overhead cables supporting its roadway. The first suspension bridges were made by the primitive people using vines as cables and they would mount the roadway directly on the cable. Then in the 4th century a much stronger type was introduced in India. They used plaited bamboo cables and then iron chain to suspend the road. In the 18th century engineers encountered many problems with the stability of the bridge. The bridge would always rock because of the wind or just collapse while in a storm. John Augustus Roebling is the solver to this problem. HE produced a web truss to each side of the roadway that gave a structure so rigid that it was successful into building the Niagara Gorge. The towers in a suspension bridge enable the main cables to drape down over long distances. Most of the weight is carried by the cables. These are imbedded in either solid rock or huge concrete blocks. Light, and strong, suspension bridges can span distances from 2,000 to 7,000 feet far longer than any other kind of bridge. Suspension bridges tend to be the most expensive to build. Many bridges in the past have had structural failure. One of the two major contributors to flaw is the weather and structural design. For example the Tacoma Narrows Bridge was the third longest in the world in 1940. The bridge would move from side to side in the wind, but after 4 months it was built the bridge collapsed in 42 mph wind. The bridge was able to hold up to 120 mph. The scientist blamed it on resonance. Resonance is when a body vibrates at its natural frequency it can shatter. There is a technique for suspension bridges called cable spinning. Which was a traveling wheel carries a continuous cable strand from one anchorage on one side up over the tower, down on a predetermined sag to the midpoint of the bridge, up and over the tower on the farther side to the farther anchorage,
Mr. Batten
5th Period
27th of April
Suspension Bridges A suspension bridge is a bridge with overhead cables supporting its roadway. The first suspension bridges were made by the primitive people using vines as cables and they would mount the roadway directly on the cable. Then in the 4th century a much stronger type was introduced in India. They used plaited bamboo cables and then iron chain to suspend the road. In the 18th century engineers encountered many problems with the stability of the bridge. The bridge would always rock because of the wind or just collapse while in a storm. John Augustus Roebling is the solver to this problem. HE produced a web truss to each side of the roadway that gave a structure so rigid that it was successful into building the Niagara Gorge. The towers in a suspension bridge enable the main cables to drape down over long distances. Most of the weight is carried by the cables. These are imbedded in either solid rock or huge concrete blocks. Light, and strong, suspension bridges can span distances from 2,000 to 7,000 feet far longer than any other kind of bridge. Suspension bridges tend to be the most expensive to build. Many bridges in the past have had structural failure. One of the two major contributors to flaw is the weather and structural design. For example the Tacoma Narrows Bridge was the third longest in the world in 1940. The bridge would move from side to side in the wind, but after 4 months it was built the bridge collapsed in 42 mph wind. The bridge was able to hold up to 120 mph. The scientist blamed it on resonance. Resonance is when a body vibrates at its natural frequency it can shatter. There is a technique for suspension bridges called cable spinning. Which was a traveling wheel carries a continuous cable strand from one anchorage on one side up over the tower, down on a predetermined sag to the midpoint of the bridge, up and over the tower on the farther side to the farther anchorage,