Dyneema Lifelines

Jethrow

Super Anarchist
Then we have SJB's rigger telling him SS lifelines are required for racing, when they clearly are not with a few exceptions.  It is always a good idea to consult a professional, but one should not abandon common sense.
Here in Australia stainless steel lifelines are mandated for all categories where lifelines are fitted. Having said that you are allowed carbon stanchions! Go figure... ^_^

Edit: Looks like World Sailing says SS wire for Cat 3 and above, dyneema okay for 4 and down. (ref 3.14.6.a)

 
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Rain Man

Super Anarchist
7,224
2,074
Wet coast.
Here in Australia stainless steel lifelines are mandated for all categories where lifelines are fitted. Having said that you are allowed carbon stanchions! Go figure... ^_^

Edit: Looks like World Sailing says SS wire for Cat 3 and above, dyneema okay for 4 and down. (ref 3.14.6.a)
Yeah, but you folks sail in real breeze all the time down there.  Up here in the PNW we get a puff over 15 kts every now and then.  A 3' chop is considered "waves".  

 

SloopJonB

Super Anarchist
68,809
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Great Wet North
I was thinking about the whole coated/uncoated wire thing and the reasons for banning coated wire.

Does anyone here have personal knowledge of anyone going over the side because a lifeline corroded undetected under the coating?

I don't.

 

Foolish

Super Anarchist
1,714
396
Victoria, BC
When my mast came down, the SAR folks quickly cut my lifelines on the starboard side, and they also cut my tangled halyards and rod rigging.   In all three cases they could have been saved with a little untangling.  But I wasn't about to question them after just towing me in. 

So, I did the sensible thing and stripped the outer layer from my halyard and made lifelines for the starboard side.  Good point is that if I fall overboard with my tether, I can cut the lifelines to crawl back on board.  (If you read the adventure of falling overboard on a Mini you'll understand the need for this.)  On the negative side, I can't seem to keep them tight. It's not that they are stretching, but I can't find any knot that will hold Dyneema without slipping a bit. 

 

zenmasterfred

Super Anarchist
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550
Lopez Island
I was thinking about the whole coated/uncoated wire thing and the reasons for banning coated wire.

Does anyone here have personal knowledge of anyone going over the side because a lifeline corroded undetected under the coating?

I don't.
No, and seen some in obvious distress.  I think on my boat I will go to rope and eliminate the coated wire (just incase they are a death trap) like offset hatch, oh, wait, my hatch is very slightly off center.  I better buy some insurance for the Admiral as my days are limited.

 

allweather

Member
419
82
baltic
but I can't find any knot that will hold Dyneema without slipping a bit.
Any particular reason why you're not splicing the lifelines and tighten them with a more conventional lashing?
It does not look quite as neat  but is still fairly minor.(while at no expense or weight a metal adjuster would bring)

About the mini adventure. The link I bookmarked is currently offline. But you are referring to the difficulty of both pulling oneself up and that squeezing through the lifelines with an inflated lifevest isn't going to happen?

Guess I never thought much of it on account of not having lifelines on the h-boat. And never being truly far off shore...
Though I did worry about how to clamber back on board.(really considering the (pulley type" tether) In bad conditions I don't fly a spinnaker on my boat and then bring back the free spinnaker halyard that I can clip into my harness. Keeps the body high should I ever slip.

 

Foolish

Super Anarchist
1,714
396
Victoria, BC
Any particular reason why you're not splicing the lifelines and tighten them with a more conventional lashing?

About the mini adventure. But you are referring to the difficulty of both pulling oneself up and that squeezing through the lifelines with an inflated lifevest isn't going to happen?
I've tried all kinds of ways to keep the dyneema lines tight, but to no success. The line itself is just to slippy.  Do you have a photo of how you've done it.

Yes, I'm talking about the difficulty of pulling yourself over/through the lifelines. But the problem is real with or without a pfd. this is a key reason why I like dyneema lifelines, because you can easily cut them to climb back on board, and then just retie them again.

 

allweather

Member
419
82
baltic
Do you have a photo of how you've done it.
No lifelines on my small boat and I don't have a pic for one in the marina with it. But looked up a website of someone describing their own switch to synthetic. Scroll down a little and you'll see how they used a smaller diameter line to tighten the lifeline. That is how I did it in aforementioned case and it held up perfectly fine.

https://mosaicvoyage.com/2021/02/16/replacing-standard-cable-lifelines-with-dyneema-synthetic-lifelines-on-a-cruising-sailboat/

half-hitch-2.jpg


lashing-the-lifeline-to-the-stanchion-with-half-hitches.jpg


I can see how rope is easier to handle compared to the standard wire considering we all tend to carry a knife of some sort but not bolt cutters while on deck. Makes sense too considering they're supposed to prevent one from slipping out between them. Of course it would be difficult to squeeze in.

 
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Max Rockatansky

holy fuckfarts!
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image.jpeg
 

this is WR2: covered UHMWPE lifeline from NERopes. I’m trying to remember what year my wife built them. Probably 2013 or-14. I never go north of 30, and they are still doing well, although the lashings probably need some love, and the whippings have been failing.

 
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Zonker

Super Anarchist
9,750
5,717
Canada
One thing people don't get is that as UHMW ropes get cold - they expand. Thus your lifelines get loose as it gets colder. Seasonally, depending on temperature swings you might have to adjust.

A lashing is a good thing to adjust your synthetic lifelines and will hold without slipping. Maybe not QUITE so many half hitches required. Allweather's lashing connected to an eye is how we did ours.

 

Alex W

Super Anarchist
3,326
316
Seattle, WA
I've tried all kinds of ways to keep the dyneema lines tight, but to no success. The line itself is just to slippy.  Do you have a photo of how you've done it.
I get the tension close with lashings (as shown in the photos above), and then use the turnbuckle in my pelican hooks to fine tune them beyond that.  

I made the simplest possible lifelines, they are just a single run from bow to stern with a fixed lashing at the bow and a pelican hook at the stern.  A nice thing about this is that you can temporarily push the lifelines down and out of the way when putting heavy things on the deck, like when bringing the dinghy aboard to lash it down on the foredeck.  I mention this because I've seen a lot of much more complicated dyneema lifeline setups with gate hinges and other unnecessary hardware that also take out the chance to use those turnbuckles.

 

Rain Man

Super Anarchist
7,224
2,074
Wet coast.
I saved my turnbuckles from the old wire lifelines.   When building my Dyneema lifelines, I build them too short by about 12-14" and use a lashing.  After they stretch they will come within range of the turnbuckle, so I just replace the lashing with the turnbuckle.  If I get it wrong I just stick with the lashing. 

It is a bit faster to adjust a turnbuckle than adjust a lashing, and I think the turnbuckles look better, but YMMV.

 

someoldsalt

Member
473
8
I am making up new lifelines now in  7mm WR2.  The challenge I find is getting exact lengths and not wasting alot of expensive line or cutting it too short.

For instance, if I do a brummel eye at one end and then want say 21' to the other brummel eye, how do I compensate for the amount lost in the splice versus the amount gained through creep when loaded to figure out where to cut the line off the spool before splicing?  This gets extra critical with gate openings where the the lengths are short and you are for instance, using a cow hitched eye to an eye fitting that goes through the stanchion (no room for adjustment) and then eye splice or eye splice for cow hitch to a pelican hook - the whole thing being only a couple of feet long?

I'd be interested to hear anyone's insights on this-it seems to me that getting exact bearing point to bearing point lengths after two splices,  compensating for splice loss and creep gain is pretty difficult or pretty imprecise?

 

El Borracho

Verified User
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Pacific Rim
On your first Brummel Eye, before you cut anything from the whole roll, place a mark 2 meters from the end. Make your first eye to specification. When done and tightened measure from the mark to the end of the eye. Subtract that from 2 meters. That is your "take-out." Your technique need to be repeatable. Counting picks and eye size, etc.

I wouldn't be so sure that turnbuckles are faster to adjust than lashings considering fussing with Ring-Dings, pins and the little splashes they make from time to time.
 

I'd test fit before making the second eyes because there are so many variables.

 

estarzinger

Super Anarchist
7,630
1,018
hmmm:

World Sailing OSR's = dyneema allowed for multihulls and cat 4 monos.  Only SS for Cat 0,1,2,3, monos. Local races and national authorities can modify that, but that's the baseline world racing standard.

There are in fact a few knots which will not slip in dyneema (like the water bowline and the estar).  But you want to use all splices in dyneema lifelines (in fact splices are requited by the WQ OSRs).  Don't use Brummel's, they weaken the splice and make it easier for DIY to screw it up. Pretty much no-one in commercial heavy lifting, where consequences are serious and stuff is actually proof tested uses Brummel's.. Find some instruction on lock stitching the bury and do that - just be careful, dont pull the stitches too tight, dont distort the weave and dont split strands.

Lashings at one end are the usual/normal way to adjust length and tension.  There are better and worse lashing techniques - the ones used by most 'yacht-ies' (and most yachting riggers) happen to be are near the worse end. But if they are made over strength it does not matter.  Just realize that the strength of the lasting is NOT = number of legs times cord strength.  It is way lower than that because of uneven tension on the legs.  Testing of actual lashings suggest you should assume only half that strength.  The WS OSR's do require the lashings to be replaced every year - and they cannot be longer than 100mm.

There are two primary failure modes - being cut by rough passages thru the stanchions and being burned by sheets zinging out over them.  The later is more a concern on bigger high performance boats - the crew on Comanche refused to use dyneema for that concern.

The OSR's do state minimum diameters - and they refer to the core alone.  So for instance if you are using a double braid like WR2 they core alone needs to meet these minimums.  And these are minimums - for the top lifeline in particular using a few mm bigger would be quite smart in most cases.

 

Rain Man

Super Anarchist
7,224
2,074
Wet coast.
I am making up new lifelines now in  7mm WR2.  The challenge I find is getting exact lengths and not wasting alot of expensive line or cutting it too short.

For instance, if I do a brummel eye at one end and then want say 21' to the other brummel eye, how do I compensate for the amount lost in the splice versus the amount gained through creep when loaded to figure out where to cut the line off the spool before splicing?  This gets extra critical with gate openings where the the lengths are short and you are for instance, using a cow hitched eye to an eye fitting that goes through the stanchion (no room for adjustment) and then eye splice or eye splice for cow hitch to a pelican hook - the whole thing being only a couple of feet long?

I'd be interested to hear anyone's insights on this-it seems to me that getting exact bearing point to bearing point lengths after two splices,  compensating for splice loss and creep gain is pretty difficult or pretty imprecise?
Roughly speaking, on a 30' lifeline I would expect about 6" of creep after the crew had been leaning on it for a regatta or two.  One solution is to load the line for a few cycles to remove the construction creep, then build your splices, but I suspect you will still get some creep after that as the splices settle in.

 

estarzinger

Super Anarchist
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1,018
One solution is to load the line for a few cycles to remove the construction creep, then build your splices, but I suspect you will still get some creep after that as the splices settle in.
there is some line constructional elongation, less in some lines than in others (like the heat set ones), but most of it comes from the splices settling in.  

If you have worked with a particular line you will know how much constructional stretch is in the line.  If you do not, take a piece, measure it carefully stretched out but not tensioned with any real load - then pull it (with a big winch or come along or hydraulic autobody puller - which are easy and cheep to get) to near working load (or by feel) let it set for 30 minutes and tension again after it has stretched, do that a few times.  Measure again and you now know the constructional stretch (it will be a hair more stretch than this over longer time period so just add a percent or so).

Then make a splice in one end of a line you have stretched - measure it before and after the above same procedure - then you know how much your splices stretch - obviously x2 for splices on each end.

This is a bit of upfront work, but you can get done pretty quick if you are efficient and then you know all you need to know to make perfect lengths (from this one line brand)

 
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TJSoCal

Super Anarchist
US Sailing SERs require uncoated stainless for Ocean or Coastal races but are silent on Nearshore. And of course cruisers can do whatever they want. 

Splicing dyneema is simple enough that you can just build the lifelines on the boat to make sure you get the length right. Do the first eye splice, attach one end, string through stanchions & then measure out where the other eye should be. Expect some construction creep as the splices work themselves in so a little short is better than a little long - you can always snug up the lashing.

I luggage tagged one end and used a lashing on the other. Better to luggage tag around the the pulpit tubing rather than the steel loop provided for attaching wire lifelines so the bend radius in the dyneema luggage tag is larger. And use a thimble in the lashing end for the same reason. 

 




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