Dynamica Ropes

[Guest]

Anybody got experience of this stuff. A mate is intending using it for standing & running rigging on a Wharram Cat. Seems to have no cover but is UV & chafe resistant as well as a doddle to splice.

C'mon KM give it to me.

[wheels 543]

KM will run rings around me in regards to knowledge on this stuff, but one thing I can say with confidence, it does not last as long as wire. In fact, the stuff pretty much start to deteriorate the day it was wound onto it's reel. It has big advantages for racing, but not a lot for cruising, due to it costing about the same and not lasting near as long.

[Guest]

Dynamica is a brand name for a heat treated SK75 Dyneema 12 strand hollow core made by DSM in Korea. It's the same stuff as Dynex Dux (the orange one ex Iceland), Ocean12HS (Donaghys Aussie), SuperroundHS (Armare Italy), Amsteel 2 (Samson USA) and many many others, it's common as muck these days and most manufacturers have versions which are all pretty much the same in all ways, including colour often, many tend to be blue for some totally and quite likely unimportant reason. The colour is just a dye in the coating, they are all white to start with, as Dyneema is. You will notice some variation in loads but that's due to one or 2 packing more fibres in, which leads to some, say 6mm's, measuring more 8mm. Also we have that 'just what load' have they used i.e. the max seen, the lowest seen, the avergae over a range or like what the smart manufacturers use - aged 6months and with terminations i.e. spliced ends .... just as it is in real use.

 

They will reasonably quickly get sunburnt and the top 10% odd will suffer UV issues but then that will help protect the remaining core better. While they are all coated some coatings are better than others. The smarter people tend to overcoat again which helps dramatically.

 

No way would I put my hand up giving it the lifespan of wire. In some situations it would have but in many........... bit early to say so it's a time will tell but I wouldn't be betting my rig on it if used as shrouds for the same general time frame.

 

But Dyneema is certainly viable for use as shrouds in a lot of cases, many of the multis here use it quite successfully. On monos?? Yes and no, too much rig tension and you will suffer creep issues which is something that would concern me a lot.

 

He'll be OK Pete. It's knot like Wharrens don't have wide shroud base and low loads. Oh and he doesn't want to get anything sharp near it if it's under load, it cuts real easy when loaded. Inspect often.

 

Yes if you couldn't splice that with your eyes closed I would have to hurt you If any splices are in a spot they could flop around unloaded at any stage I'd be locking splicing them or chucking a stitch in... just in case one start to flop loose. Unlikely but can happen.

[Steve Pope 243]

I have used Dyneema as centre board pendants for the last 5 years, at last inspection appart from a little abrading of the outer fibres they appeared as good as the day I installed them. Not exposed to sun but often submerged. Much better than the SS wire the wire they replaced, which was like a hedgehog.

I would also carry some as an emergency replacement for standing rigging.

[Guest]

I would also carry some as an emergency replacement for standing rigging.

A very good idea, one I do myself and one we have done for a fair few others.

[Tim C 23]

I think the real 'cruising' advantage of composite side stays, whatever the brand, is that the loose lee stay isn't flogging the hell out of the expensive mainsail next to it. The weight of a loose SS stay flogging a main does real damage to the batten pockets over time.

Regarding the life of a stay: Aren't we supposed to be replacing our stays after seven years anyway. Certainly my insurance company was wanting a comprehensive rig report after eight. So I replaced them anyway...

[Marshy 30]

Nah 10 years for Stainless steel wire.

[Gappy 9]

The insurance guys are getting pretty hard on this stuff and at about 7 years they are questioning replacing it even though its probably fine especially if the boats intending heading offshore they start to really press for a rerig for insurance purposes

[Guest mental outlook]

Gappy, are you talking stainless or composite? My old boys stainless rigging is 20 years old, still going strong, but for how long who knows!

[Marshy 30]

Yeah when rigging i pulled of plenty of Stainless rigging that was 20 years plus - old Chico 30's etc and H28's with original rigging,

When you actually start pulling it apart its pretty rooted and the stuff rots from the inside out so you cant tell til its too late. Dont think the insurance companies have ever enforced the replacement periods but they certainly frowned upon it not being done. And when something goes wrong its just that little bit harder to get the payout.

[Guest]

Wow two popular subjects combined, rigging and insurance.

 

We have had a few customers call up and suggest we chime in , so here we go.

 

The key thing in any failure is establishing the reason "why" the loss/failure occured in order to asertain if the policy is able to respond. This is the same for any policy be it car or boat for example. There are typical exclusions in most policies such as excluding claims/losses resulting from or caused by Rust or corrosion for example.

 

So, first establish the "Why" and see if the "Why" is an exclusion on the policy, if not, pay the claim if it fits . Metallaugists are pretty good in providing reports on metals in a marine environment and are often used to help determine the "why". ie rule in or out Corrosion as a cause of loss.

 

Other than Rust I would say the most frequent cause of loosing the lot is human error - eg Skippers not having crew numbers, or not training crew or themselves in getting the runners on when Gybing or flying the kite..

 

Chris Skinner on Truxton has a good method of Gybing shorthanded with runners and is a good example of someone who knows his rig and know s the risks.

 

Gotta love those inline rigs.

 

Other than that it would be failure of compression posts, chain plates etc, mostly on older timber boats .

 

We do not prescribe an interval for rigging replacement. We often will ask for the age of the rig, rather than when it was last checked. If someone buying a boat does nt know the age of the stainless wire and does nt have a plan to replace or at the least inspect it iminently we are unlikely to offer the best terms, if we offer terms at all. If he then goes on to say he cant afford to replace the wire as he's spending 10k on new sails we are likely to pass.

 

Even though if the whole lot went over, old rig and new sails, and it was attributable to corroded rigging we would prefer not to have to argue the point. Additionally, it can still cost thousands to decline a claim, ie appointing assessors, specialist reports etc in order to provide evidence and a justification of the loss falling outside the scope of the policy. These claims costs get absorbed by the insurer and if they get "up there' then that may have a bearing on your premium next year, so not only are we trying to avoid boats that we think are poor risks. We also do not want to cover dodgy boats on the basis of "well if X happens, it s not covered" as that still costs in terms of time, and drama.

 

Contrary to common perception insurers dont just say NO, there needs to be a good reason to say no and that often involves backing it up with the above mentioned reports etc.

 

We have some clients who replace their wire every 5 years, we also have clients with 30 year old rigging who know they are unlikely to have a claim paid in the event of failure and are happy to proceed on that basis and drop the sails in more than 15 Kts or breeze and motor.

 

So its hard to prescribe to all customers a set of actions they must take at a certain time, given that everyone uses their boats differently and has a different appetite to risk, in this case the risk of the rig going down. It is best to treat everyone the same by applying the same tests in the event of a failure or loss. In the above two examples the first guy would likely have a rig failure claim paid out and the second guy may be unlikely to have a claim paid.

 

Marshy's comments about the older boats are spot on, and it never ceases to amaze me that some people think that because they dont race, their rigs are ok for years. I had a guy with 30 year old rigging (maybe galvanised?) say because they only use the boat 10 times a year and thats 300 days (30 years x 10 days ) so actually its had "less than a year of use"

 

I nearly fell off my chair. And Im still not sure if the guy was winding me up, but he sounded commited to this school of thought.

 

We had a rig fail on a mooring the other day, just fell over.

[Marshy 30]

We had a rig fail on a mooring the other day, just fell over.

 

Fixed two of them in my time, one of which im sure is still back on its mooring having never put a sail on it... I know this because it never had a boom and still doesnt 5 years later...

[Gappy 9]

Aaron

 

Pretty fair reply there and yes there are some beauties out there when it comes to what they get away with on their boats.

 

Its also interesting dealing with different assers in insurance claims as to how they deal with things but I guess thats like any business and how the people run it.

[Guest]

Good post Arron.

 

While we have you, what about fibre rigging. Same sort of thing apply or do you have other things/additions/requirements for stuff like that?

 

Just wondering how the Insurance game looks at new products or uses of them when they are newish and don't have a huge history to look back at.

[Guest]

Good post Arron.

 

While we have you, what about fibre rigging. Same sort of thing apply or do you have other things/additions/requirements for stuff like that?

 

Just wondering how the Insurance game looks at new products or uses of them when they are newish and don't have a huge history to look back at.

 

KM,

 

1. No identified issue with Fibre rigging that im aware of. If there was a spate of rig failures going on then likely that that would point to more research.

 

2. The New products thing is interesting . I can recall a conversation with a Technical Specialist we use and is called upon for to form opinions and to analyse failures (he was involved into the investigation of the Aussie AC boat that folded up and sank).

 

I posed a similar question to him, He said the last 50 years in sailing has seen 3 major developments .

 

1. GRP boats

2. Carbon Rigs

and

3. Canting keels.

 

He made the point that te very first GRP boats were overbuilt as nobody had done them before, then when people realised how good the material was they tried to get away with using as little as possible and that the lead to claims for total losses and other failures, He mentioned a couple of 1/4 1/2 and ton boats that flexed quite a bit and delaminated at sea.

 

Carbon rigs being similar, He saw his first carbon rig in 1972 , before it was called carbon. Same thing , early ones built seemed ok, then a few failed and new ones got built with insurance payouts just a bit tougher etc

 

Canters I guess are the curent craze, and he broke it down to boats having "upgrades" by installing a canting keel system and new builds. He was nt too enthusiastic about the former and was open to the latter subject to the correct engineering but it was a case of time will tell.

 

He also wondered if there was the crew to sail the canter properly as skiff /multi sailors were maybe best equiped ie reflexes etc as opposed to crew that were more used to sailing displacement hulls.

[Guest]

Nice. Thanks A.

 

So with new stuff and ideas it's more a case of a 'case by case' sussing to see what happened/failed then make a call from that. Sort of a common sense approach.

 

I suppose you don't have much else to go on when you think about it.

[Fogg 427]

Some might find the note below interesting - it's a reply to my enquiry to my riggers about replacing AC's standing rigging which I believe is now about 17 yrs old and I feel ready for replacement despite light, coastal use...

 

 

When you should replace your standing rigging is a subjective call, as stainless rigging without any obvious manufacturing faults can from our experience last from as little as 1 1/2 years to over 30 years!

 

The big bogeyman is fatigue, which is not measurable in the practical world as it varies on every boat depending upon the 'cycling' that the material experiences. In most cases, rigging does not fail from corrosion, as by the time you get sufficient corrosion for stainless to fail, you are well into the time in it's life when it is likely to fail because of fatigue, so if it hasn't fallen over, it probably means you have had it parked more than in use! By parked I also mean in a calm spot like a marina or up a river, as if it is on a mooring where it gets any wave action, it is actually accumulating fatigue - a number of local boats have had their masts mysteriously fall over on moorings. I don't know of the truth in this, but I have heard that in Sydney Harbour, more rigs fall over on moorings than when underway.

 

So you can make some choices to make:

 

- Stick with what you have and regularly inspect for obvious defects such as cracked swages or popped strands as indicators of developing problems, and hope that you are not one of the unlucky ones who has the stays give way with a big bang.

 

- Ask your insurance company if they have a policy requiring replacement based upon age ( I believe that in Australia they are now saying that rigging must be replaced after 10 years or no coverage) Some will have wriggle clauses where they will not pay out if you have not 'taken reasonable precautions to maintain the property in proper repair." (One example)

 

- Follow the recommendations of rigging wire manufacturers. Bridon & Co. say five to eight years of seasonal ocean racing; ten years around the buoys; and possibly twelve to fifteen years of summer cruising.

 

Navtec Rigging Solutions state that wire life expectancy is based on climate variables and water salinity and at maximum eg. Florida, Caribbean Islands - five to ten years; medium levels e.g East / West coast of US (probably similar to NZ) ten to 15 years; and fresh water (let's move to Taupo) fifteen to twenty years.

 

OYS (Ocean Yacht Systems) simply recommend replacement at ten years service life. (No explanation of that)

 

From all this, we have developed a policy of recommending that if you are sailing locally, you should expect twelve to fifteen years of life, provided that you inspect at least annually, and ten years maximum if you are expecting to go offshore. If you pop a strand half way to the islands you can't just pop into a rigger, so you probably want to leave with a little more life left in the bank.

 

So after that long winded diatribe - yes, I will get you an estimate of cost to replace your standing rigging, and yes - normally we can replace stays without unstepping the mast. It depends upon fittng type and condition, spreader end cconnection etc., as sometimes we encounte problems that necessitate unstepping, but we will get an idea of if this is likely we we get some measurements for an estimate.

 

Because of the fact that we can not take everything off at once, obviously it requires a few trips up the mast, and so if you are ever considering other jobs such as wiring, hardware alteration etc, it makes sense that if you are replacing rigging, that you then consider unstepping, as the additional cost is then justified rather than a separate job later.

[Guest]

That was an excellent reply, on the strength of that I would have some faith in whoever it was.

[Fogg 427]

It's Phil Ash at Gulf Harbour Rigging. He has done all the minor rigging work on AC over the years (halyards here and there, checking the rig, mounting masthead gadgets etc) so he now gets first call to quote for 'the big job'. I want new standing rigging for the new season.

[Guest]

Next time you see him, tell him he got a free plug on Crew.org.nz