Dyneema Standing Rigging a 50' Sloop, Questions for those who have made the swap

[Stumble]

DM20 is about 20% weaker and has 50% more stretch than Dux. It is great where creep is the only consideration, but it really isn't ideal for standing rigging.

[Sysunday]

That 20% weaker and 50% more (construction-) stretch is a common misunderstanding caused by the greater weight of dux which is being compressed during the production process. You "get more dyneema" in dux for the same diameter where specific gravity for dyneema is always the same, being UHMWPE:0,97.
See for example this table:

Dyneema rigging is not sized for strength, nor for stretch, but for creep, and in that excels dm20:

[Piratelife]

Originally Posted by Sysunday

Dynex dux is finished as a brand name, Hampidjan now calls it "Dynice Dux". Hampidjan is not the manufacturer nor the inventor if the fiber; that is DSM in the Netherlands.
During the last two years I did an extensive orientation on the different dyneema variants for the use of shrouds. For that I visited DSM and got a lot of information and help from them with my project.
I ended up with using DSM's DM20. This is a quite recently introduced dyneema fiber. Specifically made with the lowest creep, with accepting a (somewhat) smaller breaking strength.
The dynice Dux ropes are nothing more toen SK75 which is heat-annealed an compressed in its diameter. You can check this: 6mm "normal" dyneema weights some 23 gram per meter, the Dux some 32grams per meter: you simply get some more weight in the same diameter.
Dyneema has three sorts of stretch: 1. "construction", 2. "Normal", and 3 " creep". Construction stretch is simply caused by the way the rope is constructed, the "weave" of the rope: if the rope consisted of all and only parallel fibers there would be none of this. Normal stretch is the (very low) elastic like stretch of the fiber. Creep is not real stretch but a slow elongation of the fibers on a molecular level and ONLY occuring with tension above around 30% of the breaking strength.
These three sorts of stretch have to be taken into account when deciding for the use of shrouds: breaking strength is in fact no issue, not even if you swap same diameter steel cable for dyneema. Key is to size for creep.
In that the New dyneema fiber DM20 excels: by far the lowest creep of all variants of dyneema.
Herewith some pictures of my project which I finished last March. I used 7mm dyneema DM20 for all my shrouds, fore and back stay. Forestry got a cover of dyneema for protection, as did the shrouds at the spreader ends.
I used tackles for adjusting for construction and "normal" stretch, and turnbuckles for finetuning. After some adjustment during the first days of sailing the first summer I did not need to make more adjustments which might have been caused by creep.
My forestay (lower end of protection not net finished):

You say that you used 7mm all around, what size SS was it before the swap? I'm curious if using dm20 rather than the others means that I can use smaller diameter. As you say, breaking strength is already higher than SS cable, but since it is sized for creep on standing rigging, I'd assume you could get away with about the same size or maybe +1mm. Just curious if you sized up?

[Emerald Sea]

There is some valid reading on this subject at ACC.

https://www.morganscloud.com/2016/10...eid=9d26578c91

If your not a member, it will cost you the subscription.

[Sysunday]

Sorry: I just checked: i used 6mm and not the 7mm as mentioned by mistake before: 6mm of DM20 all around, including forestay, but that got additional dyneema chave sleeve covering.
My original SS was 5mm.

[SF Bay Dude]

Originally Posted by Emerald Sea

There is some valid reading on this subject at ACC.

https://www.morganscloud.com/2016/10...eid=9d26578c91

If your not a member, it will cost you the subscription.

Nothing really that hasn't been mentioned on this thread. Actually there's more. And as always with ACC, it's much of a shaggy dog ending with the brevity of the post(s). In the end, it's a call as to whether you want to spend the extra money for improved performance, are willing to have a vigilant eye on your rig, and current set up is worth the changeover.

I am waiting for a ballpark quote from John at Colligo myself. If you really want answers, give him a call and get some photos of your rig to him. They are very helpful and want to help cruisers make the conversion.

[SF Bay Dude]

Would love an update on the rigging install and cost breakdown if possible.
Thanks!

[Sky Pilot]

Greetings Ciro, My name is Stephen, I live on Maui and may be able to come give you a hand with installation just for the experience and knowledge. I have a 32'ketch that will need new rigging soon, Are you at Nawiliwili? Aloha

[SailRedemption]

Hi friends,
Sorry for the delay on this, but I have been organizing boat paperwork for some time now. But, I have crunched some numbers for you guys. My boat is a 47' cutter, but we'll only be talking about everything sans headstays. I have uppers, intermediates, and lowers, backstay and babystay. My wires would have been 1/2" and 3/8". I have a high aspect rig, so my shrouds are quite longer than most with a 66' mast.

I did a quick look online at riggingonly for my wire and swage and swageless fitting prices. I did not include labor cost to make up wire ends for either. Turnbuckles were excluded as well, but for anyone interested, it was about $1200 for those in the Hayn open variety for all stays.

All prices are approximate.

For my boat:
Colligo Dux with terminators = ~$4600
Wire with swage fittings = ~$2600
Wire with swageless fittings = ~$3800

Had I chose wire I would have definitely gone swageless so it wasn't a far off battle for a rig you can fix. I may have priced "compacted wire" (dyform is not made any longer) which I'm sure wouldn't be cheap as the 1/4" is as much as the 3/8" 1x19 wire. That said I probably wouldn't have actually gotten it.

Now this is a bigger boat with bigger shrouds so it's up to you to decide. I have an old Isomat rig so I had some challenges to overcome but John at Colligo helped us work through it. Stemball and large sizes, etc. It very well could be a closer game with someone with 1/4"-5/16" wire. For instance my 65' 1/2" wire backstay needed 16mm dux which was over a boat buck, most don't need anything near that! I did shave off at least 200 pounds from aloft.

All said and done it was about $5800 to Colligo and I would definitely do it again. I could have saved about $700 if I had did the splices myself, but I didn't have time so I had them do it while my wife and I worked offshore. John Franta and his team are awesome to work with and I'm glad to be a part of the rope rigging revolution. (:

I'll soon have a write up this summer after we get some sailing done and really give the rig some love.

I wasn't paid for this and I don't work for them, just satisfied thus far with everything.

Regards,
Ronnie
s/v Redemption

[goat]

Those colligo dead eyes look really slick and are priced accordingly. A rigger I met in San Diego said they were using low friction rings as bottom terminations and just lashing through the eye. Myself, I like the looks of the colligo units, and will probably spring for them when the time comes.
Have you had any issues caused by temperature changes affecting the tension?
Keep us updated as I know a lot of us are interested in the future of standing rigging.

[Stumble]

Originally Posted by goat

Those colligo dead eyes look really slick and are priced accordingly. A rigger I met in San Diego said they were using low friction rings as bottom terminations and just lashing through the eye. Myself, I like the looks of the colligo units, and will probably spring for them when the time comes.
Have you had any issues caused by temperature changes affecting the tension?
Keep us updated as I know a lot of us are interested in the future of standing rigging.

Temperature is a real issue. Aluminium and stainless (mast/rigging) Lengthen in concert with one another, as the temperature increases they both get a bit longer, and so the net change is minimal. Dyneema and aluminium actually move opposite each other. Increase the temp and the dyneema gets shorter as the mast gets longer.

The critical temperature change seems to be about 40F. So tune your rig at 70F and you are good from 30-110F. Within a pretty reasonable margin. However if you tune your rig on a hot summer day at say 100F that winter when the temperature drops below 60 you can start to see problems.

For non-race boats this hasn't been much of an issue, but it is something to think about.

[Panope]

I am very close to pulling the trigger on new Dynemma shrouds for Panope. I would very much appreciate any advice from anyone with more knowledge than me (not much).

The current shrouds (one per side) are 1/2" galvanized industrial wire with a breaking strength of about 25,000 pounds. The rig is very "Low Stress". The shrouds are tightened just enough to not "flop around". Sailing loads are low due to the boat being quite tender. The mast is a very heavy wall aluminum pipe that (in theory) could be used "free standing" in very light wind. Boat weighs about 16,000 pounds.

I plan on covering the new shrouds 100% to achieve chafe resistance and an unlimited lifespan. My hope is that I can get away with using SK78 (cheaper than DUX) and not have a creep problem. My turnbuckles have 12 inches of adjustment.

I propose that I use 12mm sk78 which has a 34,000 pound breaking strength.

This seems ridiculously stronger than needed and I cannot imagine a problem. But.........

Question: If this material somehow creeps, is there a limit to how much total creep the rope can tolerate?

(Remember that I am expecting these shrouds to be in service for many decades).

Steve

[CAELESTIS]

Panope, you can PM me if you want the contact info for the Pretorien 35 that converted to Dux rigging with Coligo. He is in the PNW.


https://svvalerosorefitpage.shutterfly.com/499

[Stumble]

Panope,

As a very rough rule of thumb when switching from stainless wire to a heat set youneed to increase the MBL to about double the MBL of the wire. Not because you need the strength, but in order to keep creep to an acceptable level (generally assumed to be .1"/year).

Because non heat-set has about three times the creep of heat-set figure you would need to increase the MBL by the same, so your 25k MBL went to 50k MBL on conversion to heat-set, then to 150k MBL when switching to non heat-set.


I should point out that I have zero experience with steel, so you would really need to compare its stretch to stainless to have a better idea.


So very roughly you would be looking at 1.5" for standard dyneema, or 9/16 HSR.

[SailRedemption]

Panope,
Your rigging seems quite large for that boat, especially if it's a low stress rig. You could probably use 3/8 wire in SS and be good. That said you would need 13mm dux if you went Colligo and similar. You size by creep not breaking. We had 13mm dux on our 3/8" wire uppers and intermediates. We have a high aspect rig but no swept spreaders so the loads are relatively low.

If you want more information, check out Colligo website as they have a lot of free information. Also, check out 59-sailingnorth podcasts with John Franta, great information there where they discuss anything you want to know. Even talks about covering the rope and temperature characteristics. Or call John at Colligo because he's just a super nice guy and very helpful and will actually encourage you to do it yourself rather than have them make up your shrouds which is not the norm.

How do your turnbuckles have a foot of travel? I have e 3/4 turnbuckles on a few of mine and they only open 6".

Ronnie