Listed Building: LOCHABER HYDROELECTRIC SCHEME AND ALUMINIUM SMELTER, POWERHOUSE (EXCLUDING PIPES TO WEST) (LB51965)

Description William Halcrow, supervising engineer; Balfour Beatty general engineers, 1929. Deep single-storey, roughly 25-bay, rectangular-plan powerhouse of red brick with some carved sandstone panels. Part of large high-head hydro-electric scheme which supplies electricity to adjacent aluminium smelter. Red brick with some sandstone ashlar dressings. Pilastered with band course at upper ground floor (on brick corbels above main doorway) and banded eaves course with blocking course to corners. Large opening to far left (N) with metal roller door, fielded sandstone panel above inscribed THE LOCHABER POWER COMPANY. Adjacent single bay return with pilastered and corniced sandstone ashlar pedestrian doorway in recessed round arched surround with scrolled panel dated 1929 and inscribed LPC, to arch. W elevation roughly 25 pilastered bays each containing tall keystoned round arched multi-pane windows with deep sandstone ashlar transoms to top. Banded base and eaves courses (eaves corbelled between pilasters). Penstocks with control valves run perpendicular to W elevation.INTERIOR: plain interior with decorative tiled floor, painted and plastered interior brick walls. Travelling crane on steel buttresses, steel lattice roof trusses. Notes This powerhouse is a significant example of the application of hydropower to major industry at the adjacent aluminium smelter, and part of one of the most significant civil engineering schemes of the 20th century. The powerhouse utilised the head of water created by the construction of two dams at Laggan and Treig (see separate listings), with the later addition of the Spey dam to increase capacity during World War II. It originally contained five 6,800kW generators, with the turbines set deep down into an excavated chamber to maximise the available head of water. The architectural treatment of the building is the combination of functional design with a classical Modern style, characterised by the sharply rectangular pilasters and severe profile of the building fused with the detailed classical doorpiece and mural panels. The Lochaber powerhouse and smelter were part of one of the most significant British engineering achievements of the twentieth century. The creation of a pressure tunnel bored through solid bedrock under the flanks of Ben Nevis to connect the powerhouse with the Laggan and Treig reservoirs was a major technological achievement, as was the Treig dam (see separate listing) which received international attention as the first example of a rock-fill embankment dam in Scotland. The scheme was designed to a very high degree of detail, capturing every available water supply available and was highly efficient. The development of the Lochaber scheme predates the 1943 Hydroelectric (Scotland) Act which formalised the development of Hydroelectricity in Scotland and led to the founding of the North of Scotland Hydroelectric Board. Those developments which predated the 1943 act were developed by individual companies as a response to particular market and topographic conditions. The completion of a number of schemes (including Galloway, Grampian and those associated with Alcan (see separate listings) without a national strategic policy framework is exceptional as is the consistency of high quality aesthetic and engineering design across all of the schemes. Sir William Halcrow was one of the foremost engineers of the 20th century, and was highly experienced in the development of hydroelectricity having served his apprenticeship with Thomas Meik and Sons who were responsible for both Kinlochleven and Lochaber water power schemes on behalf of the British Aluminium Company (see separate listings). His work on the Grampian scheme came in between the Kinlochleven and Lochaber developments, and his experience in developing the Kinlochleven scheme can clearly be seen in the highly efficient pioneering nature of the Tummel Garry development. Halcrow's association with hydropower and water engineering was longstanding and after 1943 he went on to work on a number of projects for the North of Scotland Hydro-Electric Board including the Glen Affric and Glen Morriston schemes. The company also completed work elsewhere in the UK and overseas. Later alterations to the powerhouse have included the insertion of new turbines and generators to convert from DC to AC supply. EXCLUSIONS: the pipes which run from the rear (west) of the powerhouse to the surge chamber are excluded from this listing. (Reviewed as part of Hydroelectric Power Thematic Survey, 2010) References Peter Payne, The Hydro: a study of the development of the major hydro-electric schemes undertaken by the North of Scotland Hydro-Electric Board, 1988, p. 6; Emma Wood, The Hydro Boys,2002, p. 39; The Lochaber Water Power Scheme; Concrete and Constructional Engineering IV (1909) p. 585-587; Alcan, Aluminium in the Scottish Highlands; The British Aluminium Co. Ltd, The Lochaber Water Power Scheme