2.  Truss  Beam  Suspension

3. Red River train bridge 33.552266 ⁰ N, -94.044935 ⁰ W

4.  Strength: Truss bridges are very sturdy and can last for long periods of time. They can have many cracks in the structure before beginning to break.  Weakness: A truss bridge is best for short distances instead of long roadways. If too long, the bridge could give in and start to crack which would eventually cause the bridge to break.  Advantage: Components are easily added to the bridge and there are no waterway constrictions.  Usage: Truss bridges are used to increase the span length and/or to reduce the amount of material used for the construction of the bridge.  Inventor: The Iron Truss Bridge was invented by Squire Whipple and received patent on April 24, 1841.

5. Texarkana Stateline Bridge 33.470207 ⁰ N, -94.043060 ⁰ W

6.  Strength: They are very stiff and are able to resist twisting and bending under heavy loads.  Weakness: Beam bridges have a limited span and if over water, heavy boat traffic cannot pass underneath.  Advantage: Beam bridges are easy to build and inexpensive compared to other bridge types.  Usage: Used for mainly short distances.  Inventor: Herodotus documented the first beam bridge. It consisted of timbers supported by stone columns.

7. Golden Gate Bridge 37.8188° N, 122.4784° W

8.  Strength: Well constructed and able to withstand lots of shaking. They can last through earthquakes and are more flexible than other bridges.  Weakness: If a bridge is built in water then it requires workers to dive underwater to secure bases.  Advantage: They are very good for waterways. Large ships can easily pass under the bridge.  Usage: They are used to span over a great distance that usually involves a large body of water.  Inventor: Thangtong Gyalpo created the first Suspension Bridge.

9.  Thanks for watching!!