barrel turnbuckle separated...

[vasant]

Hi
This winter i intended to service the roller reefing so i took out the swivel. Anyhow to do so i sparated the forestay.
I then put the forestay back to the drum turned the turnbuckle maybe 10 times.
Some days later the forestay was hanging apparently the turnbuckle came undone on its own! I reatatched it now also places the jam nuts for properly admittedly though not very tight.
2 days later it come separated again.
Do i miss smth here? How is this possible?
Thanks all

 

[Iliade]

Had you introduced twists into the forestay?

Is the top swivel working properly?

Have you upset any gremlins in the boatyard?

The locknuts should be reasonably tight:
Approximate maximum tightening torques for A2/A4 stainless steel fasteners:

• M5: 4.6 - 6.1 Nm
• M6: 7.8 - 10 Nm
• M8: 19 - 24 Nm
• M10: 37 - 48 Nm
• M12: 65 - 80 Nm
• M16: 160 - 200 Nm

 

[vasant]

Thanks , one thing that triggers my attantion is that the lock nuts put a pressure to the barrel so it cant be tighten further (if you tighter you push the barrel towards the ond of the thread and also the nuts)
I suspect the critical mistake was REASONABLY TIGHT.
When in operation i add also locktite to the barrel and nuts

 

[vyv_cox]

Is the forestay slack after tightening the turnbuckle to its limit? Slackness can cause the turnbuckle to loosen and can lead to fatigue failure in other parts of the rig.

 

[Boathook]

Were you holding the stay fitting so that the wire didn't twist when you tightened up the turnbuckle ?

 

[vasant]

hi, as said i am in the middle of roller service and things were atatched temporary So yes everything very slack but nothing twisted
Thanks i refitted now with the nuts tight and secured with tape.
When in final setting everything wil be tight and with threadlocker.
Some lessons learned here...
Thank you all

 

[Refueler]

The only way the turnbuckle or bottle screw would undo itself - is if the stay its attached to had turns introduced into it when tightened. The stay will naturally want to return to its normal state of no twists.

Using the locknuts to stop this - is wrong. The stay must be held while bottle screw is tightened to make sure no twists / turns put into the stay ...

In fact - if done correctly - the locknuts are not really necessary - but are a safety measure.

 

[thinwater]

Were you holding the stay fitting so that the wire didn't twist when you tightened up the turnbuckle ?

The most common cause is what Boathook said. Easy to miss. Masts have come down because of this error.

 

[William_H]

I would advocate using lock wire through the centre of the barrel and attached to both ends to stop any unscrew of either end . ol'will

 

[Refueler]

I would advocate using lock wire through the centre of the barrel and attached to both ends to stop any unscrew of either end . ol'will

You can get purpose designed locking tabs - I have them on my 38ft ...

But my point earlier still holds ... the stay should not have any induced twists in it before locking the turnbuckles / bottle screws ....