The+Suspension+Bridge

__** Suspension Bridge: **__ Originally the most basic type of suspension bridge was made up of rope and wood, now modern suspension bridges use a box section roadway supported by high tensile strength cables. In the early nineteenth century, suspension bridges used iron chains for cables. The high tensile cables used in most modern suspension bridges were introduced in the late nineteenth century. These days, the cables are made up of thousands of individual steel wires bound tightly together. Steel, which is very strong under tension, is an ideal material for cables; a single steel wire, only 0.1 inch thick, can support over half a ton without breaking. Light, and strong, suspension bridges can span distances from 2,000 to 7,000 feet far longer than any other kind of bridge. They are ideal for going over busy waterways.

Suspension bridges are considered to be the most expensive to build. A suspension bridge suspends the roadway from huge main cables, which extend from one end of the bridge to the other, these cables rest on top of high towers and have to be securely anchored into the bank at either end of the bridge.The towers enable the main cables to be draped over long distances. Most of the weight or load of the bridge is transferred by the cables to the anchorage systems; these are imbedded in either solid rock or huge concrete blocks. Inside the anchorages, the cables are spread over a large area to evenly distribute the load and to prevent the cables from breaking free. Pictures Explaining the structure of the suspension Bridge: **

You can see why this structure is the strongest it has the most work put into so that it can stand any amount of weight or distance.

**Pictures of some suspension Bridges:**