Sapperton Canal Tunnel facts for kids
.jpg) |
|
| The Coates Portal at the south-eastern end of the Sapperton Canal Tunnel | |
| Overview | |
|---|---|
| Location | Sapperton, Gloucestershire |
| Coordinates | 51°42′58″N 2°04′00″W / 51.7162°N 2.0666°W |
| OS grid reference | SO955019 |
| Status | disused |
| Waterway | Thames and Severn Canal |
| Start | 51°43′43″N 2°04′58″W / 51.7287°N 2.0828°W |
| End | 51°42′15″N 2°03′01″W / 51.7041°N 2.0504°W |
| Operation | |
| Closed | c. 1910 |
| Technical | |
| Length | 3,817 yards (3,490 m) |
| Towpath | No |
The Sapperton Canal Tunnel is a long tunnel located on the Thames and Severn Canal in Gloucestershire, England. It's near the town of Cirencester. When it opened in 1789, it was the longest canal tunnel in England. It was also the longest tunnel of any kind in the country until 1811.
Building the tunnel was a big challenge. Workers had to dig through different types of rock and clay. This caused problems like parts of the roof falling in. Boats used to pass through the tunnel by "legging." This meant people would lie on their backs and use their feet to push the boat along the tunnel walls. The tunnel closed around 1910 and is no longer used by boats. Today, the Cotswold Canals Trust hopes to fix it up and open it again.
Contents
History of the Sapperton Tunnel
The idea for the Thames and Severn Canal was approved by the government on April 17, 1783. But there were many discussions about how big the tunnel should be. Barges on the River Severn were about 15 feet (4.6 meters) wide. Boats on the River Thames were 12 feet (3.7 meters) wide.
At that time, the only other long tunnel in England was the Harecastle Tunnel. It was only wide enough for narrow boats, about 7 feet (2.1 meters) wide. Some people thought building a wide tunnel would be too expensive. They suggested that boats should unload their goods at each end of the tunnel. Then, smaller boats could carry the cargo through.
Building the Big Tunnel
By the end of summer 1783, it was decided to build a wide tunnel. It would be 15 feet (4.6 meters) high and wide. The company started looking for tunnel builders in September. The tunnel was planned to be 3,817 yards (3,490 meters) long. At its deepest point, it would be 65 meters (213 feet) underground.
Work began in early 1784 and was expected to take four years. To make the work faster, 26 shafts were dug along the tunnel's path. The deepest shaft was 244 feet (74 meters) deep. Workers dug small tunnels, called headings, in two directions from the bottom of each shaft. The dirt and rocks were lifted up the shafts. A small temporary railway was later used to take workers into the tunnel and remove waste.
Explosives were used to make the headings wider. This created a lot of smoke and bad air. Chimneys were built in the shafts with fires at their base to try and clear the air. The main building contract went to Charles Jones. He built about a third of the tunnel. Then, other builders were hired to finish the rest.
Challenges Underground
Building the tunnel was very difficult because of the different types of ground.
- Limestone: Some areas had solid limestone, called Great Oolite. This rock had cracks that let water leak in. This caused rock falls and made springs form. In dry times, water would leak out of the canal.
- Clay: Other areas had a type of clay called Fuller's Earth. When the tunnel went through this clay, it had to be lined with bricks. But the clay could expand, pushing on the tunnel walls. This caused roof falls and made the bottom of the tunnel push up. This reduced the water depth for boats.
The tunnel officially opened on April 20, 1789, after five years of hard work. It did not have a path for horses to pull boats. So, boats were moved through the tunnel by "legging." This meant people would lie on their backs on the boat and push their feet against the tunnel walls to move forward.
There were some problems with the tunnel's construction. It had to close for ten weeks of repairs after just one year. Later, oak beams were put at the bottom of the tunnel to stop the clay from pushing the sides inward. In 1904, some parts of the tunnel were lined with concrete to make them stronger.
Later Years and Closure
The Sapperton Tunnel was the longest canal tunnel in England until 1811. That's when the Huddersfield Narrow Canal's Standedge Tunnel opened. The Standedge Tunnel is 5,456 yards (4,989 meters) long. It is still the highest, longest, and deepest canal tunnel in Britain. However, it is only wide enough for narrowboats (7 feet or 2.1 meters wide).
The last commercial boats used the Sapperton Tunnel in 1911. More parts of the roof fell in 1916. The entire canal was no longer used by 1933.
The tunnel could still be walked through until at least 1966. But now, it's blocked by many roof collapses. These collapses are mostly in areas where the ground is Fuller's Earth clay. The Cotswold Canals Trust wants to restore the tunnel. They hope to reopen the direct water route between the River Thames and the River Severn. The trust used to offer boat trips into the tunnel for tourists during winter.
There's also a Sapperton Railway Tunnel nearby. It follows a similar path under the Cotswolds. Some people have suggested using the canal and tunnel to pump water from the River Severn to the River Thames. This could help the Thames when it doesn't have enough water.
Tunnel Entrances
The tunnel has two main entrances, called portals.
- Northern Portal: This entrance is near Sapperton village. It was built between 1784 and 1789 by Josiah Clowes. It was repaired in 1996.
- Southern Portal: This entrance is near Coates. It was built by engineer Robert Whitworth. It has special Doric columns and a unique stone pattern. It was repaired in 1980.
Sapperton Tunnel in Stories
The Sapperton Tunnel has appeared in a few books and TV shows:
- In Hornblower and the Atropos by C. S. Forester, the main character, Hornblower, helps a boatman "leg" through the tunnel. The book describes the canal journey and the tunnel in detail.
- The novel Gone by Mo Hayder uses the tunnel as an important location in this crime story.
- An episode of the TV show Midsomer Murders called "The Green Man" (series 7, episode 1) was partly filmed at the tunnel.
Tunnel Locations
Here are the exact locations of different parts of the Sapperton Canal Tunnel:
| Point | Coordinates (links to map & photo sources) |
|---|---|
| Daneway portal | 51°43′43″N 2°04′58″W / 51.7287°N 2.0828°W |
| Midpoint | 51°42′58″N 2°04′00″W / 51.7162°N 2.0666°W |
| Coates portal | 51°42′15″N 2°03′01″W / 51.7041°N 2.0504°W |
