Forth & Clyde Canal
from Grangemouth to Glasgow, Scotland
date 10th June 1768-77, 1786-90
era Georgian |
category Canal/Navigation works |
ICE reference number HEW 474
The Forth & Clyde Canal was one of the earliest purpose-built long canals in Britain. It covers the width of Scotland, linking the North Sea to the Irish Sea, from the Firth of Forth at Grangemouth to the Firth of Clyde at Glasgow. Its engineer was John Smeaton, who compared it favourably with the 1681 Canal du Midi in France.
To plan the canal's route, Smeaton used surveys by Alexander Gordon (1726), and Robert Mackell and James Murray (1762). He published his reports in 1764. His preferred route was 45.5km long and followed the River Carron and the valley of the River Bonny to the route's highest area at Dullatur Bog (north of Cumbernauld). It then went down the River Kelvin valley to the Clyde at Yoker Burn, north west of Glasgow.
However, at the eastern end, the Carron Iron Company wanted a link to their factory, and at the western end, Glasgow tobacco merchants were not happy that the canal would bypass their city altogether. There were also concerns from local landowners seeking to profit from the canal. So, additional branches were added at either end — to the place that would come to be called Grangemouth in the east, and to Glasgow in the west. The total length was now 56.3km. The OS grid reference above refers to the eastern end.
A Parliamentary Bill for the work was enacted on 8th March 1768 and construction began at the east end on 10th June, with Mackell as resident engineer. In 1775, the canal reached Stockingfield (near present-day Maryhill in Glasgow), and the branch to Hamiltonhill Basin was completed by November 1777. However, owing to lack of funds between that year and 1785, the canal did not reach its terminus at Port Dundas until 1791.
Smeaton's canal was 17.1m wide and 2.7m deep, 2.1m of which represented water depth. The canal side slopes were 31 degrees. Of its full length, 25.7km runs at summit level, 47.2m above low water in the Forth. At the eastern end, the summit is reached by a flight of 20 locks, each 22.6m long and 6.1m wide. The summit stretch was supplied with water by the newly-built Townhead Reservoir, Kilsyth (1773, also by Smeaton), and several smaller sources.
Smeaton had left the project in 1773 to help the canal company's financial position by removing his salary from its liabilities. His estimate for construction using the original route had been £79,000 but by Christmas 1771, the estimate had risen to £149,000. The final cost in 1777 was £164,000.
He was invited to return in 1785 when more money became available but declined and Robert Whitworth was appointed. Additional works that now took place included extending the canal to Bowling on the Clyde, constructing the Kelvin Aqueduct and completing the flight of 19 locks down from the summit through Maryhill Locks. In 1882, the Edinburgh & Glasgow Union Canal was connected to the Forth & Clyde at Lock 16 near Falkirk.
The full 59.5km of canal officially opened in July 1790. The total cost of the whole scheme came to £305,000. It attracted considerable traffic from the start. Throughout most of the 19th century, it returned annual operating profits around twice annual expenditure.
However, with the development of railways and then roads, its use declined. Ownership passed to the Caledonian Railway Company in 1867, to the British Transport Commission in 1948 and to the British Waterways Board in 1962. It closed to navigation on 1st January 1963.
The £84.5m Millennium Link project brought the Forth & Clyde Canal back to life in 2001, when it was reopened by HRH the Prince of Wales. Part of the money was spent on dredging, new lock gates, lifting road bridges and the building of the Falkirk Wheel, which lifts boats up to the newly re-opened Union Canal.
Supervising engineer: John Smeaton (1768-73), Robert Whitworth (1786-90)
Resident engineer: Robert Mackell (1768-77)
"Reports of the late John Smeaton, F.R.S. made on various occasions, in the course of his employment as a civil engineer"
by John Smeaton, Vol.I p.353 and Vol.II p.31-51
Longman, Hurst, Rees, Orme and Brown, London, 1812