what were they used for?
Canals were built mainly for transporting heavy or delicate goods, that needed to be transported quickly and safely. Heavy goods that were frequently transported were coal, iron and brick. Delicate goods that needed to be transported by canals were mainly glass and china.
How canals worked
Canals were rivers made by men which were deep enough to cope with barges. Running barges along canals was an alternate method of transport, as delicate goods could be transported without breaking, and mining materials and more could be transported at a lower cost. Barges were manned by several men, with a horse walking up ahead on the side of the canal, attached to the barge by a rope. When the boat came to a tunnel, the horse would climb the hill and the men would lie on their backs and "walk" their feet along the roof and walls of the tunnel. Certain products, such as fresh dairy and animal produce that needed to get to market quickly were transported by canals - often with more than one horse pulling the barge.
Canals must have the same level of water the whole way - the canal could not travel up or down a hill, otherwise all the water would simply run off. Tunnels could always be built, but there was another solution - locks. Locks are used to lift or lower boats from one level to another. They have two sets of gates, one for going up and another for going down, and a boat chamber. Locks also have openings known as sluice gates at the top and bottom, and when these are opened, water is let into or out of the chamber to raise or lower the water level and the boat.
However, locks were not the only way to deal with changes in terrain. Another solution were aqueducts.
When the Duke of Bridgewater planned to build a canal, he hired engineer James Brindley to help build it. He designed a gravity flow system, including an aqueduct across the Irwell valley. It was named the Barton Aqueduct and was 183 meters above the River Irwell. After this great success, he used aqueducts and tunnels whenever possible to reduce the number of locks needed.
When the Duke of Bridgewater planned to build a canal, he hired engineer James Brindley to help build it. He designed a gravity flow system, including an aqueduct across the Irwell valley. It was named the Barton Aqueduct and was 183 meters above the River Irwell. After this great success, he used aqueducts and tunnels whenever possible to reduce the number of locks needed.
Canals worked easily for transport as only one or two horses were required to pull the barge, locks were a simple invention to bring the barge higher or lower and aqueducts were a very useful invention to take canals across rivers and valleys.