Caledonian Canal

Year:1822

Duration:18 years

Cost:£900,000 (£29m today)

Country: Fort William, Scotland

What did this project achieve?

Create an easier route for naval and commercial shipping to cut across Scotland

The Caledonian Canal is Scotland's longest inland waterway. It runs from Fort William in the west to Inverness in the east and follows the course of the Great Glen – a 100km long narrow valley – and cuts through Lochs Oich, Lochy and Ness.

The canal was designed to replace the hazardous Pentland Firth, a strait between the Orkney Islands and Caithness. Pentland Firth was then the main route for ships wanting to get from the east to the west coast of Scotland.

Critics said the canal couldn't be built as it would have to cut a course though the Highlands which is some of the most mountainous and difficult terrain in the UK.

Supporters said it could be done and saw the economic value of digging a massive canal across Scotland. Unemployment was very high at the time and the scheme would create jobs.

The country's weak economy had been made worse by the 'Highland clearances' of the previous 40 years. These were evictions from homes and farms across the region following a series of land grabs by aristocratic landowners.

Against this background Parliament passed an act in 1803 that commissioned engineer Thomas Telford to run the project.

Work started on the 97km canal in 1804. When it was finished in 1822 the scheme was 12 years over schedule and about £425,000 over budget – the equivalent of around £14m today.

Difference the canal has made

The Caledonian Canal created a new trade route across Scotland. It meant people and goods could be moved quicker and more safely. This helped boost both the local and national economies.

Building the canal created jobs both directly and indirectly. Later work (from 1843 to 1847 for example) also provided employment by extending and improving the waterway.

How the canal was built

The Caledonian Canal is 97km long. 60km of it is routed through the lochs Dochfour, Ness, Oichy and Lochy – leaving 37km of channel to excavate.

Building the artificial stretches of channel saw around 1,500 workers constructing a total of 29 locks. All of these were about the same size. At the time they were the biggest locks in the world – 55m long, 12.2m wide and 6m deep.

Engineers working on the canal faced significant environmental challenges. The Highland ground was hard and the Scottish climate harsh.

The project team was helped by some new technology, however. This included the first steam dredger seen in Scotland, purpose built in 1814.

The dredger, looking a bit like a flat-bottomed boat, was 24.4m long and 7m wide. It used 25 buckets on a 12.8m frame to scoop up material from the canal bed. Working at its best, the dredger could shift 91 tonnes an hour.

"​‌

The doubters, the grumblers, the prophets and the sneerers were all put to silence.

Inverness Courier

Local newspaper on the opening of the canal in 1822.

Fascinating facts

More than 300,000 tonnes of earth and stone were dug up to construct the canal's 29 locks – enough to cover a full size football pitch with a 25m deep pile of rubble.

Loch Ness is famous for the Loch Ness monster – also known as Nessie – a mythical aquatic creature that supposedly lives in the loch's waters. The earliest account of a monster sighting comes in a life of St Columba written in 565 AD.

The canal is now a popular tourist destination. It's still used as a shortcut for smaller commercial vessels.

People who made it happen

  • Principal engineer: Thomas Telford, ICE president
  • Consulting engineer: William Jessop

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