Power and Beauty in the Glens: Loch Sloy Dam Part 1

It was freezing cold, with snow in the air and on the hills, and colder the higher we went. But, as so often when walking in Scotland, we knew the destination would be worth it. And that destination was the Loch Sloy dam, flanked by the mighty and rugged Ben Vorlich.

Parking at Inveruglas Visitor Centre on the west bank of Loch Lomond, we followed the signposts for Loch Sloy & Hills, which took us past the impressive Loch Sloy Hydro-Electric power station. Construction of the dam began in May 1945 and was the first in the North of Scotland Hydro-Electric Board’s revolutionary scheme. Work was completed in 1949 and the station officially ‘switched on’ in October 1950. The construction work was back-breaking and dangerous, with twenty-one men losing their lives in the process.

Loch Sloy Hydro-Electric station on Loch Lomond

The dramatic history of ‘Power from the Glens’ has long interested me. The water for this power station comes from Loch Sloy, high in the hills, with its massive dam, 56 metres high and 357 metres long. From here it is channelled through a 3km tunnel, hewn through of the massive side of Ben Vorlich. On reaching the valve house it thunders down through four mammoth pipes to drive the turbines below.  Such is the power of the water that the station can generate enough electricity to meet sudden peaks in demand, reaching full-capacity within 5 minutes of a standing start!

It’s a straightforward walk, a round-trip of 11km. When you reach the access road to the dam, walk under the railway bridge and then it’s up! And the higher you go, the better the views of Loch Lomond and the surrounding hills become. The construction of the Loch Sloy dam and power station was, quite literally, a groundbreaking start to one of the most progressive and far-reaching engineering projects in the world. So when you reach the dam, take a look at your map, and wonder at how it was possible, all those years ago, to carve such tunnels through these mountains. Some of the work force were even prisoners-of-war awaiting repatriation. In a booklet published by Scottish Hydro Electric, due credit is given to these men:

After the Second World War, men from all over Scotland came to work on the schemes, attracted by high wages. The highest wages were earned by the men who dug the tunnels. Germans, Poles and Czechs were acknowledged to be skilled tunnellers. They became known as the ‘Tunnel Tigers’ because of their cavalier approach to safety in their quest to earn the huge bonuses that were available. The lower regard for health and safety issues than there is today inevitably led to high accident rates and deaths amongst the workers. No definitive accident statistics exist, but in one camp alone, which housed some 1,000 workers at its peak, there were 22 deaths in just one year. For the vast majority of workers the rewards were great. In the late 1940s, a ‘Tunnel Tiger’ could expect to earn up to £35 a week, compared to £3 or £4 for a Highland estate worker. Mostly they lived in temporary work camps built near the construction sites. Not surprisingly, the sites looked like military camps, sometimes housing up to 3,000 men.”

The scheme was masterminded by Scottish politician Tom Johnston (1881-1965) and, under the auspices of the North of Scotland Hydro-Electric Scheme, succeeded in bringing power to the glens in a way never before imaginable. By 1963 90% of the Highlands were attached to the grid, more than twice as many as when the scheme began just after the Second World War. ‘Power from the Glens’ ultimately changed the face of rural Scotland and the benefits continue to this day.

Their achievements are all the more remarkable given the harsh conditions and often unforgiving terrain they had to work in, and we owe them a great deal. For not only is Scotland a country of great natural beauty, but it’s also one rich in natural resources. And so it’s doubly remarkable that Tom Johnston and his fellow visionaries harnessed hydro-power without damaging the landscape, and also left dams and power stations of great stature and beauty.

As renewable and sustainable energy become increasingly important, the hydro-power schemes these men bequeathed us become equally more significant. We need renewable energy like hydro-power: and in a country of rivers, lochs and plentiful rain, hydro-power is definitely here to stay!

Snow- and cloud-capped Ben Lomond from the road to Loch Sloy dam

Loch Lomond and The Trossachs National Park

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