My turnbuckle has failed........

Dec 28, 2015
1,393
Laser, Hunter H30 Cherubini Tacoma
Did both failures coincide with the haulout? Maybe they contributed to the issue?
 

dLj

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Mar 23, 2017
1,886
Belliure 41 Now on the Chesapeake
I did not say galling was a part of the bronze thread failure. I was responding to a failed SS bolt photo and sayingthat I did not thing it was mismatched threads. That is all I said.
My misunderstanding.

Galling would be very unusual with bronze, which is the reason it is used for turnbuckles. Without a really close examination, this is a mystery. That fact that he said this had also happened a "a few years back" is interesting, suggesting a common factor. Fatigue seems unlikely. The boat is only sailed summers, probably not hard, and I assume the rig was professionally tuned (not slack). This makes fatigue seem unlikely. That the mechanic mentioned the lack lube is interesting. Also though t damamge is not galling, I'm wondering if the last mechanic spun the turnbuckle right up to tension, too fast (there is a LOT of heat generated if the threads are dry) and without lube, doing damamge at that time. Turnbuckles need to be tightened VERY slowly under load. Doing this fast is common, and often unnoticed error, because the damamge is hidden.
There are two types of fatigue - looks like you are talking about low stress - high cycle fatigue. I would agree with you on that. But there is also high stress - low cycle fatigue. I think that is the more likely cause. Now, what causes the high stress - low cycle fatigue would require a lot more information than we have. The damage you describe of spinning up the turnbuckles too quickly could be part of this.

We both agree, with the information given, it's a mystery... :)

dj
 
Nov 8, 2010
11,385
Beneteau First 36.7 & 260 Minneapolis MN & Bayfield WI
Lubing ?

Selden Screw Oil (impossible to find)
Boeing T-9 BoShield (Amazon)
 
Aug 7, 2013
43
O'day 39' 25th Anniversary Mystic, CT
Thank you for all the responses, collectively your responses are making me a better, more knowledgeable sailor. Continuing on with this thread, I will try to answer all questions posed. First, we have owned Faster Horses (FH) for 7 years now and although I maintain a current relationship with the PO, we have not had the discussion as to the age of said rigging, I am sure to have that conversation soon. The first time this incident happened, luckily enough we were on the Conn. river on our way to our summer mooring. I have attached more photos with the hopes of settling down those of you in disagreement and providing a clearer picture. The replacement turnbuckle in the picture is what the yard mechanic had on hand. I have no idea who the manufacturer of either of the 2 failed turnbuckles are, and I would like to know how to determine who makes a good one. Since we have owned FH, we have unstepped the mast only twice and have had the rig tuned 3 times, the first time we did it ourselves but since have had a rigger come to the boat while she was on our mooring twice. When FH is hauled, it is necessary to release the backstay or forestay, depending on the position of the travel lift. I know that there are some marinas that have travel lifts that can accommodate vessels without having to disconnect a stay, ours is just not one of those. Our plan is to have the rig inspected, however, we will probably wait till the spring and have the mast unstepped in order to do so.

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