timeline item
Here is the information we have
on the item you selected
This entry was funded by
More like this
© 2020 Engineering Timelines
engineering timelines
explore ... how   explore ... why   explore ... where   explore ... who  
home  •  NEWS  •  search  •  FAQs  •  references  •  about  •  sponsors + links
Tongland Power Station
River Dee, Dumfries & Galloway, Scotland, UK
Tongland Power Station
associated engineer
Sir Alexander Gibb & Partners
date  1931 - May 1935
UK era  Modern  |  category  Power Generation  |  reference  NX694535
ICE reference number  HEW 1457/02
photo  © and licensed for reuse under this
Tongland Power Station and its associated dam and reservoir are at the southern end of the Galloway Hydro-Electric Scheme — the power station is the scheme's principal control station. It uses water from the scheme’s entire catchment to generate electricity for the UK's National Grid. Tongland was the first power station to be controlled remotely by a telephonic operating system.
The power station at Tongland is housed is a two-storey Art Deco building, fairly typical of the period. It is symmetrical in design and constructed in reinforced concrete. It houses three Francis turbines, each with a maximum output of 11MW, and each connected to a three-phase 11kV alternator. These were the largest turbines of their type installed in Britain when the station began operating — at peak load the total water consumption is 4,240 cu m per second.
The Tongland complex consists of the power station, a dam and its reservoir, and rock-drilled and concrete aqueduct tunnels that feed the water to the power station. The dam is some way north of the power station and combines a concrete arch with a mass concrete gravity structure. The whole is 298m long and the arch section is 21.3m high. The dam impounds 8.8 million cu m of water in a long narrow reservoir to the north.
Water leaves the reservoir though a 33.5m wide intake on the west bank near the dam. It flows into a 146m long tunnel excavated through bedrock and lined with concrete. This connects to a 1km reinforced concrete aqueduct tunnel that is a flattened circle in cross section, with axes of 6.7m wide and 5.5m high. These proportions produce an approximately uniform circumferential stress in the steel reinforcement not exceeding 82,740kN per square metre under varying internal pressure.
At the end of the aqueduct is a 30.5m diameter steel surge tower (visible behind the building in the above photo) where the water enters a trifurcating steel pipe, emerging through three 3.5m diameter pipes connected to the valve house then on to the final 24m run downhill to the power station's turbines. Spent water discharges in the River Dee, which is tidal at this point, and thence into the Solway Firth.
The power station can operate with a net head of water of 29-34.75m. Power is generated at 11.5kV and then stepped up to 132kV for transmission to the National Grid by a transformer compound located on the opposite side of the nearby A711 road.
The Tongland dam complex was completed in 1934 and the power station commissioned in May 1935. As was mentioned, this was the first power station to be controlled remotely using a telephonic operating system, and is now activated from a control centre at Glenlee Power Station (NX606805). Much of the equipment at Tongland is original and in working order.
The power station building was listed as Category B in April 1990 and upgraded to A in July 2002. Celebrations for its 75th anniversary on 1st February 2010 included the unveiling of a commemorative plaque and the opening of the refurbished visitor centre. Scottish Power's Galloway Hydros visitor centre is also located here, providing information about the entire scheme.
Contractor: Payler & Son, Glasgow
Contractor (dam): John Howard & Co Ltd
Contractor (surge tower): William Taylor & Son (Glasgow) Ltd
Rack cleaning machine: Blakeborough & Co Ltd
Generating machinery: English Electric Company Ltd
Research: ECPK
"Modifications to a Fish Pass at Tongland Dam" by A. Ervine, B. Couvel, J. Stuart and C. Carnie, Scottish Power and University of Glasgow, 1998
"Galloway Hydro-Electric Scheme" information leaflet
available at www.scottishpower.com
"Galloway Hydros" series of factsheets available at www.spenergywholesale.com
reference sources   CEH SLB

Tongland Power Station