1. By Vijay Chelikani

2. Chapter 1 Suspension Bridges How they Work. The suspension bridge is held up by the cables which take the weight and send the weight to the towers, then the towers send the weight to the ground distributing the weight. Now people make suspension bridges with strength cables and box sections and the strength cables are made out of individual steel wires tightly together. What they are Made of. In the past they made suspension bridges with ropes and wood. In the 19 century made suspension bridges with iron chains.

3. Suspension Bridges Suspension Bridges in the 20 th century. Suspension bridges are the most expensive bridges to build. On November 7 th of 1940 the Tacoma Narrows Bridge shacked violently because the wind was to strong causing it to collapsed. Since that day new prototypes bridges were tested by wind funnels before being built to ensure that another bridge would not end up like the Tacoma Narrows Bridge.

4. Chapter 2 Arch Bridges How they Work The arch bridge is held up by distributing the weight using the arches in the design the arches distribute the weight by sending the force from the top to its two parts not making one piece hold all the weight. What they are made of When the arch bridges were first being made by the Romans they used stone and brick. Now arch bridges are made of concrete and steel. The oldest arch bridge is the Mycenaean Arkadiko bridge.

5. Arch Bridges Fun Facts Here are some of the oldest arch bridges in different countries like the Godavari Arch bridge which is the oldest arch bridge in India The Richmond bridge is the oldest arch bridge in Australia. The Devils bridge is the oldest arch bridge in France. The Ponte Vecchio is the oldest arch bridge in Italy. The Chaotianmen Bridge in China is the longest arch bridge in the world.

6. Chapter 3 Cantilever Bridge How they Work. In a cantilever bridge there are the outer beams, the cantilevers, and the central beam. The outer beams are attached firmly to shore, while the cantilevers are then attached to these outer beams. The cantilevers projecting out from the outer beams, or supporting piers on the opposite shores, are then joined by a central beam. What they are Made of. They are now made of iron, structural steel and pretressed reinforced concrete

7. The End