Replace rigging screws or not?

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john_morris_uk

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When I renewed our standing rigging fifteen years ago, I bought high quality bronze rigging screws thinking that the next time I change the standing rigging I can just replace the wire rigging.

A rigger (who comes highly recommended) has just been bending my ear telling me that I really ought to renew the rigging screws when I change the standing rigging again. I admit I've kicked the backside out of the normal change after ten years with not changing the wire earlier, but I have inspected it and until now the insurance company hasn't;t batted an eyelid. However, we've just been surveyed and the change is in the survey report so I've no choice.

With six rigging screws coming to £680 it's not peanuts, but I suppose I ought to bite the bullet. The real niggle is that the rigger kept saying, "How much do you value your life...?" I am REALLY allergic to hard sell and emotional selling which puts me right off. The total bill is over £3k which is rather more than I anticipated...
 
It makes no sense.

Why do we replace stainless rigging - because of the chance that there might be some sort of corrosion in the swaged joint and that with particularly T-toggle upper fitting, there may be some sort of 'work' induced micro stress occurring.

But what are the potiential issues with a chromed bronze turnbuckle.? Replace the lower clevis pin if you want as that is wear on badly aligned chainplates, but if there is no visible damage, and no history of them being bent or abused, than they are fine. I've seen bronze turnbuckles from the 1930s still with no issues.
 
Motor_Sailor said:
It makes no sense.

Why do we replace stainless rigging - because of the chance that there might be some sort of corrosion in the swaged joint and that with T-toggle upper fitting, there may be some sort of 'work' induced micro stress occurring.

But what are the potiential issues with a chromed bronze turnbuckle.? Replace the lower clevis pin if you want as that is wear on badly aligned chainplates, but if there is no visible damage, and no history of them being bent or abused, than they are fine. I've seen bronze turnbuckles from the 1930s still with no issues.
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It makes sense to the profit margins of the rigger...
 
There is too much vested interest in riggers always replacing rigging screws as well as wire standing rigging, as a routine to take their sole word for the necessity of this. I would be more interested in the views of a metalurgist who does not have a financial interest.
 
john_morris_uk said:
It makes sense to the profit margins of the rigger...
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Yes.

The "how much do you value your life" gag gets right up my nose. Tell him to go an run up a shutter ( as our Yorkshire friends so eloquently put it ).

If you wanted to replace the fittings every few years you could have bought cheap stainless ones at the outset.

.
 
In my industry we use bolts to hold together flanges with 15000 psi of pressure. The bolts are all specified but we have to dimensionally inspect them and perform NDT examination, with MPI and dye penetrant. Quite often the bolts are acceptable from a crack point and an overall dimension point but that the threads have started to wear down, thin out by flattening. The pressure at 15k cycles over the life of the bolt from atmospheric to 15k, so not a steady state.

I think there comes a time when our turnbuckles experience the same usage wear. In my bolt case, it is safety critical and could result in the drilling rig burning down and multiple deaths, so low cost assurance just to change them out; sort of the same logic I would apply in your case JM.
 
doug748 said:
Yes.

The "how much do you value your life" gag gets right up my nose. Tell him to go an run up a shutter ( as our Yorkshire friends so eloquently put it )……
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Exactly, it makes him sound like a complete prat. A competent rigger should be giving you the technical arguments - not this sort of nonsense.
 
penberth3 said:
Exactly, it makes him sound like a complete prat. A competent rigger should be giving you the technical arguments - not this sort of nonsense.
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To be fair, he did say the threads would have been jiggling away for fifteen years but then mentioned crevice corrosion as a result which reduced the credibility IMHO
 
Speaking as a fellow Sealord owner...
Previous owner had the stbd lower turnbuckle explode in the Bay of Bengal... lucky not to lose the mast
I had the port lower t-ball fail orf of W Australia... lost the mast ... boat 8yo at the time.
So everything new in 1994..
Replaced all standing rigging in 2004 except the turnbuckly bits
Replaced the 'staples' in BA in 2010 as had heard of failures ...
Replaced all standing rigging including turnbuckly bits between 2013/14..
Nearly lost rig when stbd lower staple failed between Tonga and NZ in late 2014...
Replaced all 'staples' with 10mm rather than 8mm in 2014 in NZ
Upon arrival back in Chile in 2017 replaced lower T-balls with tangs having found issues with swages... broken strands...

Current policy... standing rigging every 8 years or so.. all turnbuckly bits every 16...... its only money...

And with a Sealord... Sort out your staples!!!!
 
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john_morris_uk said:
To be fair, he did say the threads would have been jiggling away for fifteen years but then mentioned crevice corrosion as a result which reduced the credibility IMHO
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"To be fair, he did say the threads would have been jiggling away for fifteen years". Undo one of them and detach it from the deck, then screw it back together and see how much play there is in the threads. I'd lay a pound to a pinch of sh1t that they'll be as tight as the day they were fitted. Then ask him to show you all this wear he's been on about. Compare it to a new one if you're unsure.
 
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BlowingOldBoots said:
In my industry we use bolts to hold together flanges with 15000 psi of pressure. The bolts are all specified but we have to dimensionally inspect them and perform NDT examination, with MPI and dye penetrant. Quite often the bolts are acceptable from a crack point and an overall dimension point but that the threads have started to wear down, thin out by flattening. The pressure at 15k cycles over the life of the bolt from atmospheric to 15k, so not a steady state.

I think there comes a time when our turnbuckles experience the same usage wear.
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I agree. Repeat story alert: A couple of years ago I discovered at Ulva Ferry that the bottle screw on my single backstay (pointy derrière) was holding by one turn. When I slackened it slightly (I can't remember why, now) I could simply pull the lower end out of the barrel. The male threads at that end were almost nonexistent. I have no idea why. The backstay gets unwound for release twice a year for lifting in and out but otherwise leads the same live as all the other bottle screws. So yes, they can definitely wear out.

However. we can check bottle screws. I was planning to replace all my others, but I have checked them individually and there is no similar damage visible, and I am therefore confident in them. We replace rigging, fairly tenuously, because there is no effective inspection testing system, but I would have confidence in a bottle screw with no visible damage. Is that misplaced? Should I crack test as well?
 
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Frank Holden said:
Current policy... standing rigging every 8 years or so.. all turnbuckly bits every 16...... its only money...
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Have you increase the size on replacement? With so many bits failing, it sounds as if your whole rig was originally underspecced. I'm lucky in that respect, because although my boat is similar in size and weight to a Centaur or Nicholson 26, everything in the rig - mast section, rigging, bottle screws - is a size bigger then they have. Victoria didn't skimp on materials.
 
Why not get an independent quote from other suppliers? I've found Jimmy Green marine competitive with quick delivery - then diy if necessary. I also had this quandary when renewing my rigging 2 yrs ago - when mast was down and all rigging and turnbuckles inspected, nearly all the turnbuckles showed signs of wear(all stainless steel), some badly so renewed with bronze from Sta-Lok in Manningtree. Also found the baby stay mast fitting was damaged so renewed as well.
 
So, all riggers are con men who dont know what they are talking about despite having vast experience of hundreds of boats over many years. I see.
 
Where does it end? If you're going to renew the rigging screws, what about the chain plates, their attachment to the hull, the hull itself? It may not be a completely full proof test, but your eyes can determine if there is wear on the threads of the turnbuckles, although I really can't see how the threads would be "jiggling about".
 
We worry about bits on our boats which very seldom fail and then usually only after abuse but no-one ever worries about those little M10 studs holding the wheels on our cars as we brake from 70mph....not to mention hundreds of other similar pieces of kit upon which we rely every day. I don't even buy the stuff about wire replacement after a given number of years regardless of condition. If a strand breaks I'll see it and replace the wire. They're not all going to break at the same time without warning, especially in the sort of everyday sailing I do. I'm not usually afloat in force 11.
 
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