How to Build a Suspension Bridge. Suspension bridges are able to span great distances of 4,000 feet up to 6,527 feet. But building a suspension bridge is a time-consuming and often dangerous process. The main cables must be anchored correctly, stresses must be monitored and decking must be properly attached. Here are the basics for building a suspension bridge.
Set the anchors for the cables. The cables, which bear most of the weight of the decking, must be anchored in solid bedrock or enormous concrete anchors on each side of the bridge. These cables are then spread into the rock or concrete to more evenly distribute the weight.
Pour the concrete footing for the pillars. You must place the water-tight forms in the waterway, pump the water out, excavate to a solid base and pour your footing.
Build the suspension bridge's towers on the concrete footings. These enable the cable to be stretched over a long span. The higher the towers, the longer the cable can span.
Stretch the cable over the towers and set them into the prepared anchors. This cable is made of twisted steel cable, many steel wires bound together or individual solid steel cables, which are very strong under tension forces.
Attach trusses to the main cable. The cables that hang from the main cable are called "suspenders." These are attached to the trusses that stiffen the bridge so it does not bend in the wind.
Apply bridge decking to trusses. This may be made out of any number of materials, including aluminum or new composite material that resists corrosion.
Pave and enjoy your new suspension bridge.
Building a bridge is a long, complicated and dangerous process. A building company experienced in the bridge building process should do this type of work.