Article

Canals

A canal is an artificial waterway, most we may think of being used for boating leisure today or delivering goods in the past, but some were also built to move water from one place to another, while some others shorten the journey for ocean going ships. Some are completely new developments, while some others involve the canalising of some existing route such as a river, such as dredging, adding weirs and locks. Different countries have overall titles for these, in Britain we call them navigations, in that a boat may navigate up them. Some are large, designed for ships to pass through, while others are small, only being wide enough for a canal longboat to pass through.

Water finds its own level, so any canal that is just a ditch that boats may pass along has to stay at the same height, following the contours of the hills. Where we don't want to follow the contours or cannot, we have to either move the boat through the air, as going across a valley on an aqueduct, a bridge holding canal, or we have to go down one side and up the other. Going up and down hills is usually done with locks, and where a lot of height has to be gained having flights of locks. The other alternative is boat lifts, such as the Falkirk Wheel or Anderton Boat Lift, both of which you can see working today. The remains can also be seen of inclined planes, these were a type of railway that took a boat sideways up the side of a steep hillside.

Falkirk Wheel, Scotland

Another alternative was to choose a lower level and then tunnel though hillsides, in some cases creating tunnels several miles long. With many tunnels, to keep the size and cost down they were built with no towpath, so instead of the canal boat being pulled by horse the people had the lay on their backs and use their feet to push their way through, in effect walking on the roof, this is known as legging.

One canal was built in 1797 with a Caission lock, this was a sealed box that the boat went into and was then lowered through the water until it lined up with special doors at the bottom. So in effect the box was a submarine taking the boats and occupants from one level to another, the advantages seen was less water loss and greater drop in a single step. However after it jammed and nearly suffocated the occupants the design was dropped and further locks of this style were not built.

Where hillsides were steep you may get a flight of locks one above the other, and when even steeper a staircase, the difference is that with the staircase the lower gates of one lock become the upper gates of the next. When a series of boats are going through in the same direction they use the same amount of water as other locks, but when a boat is entering from the bottom, after one has come from the top, all the steps in the staircase is empty and all have to be filled in order for the boat to go up through the system, although there are some sequences that can also fill faster. It takes both more thought and water to make these work.

Hatton Locks, Warwickshire

The largest problem for the canal builders was how to get a sufficient supply of water to the top of hills. In order to make locks work you use a lock full of water every time you move a boat up or down, and the supply of water to do this is needed at the high points along the route. In some cases this is achieved by diverting streams, adding lakes or using pumping engines of some type. A common problem was running out of water. Generally it was to overcome this, rather than to save time, that justified the building of aqueducts and cutting of tunnels.

Many canals have a very wide range of features including locks, flights of locks, aqueducts, tunnels, parking up areas or canal basins, wharfs for loading and unloading, and the water supply features. In addition to photographing these the photographer will get a lot of wildlife opportunities, scenic shots and of course boats of different styles, colours and ages.

Bruce Tunnel on the Kennet & Avon Canal, Wiltshire

History of canals in the UK

The earliest canals we are aware of were constructed by the Romans, mostly to move water about. Long after they had left the only way to move goods about was by cart or pack horses, along less than ideal tracks.

Many rivers were used originally to drive water mills, so dams and weirs were common place along their length, and although they tended to make rivers deep enough for boats, there were major obstacles that had to be overcome often by flash locks.

Prior to the industrial revolution boats went up many rivers and some of these had some form of locks. In the earliest of these, were flash locks that had a single paddle that was released and the boat pulled up against the water flowing through, or systems that involved winching the boat over rollers to a higher level. This used a lot of water, and was only applicable to flowing rivers. Later pound locks, of a design similar to what we see today, were used. In the 15th, 16th and 17th centuries 29 river navigations improvements took place, starting with the River Thames and River Wey, today 20 miles from south London into Surrey.  Most were undertaken in stages, often connected with a new canal or other expansion of the navigation. The Thames for example is navigable to a point just beyond Lechlade in Gloucestershire where it joined the Thames and Severn canal, parts of which are currently being restored. The last of the 45 locks on the Thames was added in 1928.

In the industrial revolution in the mid 18th century, there came a need to move far more, not only finished items but also coal and raw materials.  It was at this time that most of the canals were built, joining up to form a large network, many more were planed but never built. The network of navigations, including canals and canalised rivers covers the south, midlands and north of England, as well as some parts of Wales and a few in Scotland. With the exception of some of the Scottish canals the others joined up allowing goods to be taken from one place to another completely by canal. Today most of the major canals still exist, but many of the spurs and a few others have been lost. However most of the major network still connects, it just now takes far longer to get from some places to others due to the distance around.

 

As building techniques improved many were widened and straightened, and cuttings, embankments, aqueducts, inclined planes and other features added to save water, as well as to allow more throughput but also to speed up the journey time. In the 19th century a number of major shipping canals were constructed. The coming of the railways In the early 19th century the railways were built, providing far faster and a more cost effective way to move goods around the country. Many canals were bought by the railway companies. While some that were not tried to compete by cutting prices but generally the smaller ones failed. At the same point however a large number of very short canals were constructed to bring goods to the railways, this option being chosen when the cost of building a spur was too expensive due to the distance it would need to go to gain or lose height.  Roads With the building of roads and road haulage, canals became less important and by the second world war (1939-45) only the very strongest canals still survived. After the war the decline of canals was even more rapid with virtually nothing moving and most being unmentioned and no longer navigable by the the 1960's.

Hay Inclined Plane, Shropshire

2nd Life - Leisure

In the mid 1960's some people started to show an interest in restoring the canal system, increasing in the 1970's. Using them not for moving goods but for boating and leisure. Since that time it has picked up momentum and is now big business, with housing complexes around some, moorings and revenues from licences to use them. Several major restoration projects have brought back major features including the Falkirk Wheel and Anderton Boat Lift, . Today there are more boats on the canal system than there were at the height of its industrial use. A large percentage of the overall network is navigable, and many sections of canal and some canals that had been lost are being restored.

Today you can work out a route to go from nearly any point on the network to any other point, but it can take some time. A journey from Gloucester to Bristol, 40 minutes by train for example, if you don't use the tidal River Severn, involves a 3 week trip by boat.

In the article Canals for photographers we consider how to best photograph the features available to us on a canal.

We have a number of lists relating to canals and features including:-

• Major Canals and Waterways

• Major Canal Features

• Canal Tunnels

• Lock Flights and Staircases

• Canals in England  

• Canals in Wales 

• Canals in Scotland 

• Canals in Northern Ireland 

• Non Navigable and Lost Canals

To find out more check our Canal and Waterway Section or see

• Further information - canals