Civil Engineering heritage: Scotland - Highlands and Islands
Date 2007
Event ID 934200
Category Descriptive Accounts
Type Publication Account
Permalink http://canmore.org.uk/event/934200
Kinlochleven Hydro-Electric Works and Blackwater Dam
(Institute Civil Engineers Historic Engineering Works no. HEW 0611/0611)
The Loch Leven Water Power Acts of 1901 and 1904 authorised the generation of electricity for the production of aluminium in the West Highlands. Work on what was the first major hydro-electric project in Britain began in 1905 by harnessing the water power available from the
western section of the Blackwater chain of lochs stretching from Rannoch Moor to Kinlochleven and was completed in 1909 at a cost of about £600 000.
The Blackwater was dammed to create an 8-mile long reservoir drawing on a catchment area of about 55 square miles. Water from the dam was led to a generating station at the head of Loch Leven which supplied electricity to the aluminium smelters and associated works. The Pelton
wheel turbines produced an aggregate power of 30 660 hp with an generator output of 21 088 kW.
The main feature of the hydro scheme was a mass concrete gravity dam 3112 ft long and 86 ft high. It was necessary to amend the cross-section of the dam when it was found that the unit weight of concrete made with
locally obtained aggregate was less than that used previously in calculations. The dam profile was amended to give a heavier section with a base 62 ft wide and a factor of safety against overturning of 2.28.
The dam, with a storage capacity for 24 billion gallons, was connected to the 25MW generating station through a closed concrete conduit 3 1/2
miles long and six steel pipes each 39 in. diameter and 935 ft long.
The transport of materials to site from the wharf at Loch Leven was by means of a cableway 6 1/2 miles long with trestles from 10 ft–130 ft high and spans from 100 ft–1000 ft driven by a 250 hp Pelton wheel. A railway between the same termini followed the general contour of the valley
except for two rope inclines of 200 ft and 600 ft rise. This and the derricks at the dam were electrically driven, the power being obtained from a temporary hydro-electric plant provided by the contractor.
The works were designed by Thomas Meik and Sons with Sir A. R. Binnie consulting and the resident engineer A. H. Roberts. The main contractor was Sir John Jackson Ltd, and during construction between two and three thousand navvies laboured in rain-soaked conditions. During one period of 24 hours 5.59 in. of rain fell at Kinlochleven drowning the inner shell dam by 15 ft but it stood perfectly. Robert McAlpine & Sons constructed the jetty and laid the water mains throughout the village.
R Paxton and J Shipway, 2007.
Reproduced from 'Civil Engineering heritage: Scotland - Highlands and Islands' with kind permission from Thomas Telford Publishers.
