Were there two wind turbines tested on South Barrule on the Isle of Man in the early 1960s, not just one? That’s the inescapable conclusion from photos that have recently come to light.
During research for an article on the development of the modern wind turbine, (see History of Conventional Wind Turbines Published—Finally) Etienne Rogier pointed me to rare documents on the 100 kW Isle of Man wind turbine. This long-forgotten wind turbine was an unheralded success of the early British wind program.
The 100 kW Isle of Man turbine (see Another Long-Forgotten Wind Turbine–This Time on the Isle of Man) is listed in the 1976 re-issue of E.W. Golding’s classic The Generation of Electricity by Wind Power.[1]
Though Golding died in 1965 the oil crisis of the 1970s stimulated renewed interest in wind energy, leading to his book being reissued in 1976 with an additional chapter by R.I. Harris, Director of Sciences Research Unit at the College of Aeronautics, Cranfield Institute of Technology. This includes Table A1 on page 323 which lists wind turbines not mentioned by Golding in his table on page 220 of the book proper. It is in this table by Harris that the Isle of Man turbine was listed, along with a mysterious Dowsett wind turbine. Harris comments that several of the “Dowsett” turbines had been manufactured. However, he provides no further information on the Dowsett turbine except what was listed.
Recently, David Wales contacted me about records kept by his father John (J.R.) Wales who had worked for Britain’s ERA (Electrical Research Association) from 1958 through 1965.[2] These records included rare photos of the wind turbines tested on the Isle of Man, including the 100 kW unit and another simply labeled “The Isle of Man Windmill.”[3]
At first glance I thought it was a Geman Algaier developed by Urich Hütter. Upon closer inspection it clearly was not an Algaier. David Wales soon thereafter sent some additional documents and it became clear that this was the long lost “Dowsett” wind turbine.
The site is the same one in the photos of the 100 kW Isle of Man turbine. At the bottom right of the photo of the Dowsett turbine is the fantail from the 100 kW unit laying near the shed. J.R. Wales’ timeline on the testing of the Dowsett wind turbine specifically mentions the Isle of Man Electricity Board.
This is the data on the “Dowsett” wind turbine listed by Harris.
Diameter: 42 feet (13 m)
Rated Wind Speed: 25 mph (11 m/s)
Generator: 25 kW induction (asynchronous)
Rotor: 3 blades (uncertain whether upwind or downwind)
Overspeed Control: Variable pitch hydraulic
TSR: 3.9
RPM: 65
Tower: 33 feet (10 m)
Note that the table by Harris lists characteristics that appear incorrect for both machines. Harris notes that the 100 kW Isle of Man turbine used a tail vane. It did not, at least in the photo documentation I have. Similarly, Harris’ table shows the Dowsett turbine using twin fantails. It does not. The photo shows only one fantail.
Both turbines were connected to the lines of the Isle of Man Electricity Board.
The 25 kW Dowsett machine was seldom operated unattended, mostly for a few months in 1959. It then operated sporadically during tests from 1960 to 1964. It ran on “automatic control” in late 1964. Altogether, the turbine generated less than 24,000 kWh during the entire period at one of the windiest sites in Great Britain.
One photo, likely taken by J.R. Wales, shows damage to a gear inside the transmission after conclusion of the tests.
[1] Golding, E.W. The Generation of Electricity by Wind Power. Reprinted by John Wiley&Sons 1976. E. & F.N. Spon, 1955. Table A-1, page 323.
[2] J.R. Wailes DFH, MIEE (Diploma Faraday House & Member of Institute of Electrical Engineers) was a professional electrical engineer practicing in Great Britain.
[3] Wales, David. 2021 Article – Isle of Man Wind Turbine. personal communication. August 12, 2025, and Wales, David. Isle of Man 100 kW Dorsett 25 kW Wind Turbines. personal communication. August 31, 2025, and Wales, David. J.R. Wales Title. personal communication. September 1, 2025.
