A cable-stayed bridge is a bridge design which uses large steel cables suspended from high towers or pylons to support the bridge decking. The cable-stayed bridge design is typically used on bridges that span great distances. Some of the longest bridges in the world are built using the cable-stayed bridge design.
One of the greatest difficulties in building a long bridge is the wind. The constant battle between the bridge and the wind can cause the bridge to sway drastically. In an effort to eliminate the effects of the wind on the cable-stayed bridge design, the bridge's roadway is made up of open grid iron panels. These open panels act much like screen doors in the bridge's decking and allow wind to pass right through without placing any interference on the bridge. The result is a cable-stayed bridge that does not sway in the wind.
The use of open grid panels works so well that most cable-stayed bridge design are able to remain open and safe for use in all but the most severe windy situations. In the event of an unusually strong wind or storm, the bridges will typically close to traffic. Upon the reduction of the wind speed or the dissolution of the storm, the bridge will re-open. This action has been adopted due to vehicles being blown off of the huge bridge's roadway.
The large cables traveling the length of a cable-stayed bridge are not single cables. These large cables are actually composed of thousands of small cables wrapped around each other to form a single large cable. The multi-weaved cable is actually many times stronger than a single strand cable of the same dimensions. The large cables hold up all of the smaller cables which are attached to the decking of the bridge. The cables all work together in order to create a strong and safe bridge which can support heavy traffic volumes for a very long time.
Most of the largest cable-stayed bridges in the world are toll bridges. This is due in part to the tremendous cost in building the large structures as well as the convenience in having a bridge which connects two points of land otherwise unconnected by any other means. Prior to the completion of many cable-stayed bridge projects, the only way for a person to travel across the path of the bridge was by boat. This made the route nearly unusable for every day travel.
