Rod rigging

[Resolution]

Does anyone here know the usual working life of rod rigging? It's on a medium displacement cruising yacht. Not much heavy weather usage either.
The question is prompted by the other thread on wire cutters!
Informed comments welcomed.

 

[dom]

Spoke with Thyssenkrupp re the lifespan of steel wire a couple of years ago and their advice was 15Yrs, or 50,0000 miles (depending on how one sails) whichever comes first - annual inspections are however an absolute no argument must in their opinion.

Re rod, their advice was 5-6Yrs, or 50-60,0000 miles, whichever comes first - annual inspections still necessary, but the detailed scanning required becomes cost ineffective after a few years and proper inspection of the rod heads will either require the stick to come out, or depending on the fitting, a heap of messy in-situ dismantling.

Not sure what the advantage is on a medium displacement cruiser?

 

[Resolution]

Thanks Dom, that's usefully specific. And worrying, since Resolution is now thirteen years old. At a guess, mileage is around 10,000, so less of a factor. And I am not sure how many riggers I can find out here in Turkey with rod skills.
Rod rigging was chosen by my business partner when he spec'd the boat over in Maine. He wanted to go for the best kit all round, regardless of cost.
Cheers
Peter

 

[Clive]

I replaced my rod at 17yrs, only just starting to show hardening at the rigging joints. So as long as the rigging screws are free to flex where they join the hull or mast , the joints will not harden and should last at least 15yrs.

I removed the old rod and had it copied by the The Rig Shop, Southampton UK. I then fitted the rod my self. Harry at The Rig Shop, Southampton was brilliant giving me advice fitting the replacement rigging. Went on boat perfectly.

you could remove old rigging, send it to Harry, get him to copy it and sent it back for you to fit,
regards

 

[William_H]

It should be practical to use dye penetrant non destructive testing on old rod rigging by yourself. Other NDT systems like Edddy current might be useful but cost to get a professional to do it might rival the cost of replacement. (unlike wire rigging where IMHO NDT is useless) It does seem from Clive's comments that near the end fittings is areas of greatest concern. I have not heard of rod rigging failure unlike wire rigging which is horribly common but then I have not seen a lot of rod rigged boats at our club. So good question about safe life but what we need is some good answers. olewill

 

[penberth3]

It should be practical to use dye penetrant non destructive testing on old rod rigging by yourself...

Subject to access difficulties, yes. But surely dye penetration will only show up existing cracks, not any impending fatigue failure.

 

[DownWest]

I used to use dye penetration on aircraft. But it mainly to confirm what I thought I could see.
William H's comment about not hearing about failures might be because those with rod are careful about renewing within the expected life.

 

[dom]

Thanks Dom, that's usefully specific. And worrying, since Resolution is now thirteen years old. At a guess, mileage is around 10,000, so less of a factor. And I am not sure how many riggers I can find out here in Turkey with rod skills.
Rod rigging was chosen by my business partner when he spec'd the boat over in Maine. He wanted to go for the best kit all round, regardless of cost.
Cheers
Peter

Just a thought - given that use is so low, it might be possible to rehead the rods, as the rods themselves will last up to 2x longer than wire.

Re-heading does, however, require enough space in the bottlescrews to make up for the slight shortening which naturally occurs. This process generally only works on discontinuous rigs, as if the rod is bent (inside a little aluminium or stainless sleeve) at the spreader points, the preformed rod bends will be in the wrong place after reheading.

Aside from this, I would in any event replace the forestay if also rod; it’s the worst stay to break and is shaken around a lot more than the others, which can in turn accelerate wear at its heads.

 

[Zing]

Navtec answer this question in their manuals. They should be found online. From memory they recommend 6 years then to disassemble and dye test the rod ends, if ok, do it again after 3 more years and Re-head. Replace rods after 12 years or so max, or is it 10? Time between service depends on miles sailed also, type of rig (racing or less safety factor is less life), temperature (hot is less life). Fresh water means a much longer life.