Building Canals
Building a canal was a very big and costly job. It could take a lot of time and effort just to
raise the money to build a canal. Canal companies also had to fight to get planning permission
from Parliament and local people. Once a canal company had got over these problems then
their engineers would then have to get on with the job of overcoming the shape of the land
through which the canal was to be built.
In order for a canal to work it must be built on an even level. To cope with uneven land
engineers had to design a way to pass boats up or down a small hill. In order to do this they
had to build a lock, which was a set of large gates to hold back the water in a space big enough
to fit a canal boat. The diagram below shows how these locks worked.
Source C: Canal locks
These locks were built so that a canal boat could be raised to a higher level of water. In some
parts of the country the uneven shape of the land meant that many locks were needed. If a
canal had to go up a steep hill several locks were joined together to form a staircase.
When a canal engineer was faced with a very large hill to pass he would have to tunnel through
it. James Brindley started the first great canal tunnel called the Harecastle Tunnel on the Trent
and Mersey Canal. It was over a mile and a half (2.5 km) long and took eleven years to build.
However, canals did not only have to go through hills, there were places where they had to
build cross roads and rivers. These bridges were called aqueducts.
Source D: Overcoming the shape of the land with tunnels & aqueducts.
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Building Canals
Canal tunnels were built by sinking shafts down to the line of the canal and then working left
and right from the bottom of the shaft. Once these tunnels were finished the shafts were left
open so that air could get into the tunnel. The width of tunnels was very small so as to keep
costs down, so towpaths for horses to pull the barges were rarely used. In order to stop the
canal boat hitting the side of the tunnel ‘leggers’ carefully walked them through. Sources E
and F describe how this was done:
Source E: Crick Tunnel 1815
Source F: ‘Legging’ through a canal tunnel
The tunnel is built wide enough to
allow two boats to pass, but our boats
must not touch the sides. To get
through we laid a plank at the front
part of our boat. Upon each end of this
plank a man laid himself down on his
back with his feet touching the wall.
They then pushed the boat forward by
crossing their legs at every step. This
was a dangerous job but if a man was
experienced then he could ‘legged’ us
through in 47 minutes a distance of
1518 yards.
Source G: The largest canal tunnels in Great Britain, 1985
Tunnel
Place
Length
Standedge
Old Harecastle
Blisworth
Sapperton
Dudley
Netherton
Crick Tunnel
Huddersfield
Trent & Mersey
Grand Union
Thames & Severn
Dudley
Birmingham
5456 yards
2897 yards
3956 yards
3808 yards
3172 yards
3027 yards
1518 yards
Comment
The longest tunnel
11 years to build
5 years to build
The last to be built 1858
Use this one to calculate
the time for the others.
Time to be
legged
through
47 minutes
Until the middle of the 19th century canals were the cheapest form of transport for heavy
industrial goods and raw materials. This was to change after 1840 when competition with the
new railways got into full swing. In order to compete some canal owners started
experimenting with using steam power instead of horses to pull the canal boats along.
However, the wash from these faster boats started to damage the canal banks and before long it
became cheaper to send goods by train.
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Activities: Building Canals
1. What problems did a canal company have to overcome before they started building?
2. Copy out the statements that are true:
The biggest problems for canal engineers was building a level channel
In order to get over a hill engineers would build a tunnel
In order to get over a hill engineers would build a system of locks
In order to go through a hill engineers would build a tunnel
The longest tunnel was the Standedge Tunnel
The last tunnel to be built was the Netherton Tunnel
A 'legger' was someone who could run fast
A 'legger' was someone who walked a canal boat through a tunnel
An aqueduct was used to keep the canals filled with water
An aqueduct was a special bridge built for canal boats.
3. Copy diagram C into your books and then explain in your own words how canal locks
worked.
4. Look at Source E. How long did it take to 'legged' it through 1518 yards in Crick
Tunnel?
5. How many yards could these men have ‘legged’ in a minute? (Hint: 1518 / 47)
6. Copy Source G into your book.
7. Calculate how long it would have taken to have 'legged' through each of the tunnels on your
table. Write your results into the last column on your table.
8. Why did fewer industries use canals to transport their goods after 1840?
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