Jump to content

Tummel hydro-electric power scheme

Add links
Coordinates: 56°42′54″N 3°56′20″W / 56.715°N 3.939°W / 56.715; -3.939
From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by Skenu (talk | contribs) at 10:59, 14 June 2021 (add Sub-headings). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

56°42′54″N 3°56′20″W / 56.715°N 3.939°W / 56.715; -3.939

Pitlochry hydro-electric power station and River Tummel.

The Tummel hydro-electric power scheme is an interconnected network of dams, power stations, aqueducts and electric power transmission in the Grampian Mountains of Scotland. Roughly bounded by Dalwhinnie in the north, Rannoch Moor in the west and Pitlochry in the east it comprises a water catchment area of around 1,800 square kilometres (690 sq mi)[1] and primary water storage at Loch Ericht, Loch Errochty, Loch Rannoch and Loch Tummel, in Perth and Kinross. Water, depending on where it originates and the path it takes, may pass through as many as five of the schemes nine power stations as it progresses from north-west to south-east.[2] The scheme was constructed in the 1940s and 50s incorporating some earlier sites. It is currently managed by SSE plc.

Early Development

With a growing need for electricity in the central belt of Scotland[3] individual power stations at Rannoch and Tummel Bridge plus associated dams and infrastructure were constructed in the 1930s for the Grampian Electric Supply Company.[4] These were notable for being the first storage high-head stations, where water is held in a reservoir above the power station, rather than simply relying on water passing as part of the run of the river as had previously been done in Scotland.[5]

Water started in the catchment of Loch Ericht, where a dam was built to raise the natural level by 14 feet (4.3 m) which, along with a 5 feet (1.5 m) deepened section of loch, resulted in approximately 78,050 acre feet (96,277,000m3) of water storage. Water would then pass through tunnels and increasingly narrow pipes, reducing from 12 ft 4 in to 7 ft 10.5 in (3.7 m to 2.4 m), as it dropped the 485 feet (148 m) to Rannoch power station on the northern bank of Loch Rannoch. At that time Rannoch was fitted with two 22,000 hp (16,500 kW) water turbines with provision for a third. Steel towers, some 97 feet (30 m) high, carried 132 kVA power lines east along the bank of the Loch.[6]

Loch Rannoch formed the main storage for the next station in line at Tummel, about 8 miles (13 km) downstream to the east. A weir was built at Kinloch Rannoch to regulate the depth of Loch Rannoch to 8 feet (2.4 m) with water passing down the River Tummel for 5 miles (8.0 km) to a narrow point where Dunalastair dam was constructed creating an artificial loch known as Dunalastair Water. From here an open aqueduct carried the water the remaining 3 miles (5 km) to Tummel where a head of 170 feet (52 m) was provided for two 24,000 hp (18,000 kW) horizontal generators with the electricity generated connected into the same transmission line as Rannoch.[6] The discharge water then rejoined the river Tummel for 2 km before entering Loch Tummel.

The various works were designed and built by Balfour Beatty with consultant engineer William Halcrow.

Main Scheme

Background

In the early 1940s various schemes were proposed for electricity development across Scotland and the North of Scotland Hydro-Electric Board was established in 1943 to undertake some of them. The schemes, including the then named Tummel-Garry Scheme, were not universally welcomed[3] and this resulted in the resignation of the first chair of the board. Tom Johnston (British politician) was appointed to run the board in 1946 successfully completing many projects by pushing an agenda of social change through development.[7][8] Edinburgh based architect Harold Tarbolton of Tarbolton & Ochterlony was part of the NoSHEB architectural panel, along with Reginald Fairlie and James Shearer. The panel was responsible for much of the design of the later scheme's structures several of which are now listed. Listings include Pitlochry which is Category A (defined as "Buildings of special architectural or historical interest which are outstanding examples of a particular period, style or building type.") and is described by Historic Environment Scotland as "an outstanding example...a bold modernist design by Harold Tarbolton." [9] Many of the scheme's buildings were engineered by Sir Alexander Gibb and Partners.

The earlier Tummel Bridge and Rannoch power stations are also listed as Category A, being designed in "a simple classical style and with a bold outline."[5][10]

Water route

The 'green energy trail' map[11] shows the completed scheme as offering four main water paths all of which ultimately arrive into Loch Tummel to feed the Clunie and Pitlochry stations. From the north the highest storage point in the scheme is at Loch an t Seilich (427 m above sea level). Water passes through a tunnel to Loch Cuaich at 397m to feed the Cuaich station discharging in to the north-east end of Loch Ericht at 359 m.

Alternatively water from Loch Garry at 415m feeds west through a tunnel to Ericht power station to also join Loch Erich. The combined water, along with Ericht's own catchment, then feeds to Rannoch and onto Tummel as per the 1930s scheme.

From the west water from Rannoch Moor is impounded at Loch Eigheach on the River Gaur to feed Gaur power station before discharging along the river and into Loch Rannoch to join the Ericht feed as well as Loch Rannoch's catchment.

In the centre of the system water from the River Bruar and River Garry is fed to storage at Loch Errochty at 329 m. Here it feeds directly to Errochty power station discharging into the mouth of the River Tummel. Some bypass water, used to maintain a small river known as the Errochty Water, is used to generate power at Trinafour.

Regardless of path the water arrives at Loch Tummel where it is impounded by the Clunie Dam located in a narrow valley at the eastern end of the loch. This creates a reservoir with a capacity of 36,400,000 cubic metres. [12] Water then passes through Clunie station to Loch Faskally which feeds the Pitlochry station.

The scheme power stations are generally, though not exclusively, named for their physical location as opposed to their feedstock. For example; Loch Ericht station is fed from Loch Garry but is adjacent to, and discharges into, Loch Ericht. A notable exception is Errochty power station, which discharges into Loch Tummel. It is also known as Tummel Bridge to disambiguate from the nearby, pre-existing Tummel station.[13]

Power Station Information[8][14]
Station Name Capacity (MW) Head of Water (m) Year Completed
Cuaich 2.5 27 1959
Ericht 2.2 55 1962
Rannoch 44 156 1930
Gaur 7.5 30 1953
Tummel 34 53 1933
Errochty (Tummel Bridge) 75 186 1957
Trinafour 0.5 91 1959
Clunie 61 53 1950
Pitlochry 15 15 1950

The scheme has nine named dams and one weir. The 1930 dam at Ericht (for Rannoch) appears to have been extended as part of the later scheme.

Listed by SSE[14] as main dams are: Gaur, Errochty, Clunie and Pitlochry. Other dams are at Ericht, Dalwhinne, Dunalastair, Cuaich[15], and Tromie (Lochan-t-Seilich). A significant weir at Kinloch Rannoch is also part of the scheme.

Dam information[14][16][17][12]
Dam Name Type Height (m) Length (m) Year Completed Approximate Altitude
Gaur (Loch Eigheach) Concrete Gravity 13 110 1958 259
Errochty Buttress 49 501 1957 329
Clunie (Loch Tummel) Concrete Gravity 21 116 1951 144
Pitlochry Mass Gravity 16 145 1951
Ericht Concrete Gravity 14.5 340 1930 / 54 359
Dalwhinne Concrete Core embankment 4.5 350 1954
Dunalastair Concrete Gravity 11 88 1933
Kinloch Rannoch Weir 1930s
Cuaich 397
Tromie
Clunie Concrete Gravity 21 116 1951

References

  1. ^ "updating-the-floodgates". Water Power Magazine. 3 March 2010. Retrieved 13 June 2021.{{cite web}}: CS1 maint: url-status (link)
  2. ^ "Kinloch Rannoch Weir, Tummel Valley Scheme". Green energy trail. Retrieved 13 June 2021.{{cite web}}: CS1 maint: url-status (link)
  3. ^ a b Ross, Duncan. "Contested Energy: A Long-term Perspective on Opposition to Renewable Power Developments in Scotland" (PDF). European Business History Association. Retrieved 13 June 2021.{{cite web}}: CS1 maint: url-status (link)
  4. ^ "A REAL GEM IN HYDRO HISTORY". SSE Renewables. 30 November 2020. Retrieved 13 June 2021.{{cite web}}: CS1 maint: url-status (link)
  5. ^ a b "GRAMPIAN HYDRO ELECTRIC SCHEME, RANNOCH POWER STATION". Historic Environment Scotland. Retrieved 13 June 2021.{{cite web}}: CS1 maint: url-status (link)
  6. ^ a b "SCOTTISH POWER COMPANY. THE_HYDRO-ELECTRIC POWER WORKS OF THE GRAMPIAN ELECTRICITY SUPPLY COMPANY". Graces Guide. Retrieved 13 June 2021.{{cite web}}: CS1 maint: url-status (link)
  7. ^ "TUMMEL GARRY HYDRO ELECTRIC SCHEME, ERROCHTY DAM INCLUDING TUNNEL INTAKE GATEHOUSE". Historic Environment Scotland. 11 February 2011. Retrieved 13 June 2021.{{cite web}}: CS1 maint: url-status (link)
  8. ^ a b SSE. "Power from the Glens" (PDF). SSE. Retrieved 20 December 2019.{{cite web}}: CS1 maint: url-status (link)
  9. ^ "TUMMEL GARRY HYDRO ELECTRIC SCHEME, PITLOCHRY POWER STATION AND DAM, INCLUDING BOUNDARY WALLS". Historic Environment Scotland. Retrieved 13 June 2021.{{cite web}}: CS1 maint: url-status (link)
  10. ^ "GRAMPIAN HYDRO ELECTRIC SCHEME, TUMMEL POWER STATION". Historic Environment Scotland. Retrieved 13 June 2021.{{cite web}}: CS1 maint: url-status (link)
  11. ^ "Tummel Valley Scheme". Green Energy Trail. Retrieved 14 June 2021.{{cite web}}: CS1 maint: url-status (link)
  12. ^ a b Gregory, A. W. (2008). "Clunie Dam Anchoring Works" (PDF). British Dams. Retrieved 14 June 2021.{{cite web}}: CS1 maint: url-status (link)
  13. ^ "errochty-power-station". Canmore. 2010. Retrieved 13 June 2021.{{cite web}}: CS1 maint: url-status (link)
  14. ^ a b c SSE Renewables. "TUMMEL HYDRO SCHEME". SSE Renewables. Retrieved 13 June 2021.{{cite web}}: CS1 maint: url-status (link)
  15. ^ "Cuaich Dam". Canmore. Retrieved 13 June 2021.{{cite web}}: CS1 maint: url-status (link)
  16. ^ Dempster, K (2004). "Ericht and Dalwhinnie Dam refurbishment and protection works" (PDF). British Dams. Retrieved 13 June 2021.{{cite web}}: CS1 maint: url-status (link)
  17. ^ Morison, A. C (2010). "Dunalastair Emergency Response" (PDF). British Dams. Retrieved 13 June 2021.{{cite web}}: CS1 maint: url-status (link)
Wikimedia Commons has media related to Tummel hydro-electric scheme.


This article about a British power station is a stub. You can help Wikipedia by expanding it.

Retrieved from "https://en.wikipedia.org/enwiki/w/index.php?title=Tummel_hydro-electric_power_scheme&oldid=1028504746"