Dynex Dux Synthetic Rigging

[w32honu]

Most of us have been reading and researching Dux rigging with interest. Many of us have converted part of their rig (life lines, runners, removable fore stay......etc) to see how it holds up. And some of us have taken the leap and converted their entire rig............

Perhaps a new thread to judge our confidence at this point......

Where do we fall on the knowledge/confidence curve??

Is Dux suitable for only part of the standing rig??

Are we comfortable with this material only as a coastal cruiser??

Are long distance, self sufficient, off shore cruisers comfortable with this rig??

If the longest off shore passage averages 15 to 20 days; How is that different from the coastal cruiser..........say half a season????

And finally, those of us that have converted......whats the verdict?? What has been your experience?? How long?? Reservations?? Satisfied?? No doubts??

Any comments and opinions are welcome..........even if we haven't converted any part of our rig.............. yet.

Cheers.

[Mark Johnson]

This is currently being discussed on Spar talk:

Issues with synthetic rigging? - SparTalk

Having used it on my runners, I am pleased, "for this application". I have noticed a PRONOUNCED difference in the way the runners change tune, VS the old wire, over a 40 degree temperature range. For a shorter, fatter, extrusion that is easy to keep in column, this may not be an issue. Indeed, many are pleased with their results. For long, skinny extrusions like mine, where lowest stretch and temperature stability are paramount, I will be switching to "compact strand wire", and stick with my StaLocs. M.

John Franta's last comments:

Originally Posted by echidna
Hi Brion,

Well, I would say that my 0-30 Centigrade temperature range is quite reasonable, even conservative, for a boat left in the water year round (or hauled for winter rig-in) in New Jersey (where I used to sail), having on the one hand wilted in summer heat in the high 90's (Fahrenheit), and used my former boat as an ice breaker in the destination harbor (and near frozen to death) on a December trip to Mamaroneck, NY.

Regarding loads and creep, I just went to the Colligo site to refresh my memory on their creep data, and could not find the relevant information. It seems to have been removed - Google cache still has it though.

Assuming the old data was correct, a load 12% of breaking strength would cause creep of over 3" per year in 50ft at 22 deg C. I'm not sure that is acceptable.

The question now is, was that old Colligo data valid, and what happened to it? Insofar as creep is probably the dominant consideration in sizing Dyneema for stays, it's important to have good information on it.

I'd also like to raise another point related to temperature effects, and that is the temperature dependence of creep. Creep is typically strongly dependent on temperature, and the equation on the old Colligo graph would imply that the creep rate for a given load in Dyneema doubles with every 4 deg C temperature increase. So in discussing creep, it is surely essential to indicate the expected ambient temperature. Temperatures in the tropics could easily be 5-10 deg C higher than the 22 deg C reference point used in the old Colligo data. Probably a topic for another thread, really.


John: Due to many issues with understanding the creep data (or misunderstanding it), we are keeping it interrnal now. We can assist with sizing Colligo Dux Rigging with anyone who asks. For the time this is how we size the line in order of priority:

1. Stretch
2. Creep
3. Breaking strength.

We almost always have the line at much less than 10% of strength effiiciency, mostly based on stretch. Creep is figured at pretension and 0.1" per year is a maximum target. (@22C). This seems to be a good conservative number as we have many boats now rigged with normal travel turnbuckles that have not gotten into creep issues. One 65' monohull in the Carribean. For offshore boats we factor in long term dynamic loads as well. Keep in mind that creep happens over time, so average temperatures are what you need to look at, or time at temp if you have access to that kind of data.

A couple of comments on pretension: Since steel has such a low creep rate, sailors for years have been over tensioning with no short term consequences. This makes it easy to over tension at the dock and cover for any load conditions you may encounter. Some long term issues may result, stainless stress crack corrosion, Creep in the fiberglass at the chainplates, etc., but who cares about the long term stuff we are Americans!

If you oversize slightly you will be really surprised how little tension you need with Colligo Dux Rigging. I just installed/tensioned the diamonds on a F27 yesterday. We used 9 mm dux to replace the 1/4 inch wire, oversized for creep. The 1x19 1/4" wire was previously tensioned at around 2,000 lbs to get the required mast bend. With the 9 mm Colligo Dux we tensioned to around 400 lbs to get the same amount of mast bend! Yes, we have loos gauge calibrations for it now. For a 50 foot length of 9 mm UHMWPE line at 1200 lbs pretension you will get about 0.1 inches of creep per year. So this is 400 lbs and only about 20 feet long, so creep will be much less @ 22 degrees C and can tolerate much more temperature before you get into creep issues.

I don't have the time now to go thru the thermal expansion math again but suffice it to say that pretension seems to take care of it. You should expect to adjust some over long periods of environmental cycles. Fall to winter, etc will need some adjustment if pretension is critical. I can tell you I met a customer at the Oakland show this month that has a Catalina 36 (with turnbuckles) and Colligo Dux standing rigging in the Bay area, (pretty big daily temp cycles) and he was literally jumping up and down with joy about the performance of his boat. The pretension seemes to mask the linear expansion/contraction of his rigging and it still stays in the performance window for stretch.

We did have a boat (50 foot ketch) that sailed from Argentina to Greenland that used lashings initially but after getting into the cold north needed to change to turnbuckles. Lashings are somewhat limited in their ability to create pre-tension.

So bottom line as I always say, this is a new material, it is not steel and should not be sized like steel. Stretch and creep are its limiting parameters. Do not, and I repeat do not size it for breaking strength. We also like to think of it more as plastic than rope as rope carries with it certain paradigms that do not apply here either. Did I say do not size it for breaking strength???

Hope this helps. Would like to say more but no time. Please stay tuned to our website for Newsletters and our Facebook page for more and more examples of this rigging. The proof is in the pudding.

John Franta, Colligo Marine

[w32honu]

Not much news out on this topic thus far. It seems we are all a bit cautious on this one.

Us too...........

Just rigged the boat with dux life lines. 5mm with terminators from Colligo Marine. We have also done the topping lift and the running backs. I think that is a good start for us. And we will see how the Dynex Dux holds up.

I can say that the splicing and handling of this material was surprisingly user friendly. To make up a tapered locking Brummel splice took only a few minutes. Similar to splicing wire..............but far easier to work with.

That said......this stuff would fit right in with the self sufficient cruising sailor. There is no question as to the strength of the material. Other issues like "creep" can be addressed with design. Just going to have to wait and see about the longevity of it. Chafe and UV being the main culprits. Personally I am not too worried about the chafe issue. One can watch that very closely. And it might motivate any perspective passage maker to do a thorough rig inspection........ always a good idea. Any repairs or replacements could be easily done in the remotest locations, or under way.

UV............. I guess thats the big question. It seems that the suppliers are eager to suggest that testing is under way. And that the expected life of the rig due to UV will be acceptable. But so far I have not seen anyone post results of any testing. I believe they have data that is longer than 5 year exposure. It would be nice to know......

S

[Bash]

Originally Posted by w32honu

I can say that the splicing and handling of this material was surprisingly user friendly. To make up a tapered locking Brummel splice took only a few minutes. Similar to splicing wire..............but far easier to work with.

What sort of fid did you use for the Brummel splice?

[w32honu]

bought some short lengths of 1/4 inch and some 3/8 inch round aluminum stock from Lowes (its fairly cheap). Cut and filed the ends to shape.

Just used the 1/4 inch on the 5mm Dux. Found a small philips head screw driver handy as well.

Some folks find it easy to cut the end of the Dux with a taper in order to feed it back through and form the bury section. This did not work for me. Found that even the slightest edge would snag...... and this stuff is tough. Couldn't feed it in that way. So I ended up pushing the fid (it was long enough) up the center to the exit point. And then taping the insert end of the Dux to the butt end of the fid and pulled it through that way.........worked great.

Hope that helps........

[SV Demeter]

Originally Posted by Bash

What sort of fid did you use for the Brummel splice?

I have always used swedish fids for splicing dyneema

[tamicatana]

I've got about eight-year-old Précourt Dux shrouds on my F-27GS, and I couldn't be happier.

I've noted in the various discussions, there is some confusion, though. With new Dux/Dyneema, you will initially experience what is actually known as 'constructional stretch' as the fibres mesh together under load. Once that's done, then if there's creep, then that is a different animal altogether. For me, having a trailerable boat, I am fairly certain that I don't experience creep (plastic elongation under sustained load). I'm given to understand that sized appropriately, Dux shrouds experience minimal to no creep. That, and since they're easily adjustable, you can always retighten.

I'll go textile rigging from now on. I'm sold on it.

p.s. the Toss splicing wands are the greatest things since sliced bread.

ppss. Toss is very detailed as to how one should taper and how long the tail should be (72x diameter tail and a very fair taper.)

[w32honu]

Nice fids...........

Makes mine look like the home spun garage sale variety.

At least they got the job done.................

[w32honu]

Tami,

Thanks for the input. Any signs of UV degrade? Or chafe issues?

8 years is a good long while. That is encouraging.

[w32honu]

Its been our first season with the dux lifelines and running backs. Everything appeared to hold up fairly well.

There was one area that would chafe the lifeline. It was tensioned against a wire shroud (1X19) on one side of the boat. I purposefully left it in contact to see if there was any effect on the dux. And it did show signs of chafe and wear!!!

Something to think about when trying to control any chafe issues at the spreader ends of a full dux rig. Or any area of potential chafe..........

The damage to the dux was very minimal. Probably wouldn't compromise the strength of the line. I will probably leave it as is to see how much wear the line can take.

My guess is that it is one thing to drag dux rigging (a full length of line) across an abrasive surface.......(Alaska fishing trawls and rusty decks....etc.) probably holds up pretty well. Its another thing to have any dux line chafing at a single focused point. Im thinking it would suffer damage. At least thats been my experience thus far.

The moral to this story is ...."don't give chafe a chance."

[tamicatana]

sorry to answer so late, didn't see your question.

The only things that run against my shrouds is the screacher and spinnaker sheets, and there is some small marking.

If worried about chafe, there's two ways to handle it:

You can cover the line in the area of interest. Précourt used this stuff: http://www.apsltd.com/c-1575-dcs-new-england.aspx

Otherwise, you can coat the line with Yale Maxi Jacket or some such similar.


forgot to say... boat with the textile shrouds is a trailerable boat so it didn't see UV full time. I'd guess that the life expectancy would shorten, but then you can coat with the Maxijacket and that'll help to fix that issue

[Jim Cate]

FWIW:

We have had Dyneema 75 lifelines, runners and baby stay for about 18 months now. Some signs of chafe were noted on teh lifelines where the genoa sheets fouled them when running wing/wing, so I put some lengths of Davis split plastic "shroud covers" in the affected areas... also where the line passes through the stanchions. Has seemed to work.

Other than that, I'm not sure how to comment on how they have held up. Nothing has broken, but is that a good diagnostic? Bottom line is that while I am pleased so far, I'm not ready to use it for shrouds, etc. (We do a mix of coastal and off-shore passages, and have averaged around 5K miles/year.)

Question for all: Since Samson ropes says that a simple splice with a few stitches stuck into the throat of the splice will hold 95-100% breaking strength, why should one go to the trouble of using Brummel splices? I have been using these splices in highly loaded areas (running backstays) with no noticeable slippage. Comments?

Cheers,

Jim

[tamicatana]

The thing about Dyneema fibre lines isn't that they slip under load, it's when the line is lightly or not loaded that it slips, hence the locking splice. If you stitch, that's fine too. Personally, I do both Brummel and stitching.

[Jim Cate]

Originally Posted by tamif27

The thing about Dyneema fibre lines isn't that they slip under load, it's when the line is lightly or not loaded that it slips, hence the locking splice. If you stitch, that's fine too. Personally, I do both Brummel and stitching.

Thanks for that! Kinda what I thought, but it is nice to have some positive feedback.

Cheers,

Jim

[tamicatana]

Go have a look at Brion Toss' website for discussion re: textile rigging. Toss does a fair number of older boats with textiles

Brion Toss Yacht Riggers, Sailboat Rigging