The Caledonian Canal by Chris O'Connell, Heritage Manager, Scottish Canals - Thursday 1 December 2022

At a joint meeting with the CIHT and ICE Chris O'Connell, Heritage Manager, Scottish Canals gave a presentation on the Caledonain Canal.

It was an act of genius by Thomas Telford that merged the natural and manmade landscapes by threading together in only sixteen miles of new construction four lochs to create a navigation stretching all the way from the Atlantic to the Moray Firth and thus cutting out the long detour round Cape Wrath.

An early map from 1848 shows the Caledonian Canal's profile, some of the lochs having had to be dredged using a metal headline to take them to a uniform depth.

Originating between 1768 and 1818, today the network owned by Scottish Canals comprises two operational and one defunct route in the Lowlands, all of which declined in the face of railway competition, and two in the Highlands which did not share their decline. A pantheon of heroes lies behind their development - engineers Smeaton, Telford, Rennie and Baird, geologist Hutton, inventors Watt, Russell and Symington - but it was the Brahan Seer put to death by the Countess of Seafield who first foresaw that ships would run round the back of Inverness's Tomnahurich Hill.

An initial survey by James Watt in 1794 prompted a feasibility study in 1803 by Thomas Telford which led to the opening in 1822 under a corporate body of Commissioners and then a lease to private undertakings followed by transfer to the Ministry of Transport in 1920 and thence the British Transport Commission and in 1962 the British Waterways Board.

Canals were built for the improvement and future welfare of the communities that they served, and Telford also delivered roads, bridges and even churches. The other parent of the Caledonian was the Royal Navy, for the passage of whose vessels locks were built to dimensions of 140 x 40 x 20 feet, but the lasting peace that followed Waterloo meant that its only military use would be in the Great War when the US Navy delivered mines to Inverness's Muirton Basin to hold off any German advance. What did however materialise was fishing boats chasing the herring shoals for whose landings for processing on the banks of the Canal dues could be charged, and there was also timber from the Baltic countries, with all incomes carefully documented to Parliament.

Telford was a very hands-on chief engineer, living on the job at Banavie and then Clachnaharry. He adopted a somewhat piecemeal approach to construction, and his navvies being mostly Highlander were prone to yearning for their crofts so he built them bunkhouses and even a brewery.

The northern end at Clachnaharry had soft ground that needed to be built up with rock whereas the southern at Banavie had to be blasted through solid rock. Lighting was provided from the early years for safe passage, and today despite discouraging night travel there are four beacons.

Queen Victoria's tour of 1873 made the Highlands fashionable, and since then the Caledonian has never lost its allure, with steamships giving way to modern vessels like the Lord of the Glens which just fit the dimensions of the locks. Today about 22M visits are made annually to the Scottish canals, and at Fort Augustus which has grown around the Canal its visitor centre is a major attraction.

With assets that include 140 miles of water, 104 properties, 227 embankments and 560 moorings, Scottish Canals is nowadays a major landowner that must respond to the global challenges posed by climate change. Dry spells can be as problematic as wet, with groundwater variations threatening the integrity of structures, and threats that include coastal erosion must be banished by heightening resilience, which entails systematic prioritisation of the locations posing the greatest threat.

The methods used today are ones that Telford would doubtless have loved to get his hands on, and include sheet-piling and rip-rap. Lock gates must be replaced whenever any cracking is detected, and draining them sometimes reveals masons' marks. Locks that were once worked by brute force have been gradually mechanised first by hydraulic operation and now by use of electric power. Scottish Canals are reducing their carbon footprint by fitting solar panels, harnessing hydroelectricity and reusing locally sediment dredged from them that might formerly have been driven to landfill, while biodiversity is being respected by removal of invasive non-native species such as the New Zealand pygmyweed.

Canals have gone from moving coal to becoming green-blue corridors for recreation and active travel whose contribution to wellbeingness was much appreciated during lockdown. Fish stocks must be conserved during maintenance work, and the otter is perhaps the most loved of the animal species making a return to the canalbank. Canals' role is kept sustainable by commercial opportunities that include holiday lettings in lock-keepers' cottages, charging for moorings, the income from visitor centres and charging for acceptance of urban water discharge which gives them a role in modern flood management.

Report and photograph by John Yellowlees.