My Science School

It was the industrial revolution which brought about the introduction of metal bridges. In the past, bridges were constructed of stone and timber, which were available in large quantities. Iron was used because it was much stronger than either wood or stone, and was, on the whole, less expensive to produce. Bridges made from timber or stone become fewer and fewer.

The first ever metal bridge was built in England in 1779. The Coalbrookdale Bridge, which spanned the River Severn, was designed by Thomas Pritchard and built by Andrew Darby. This bridge, the first to be built solely of iron, spanned almost 100 feet across the river in an almost perfect semi-circular arrangement of cast-iron pieces.

Fact File The drawbridge originated in medieval Europe as a defensive feature of castles and towns. It was operated by a counterweight and winch. In the late 19th century drawbridges began to be built specifically to aid navigation; the Tower Bridge, London, being a fine example.

 

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People have used canals to transport heavy goods for thousands of years. It is believed the first canals were built to join together existing rivers to make a transport route. Indeed, the city of Venice in Italy was built on a system of canals rather than roads; six thousand years ago the Aztec city of Tenochitlan was built with an impressive system of canals within it for transport.

However, the heyday of canal building was much more recent. The industrial revolution was responsible for the upsurge in canal building. There was a huge need during this era for cheap and easy ways to transport goods from factories to ports. Horse-drawn canal boats and steam-powered canal boats were faster than carrying cargo by horse-drawn carts along the road.

Fact File Locks are an essential feature of any canal which needs to gain or lose height. A lock has gates that can be closed to control the water level in a section of the canal. Water is let into or taken from the section, raising or lowering the vessel inside.

 

Picture Credit : Google