Wouldn't want to be close to this one, each blade is longer than a semi trailer. Ouch....

http://www.youtube.com/watch?v=u14tB...eature=related

 

I think to my recolection they're suposed to have limiters, 30mph or so?

well least the ones up around here

 

That one was made of some kind of composite material, none of the ones I have seen in the US are made from anything other than steel.

The ones around here have brakes applied above 55 MPH winds.

 

"Windmill collapse during a storm in Denmark. The braking system failed while two technicians worked in the turret at the top. The technicians were able to get out before the collapse. A 19 meter piece of the blade was thrown 20 metres away; Smaller pieces were sent more than 500 meters away."

Thats what the description said, so I'm guessing since the brakes failed there was nothing slowing it down.

 

None of the large turbines have blades made of steel (WAY too heavy) By large I mean 300'-500' tall to the tip of the blade. http://www.gepower.com/prod_serv/pro...s/en/index.htm

 

Yep - Brakes failed here. And Tech's were actually in it and got out before it failed...wow, wonder if they got hit with any of the carnage scattering itself around!? I'm thankful my marginal fear of heights prevents me from taking certain jobs, like that one.

 

they build the blades up here in ND. My buddy builds them, they build 3 or 4 a day.

 

The light parts going 500 meters when this happens do not surprise me. Glad the techs got out.

There is an emergency exit from the gondola- it's a rope that you kind of ride down with a set of brakes- like parachute jumping.

AlpineRAM

 

Yea, I knew the blades were Composite, I was just surprised that the tower was also composite.

The other question I have, perhaps Alpine can answer, on the ones over here, the blades feather prior to the brakes engaging. The ones in that video did not appear to be even trying to feather. Do the units overseas feather the blades prior to applying the brakes, or do they rely on braking only?

That one also looked much smaller than the units they are putting up around here, towers are roughly 300 Ft up ( roughly 91M ) to the hub.

 

Whoa, just looked at that again, the tower was not made of Composites..........

That is truly impressive.

 

I see those blades going down I-94 all the time, a person doesn't realize how big they are until you see them behind a Semi.

 

From the video it looked like it was not a case of the
EDIT hitting the fan.. however those would make for some hefty impellers for the turbo charger

 

we have the assembly point, and put the machinery in the turbine heads. two wind farms west and south. over 300 windmills each- look like war of the worlds scene....

yes- turbine blades are steel. we get them from freighter to Oswego, NY then police escort truck with special trailer, to Dansville, NY base. I had posted pics of this in a 'wind power' thread. awesome to see over 1,000 toer column pieces laid out, with another area just for turbine heads (fills a tractor trailer flatbed) and the stacked propeller blades 72-100 feet long.
then they clear that loading area out - 5 complete wind turbines a day. imagaine the state police pay going for all the escorts....eek

the one town gets 660,000 every year. no one pays property taxes in the other.

amazing- Heidi in NY

 

The blades should feather in the standard braking procedure. The problem when you do not feather the blades is that there is a static torque on the gondola in addition to the dynamic torque of the braking. Emergency braking means that the big disk is activated regardless of the blade pitch. The torque of the brake makes the gondola swing out approx 25 feet. No fun to be up there at the moment, therefore you should wear the harness if the gondola is open and the prop is running.
You would not want to fall out there..

To me this looked like a main shaft coupler failure- the blades would not feather and the brake didn't seem to apply.
The brake is after the main gears, so a defect in the main gears will disable the brake.



Just my 2c

AlpineRAM

 

LOL, That's why they will not be putting one up closer than 1350 feet from any house here and no closer than 750 feet from the road....... Pretty darned impressive failure!