The Grand Western Canal ran between Taunton in Somerset and Tiverton in Devon in the United Kingdom. The canal had its origins in various plans, going back to 1796, to link the Bristol Channel and the English Channel by a canal, bypassing Lands End. An additional purpose of the canal was the supply of limestone and coal to lime kilns along with the removal of the resulting quicklime, which was used as a fertiliser and for building houses. This intended canal-link was never completed as planned, as the coming of the railways removed the need for it.
Construction was in two phases. A level section, from Tiverton to Lowdwells on the Devon/Somerset border, opened in 1814, and was capable of carrying broad-beam barges, carrying up to 40 tons. The Somerset section, suitable for tub boats (which were about long and capable of carrying eight tons) opened in 1839. It included an inclined plane and seven boat lifts, the earliest lifts to see commercial service in the UK. The lifts predated the Anderton Boat Lift by nearly 40 years.
The 11 miles of Devon section remains open, despite various threats to its future, and is now a designated country park and local nature reserve, and allows navigation. The Somerset section was closed in 1867, and is gradually disappearing from the landscape, although sections are now used as a footpath. It maintains a historical interest and has been subject to some archaeological excavations.
History
The Grand Western Canal was conceived as one of several competing schemes to alleviate the hazards and delays of coastal sailing ships making a passage around Land's End to get between the Bristol Channel and the English Channel. A canal from the mouth of the River Exe to Exeter had been opened in 1566, and eight miles of the River Tone had been made navigable in 1638. Navigation of the River Tone had been extended to Taunton in 1717, by the construction of locks on the upper section.
Against this background, in 1768 a committee commissioned James Brindley to survey a route, in the form of a canal, between Taunton and Exeter; and the survey was duly carried out by Robert Whitworth in 1769. This was to have been called the Exeter to Uphill Canal, as it involved a route from Topsham or Exeter to Taunton, then the use of the River Tone and a second canal from Burrow Bridge, via Bridgwater, Glastonbury, Wells and Axbridge, to Uphill, near Weston-super-Mare. Nothing further came of the plan until the 1790s, when various canal engineers were consulted, and in 1794 John Rennie was asked by a different committee, the Grand Western Canal Committee, to make another survey, which was adopted, and formed the basis for a planned act of Parliament. Opposition from the City of Exeter, who feared it would compete with the Exeter Canal for transportation of coal, was eventually softened; and the (36 Geo. 3. c. 46) was passed on 24 March 1796.
The act authorised a canal from Taunton to Topsham with branches to Tiverton and Cullompton. Water supply would be derived from proposed reservoirs, one on the River Tone and two on the River Culm, and from any other available sources within of the line of the canal.The canal company was also authorised to improve the River Tone near Taunton, and to raise £220,000, plus an additional £110,000 if required. Navigation onwards from Taunton was via the River Tone and the River Parrett. Construction did not start immediately.
Construction
Finally in 1810, work started under the direction of John Thomas. Surprisingly, the decision was taken to start in the middle, with a section of the main line and the branch to Tiverton. The logic for this was that there was a large potential trade in limestone between quarries at Canonsleigh and Tiverton, and this would generate income. The summit level was cut lower than the original plans, so that no locks would be required, but this greatly increased the amount of earthworks required. A further act was obtained, the (51 Geo. 3. c. clxviii) to sanction this, and to re-route the canal near Halberton, where Rock Bridge was constructed to carry the road over the canal. The same engineers that built the canal also built a substantial country house, turnpike house and cottages at the site. Several other bridges, including Batten's Bridge, Crownhills Bridge, Greenway Bridge and Sellick Bridge were also constructed at Halberton to carry minor roads over the canal.
With costs much higher than anticipated, work ceased in June 1811. After much deliberation, it was decided to continue construction, and to obtain a third act of Parliament, the (52 Geo. 3. c. xvi), to authorise increased charges for carriage of goods. By 1812, progress was being made, but was hampered by the need for rock cuttings at Holcombe Rogus. Leakage also meant that some sections needed to be lined with puddle clay. Lime kilns were constructed to provide the materials. These kilns can still be seen beside the canal, close to the Waytown Tunnel. Fenacre Bridge and Fossend Bridge were constructed at Burlescombe, where culverts were also needed to manage the streams. At a total cost of £244,505, the canal was opened on 25 August 1814, when the first boat travelled from Lowdwells to Tiverton, laden with coal.
At Sampford Peverell two rectories were built in 1836, at the expense of the Grand Western Canal Company, in compensation for cutting through the grounds and demolishing the south wing of the Old Rectory. Two road bridges were also needed in the village.
Second phase
Traffic on the opened section was much lower than anticipated, and the prospects of building the rest of the canal dwindled, as profits were minimal. However, in 1829 James Green turned his attention to the link to Taunton. He had been the architect of the Bude Canal, which was built for tub-boats and used inclined planes to change levels, and proposed a similar solution here. The Bridgwater and Taunton Canal had opened in 1827, making navigation from Taunton to Bridgwater easier than on the River Tone. In a report of 1830, Green proposed using vertical lifts instead of inclined planes, and estimated the cost of the canal at £65,000.
Work started in 1831, and progressed quickly, including the construction of a bridge at Bradford on Tone and Harpford Bridge at Langford Budville, where a new warehouse was also built. In addition to the boat lift in Nynehead two aqueducts were required within the village.
The original Grand Western Canal Act 1796 had envisaged the canal joining the River Tone at Taunton, and made provision for the improvement of some of the river, which would then be granted to the canal company and effectively become part of the canal. They could build warehouses and wharves on this section. By late 1830, there was considerable hostility between the Conservators of the River Tone and the new Bridgwater and Taunton Canal company, who had constructed a connection into the river at Firepool, so that barges could reach Taunton Bridge. The Conservators had retaliated by reducing the water supply to the canal. Litigation followed, and the Grand Western Canal company, having decided that a direct connection to the Bridgwater and Taunton Canal was a better option, had succeeded in purchasing the land required by agreement with landowners.
Meanwhile, as a result of the litigation, an act of Parliament, the Bridgwater and Taunton Canal Navigation Act 1832 (2 & 3 Will. 4. c. xliii) was obtained which required the Bridgwater and Taunton Canal to build a link between the Tone and the Grand Western Canal. This was built in 1834, leaving the Tone below French Weir, and heading north-west to Frieze Hill, where there was a right-angled connection to the line of the canal. Although there is little evidence that it was ever used, it appeared on the 1840 tithe map, on John Wood's town plan of the same year, and on the 1890 Ordnance Survey map.Ordnance Survey, 1:2500 map, Taunton Plans for the main line of the canal included seven lifts and one inclined plane, and it was these features that caused the subsequent delay in the completion of the canal. Teething problems with the design of the lifts gradually came to light, and although the cost of rectifying these was borne by Green, the canal could not be opened. There were also problems with the inclined plane. The canal was partially opened to Wellington, in 1835, but in January 1836, Green was dismissed.
Completion The engineer W. A. Provis was asked to survey the works, and to report on the lifts and the causes of the failure of the plane. His clear report is an important source of information on the canal at the time of its construction. Some remedial work was instigated, following the report, including the provision of a steam engine to power the Wellisford incline. The extension was fully opened on 28 June 1838, at a cost of about £80,000.
Boat lifts
Green's use of boat lifts was innovative. The idea was not new, as he acknowledged in an article describing the lifts which he published in TransactionsTransactions of the Institution of Civil Engineers, Volume 2, 1838 in 1838, having been suggested in principle by James Anderson of Edinburgh in 1796. Robert Weldon had tried to build one at Combe Hay on the Somersetshire Coal Canal in 1798, which was replaced by a lock flight after persistent failures. One was built at Ruabon on the Ellesmere Canal in 1796, but was replaced as it was not robust enough for regular use. James Fussell built one on the abortive Dorset and Somerset Canal, but the works were abandoned before it was ever used regularly. The lift at Tardebigge on the Worcester and Birmingham Canal was replaced by locks in 1815 as it was "too complex and delicate", according to Rennie. Finally, another lift at Camden Town on the Regent's Canal was replaced by locks in 1815 because it could not be made to work.
Principles With no working prototypes, Green set about building seven lifts. The principle was simple. Two caissons were suspended from three carrying wheels of diameter, by wrought iron chains. The caisson at the bottom was jacked against the front wall of the lift to seal it, and a door or gate was opened to allow the boat to float in. The caisson at the top was jacked against the back wall in a similar manner. When both boats were in, the doors on the caissons and lift were closed, and the jacks released. Because a boat displaces its own weight in water, the system should be balanced, and a small amount of energy is required to start the boats moving. When the top caisson reaches the bottom, the jacks are applied, the doors are opened, and the boats can continue.
In order to maintain the balance, a second chain was fixed to the bottom of the caisson, so that the total length of chain on each side of the lift remained the same. As a caisson descended, the chain coiled up at the bottom of the lift. The small amount of energy was created by ensuring that the ascending caisson was a little too low by the time the descending one reached the bottom. Thus it would hold a greater depth of water by the time it was ready to descend again. In practice, about of water, weighing about a ton, was found to be sufficient.
Problems The difficulty was that Anderson had suggested that the water in the caisson chambers should be at a lower level than that in the canal. This had not been implemented, and so the lower caisson would not sink deep enough for either boat to be floated out. Attempts to fit gates and to let the water in the chamber drain to waste had proved ineffective. Ultimately, lock chambers were built at the foot of each lift. These were filled with water from the upper level, so that the boat could float out, and it then descended the final as it would in a conventional lock. Only the lift at Greenham used Anderson's principle, and included a proper drain to lower the level in the chambers.