History and Construction

The canal was completed in 1789 at a cost of GBP 250,000. With the Stroudwater Navigation, which had been completed in 1779, it completed a link between the River Severn and the Gloucester and Sharpness Canal in the west and the River Thames in the east. Both the Stroudwater Navigation and Thames and Severn Canal are broad canals. This means that boats with a 14 foot beam could use them.

Specifications

The Thames and Severn Canal was just under 28 miles long and had 44 locks. The branch to Cirencester added a further 1.5 miles. The canal's summit is 363 feet above sea level and includes the 2.1 mile long Sapperton tunnel. At the time of its completion, this tunnel was the longest in England.

Water Supply Challenges

The canal always had problems with its water supply due to springs breaking through the clay lining of the canal bed. In summer, when the springs receded, water was lost through these holes at a rate greater than the available supply. In an attempt to rectify this problem, the size of the locks was reduced, resulting in their unusual double-headed appearance.

In a further effort to prevent water loss, King’s Reach, the section immediately east of Sapperton tunnel, was lined with concrete rather than puddle clay.

Later Developments and Decline

In 1819, another canal company, the North Wilts Canal, completed a link between the Wilts and Berks Canal at Swindon and the Thames and Severn Canal at Latton. As the 19th century progressed, railway competition took much traffic from the canals. The Thames and Severn Canal was in economic difficulties by the 1890s. Much of the canal, including Sapperton Tunnel, was abandoned in 1927. A western section survived in use until 1933, and the Stroudwater Navigation was not abandoned until 1941.