Canals

Canals are artificial waterways made to move water and watercraft. They often extend or connect natural water resources like rivers, lakes, seas, and oceans and can be found in many different parts of the world.

Canals
image by Marco Secchi

Canals are an ancient technology that plays a vital role in today’s high-tech world. For example, the Panama canal handles about 5% of world trade, and twice that much travels through the Suez canal. So, there’s a very good chance that you own at least one object that was transported via a canal.

Humans have been making canals for thousands of years, initially for irrigation and then to improve natural river transportation. Early examples can be found in ancient Egypt, Mesopotamia, China, and the Americas. Early attempts to build a Suez canal to connect the Red Sea with the Nile delta date back to the second millennium BCE.

Unlike rivers, most canals do not have currents to carry watercraft along, so a variety of power sources have been used to move people and cargo, from sails and oars to horses and piston engines (steam and internal combustion). Relatively little power is needed to maintain the motion of a heavily laden watercraft if it is traveling on a level and sheltered body of water. To extend canals across valleys and over hills, the technology known as a canal lock was developed.

In the early stages of the Industrial Revolution in Europe and America, canals were the preferred mode of transportation for heavy goods like coal and iron ore, but were also a safer bet to deliver delicate cargo like pottery (rather than horse-drawn wagons on rough roads). Canal building took off in Britain In late eighteenth century and over 4,500 miles of canals were created by 1850. Even after rail and road became preferred modes of transportation, canals survived in many countries as a recreational and residential resource, becoming a part of life in both town and country.