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Dorset & Somerset Canal

Canals That Never Were: NarrowBoat, Summer 2007

Richard Dean

We follow the proposed route of an ambitious canal to link Bristol with the south coast that was to have four unique ‘balance locks’ or boat lifts, one of which was built

Blue line - canals built.

Red line - proposed D&S Canal.

Dashed blue line - Kennet & Avon Canal as originally authorised.

Based on Ordnance Survey mapping © Crown copyright: AM02/07

A small extract from William Bennet’s careful survey of the proposed canal for the 1796 Act. The main line is in red, with the Colliery Branch yellow. North is to the right.

Parliamentary Archives HL/PO/PB/3/plan 5

Unfinished excavations for Balance Locks at Barrow Hill, as shown on the 1880 Ordnance Survey.

Canalmaps Archive

The area between Bristol and Poole on Smith’s Map of Inland Navigation, 1810.

Canalmaps Archive

The desirability of a water route from Bristol to the south coast avoiding the rigours of sailing around Land’s End prompted several canal schemes, particularly during the ‘Canal Mania’ of the early 1790s. The Dorset & Somerset was one of these, with a line connecting the proposed Western Canal (later to be known as the Kennet & Avon Canal) with Poole Harbour, via Frome and Wincanton. Robert Whitworth carried out the initial engineering appraisal for this narrowboat canal in 1793, but soon dropped out of the picture in favour of his assistant William Bennet who undertook the detailed surveys and became the company’s engineer. He took some time carefully measuring the ground, and the plan produced is a model of accuracy for its time.

After difficulties with landowners and the choice of a route, the southern part was deferred, and the Act obtained in 1796 (36 Geo 3 c.xlvii) covered only the first 48 miles as far as Gains Cross, a remote roadside location near Shillingstone in Dorset, with a branch from Frome to the collieries around Nettlebridge, at a total estimated cost of £146,000. No subsequent application was ever made for the continuation to Poole.

The majority of the lockage was to be by means of James Fussell’s patent Balance Locks, which were simple lifts using pairs of counterbalanced caissons. The Act required that the branch had to be completed before the main line could be started, and about nine of its eleven miles were cut, including two aqueducts, 25 bridges, part of a tunnel, and one complete and four unfinished ‘Balance Locks’, but nothing was started on the main line. The company had spent about £56,000, but at this point the money ran out, and it is doubtful if any of the works were ever commercially used. The company maintained a shadowy existence for several decades, and figured in early railway schemes during 1825–6, but no further construction was done.

Red line - proposed D&S Canal

Based on Ordnance Survey mapping © Crown copyright: AM02/07

Red line - proposed D&S Canal

Based on Ordnance Survey mapping © Crown copyright: AM02/07

The first four miles of the intended main canal were in Wiltshire. From the junction point with the Kennet & Avon’s line (as then proposed) at Widbrook near Trowbridge, the line was to rise 217ft by eight lifts to a summit level over 10 miles long between Frome and Wincanton. This was to include a 1009-yard tunnel, then falling 150ft by a mixture of lifts and locks to Stalbridge, from where there would be a level pound to Gains Cross. Several lifts at Barrow Hill would have raised the branch 207ft, with a further two proposed on the last mile to Nettlebridge. The completed lift at Mells was successfully tested between 1800 and 1802, raising and lowering boats 20ft, but it appears that rises of 28–40ft were envisaged for most of the others on the canal.

For many years the canal appeared on maps as if it had been completed. Nichols Priestley & Walker’s publication of 1830 avoids this error by referring to it as ‘Intended’.

Canalmaps Archive