"Run away windmil collapses in Denmark, 22.02.08"

[d00n]

After replaying a few dozen times, it looks like a blade broke
off at near 10 o clock, the other two broke off immediately after that, and one of them struck the tower.
http://www.liveleak.com/view?i=cdd_1203701257

This thing is massive! The turbine is the size of a bus! Here's a
great pic to get some sense of scale:
http://tinyurl.com/36zy47

[CdoG]

AmazinG..
the power of moveing mass.

[Bob]

What a site!

AmazinG..
the power of moveing mass.

Yes never underestimate the power of an Arrogant Bastard accumulated in the belly.

[Loscocco]

damn thats insane

[windhorny]

was probably something stupid like not being lubricated properly. maybe there was a sabot in the cogs.

[Loscocco]

or a hummingbird flew into the propeller lol

[windhorny]

Unless a blade flexed and hit the pole, which i dont think happened, it looked more like the internals just locked up and the rotational mass just had enough force to snap it to pieces.

[Bulldog]

Why would the support tower break if the motor locked up, especially going towards the wind? There are inoperative windmills in Rio all the time on windy days -- they don't all explode if the blades stop spinning on a windy day. It seems more likely that there was a fatal flaw in the tower, and once it started to bend, the blades hit it and the whole thing exploded.

[K. Cliff]

They are actually designed to spin slow. They have brakes on them so they don't spin out of control. This one lost it's brakes and that's why they call it a run away. They also will shut em down in high wind. I've seen one break in person but I've never seen one explode like that

[windhorny]

I think its a lockup because if you take something with that much rotational mass and momentum and suddenly stop it, that energy has to go somewhere. It looked to me like one of the blades started to break off causing the whole thing to distort from unequal load. With a 200' blade weighing many tons, it wouldn't be inconceivable to have it tear the tower to pieces. Perhaps one of the blades hit the tower as well, after all, the tower is downwind of the blades.

I watched it again and the only thing that would make sense is that the wind load pushed the blade into the tower. You can see the crease in the pole where the blade hit.