1. Or How to get across a big gaping hole. Safely. Sometimes…
Bridges!
Or How to get across a big gaping hole.
Safely.
Sometimes…

2. Why are bridges different?
What is the point of having different styles?

3. Want to get from here to here

4. Europe’s oldest covered bridge
Lucern Switzerland – 1333! That is pretty old…

5. Some idiot set it on fire in 1993 while smoking

6. Rebuilt and the wooden timberframing is amazing!

7. Different areas need different bridges
Relatively short spans you can have an Arch Bridge
This is in Ironbridge villiage England

8. It was the world’s first cast iron bridge - 1779

9. Beam bridges
Horizontal beams supported at each end by piers. The first ones were pretty simple.

10. Each end is supported and the force applied is pressing down on those points

11. Cantilever Bridge
Is built using cantilevers, beams that project horizontally into space, supported on only one end

12. They figured out this out in the 19th Century

13. Forces

14. Suspension Bridge
Suspended from cables. The cables hang from towers that are attached to caissons.

15. Forces

16. Tacoma Narrows Suspension Bridge
Opened in 1940

17. Collapsed 4 months later
Due to it being very very narrow and wind vibration

18. Cablestay Bridge
Is a bridge that consists of one or more columns (normally referred to as towers or pylons), with cables supporting the bridge deck

19. It looks a lot like a Suspension Bridge but the key difference is the cables form a “fan shape” rather than a curve. Is a hybrid of a Suspension and Cantilevered Bridge

20. Forces

21. Truss Bridge
One of the oldest and easy to produce for cost, time and effort. Great for short distances

22. Really popular 1870’s – 1930’s

23. Forces and construction