When things go bad

[Putte]

I read this on the news a 30 meter wings machine in denmark lost its wings when a it had a falier on the gearbox and breaks as well.There was evacuation so no one was hurt.I think it did some 3 times the normal speed.

Pictures like that are rare.

Putte.

[pyrocasto]

O_O  Thats not going to be cheap to fix.

I cant even think of seeing the big ones spin fast out of control, it would be a strange sight to see.

[Trivo]

Yeah they don't all stay up

[Chiron]

Hey Putte, that looks like a Micon 750/900. If the gearbox let go on it the mechanical brake would not have done any good since it's on the Gen. side of the gearbox.

What should have happened if everything had been operating correctly is the blades would have pitched to 90 Deg. and areobraking would have taken it down fairly quickly once the hub overspeed and hub/gen speed mismatch was detected. 2 seperate safety systems had to fail at the same time the gearbox let go.

I suspect poor maintanance and/or bypassing saftey devices as the cause/s of the failure. It's alos possible that the Euro models don't have the same safety systems that the US turbines are required to have.

The pic of the folded tube posted by Trivo looks like what happened at Delaware Mountain in Texas. Don't know if that's a pic from that site but the folded tube in Texas happened because it was located too close to the edge of a cliff and the force from the turbulance from the updraft broke some of the tower bolts and once it went off balance...

[Putte]

Hi Chiron thanks for clarified the brake problem that was not to read in the news i remember that there was a comment that the turbine had gone in the wrong direction also so there was series problem.

Putte.

[Chiron]

If it was turning backwards then it was probably yawed 180 to the wind. Normaly if there were a hydraulic failure the wind witting the blades (when yawed into the wind) would push them back to the pause position and the turbine would stop. If there was a hydraulic or pitch control problem the blades would be pushed forward to the max speed position.

Did it get yawed out of the wind on purpose to work on the gearbox problem by chance? that would explain a lot. Anyway I still expect that the root cause will be found to be human error/stupidity.