Ooops, hope they were insured or was it a "I hate windmills kinda thing." Thought you would all be interested in this, I suspect ball lightening myself. But it's worth a laugh.

Balveda


"No I said turn to the left!!!"

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I was just going to post this story.

Ice? Maybe, but doubtful.

Ball Lightning? Maybe, but why isn't anything burnt?

It's a thought provoking story given all the eye witness reports...

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I was just going to post this story.

Ice? Maybe, but doubtful.

Ball Lightning? Maybe, but why isn't anything burnt?

It's a thought provoking story given all the eye witness reports...

It's one of those things Andy, what is the liklier explaination? Ball lighting has been known to pass through aircraft without leaving a mark. Still be interesting to find out if they find some samples of unknown alloys on the damaged turbines.

Balveda

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I was just going to post this story.

Ice? Maybe, but doubtful.

Ball Lightning? Maybe, but why isn't anything burnt?

It's a thought provoking story given all the eye witness reports...

Still be interesting to find out if they find some samples of unknown alloys on the damaged turbines.

Yes, that's going to be the thing isn't it, but I don't believe for a moment the Government would let them announce an unknown alloy to the World, so this will get put down to Ice...

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I'm leaning toward the flying cow theory.

Yes, that's going to be the thing isn't it, but I don't believe for a moment the Government would let them announce an unknown alloy to the World, so this will get put down to Ice...

Are you suggesting that we should blame Ice? I thought that was Misfit's claim.

Seriously though ...

There is a considerable level of out of balance vibration in these machines, which is exacerbated by the changing/gusting wind requiring continuous monitoring and turbine blade adjustment/feathering.

Over a long time, balance weight can dislodge and make any slight out-of-balance vibration worse.

It has not been unknown for this vibration to damage the glass fibre structure of the blades and for them to break off. This means monitoring and detection systems are being developed to try and prevent this type of damage. The replacement and re-balancing costs are high.

More to the point, during cold weather, like we have recently seen in the UK, Europe and North America, icing of the blades leads to very strong out-of-balance vibration. This will be much more important for blade damage, like the historical icing of ship superstructure when in Arctic conditions.

The engineering of turbine shafts for out-of-true-rotation is moving to have rotating components machined to a tolerance of 5 micron max. That means the out-of-true rotation must be within + or - 2.5 microns. This engineering will be seen in new turbines during 2009/2010.

Inspite of rotating components being machined to very tight tolerances, the final out-of-balance problems still need to be re-balanced, just like the steering tyres of a car.

Yes, that's going to be the thing isn't it, but I don't believe for a moment the Government would let them announce an unknown alloy to the World, so this will get put down to Ice...

Are you suggesting that we should blame Ice? I thought that was Misfit's claim.

Seriously though ...

There is a considerable level of out of balance vibration in these machines, which is exacerbated by the changing/gusting wind requiring continuous monitoring and turbine blade adjustment/feathering.

Over a long time, balance weight can dislodge and make any slight out-of-balance vibration worse.

It has not been unknown for this vibration to damage the glass fibre structure of the blades and for them to break off. This means monitoring and detection systems are being developed to try and prevent this type of damage. The replacement and re-balancing costs are high.

More to the point, during cold weather, like we have recently seen in the UK, Europe and North America, icing of the blades leads to very strong out-of-balance vibration. This will be much more important for blade damage, like the historical icing of ship superstructure when in Arctic conditions.

The engineering of turbine shafts for out-of-true-rotation is moving to have rotating components machined to a tolerance of 5 micron max. That means the out-of-true rotation must be within + or - 2.5 microns. This engineering will be seen in new turbines during 2009/2010.

Inspite of rotating components being machined to very tight tolerances, the final out-of-balance problems still need to be re-balanced, just like the steering tyres of a car.

I'm not saying we should blame Ice at all. I am an avid believer in UFOs, having witnessed "unexplained" somethings 3 times during my short existence.

There is another take on this story here from the Register: http://www.theregister.co.uk/2009/01/08/ufo_turbine_prang/

Even the Turbine manufacturers say the damage is "unique" and they they, themselves, will not rule out a UFO until they can prove otherwise.

The thing that strikes me most is that there were UFO reports ahead of the damage occuring.

I'll sit on the fence on this one.

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Yes, that's going to be the thing isn't it, but I don't believe for a moment the Government would let them announce an unknown alloy to the World, so this will get put down to Ice...

Are you suggesting that we should blame Ice? I thought that was Misfit's claim.

Seriously though ...

There is a considerable level of out of balance vibration in these machines, which is exacerbated by the changing/gusting wind requiring continuous monitoring and turbine blade adjustment/feathering.

Over a long time, balance weight can dislodge and make any slight out-of-balance vibration worse.

It has not been unknown for this vibration to damage the glass fibre structure of the blades and for them to break off. This means monitoring and detection systems are being developed to try and prevent this type of damage. The replacement and re-balancing costs are high.

More to the point, during cold weather, like we have recently seen in the UK, Europe and North America, icing of the blades leads to very strong out-of-balance vibration. This will be much more important for blade damage, like the historical icing of ship superstructure when in Arctic conditions.

The engineering of turbine shafts for out-of-true-rotation is moving to have rotating components machined to a tolerance of 5 micron max. That means the out-of-true rotation must be within + or - 2.5 microns. This engineering will be seen in new turbines during 2009/2010.

Inspite of rotating components being machined to very tight tolerances, the final out-of-balance problems still need to be re-balanced, just like the steering tyres of a car.

You're quite right, Martin and I'm pretty sure that your summation is the correct one. The company that I used to work for, made bearings for wind turbines (amongst many other things) and it was work that had to be done to much tighter tolerances than most other RPBs (rotating plant bearings). The loadings involved can be huge and when you have things of that size, balance is critical to avoid a premature catastrophic failure. As you say, the cold weather causing icing, would also be a significant contributory factor.

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Don't take life too seriously, as you'll never come out of it alive!

I was just going to post this story.

Ice? Maybe, but doubtful.

Ball Lightning? Maybe, but why isn't anything burnt?

It's a thought provoking story given all the eye witness reports...

It's one of those things Andy, what is the likelier explanation? Ball lighting has been known to pass through aircraft without leaving a mark. Still be interesting to find out if they find some samples of unknown alloys on the damaged turbines.

Balveda

Do they know even to this day how ball lighting is made?

http://en.wikipedia.org/wiki/Ball_lightning

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Savoir-Faire is everywhere!
The T1 Trust, T1 Class 4-4-4-4 #5550, America's First HST

Apparently somebody was having an 80th birthday party in the area with fireworks etc. So the the reports of mysterious lights in the sky and 'fireballs' are most likely fireworks. However this still doesn't explain what happened to the turbine...

Apparently somebody was having an 80th birthday party in the area with fireworks etc. So the the reports of mysterious lights in the sky and 'fireballs' are most likely fireworks. However this still doesn't explain what happened to the turbine...

Maybe It's a Defective Blade?

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Savoir-Faire is everywhere!
The T1 Trust, T1 Class 4-4-4-4 #5550, America's First HST

Yes, that's going to be the thing isn't it, but I don't believe for a moment the Government would let them announce an unknown alloy to the World, so this will get put down to Ice...

Are you suggesting that we should blame Ice? I thought that was Misfit's claim.

Seriously though ...

There is a considerable level of out of balance vibration in these machines, which is exacerbated by the changing/gusting wind requiring continuous monitoring and turbine blade adjustment/feathering.

Over a long time, balance weight can dislodge and make any slight out-of-balance vibration worse.

It has not been unknown for this vibration to damage the glass fibre structure of the blades and for them to break off. This means monitoring and detection systems are being developed to try and prevent this type of damage. The replacement and re-balancing costs are high.

More to the point, during cold weather, like we have recently seen in the UK, Europe and North America, icing of the blades leads to very strong out-of-balance vibration. This will be much more important for blade damage, like the historical icing of ship superstructure when in Arctic conditions.

The engineering of turbine shafts for out-of-true-rotation is moving to have rotating components machined to a tolerance of 5 micron max. That means the out-of-true rotation must be within + or - 2.5 microns. This engineering will be seen in new turbines during 2009/2010.

Inspite of rotating components being machined to very tight tolerances, the final out-of-balance problems still need to be re-balanced, just like the steering tyres of a car.

You're quite right, Martin and I'm pretty sure that your summation is the correct one. The company that I used to work for, made bearings for wind turbines (amongst many other things) and it was work that had to be done to much tighter tolerances than most other RPBs (rotating plant bearings). The loadings involved can be huge and when you have things of that size, balance is critical to avoid a premature catastrophic failure. As you say, the cold weather causing icing, would also be a significant contributory factor.

Although the turbine, and wind farm concerned, has relatively small turbines (<50m at turbine centre). One needs to not forget these machines, including their tower, are now of the order of 90 - 95 metres at the turbine centre.

The blades are also of the order of 60 metres, giving a ground to blade sweep top point of 125 metres for the 2.3 MW models.

The ones planned for the UK's 7,000 offshore turbines will be using 5MW models with a sea bed to turbine top swept point in the order of 260 metres.

The rotating forces, vibration and wind effects on towers/turbines this large are complex and severe.

So the Mean Operating Time to Failure can be significant, which leads to demand for high quality design, materials and low costs are demanded

You have to love sensationalist Journalism :D

http://www.thesun.co.uk/sol/homepage/news/ufos/article2108149.ece

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You have to love sensationalist Journalism :D

http://www.thesun.co.uk/sol/homepage/news/ufos/article2108149.ece

That looks more like a story the Daily Sport would run, but milder. Clearly, they are in favour of keeping the truth out of a good story line.

You have to love sensationalist Journalism :D

http://www.thesun.co.uk/sol/homepage/news/ufos/article2108149.ece

Ah, The Sun..... No more needs to be said.

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Don't take life too seriously, as you'll never come out of it alive!