Thames and Severn Canal

The canal at Brimscombe

The Thames and Severn Canal is a canal in Gloucestershire. It was completed in 1789 and conceived as part of a canal route from Bristol to London. At its eastern end, it connects to the River Thames at Inglesham Lock near Lechlade, while at its western end, it connects to the Stroudwater Navigation at Wallbridge near Stroud, and thence to the River Severn. It also has one short arm from Siddington to Cirencester.

The route of the canal includes Sapperton Tunnel, which when built was the longest canal tunnel in Britain, and remains the fourth longest. There were always problems with water supply, as no reservoirs were built, while the summit section near the tunnel ran through porous limestone, and there were constant difficulties with leakage. Competition from the railways took much of the canal's traffic by the end of the 19th century, and most of the canal was abandoned in 1927, the remainder in 1941.

Since 1972, the Cotswold Canal Trust has been working to restore both the canal and the Stroudwater Navigation, so that it can again provide a navigable link between the Thames and the Severn. A number of the structures have been restored, and some sections are now in water. A grant of £11.9 million from lottery funding and as much again from taxpayers' money, awarded in 2006, is intended to restore navigation from 'The Ocean' at Stonehouse to Wallbridge on the Stroudwater Navigation, and from Wallbridge to Brimscombe Port on the Thames and Severn Canal. In 2010, British Waterways gave Inglesham Lock to the Trust, and the Inland Waterways Association mounted a national campaign to fund its restoration and around 420 yards of canal above it. The intention is to re-open the whole canal, but there are some major engineering obstacles to be overcome to achieve this.

History

Since the 1730s, when the first Act of Parliament to authorize a canal from the River Severn to Stroud had been passed, the Stroudwater Navigation had been seen as part of a larger plan to link London and Bristol by waterway. No work took place immediately, but the Stroudwater was eventually opened in 1779, and within two years the shareholders commissioned a survey for a canal from Dudbridge to Cricklade, which would complete the link. It is likely that John Priddy – previously the engineer for the Stroudwater scheme – carried out the survey, but others were soon involved including Sir Edward Littleton, who was part of the Staffordshire and Worcestershire Canal. Priddy suggested that there were better terminal points at Wallbridge and Lechlade. Robert Whitworth then surveyed two routes, the first as suggested by Priddy, and the second direct from the Severn to the Thames following the valley of the River Coln. The first route was chosen, based on excellent water supplies at Cirencester, although the estimates of the amount of water available proved to be wildly optimistic.

The estimated cost of the project was £127,916, most of which was promised within three weeks. The bill to authorise the canal passed through Parliament relatively easily, and became an Act on 17 April 1783. The company could raise an initial £130,000, with an additional £60,000 if required. The canal was to be suitable for boats 12 feet wide, and so could accommodate Thames barges, but not Severn Trows. Josiah Clowes was appointed head engineer, surveyor and carpenter to the canal in 1783 to assist Whitworth. Clowes became resident engineer and was paid £300 a year. Clowes' work on the canal gave him a reputation which made him highly sought after in the last five years of his life. He left the construction of the canal shortly before completion to work on Dudley Tunnel.

There was great debate about the gauge of the tunnel required at Sapperton. Commissioners from the River Thames thought that it would have to be built for narrow boats, since the cost of a larger tunnel would be prohibitive. It was also going to be longer than any tunnel yet built. However, a decision was made that it would be built as a broad tunnel, 15 feet wide and high, and so the company advertised for tunnellers. The tunnel was expected to take four years to complete when work began at the start of 1784, but it was not completed until April 1789. The canal opened in stages as it was completed. The first 4 miles from Wallbridge to Chalford opened in January 1785, and by mid-1786, the navigable section had reached the western portal of the tunnel, 7.5 miles and 28 locks from Wallbridge. A wharf was built at Daneway Bridge, equipped with a warehouse and coalyard.

East from Upper Wallbridge Lock

The tunnel was constructed from many workfaces, with 25 shafts sunk along its course to provide access. After completion there were problems, and the tunnel was shut for two and a half months during 1790 for further work to be carried out. The summit level and a branch to Cirencester were completed in 1787, and became operational as soon as the tunnel opened. The final section to the junction with the Thames at Inglesham, which descends through 16 locks, was finished in November 1789. The canal was completed at a cost of £250,000. With the Stroudwater Navigation, which had been completed in 1779, it completed a link between the River Severn in the west and the River Thames in the east.

As built, the main line was just under 28.7 miles long and had 44 locks. The branch to Cirencester added a further mile and a half. The first 2.5 miles from Wallbridge to Brimscombe, where there was a transhipment basin, was built with locks 69 feet by 16 feet, enabling Severn trows to use it. Beyond that, the locks were 90 feet by 12.7 feet and the boats used were Thames barges. The canal's summit, which is 362 feet above sea level and 8.1 miles long, includes the Sapperton Tunnel: 3,817 yards long and at the time, the longest in Britain. Its length has since been exceeded only by two other canal tunnels, at Standedge in the Pennines and at Strood in Kent.

Operation

Until the summit level was completed, little thought seems to have been given to water supply. It was assumed that the River Frome, to the west of the tunnel, the River Churn which flowed through Cirencester, and the River Coln, together with springs at Boxwell and a well near the source of the River Thames at Thames Head, would be sufficient. The original horse pump at Thames Head was replaced by a windmill, but Clowes discovered that he could not stop the summit pound from leaking. The flow on the River Churn was 1.7 million gallons a day, while the calculated flow at the start of the project had been more than ten times this value. The summit level was losing around 1.1 million gallons a day, largely because the underlying rock was porous limestone, and it was estimated that around half of the daily requirement could actually be supplied. The wells at Thames Head were extended and a Boulton & Watt steam engine was installed in 1792 to pump the water into the canal. An extra, shallow lock was built at Boxwell, which allowed the level of the canal to be dropped beyond it, and more water to be taken from Boxwell springs. The new arrangements were adequate, although some of the reason was the failure of traffic to develop to the levels anticipated.

Leakage was affected by 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 one of the attempts to rectify this problem, the size of the locks was reduced which resulted in their unusual double headed appearance. In a further attempt to prevent water loss, at King's Reach, the section immediately east of Sapperton Tunnel, the canal was lined with concrete rather than puddle clay.

Neither of the river navigations to which the canal connected were satisfactory. In the west, the situation was remedied in 1820, with the construction of the Gloucester and Sharpness Canal seven years later. On the Thames, there had been a proposal for a canal from Lechlade to Abingdon in 1784, and for a cut from Inglesham to Buscot in 1788, but neither had been built. Some improvements were made to the river after 1786, but the canal company encouraged the building of bypasses. The Wilts and Berks Canal was one, providing a link to the river at Abingdon, but although it was proposed in 1793, it was not opened until 1810, and the North Wilts Canal, which provided a connecting link from Latton to Swindon was not completed until 1819. Ultimately, most of the Bristol to London trade used the Kennet and Avon Canal after it opened in 1810, as it provided a much shorter route than the Thames and Severn Canal.

Decline

Railway competition began in 1836, when the Cheltenham and Great Western Railway proposed a line between Swindon and Cheltenham, by way of Gloucester. The canal company opposed the scheme, and received compensation of £7,500 from the railway company over the next four and a half years. The tolls on the carriage of materials for the railway's construction improved the financial position of the canal for a short time. The railway company was then taken over by the Great Western Railway, who built a new tunnel at Sapperton, and opened the railway to Gloucester in 1845. Canal tolls were cut, in an attempt to retain traffic, but toll revenue fell from £11,000 to £2,874 between 1841 and 1855. The Thames Commissioners were also in financial difficulties, and the Thames was nearly unnavigable from Oxford to Lechlade after 1855. In 1866, plans to convert the canal to a railway were rejected by Parliament, but the Thames Commissioners were replaced by the Thames Conservancy, and most of the river was soon returned to a navigable state.

The condition of the canal continued to decline. Complaints were made about its state in 1874 and 1885, which resulted in surveys being undertaken, but little was done to remedy the situation. In 1893, the Thames and Severn Company announced that the canal between Chalford and Inglesham would close two days later. Negotiations with a number of interested parties took place, and having given an assurance that it would not be converted into a railway to the Great Western Railway, an Act of Parliament was obtained in 1895, which formed a Trust with powers to raise £15,000. The Trust included representatives from the Sharpness New Docks & Gloucester & Birmingham Company, the Stroudwater Canal, the Staffs & Worcs Canal, the Severn Commissioners and local councils. At the same time as the Trust refurbished the canal, the upper Thames was upgraded by the Thames Conservancy. Although the canal was re-opened in March 1899, lack of water on the summit level soon closed it again, after which Gloucestershire County Council suggested that they take it over. They did so on 2 July 1901. In 1925 they began negotiations with interested parties which ultimately led to the abandonment of the canal from Chalford to Inglesham in 1927. The Stroudwater Canal managed to keep the remaining section open until 1933, when it was abandoned, and their own canal closed in 1941.

Restoration

The canal towpath at South Cerney

Following the publication of Ronald Russell's influential book entitled Lost Canals of England and Wales in 1972, a number of canal restoration schemes sprang up. Among the organisations established that year was the Stroudwater Canal Society, which soon became the Stroudwater, Thames and Severn Canal Trust, and from 1975, the Cotswold Canal Trust. Volunteers for the Trust have since been working to restore both the Stroudwater Navigation and the Thames and Severn Canal. Extensive lobbying in 1979 resulted in Gloucestershire County Council deciding to rebuild a damaged bridge at Daneway, rather than replace it with a much cheaper low-level causeway, which would have severed the route. Two years later, County Council support was required when the project benefited from 20 workers and a £17,000 budget for materials under the Job Creation Scheme set up by the Manpower Services Commission, as the Council had to manage the scheme.

In 1991, the Trust commissioned Halcrow to conduct a feasibility study for restoration of the eastern end of the canal, whose report demonstrated that there was a good case for the provision of a navigable culvert beneath the proposed Latton Bypass. Despite initially saying that a culvert would not be built, negotiation continued, and – helped by large grants of taxpayers' money – the Department of the Environment decided in 1997 that a culvert would be provided under the road.

Development

The final section of the canal before it joins the Stroudwater Navigation presents particular problems for restoration, as the channel had been used as part of a flood relief scheme by the Environment Agency. Water from the Slad Brook, which is culverted beneath Stroud, joins the canal a short distance above Lower Wallbridge Lock. The Painswick Stream and Ruscombe Brook join the channel below the junction and flow through the Dudbridge locks, after which the water is discharged into the River Frome below the A419 Dudbridge Road bridge. As a consequence of its flood relief function, the channel here is classified as a "main river". Designs for reinstatement of the canal have had to accommodate large flows on this section, and include underground bywash culverts, capable of carrying the full flood flow of the streams.

At Capels Mill, the bed of the canal was used as the route for the Stroud Bypass in the 1980s, and so a diversion had to be built at this point. It passes through an area which was used as a landfill site in the 1960s and 1970s. Some 355 yards of new channel was constructed, some of it edged with sheet piling. After passing through a railway viaduct, the bank is supported by a series of contiguous concrete piles, which were drilled to a depth of between 30 feet and 49 feet and provide a retaining wall 35 feet tall at its highest point. The new section was filled with water and officially completed on 2 June 2013.

The original line of the Stroudwater Navigation between Stonehouse and Saul Junction on the Gloucester and Sharpness Canal has been divided by both the construction of the M5 motorway and development of the A38 trunk road. Plans to overcome these obstacles have been produced, but await the necessary funding.

Sights beside the canal

Chalford Roundhouse at the site of Chalford Wharf

A number of the buildings associated with the canal have survived and are now listed buildings, including five circular cottages, built with three floors. The lower floor was intended to be used as a store and has access to the outside. A set of outside steps leads up to the first floor, which is around 16 feet 10" in diameter. It was designed as a living area and was equipped with a cooking range. A staircase, built between the inner and outer wall, leads up to a circular bedroom on the second floor. The round houses are situated at Lechlade, by the entrance lock from the Thames; at Marston Meysey; at Cerney Wick near Latton, next to lock 39; at Coates, close to the eastern portal of the tunnel; and at Chalford, next to lock 13. Some had a pointed slate roof, while others had a lead cone, which collected rain water for drinking. They were built in the 1790s for use by lock-keepers and lengthmen, but were not particularly popular due to the limited amount of space and problems with finding suitable furniture for a circular room.

Literary connections

In 1953, C S Forester published Hornblower and the Atropos, a historical novel set during the Napoleonic Wars, in which Horatio Hornblower, a captain in the Royal Navy, travels along the canal to London. He assists with legging the boat through the Sapperton tunnel and then steering it after the postillion in charge of the horses is injured.

Outside links

("Wikimedia Commons" has material about Thames and Severn Canal)

• Cotswold Canals Trust
• Cotswolds Canals Partnership
• Cotswold Canals in Pictures

References

Books

• Hadfield, Charles (1969). The Canals of South and South East England. David and Charles. ISBN 0-7153-4693-8. 
• Forester, C. S. (2006). Hornblower and the Atropos. Penguin. ISBN 978-0-14-102504-9. 
• Jackson, W Turrentine; Chaloner, W H (1962). The Development of Transport in Modern England. Routledge. ISBN 0-7146-1326-6. 
• McKnight, Hugh (1981). The Shell Book of Inland Waterways. David & Charles. ISBN 0-7153-8239-X. 
• Skempton, A. W. (2002). A Biographical Dictionary of Civil Engineers in Great Britain and Ireland. Thomas Telford. ISBN 0-7277-2939-X. 
• Squires, Roger (2008). Britain's restored canals. Landmark Publishing. ISBN 978-1-84306-331-5.