.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, partially collapsed |
| 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 | |
| Opened | 20 April 1789 |
| Closed | c. 1910 |
| Technical | |
| Length | 3,817 yards (3,490 m) |
| Towpath | No |
The Sapperton Canal Tunnel is a tunnel on the Thames and Severn Canal near Cirencester in Gloucestershire, England. With a length of 3,817 yards (3,490 m), it was the longest tunnel of any kind in England from 1789 to 1811.
Construction, following an Act of Parliament, began in 1784. Twenty-six shafts were dug along the line of the tunnel and workfaces dug in each direction eventually joining up before the diameter of the tunnel was expanded. Difficulties were encountered related to strata of Great Oolite (solid limestone) and Fuller's Earth clay. These caused roof falls and narrowing of the channel which continued after the tunnel opened in 1789 and required frequent maintenance. The stone portals at either end are listed buildings.
Boats passed through by legging until 1911. The canal was abandoned by 1933 and subsequent roof falls mean that it is no longer navigable. Cotswold Canals Trust have proposed restoration.