CIHT/CILT/ICE Webinar on the Union Canal, with Chris O'Connell - Wednesday 11 May 2022

Scottish Canals is the trading name in Scotland of British Waterways, with five canals still extant. Both the Union and the Caledonian attain 200 years of age in 2022, and on their inception the canal age in Scotland which had begun with opening of the Forth & Clyde in 1768 reached maturity, which would be followed by a long slow decline as first passenger and then freight traffic was lost to the railways and then to road transport. In recent decades there would be renewed appreciation of their value for leisure, culminating in the Millennium Link reopening in 2001.

Scottish canals were a product of both Enterprise and Enlightenment, with many great names involved in their development such as engineers John Rennie, James Watt Hugh Baird and Thomas Telford, geologist James Hutton and the inventors William Symington (creator of the "Charlotte Dundas") and John Scott Russell. It took from first concept in 1793 until 1817 to get the Union Canal approved by Parliament. By 1849 ownership had passed to the Edinburgh & Glasgow Railway, and contraction would begin at both ends with infilling at Edinburgh in 1921 and closure a dozen years later of the locks that had connected the Union to the Forth & Clyde at Falkirk. Formally closed to navigation in 1965, the Union became a dumping-ground for rubbish, an eyesore and perceived risk to children, with frequent calls for it to be filled in throughout, but opinion would change and its revival as part of the £843M Millenium Link in 2001 would comprise Britain's biggest canal reopening.

Built primarily to convey coal, building materials and agricultural produce carried in horse-drawn vessels known as scows, the Union was designed as a contour canal hugging the 240 ft line, its only locks being those for the 30 ft drop at Falkirk, but it still had to negotiate topographical features with a tunnel at Falkirk and aqueducts across three rivers - the Water of Leith at Slateford, Lin's Mill across the Almond and the Water of Leith at Slateford, Lin's Mill across the Almond and the mighty Avon, tallest in Scotland and at the time of construction the second longest in Britain.. Use of iron troughs made these crossings more waterproof than the puddle clay deployed elsewhere. Water was drawn from Cobbinshaw Reservoir, built in a natural basin, with sluices owned and operated by the canal without which it would be dry, and water management was also required to control discharge from agricultural land and from residential developments.

At Port Downie, the junction with the Forth & Clyde, the site of the old Barr's Irnbru factory is being redeveloped as Scottish Canals' new headquarters. The old locks survive under a covering of soil, but no trace remains of a narrow-gauge railway that accompanied the flight. It was around here that John Scott Russell identified a wave created by the sudden stopping of a vessel, a phenomenon rediscovered in the 1990s and made appropriate by modern use of the towpaths to convey fibre-optic technology.

Edinburgh's demand for coal had originally been driven by the rising price of timber, and an early scow was found in the silt while excavating at the present Lochrin basin. Hailes Quarry provided another staple traffic, but in the early 1920s the London Midland and Scottish Railway sold the Port Hamilton and Port Hopetoun basins to Edinburgh Corporation for redevelopment. The Second World War saw some revival with the North British Rubber Company which paid for the water that it abstracted kept busy supplying apparel for the protection of the Home Guard, but decline thereafter was graphic until a grassroots movement got going to champion revival for the leisure benefits. Where the Canal had already been filled in at Wester Hailes, a new course had to be built using concrete rather than puddle clay. The Falkirk Wheel proved to be a masterpiece of innovation, the world's tallest ship lift that can raise and lower pairs of vessels using only the energy needed to power a dozen kettles.

Scottish Canals today possesses a diverse estate containing for example five lighthouses as well as two modern tourist icons in the shape of the Wheel and the Kelpies. An asset management plan is therefore needed to address competing priorities and guard against the risk of earthworks failures driven by global climate change. Regulatory interfaces are required with many agencies including Marine Scotland, Natural Scotland, Historic Environment Scotland, the Scottish Environmental Protection Agency, the Crown Estates and the Forth District Salmon Fishery Board. The canals together comprise no less than 42 scheduled ancient monuments, with classes of consent available for routine work, maintenance, health and safety issues including vandalism and for works provided under the enabling legislation. A sign of the times came in August 2020 when torrential rain washed away a 22 x 3 metre section of the towpath east of Polmont, buckling rails and stanchions on the adjoining railway. Sheet piling was required to restore the course of the canal, whose appearance will soften in time. Measures to cope with climate change include concrete modular weirs with telemetric monitoring of water levels, and by functioning as Smart Canals they can assist by taking floodwater away from new housing developments.

During lockdown canals came further into their own in offering easily accessible landscapes for walking and angling whose quiet appreciation benefits mental health - and more energetic opportunities are provided by rowing clubs and by cycling and running along the towpaths. Former lock-keepers' cottages offer holiday accommodation in some places, while at others there are residential moorings which provide Scottish Canals with an income-stream, as does retail at places like the Falkirk Wheel. Sustrans have become substantial investors in upgrading towpaths for active travel. In drawing on such support, Scottish Canals must prioritise the management of water and of the ancient monuments in order to ensure that these historic assets may remain fit for the purposes that will be expected of them over the next 200 years.

Report and photograph by John Yellowlees.