OnThisDay 1951: An experimental wind turbine was being erected at Costa Head

[DamonHD]

https://twitter.com/BBCArchive/status/1470075978240118795

"If successful - it will represent another step in harnessing the power of the elements"

edit: didn't notice "Orkney" getting mangled at the end of the title!

[taylorp035]

Thanks for sharing that.  Shutting down at 70 mph seems fairly aggressive, but if they average 30 mph winds, I suspect the blades were fairly small for the size of generator.

[MattM]

1,000 kilowatts isn't very small IMHO.

[SparWeb]

Thanks Damon!

The Orkneys are even more hostile than Hugh's little island.

[Adriaan Kragten]

In the Dutch report "Windenergie" dictaatnr. 3323 of the University of Technology Eindhoven of 1974, there is a photo of this wind turbine at page 34. I have scanned this picture and added it as an attachment. The rotor has three very slender blades. It is unclear to me if the rotor is turning in front of the tower or at the back side. It is mentioned that it has a 100 kW generator.

[Bruce S]

Adriaan;
Is that active pitch mechanism I see in the scanned picture?

Bruce S

[Adriaan Kragten]

Adriaan;
Is that active pitch mechanism I see in the scanned picture?

Bruce S

In the report there is no detailed technical information about this wind turbine. So everything must be derived from the photo. I think that the rotor is turning before the tower and that it is turning left hand like traditional windmills do. It seems that the airfoil starts at about 0.25 R from the hub center and that the inner part of the blade is a round rod. For the right blade, there is a separate beam in parallel to the central rod and so it might be that the blade has an active pitch mechanism which is activated by this rod. Pitch control would be very advanced for that time.

[Adriaan Kragten]

I own the nice book: "The generation of Electricity by Wind Power of E. W. Golding. The first print is of 1955 and I have a reprint of 1976. This book contains another photo of the 100 kW wind turbine of John Brown at Costa Hill at the Orkney Islands (Plate XXIV). All plates in this book are put together in between page 78 and 79. There is a reference to plate XXIV at page 223 but no more information is given there. Table XXXII is given at page 220 and 221. In this table, some basic technical information is given about a range of wind turbines. Information about the wind turbine at Costa Hill is given at John Brown, Ref. 60. Ref. 60 is the article: "The Orkney Windmill and Wind Power in Scotland" from J. Venters published in The Engineer, 27th January 1950. The following is mentioned at page 221 in the columns of table XXXII.

Project or machine: John Brown
Ref.: 60
Rotor diameter (feet): 50
Rated wind speed (m.p.h.): 35
Output (kW): 100 a.c. induction generator
Form of rotor: Three tapered untwisted blades free to cone and drag
Speed or output control: Hydraulic control of blade pitch
Optimum tip speed ratio: 6.5
Rotational speed of rotor (r.p.m.): 130
Tower height (feet): 78 to hub centre
Method of weather-cocking: Automatic electrical control

So the rotor diameter is 50 feet = 15.24 m which is rather big for that time. It is mentioned that the blades are free to cone and therefore I think that the rotor is turning behind the tower. This also matches with the torpedo shaped nacelle. However, this means that the rotor blades have to pass the tower shadow and this must have caused aerodynamic instability of the flow around the airfoil. It is also mentioned that there is hydraulic control of the blade pitch which is very sophisticated for a wind turbine of that time.

[MattM]

My guess is a helicopter's mast mechanism re-purposed as a wind turbine rotor.

[Adriaan Kragten]

My guess is a helicopter's mast mechanism re-purposed as a wind turbine rotor.

This might be true. To be sure, one should read the article in The Engineer of 1950 if it can be found somewhere.

[kitestrings]

Not much in the way of PPE for those early workers, huh?  Much was left to the daring, and chance of young men in projects like this (e.g. dams, suspension bridges, tunnels, mining)?

It doesn't seem from face value that the tower is anywhere near heavy enough for the size turbine.  As Adriaan suggested too, the tower shadow must have been significant, and with all those work platforms... it's a wonder if it held together long.

Thx for sharing.