From sea to shining sea

On the 200th anniversary of the opening of Thomas Telford’s Caledonian Canal, Mary Miers explores the greatest manmade marvel of the Highlands

- Mary Miers

IN 1825, an unusual order from a Highland woollen mill was delivered to Dunaincroy near Inverness, where the recently opened Caledonian Canal was causing severe problems. So porous were the glacial gravels along this stretch that the waterway could not be maintained to the required 15ft level and so, faced with yet another setback, the engineer James Davidson chanced a radical solution. He ordered the basin to be drained and dredged, then had its bed and banks lined with webs of thick tweed and matting, over which was poured a layer of puddled clay and sand. It worked! The cloth provided a bond for the clay, which dried into a watertight skin, and the canal stopped leaking.

Sailing peacefully along the canal today, it’s difficult to imagine the challenges that beset Thomas Telford’s boldest feat of civil engineering. Politically controversial, vastly over budget and fraught with logistical problems, the Caledonian Canal was the HS2 of its day. When eventually it opened (unfinished) in 1822, it had taken 19 years, instead of the predicted seven, to construct and set the government back nearly £1 million (instead of the quoted £350,000). This was by no means the final bill.

Yet, there can be no doubting the marvel of Telford’s project, which introduced the north of Scotland to the industrial age. The Herculean task involved diverting roads and rivers, dredging lochs, cutting through rock and fossilised oaks, excavating millions of cubic yards of earth and building embankments, aqueducts, dams and 29 locks to create a navigable waterway across 60 miles of wild and uncharted terrain.