Wind turbine collapse in Victoria, Australia

[FacEngrPE]

I am going to offer a different theory of failure, based on some knowledge of slewing ring bearings, and this enlarged clip of the top of the mast, which looks like it is still circular. This indicates (to me) that the mast tube did not fail in buckling.

Slewing bearings have very exacting bolt tension requirements. They also have periodic re-tightening requirements. Low bolt tension can increase the risk of bolt fatigue failure.

Slewing rings have also been known to have internal failures which can lead to rapid disassembly.

By this theory the failure could have occurred at a time when the windspeed was much lower than the stated design speed,

 

[Tomfh]

and this enlarged clip of the top of the mast,

That's not the top of the tower. It's a mid height splice. See here, the top bit of the tower, which has come loose.


top

 

[SWComposites]

How the heck does that mid tower joint cleanly separate without any apparent deformation in the flanges?? Its almost as if some of the bolts were not installed and the others cleanly sheared off. Or the bolts were installed but the nuts were not installed, and the upper part just lifted right off.

 

[Tomfh]

Early friday knockoff maybe?

 

[TugboatEng]

The site recently has another accident caused by missing bolts...

Worker crushed and killed by wind turbine blade | WorkSafe Victoria

WorkSafe is reminding employers about the risks of lifting loads with cranes.

www.worksafe.vic.gov.au

And there is always this common theme: Priorities other than safety.