Simple question, not so simple to find answer?

[biggeorgetechnical]

Question: I am wondering why the bases of the large wind turbines I toured recently had something like 64 large, "left hand" thread bolts in the base. The tour guide did not know, but he did say they were torqued to something like 2000 lbs. Why the '"left hand threads?
Thanks,
George

 

[biggeorgetechnical]

Being an electrical guy, these civil and mechanical concepts are tough for me to wrap my mind around.

Here is one explanation I have been able to find.

http://www.pat2pdf.org/patents/pat20090044482.pdf

Link

"When you go looking for problems, you will find them... But they may not be the problems you went looking for!"

 

[FACS]

Someone mentioned to me that meeting that standard is insured by using left hand fasteners. An anchor with right hand thread would be a warning...
But someone else just mentioned that you can tighten the bolt without it coming loose in the resin used to secure the anchors in the cage. So maybe I don't know.


"The "Kelislipped" Anchor is installed in the usual manner. The nut can be wrench tightened by hand without risk of rotating the anchor within the cured resin."

I'll just read then, but it's a fun post

Charlie

http://www.facsco.com

 

[Sparweb]

I see left-hand threads wherever turnbuckles are involved. Any such beasts or two-threaded mechanisms used in concrete foundations? Either in the foundation itself or tooling that installs the anchor bolts?
I think I get the post-tensioning principle, but I've no experience in the civil sector. Just guessing that the tooling that actually installs it is standardized to have the RH thread in the machine, and the LH thread on the anchor. Then just drive the anchor nut and everything gets tighter as you go...
So, how do the post-tensioning machines work anyway?

STF

 

[FACS]

Here is a building of the cage:

http://www.windfarmbop.com/tag/bolts/

Charlie

http://www.facsco.com