Rigging screw poll .... 2nd attempt

[VicS]

Prompted by the rigging screw thread

Do you have lock nuts, do you rely on them or also secure them by some additional means.

 

[Tranona]

Have locknuts on open body bronze rigging screws on one boat. Never come undone - problem is usually the opposite, getting them undone for adjustment.

Bavaria has locking pins and clips - always worried they will fly off into the oggin when trying to get them out, so take extra care.

 

[Leighb]

Mine are all open bodied, secured with locking wire, it is a bit of a faff, but I can be sure they will not come undone.

On my previous boat which had a mixture of types, I did once have a shroud come undone that used a bottlescrew with locknuts, but this was due to the locknuts not having been done up by the yard when they rigged the boat, and my failure to check this before the first race. Fortunately it was a lower and we did not lose the mast.

 

[pyrojames]

Had lock nuts on the previous boat and never had any trouble in 20k odd miles. Now have lock nuts and pins...

 

[Ammonite]

Same as Tranoma - you have to use a fair amount of force to get then undone. There's nothing unusual about my setup so it's hard to imagine why they come undone on similar boats sailing the same waters - although it sounds as if they do. There must be something fundamentally different. I just have no idea what it is but would be interested to know the answer - but somehow I doubt we'll get to this. I've thoroughly enjoyed the original thread though ;-)

 

[TSB240]

Use open sided type with torqued up locknuts only. I also use plenty of vaseline on the threads.

As we have A TS our mast gets put up and down probably 3 or 4 times more than the the average boat per year.

Fractional rig with plenty of tension.

Never had and never expect to have the screws work loose.

I use straightened split pins to prevent the open screws from rotating when I have slackened off the locknuts and screws in preperation for lowering the mast.

Bent Split pins on inboard ends of threaded parts prevent the assembly unscrewing completly in worst case scenario anyhow.

Wouldnt ever use a bottle screw now.

If i did it would be seized.

 

[prv]

I have locknuts on most of my bottlescrews (one is a replacement which is open-bodied and secured with pins). I do check them from time to time, same as I check the keyrings in the cotter pins, but never had any loosening so far.

Pete

 

[Bilgediver]

I have locknuts and never had a moments problem. I am at a loss to understand how they can come loose if correctly tightened and have had no problem with similar arrangments on marine machinery in over 40 years in the merchant navy and oilfield environments. In fact the lock nut principle is so good it is used as a connection means to stuck studs in order to extract them . This can be with just two locknuts or with a custom stud extractor/driver.

 

[MM5AHO]

Not enough options.
What about not having locking nuts but still securing them by other means?
We don't use locknuts but do use wire between ends inside the bottle.

But the wire has to be small enough to go thru the hole and this last summer two of the wires corroded and snapped, and the jack started to loosen. I changed to stainless split pins.

 

[VicS]

Not enough options.
What about not having locking nuts but still securing them by other means?
We don't use locknuts but do use wire between ends inside the bottle.

But the wire has to be small enough to go thru the hole and this last summer two of the wires corroded and snapped, and the jack started to loosen. I changed to stainless split pins.

Covered by "I do not have lock nuts.... " Tick that box.

Poll beginning to show what I expected it to; that the majority of people who have locknuts do in fact rely on them

 

[Deleted member 36384]

I have locknuts and never had a moments problem. I am at a loss to understand how they can come loose if correctly tightened and have had no problem with similar arrangments on marine machinery in over 40 years in the merchant navy and oilfield environments. In fact the lock nut principle is so good it is used as a connection means to stuck studs in order to extract them . This can be with just two locknuts or with a custom stud extractor/driver.

The standard lock nut is in fact the least preferred solution on many drilling rigs now because it has a higher risk of backing off in situations where cyclic loads and vibration can be expected.

There has been a significant campaign over the years to prevent dropped objects (3rd biggest killer in the OandG Industry) and one of the early findings was that a lock nut was not a reliable method of securing for the reasons stated above. Rigging that is subjected to a flogging sail in high winds or heavy weather, for example, could present a dynamic (cyclic) load situation which would increase the risk of a lock nut backing off. This risk would be greatly increased if rigging was not tensioned correctly.

IIRC their was a video produced which showed how lock nut securing could come loose. The principle mechanism was where the device (bottle screw, second nut) below the lock nut was rocking back and forth (micro level) where the lock nut saw stress reversals 180 degrees across its face i.e. on one side of the face the lock nut stress was increased, and 180 degrees round on the face, the stress was being reduced; this caused the lock nut to start to turn. There are better systems that resist this mechanism.

Post Posting Edit: See Post 69 of this thread, from DaveS, for the video http://www.ybw.com/forums/showthread.php?t=294463

 

[Deleted member 36384]

Covered by "I do not have lock nuts.... " Tick that box.

Poll beginning to show what I expected it to; that the majority of people who have locknuts do in fact rely on them

Thats not what the poll says at 06:30 GMT 01.12.11! At the time of this post 60.27% did not have lock nuts! This increases to approximately 72% if you include the ones that have lock nuts but use a secondary method of securing. The lock nut only group is by far the minority.

 

[VicS]

Thats not what the poll says at 06:30 GMT 01.12.11! At the time of this post 60.27% did not have lock nuts! This increases to approximately 72% if you include the ones that have lock nuts but use a secondary method of securing. The lock nut only group is by far the minority.

UHH ??

I said "Poll beginning to show what I expected it to; that the majority of people who have locknuts do in fact rely on them"

The numbers now are

20 have lock nuts and rely on them
only 9 have locknuts but also secure them by other means.

20 is the majority of the 29 who have lock nuts!! approx 2/3 of them.

 

[lustyd]

Poll beginning to show what I expected it to; that the majority of people who have locknuts do in fact rely on them

I ticked that box and as you know have had several failures. Relying on something is not the same as trusting it and neither are the same as that something actually being reliable under all conditions. As has been said in numerous places there are better solutions and locknuts have been shown not to be reliable - there's even a video on the other thread of them coming undone under vibration. I'll say it again as it's now apparently my catchphrase - just because YOU haven't seen them fail doesn't mean they CAN'T fail, it just means you have yet to see a failure. This is exactly the same as the seacock issue - many people refused to believe the evidence because they personally had not seen any failures.

 

[Deleted member 36384]

UHH ??

I said "Poll beginning to show what I expected it to; that the majority of people who have locknuts do in fact rely on them"

The numbers now are

20 have lock nuts and rely on them
only 9 have locknuts but also secure them by other means.

20 is the majority of the 29 who have lock nuts!! approx 2/3 of them.

Yes that's true, you are right. A more complete analysis so far shows that lock nuts are not used by the majority. If considering reliability of lock nuts the analysis has to include the total statistical population. It therefore presents the question why are locknuts not used for the majority of rigging applications, which is all one can really say.

 

[VicS]

Yes that's true, you are right. A more complete analysis so far shows that lock nuts are not used by the majority. If considering reliability of lock nuts the analysis has to include the total statistical population. It therefore presents the question why are locknuts not used for the majority of rigging applications, which is all one can really say.

I'd suspect lock nuts are more common for little boats at the bottom end of the market ( like mine or Lusty's Vivacity) while the other types, that take locking pins etc, are more common on the big expensive flashy yachts that the majority of this forums users own.

While I am more than happy with my locknuts on a boat that only potters about the Solent ( at best ) I think if I owned a large yacht for offshore sailing I'd have rigging screws that could be positively secured.

The reson i did the poll was because one poster on one of other threads said, "Basically, the idea is that you tighten the lock nut against the bottle of the bottlescrew. ........................................................................................................... Most people also lock the bottlescrew using either monel wire, split rings, or in my case, small nuts and bolts,

I did not think "most people" was correct. My survey is suggesting indeed that it was not. The majority of those with lock nuts simply rely on them.