Question

How are bridges built?

Answer 1

The bridge is not fixed at both ends. at one end, there are wheels. Very small but still present. The reason is because metal expands when in warmer temperatures and subcontracts when in cooler temperatures. so for the material to last longer, wheels will reduce the stress on the parts during the change of temperatures.

Answer 2

They are often built from the fix end to the mobile end. from bottom to top.
Depending on the length of the bridge the build maybe divided into sections. Most often both ends would be built at the same time and the wheels would be incorporated on one end.

Answer 3

If it is for a general explanation such as naming steps:
1. Location, list of restrictions
2. create a few ideas + analyzing them (materials, lengths)
3. create a model and run it through tests
4. Build

Answer 4

Well well well - You learn something new everyday!

Answer 5

this is a odd question. i mean why would you want to know this? is it for school or something? o.O

Answer 6

Pretty interesting. I know bridges have been around for a long long time.