Construction of bridges > Part 1 | Part 2
Here is some background information about the designs of bridges. There are three main types:
The beam bridge
The beam bridge is the simplest design of bridge. This type of bridge is constructed from large beams which span the river or road. If they are long then they need to have an intermediate pier in the middle to strengthen them. Sometimes parts of the bridge can open by swinging up or across; this is necessary on some river bridges to allow tall ships to pass through. An example of a modern beam bridge which opens is Pero's Bridge, on Bristol Harbourside. An example of an ancient beam bridge is Tarr Steps on Exmoor, which is a clapper bridge made of stone slabs.
