Death Of A Windturbine

[gozone]

Today, we have had a bit of stormy weather around here where i live, and this turbine is situated approx. 2 miles from my house..

Tecnicians had been alerted of a malfunctioning braking system, but they soon realised, that there was nothing that could be done, and evacuated the turbine, and set up a safety perimeter..

Good plan, i think, as having worked as a turbine mechanic earlier..

Watch this video, and see what happens to the turbine:

Cheers..

Michael

[blakeatron]

ouch! so how many KW was that making before destruction?

[gozone]

LOL, i dont know, but surely more than it was rated for. ..

[RichieRich]

Amazing. I don't think people realize how big these are. The ones we have out in the California desert are so large, you can stand inside the blades.

[madaz75]

Gor!

It literally exploded..

good thing they set up a safety perimeter.

[callum40]

cool that was well good!!!!

[ryanbored]

Amazing. I don't think people realize how big these are. The ones we have out in the California desert are so large, you can stand inside the blades.

Imagine how dizzy you'd be after getting out again!

[TWINSET]

Amazing. I don't think people realize how big these are. The ones we have out in the California desert are so large, you can stand inside the blades.

Here's a couple of blades heading north up the UK last year

[ryanbored]

Geez, Imagine the turkey that thing could carve on christmas!

[RichieRich]

Looks like a giant prehistoric whale fin.

[Tamiya1/10]

Just curious. What is the amount of energy required to make, transport and install one of these wind turbine in relations to the amount off energy that it can generate over its useful life? I wonder are we ahead using alternative energy or we are just playing the environemental game with the existing technology. I think by making machine that are more efficient and use them more prudently will likely save more energy than by dotting the land scape with windmills or solar panels.

[ryanbored]

Valid point 1/10. One would assume that they have looked into this sort of thing. Ah, unreserved faith in our government. Ignorance is bliss!

[gozone]

The same crash, from a slightly different angle.. Note the service-truck close to the turbine..

[Stefan(2)]

Some more wind damage

Last night on the factory i spend many hours working.

Cargill , Sas van Gent

It almost went fully acording to the tech guys

could give a nice -bang- but, not so big as that turbine!

Stefan

[Wireless]

From the grainy video it's hard to see what happened. Looks to me like a blade failed under load, the sudden deceleration caused by the aerodynamic braking from the failed blade then caused the other two to let go in quick succession as they too were right at the limit.

Reminds me of my Kyosho Concept 30 from 2 weeks ago...!

[gozone]

The thing that happened was that it ran out of control, due to a worn out gearbox (bad balance), combined with neglecting the service-intervals.. The service on this turbine was due for more than half year ago. The brakepads must have been worn out, and it was unable to perform the standard emergency braking procedure..

The company i worked for some years ago, (who i am still talking to a lot), has the service on 2 other turbines in the same "park", and their surveillance also covers this one, so they could follow the out-of-control run from the start..

As i remember, the maximum allowed revolutions pr. minute for this is around 39 RPM on the main shaft as i recall, and this one was around 200 (!) RPMs on the main shaft when it crashed, so it has clearly been a question of imbalance at high speed, causing the blades to bend, and hit the tower..

Now, there is the question on the insurance-matter.. Obviously, when neglecting to get the turbine serviced when its supposed to, cant have good influence on the insurancecompanys willingness to pay for a new turbine....

[Stefan(2)]

The thing only dies at 500% of his design operation spec's ,

These things are strong !

( make's me feel better , they just build a load of these quite close to my back garden )

[B.M.T.]

The brakes on these are mean to keep them at 39RPM.

When they fail, this is how they stop.

[Wireless]

As i remember, the maximum allowed revolutions pr. minute for this is around 39 RPM on the main shaft as i recall, and this one was around 200 (!) RPMs on the main shaft when it crashed, so it has clearly been a question of imbalance at high speed, causing the blades to bend, and hit the tower..

I'm not sure an imbalance would cause a blade flex or failure - more likely, physics suggests that this would actually limit the rpm, but cause premature wear or load on other parts of the device - Main bearings, tower structure etc). If you slo-mo the video you can see one of the blades fractures, presumably due to load rather than imbalance. The sudden deceleration of the rotor section would have placed huge decelerative loadings on the other already highly stressed blades causing them to fail. Slo-mo on a bit and you can see that the subsequent massive deceleration when the second blade goes causes the tower to buckle under torque-reversal and the blades then strike the tower crippling it completely. Or so the Aeronautical Engineer in me thinks...! Either way, spectacular example of a runaway...

Now, there is the question on the insurance-matter.. Obviously, when neglecting to get the turbine serviced when its supposed to, cant have good influence on the insurancecompanys willingness to pay for a new turbine....

Whoa...! That's bad news. Definite write-off...! Oops

[gozone]

Yeah, well anyhow, its toasted, LOL..

BMT> When in normal operation, the turbines pitch their wings, or a part of their wings (mostly the tip itself), to loose "momentum" from the wind, keeping the RPMs down, just like on a sailboat, where you "adjust" the angle of the sail itself to the wind, giving more or less speed.. Also, they can simply turn the top of the turbine out of the wind, also losing speed and wind-pressure on the blades.. All this is fully automatic and controlled by an onboard computer, also transmitting data to the sevice-company and the owner of the turbine (if he has chosen to, but most do). This computer-uplink tells all the technical info you might need, along with actual output-measurements of the turbine, RPMs, kilowatts produced, temperature of gearbox oil and so on

Apparantly, these systems must all have failed for this to go this wrong. :S But as stated earlier. Once a turbine "runs wild", there is only one thing to do RUN!!!.. When all the emergency systems have failed, nothing can be done, except set up the safety perimeter (which needs to be a couple of hundred meters in a storm), and keep people from entering the safety-zone, especially from down-wind area, as the pieces from the blades can fly VERY far away, and even though they look kinda small in the video, theyre actually pretty large, LOL..

[Wireless]

Actually, what you can't see at first are the two pranksters on the video. Look closely and you can see one of them chuck a broom handle into the blades while the other one films it on his mobile phone From here it looks like Moosey and Volksrod.

[ryanbored]

Can someone do the math for me?

I recon you can guess the length by comparing it to the trailer on the lorry. And you know It's doind a complete revolution (Till the end ) and it's doing 200 of those per minute, so surely someone here can work out the tip speed, as i recon that is properly motoring!

[Wireless]

Can someone do the math for me?

Good idea...!

OK. If it's a small turbine, say 30m diameter blades then the tip speed at 200rpm is a shade over 700mph (almost mach 1 at 15C)

If it's one of the biggest turbines with a 65m diameter then the tip speed is over 1500mph. (Over mach 2 at 15C)

Hrm. Now either it's a very small wind turbine (30m one) or it wasn't doing 200rpm. No way the tips could go much beyond supersonic without destructing. My estimate is they started to flutter around supersonic and fell to bits.

Let's see Windy Miller leg it into the base when they're going that fast...!!!