Bridges

An image of a bridge

The bridges made by nature were made even before the human appearance. When the roots of the trees become ineffective then they fall on the stream they automatically become a bridge. When the vines make a bridge by falling in water branch by branch then they are called (suspension bridge). Like this when the stones fall in the stream, the rock surface is higher than the surface of water, that pull is called (arch pull). But when the branches fallen on one side of the stream connects with the branches on the other side of the stream then that is called (broken bridge).

Bridges are made to cross the canals, streams and the mountainous and difficult terrains. There are at least three important parts of a bridge. In which there are two supports or pillars on the edges and the part which connects those two supports is called arch. However, there can be more than one arch in a bridge. In the beginning, bridges were made across the streams by big trees. Later with the development that formed into a stone arch. In the later period instead of small bridges there were big and long bridges. Then wood and stones were replaced by steel. By the mid of the nineteenth century wrought replaced wood bridges. The process of converting molded iron into steel made a revolution. Professionals made new designs of the structure of a bridge. And that’s how new and advanced bridges came into being.

There are five different types of bridges, in which there is a bridge a swing bridge in the middle, broken bridges, suspension bridge, vertical lift bridge, total or fixed bridge and includes arch bridge.

There are two types explained:

Swinging bridge from the middle:

These types of bridges are made to give way to the big ships that pass through the sea and it rotated like a base.

Total or fixed bridge:

This bridge is free from one side and from the second side, there are heavy steel tools are installed, which pulls it upwards.