Rigging Replacement - Screws as well?

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fireball

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We're replacing the standing rigging - mostly so we know the age/condition rather than any visible terminal problem with it ...
The rig is "only" 10 years old ... but I don't know how it was sailed before we got her ...
Do I need to replace the rigging screws as well?
I can't see anything wrong with them - but then you generally can't!
 
I am right in thinking that above deck rigging failures are usually the join between wire and terminals and not the screws or terminals themselves??
 
Yes, failure is most frequent where the wire emerges from the fitting, I can't recall seeing it any where else. I have always replaced the tangs and the bottle screws with the wire, unless you are sure you are going to take double the life out of the screws it is not worth the hassle. I suspect your rig is still OK for a year or too unless you have been giving it a hard life. On a boat which is not sailed continually all year round and where the mast is left up or taken down with care not to snag the rig I would go for 12- 15 years then replace the lot. Masthead or near m.head rigs are subject to much lower loadings than fractional where you are adjusting the rake and prebend from week to week; and even when racing a Sigma 33 all year round with a high loaded fractional rig, I never found anything that looked remotely shot when we changed at ten years, and when the mainsail was a couple of seasons old we were screwing the shrouds down with a couple of very big spanners, making a puddle on the coachroof. Back stays are lightly loaded, almost running rigging type loads and should last even longer than the rest of the rig.
Never use a screwdriver through a bottle screw when adjusting this is when most of them are damaged, use good quality spanners like all the riggers.
If you decide to defer, inspect carefully where the wire emerges from the swages for reassurance
 
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My opinion is that if rigging screws are fairly massive by comparison with the wire diameter they should be inspected closely for cracks. These will be at changes of section, penetrations, and similar stress concentrators. If nothing is found after a close inspection with a magnifying glass, or using a dye penetrant if you really want to be certain, then they should be fine. Mine are 25 years old with no problems, although my babystay screw was scrapped when the threads galled.

If the screws are of small section, if the boat has been used very heavily, or if there is any other damage, such as bends, impact damage, unfair loading, then replace them.
 
An apposite question as I've just had Indigo's rig examined and will be replacing the wire (2 x caps, 4 x lowers, forestay, inner forestay, backstay). However, the rigger only wants to replace 2 rigging screws (cap shrouds) and that because the screw threads are damaged* rather than any fatigue in the metal.

*Apparently, by lack of lubrication when tightening. So remember, always use plenty of lube when you screw.
 
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rigging screws

mine are 33 years old but made of chromed bronze, when i renewed wires 8 years ago i was told by (trusted) rigger that they were good as new.
i always grease them when putting up mast every spring and use a spanner not a screwdriver, i think that stainless ones dont last as long as they can gall.
 
Spoke to the rigger who has the rigging in his workshop - apparently the screws are SS and he strongly suggests we replace with Chromed Bronze ...

We're getting a second opinion on the price - but otherwise I think I'll take his recommendation .. and perhaps the new ones will last a bit longer!!
 
I've got a similar situation, and having just had some quotes it's oh so tempting to replace just the wires.
The boat (an Albin vega) has been lightly used, and is masthead rigged. The mast has been lying unstepped for over a year. Standing rigging was last done ten years ago so it's had nine seasons of use. I don't like the look of the forestay, and one cap shroud has a slight bend in it (not sure it really deserves the name 'kink') so I've decided to replace the wires. But as to the screws, what would the panel suggest?
 
I don't think so,unless they're damaged.The rigging screws are usually over specified and to the best of my knowledge don't fail due to age.The best ones are the bronze bodied ones.Instead of replacing the wire and screw you can ask for threaded fittings that will go into the old screws.
 
If you replace the screws you might consider Sta-lok terminals. It then becomes easy to replace the rigging yourself - one (say) shroud at a time. They aren't cheap but then riggers aren't either.
 
Isn't that the thing with SS - they don't show any signs of fatigue - then pop ... and your rig is gone ... ??
 
fireball said:
Isn't that the thing with SS - they don't show any signs of fatigue - then pop ... and your rig is gone ... ??
Click to expand...

No. Nothing shows no sign of fatigue. Fatigue failure occurs when a crack grows as a consequence of cyclic stress. It propagates through the component until the remaining cross-sectional area is unable to sustain the applied load, when it fails due to overload. Assuming the component to have been designed to conservative engineering principles, the final fracture area will be somewhat less than 20% of the total area.

Fatigue fractures are often easy to identify, the fracture face has an appearance known as 'beach marks', rather like ripples in sand. The example below shows many.

The reason that people experience what you describe is that they have never inspected parts that are liable to fail. In most cases the crack is propagating for a considerable time before failure, so could have been detected by looking at it. The message is simple - inspect regularly.

Here's an example, which I have posted before
crosssection.jpg

It's a forestay on a yacht whose rig failed on its mooring. A perfect example of fatigue failure in cable. You can see that the cracks started at the top, where some strands have been broken long enough for corrosion to have occurred. Fracture progressed towards the bottom, where the last couple of strands show no sign of fatigue. Of the 19 strands only two do not show fatigue. So this expensive failure could have been prevented easily at any time, by examining it or perhaps just by feeling the broken strands with a finger.
 
So you're saying that, in the above example, there were broken strands for some time before the final failure? That does go against what most people say (i.e. sudden and complete failure).

Of course it's all well and good to look for these sorts of failures at deck level...
 
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Robwhelton said:
So you're saying that, in the above example, there were broken strands for some time before the final failure? That does go against what most people say (i.e. sudden and complete failure).

Of course it's all well and good to look for these sorts of failures at deck level...
Click to expand...

In the history of the world there has never been a fatigue failure that did not start with a crack:)
 
fireball said:
We're replacing the standing rigging - mostly so we know the age/condition rather than any visible terminal problem with it ...
The rig is "only" 10 years old ... but I don't know how it was sailed before we got her ...
Do I need to replace the rigging screws as well?
I can't see anything wrong with them - but then you generally can't!
Click to expand...

It seems that it is "Best Practice". However if you do replace do get Bronze ones and NOT stainless Steel which are cheaper. The threads strip under load.
 
I eliminated all SS wire and bottle screws. I replaced my wire with Dynex Dux, and dead eye fittings from Colligo Marine. I relaced 7/32" and 1/4" wire with 7mm Dux. About twice as strong and 1/9th the weight.
I am unable to post a photo (not sure why) there are a lot of photos on my links below.
No more worries about corrosion, stress cracks, fatigue, those hidden things you cannot see.... . It is new, but not new. Kind of a back to the future solution. I am very happy. My Avatar is me holding my entire rig in one hand. Fittings and all 15lbs.
Links below show both my 34' Cutter Rig and a 32' Westsail. Both are wireless now. We shed the weight, the worry, and picked up double in strength.:D
 
Jmolan said:
I eliminated all SS wire and bottle screws. I replaced my wire with Dynex Dux, and dead eye fittings from Colligo Marine. I relaced 7/32" and 1/4" wire with 7mm Dux. About twice as strong and 1/9th the weight.
Click to expand...
Out of interest - what is the expected lifespan? One of the main failures to standard running rigging is UV damage, which doesn't affect wire rigging (well - not before it cracks and fails anyway!).
 
Jmolan said:
I eliminated all SS wire and bottle screws. I replaced my wire with Dynex Dux, and dead eye fittings from Colligo Marine. I relaced 7/32" and 1/4" wire with 7mm Dux. About twice as strong and 1/9th the weight.
I am unable to post a photo (not sure why) there are a lot of photos on my links below.
No more worries about corrosion, stress cracks, fatigue, those hidden things you cannot see.... . It is new, but not new. Kind of a back to the future solution. I am very happy. My Avatar is me holding my entire rig in one hand. Fittings and all 15lbs.
Links below show both my 34' Cutter Rig and a 32' Westsail. Both are wireless now. We shed the weight, the worry, and picked up double in strength.:D
Click to expand...

That's interesting. How did the cost compare to stainless?
 
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