Cruachan was the brainchild of Sir Edward McColl, a Dumbarton-born engineer and pioneer of hydro power in Scotland.
Having started his career at the Glasgow Corporation and Clyde Valley Electric Power Company, McColl turned his attention to bringing hydroelectricity to the Highlands and conceived the idea for Cruachan Power Station in the 1930s.
Tom Johnston pushes Cruachan through parliament Tom Johnston, a native of Kirkintilloch and wartime Secretary of State for Scotland, was a huge advocate of hydroelectric power in the region. When he came across the scheme for the Hollow Mountain he forced it through Parliament in 1947.
Design begins The designer of Cruachan was James Williamson, a civil engineer from Lanarkshire. A lot of time was spent at the design stage, optimising all aspects of construction and operation. Many working models of the turbines were built and work tests were carried out on completed alternators before being delivered to the site.
The Tunnel Tigers get to work During the six years of construction, there was a large workforce of 1,300 men, affectionately known as the Tunnel Tigers. But before they could build the power station inside the mountain, they had to drill and blast into it. The men used handheld air drills to bore holes in the solid granite rock, which were then packed with gelignite and blasted.
Because of the limitations of local roads and the size of the access tunnel, all the equipment had to be broken down into manageable loads for transportation. The first plant items to be installed were the turbine casings, which were mounted at the lower levels of the cavern.
Connecting Cruachan A 275,000V transmission line was constructed to carry power from the top of the cable shaft just in front of the dam to Dalmally substation, five miles east of Cruachan, and then on to Windyhill, north of Glasgow. This line remains in place today, passing through rough terrain and reaching 550 metres above sea level at its highest point.
The Royal Opening Cruachan Power Station was officially opened by Her Majesty The Queen on 15 October 1965. It was the first reversible pumped storage hydro system on this scale to be built in the world.
Reaching full load At the time The Queen officially opened the power station just two of the turbines were completed and operational. It was with the two remaining turbines coming into service in 1966 and 1967 that the Cruachan Power Station reached its full capacity.
