New lifelines - open-bodied vs tubular turnbuckles?

[s/v Jedi]

Originally Posted by sailcrazy

I can see the benefit added of using uncoated, straight s/s cable over the vinyl-coated stuff. But I don't see the added value of Dynema over the cable??? Sure, it's a little added weight, but on a cruising boat-not an issue. The 1/4" cable is certainly strong enough, so what's the benefit of going Dynema...for those of you that have? We use the open turnbuckles on one end of ours, vice the tubular ones, and have never had an issue. And to my eye, they are not only functional (so I can adjust them as I might need to), but they are smaller and less bulky than the wraps/spicing I've seen. Until I see the value added, we'll stick with s/s cable.

An acquaintance of me went overboard mid Atlantic because of a snapshackle opening while peeing. Others reports involve failing swages etc. This happens relatively often.

With Dyneema there are no swages, turnbuckles etc, any failures you see long before they happen. Also, for laundry on the line, no more rust stains.

[40 South]

Originally Posted by s/v Jedi

Your splicing and lashing look top notch, love the French whipping

That said, I noticed the fuzziness on the Dyneema and it looks like the kind that had many reports on the forum where it broke when used as topping lift or halyard.

I only tried a couple different brands and keep it with Samson who uses genuine DSM Dyneema (Amsteel, Warpspeed etc.) which has proven to be reliable. None of the posters who reported failure could tell which brand the Dyneema was, which worries me but is also telling for the reason of failure.

I have Vectran that does that but is reliable, so fuzziness by itself doesn’t say anything.

Thanks for your reply Jedi.
The fuzziness is from dragging the dyneema through the staunchion holes, it was a tight fit. Probably should have used 6mm😁

[sailcrazy]

I'm sure turnbuckles have failed, just as I'm sure the Dynema and lashings have failed due to chaff, UV or??? Nothing is failsafe. Personally, I've never had, not heard of a turnbuckle fail.....but then we've only at this ocean cruising thing since 1996. I'm still looking for the reason(s) why it's a change to make!. And I can see plenty of places where the chaffing/wearing would not be easily seen and could cause a major issue (ie, where the Dynema goes thru the hole at the stanchion top). Please enlighten me. We have switched from cable to Dynema halyards on both the main and the headsail, but we do take considerable care to rotate the line (reduce UV, and chaffing),switch ends, cover the spools on the mast-mounted winches(both the main and headsail are on roller reefers), etc.

[Mike Banks]

Why use either? Use frictionless rings as dead-eyes and lace them up using light gauge dyneema or some other durable UV resisting polymer twine.

[s/v Jedi]

Originally Posted by sailcrazy

I'm sure turnbuckles have failed, just as I'm sure the Dynema and lashings have failed due to chaff, UV or??? Nothing is failsafe. Personally, I've never had, not heard of a turnbuckle fail.....but then we've only at this ocean cruising thing since 1996. I'm still looking for the reason(s) why it's a change to make!. And I can see plenty of places where the chaffing/wearing would not be easily seen and could cause a major issue (ie, where the Dynema goes thru the hole at the stanchion top). Please enlighten me. We have switched from cable to Dynema halyards on both the main and the headsail, but we do take considerable care to rotate the line (reduce UV, and chaffing),switch ends, cover the spools on the mast-mounted winches(both the main and headsail are on roller reefers), etc.

You see the chafing long before it becomes a problem. That’s so nice about using rope products over stainless steel. For stainless steel you need to do dye tests etc. which is so impractical that nobody does that. With Dyneema you see fraying, you replace the lashing. When it chafes where it goes through stanchions, you see fraying right at the stanchions.

[thinwater]

Originally Posted by 40 South

I did mine in 7mm dyneema, complete with gates, 2mm dyneema lashing with 4 wraps and S/S thimbles a few months ago.

I would avoid steel cable-style thimbles and their sharp edges. They can cut ropes. Sailmaker's thimbles are a better choice. Or just thread a piece of webbing for chafe. There is no structural argument for strength use 12-stand Dyneema.


When calculating the number of passes on a lashing, use only 40-50% of the strength of the lashing lines. This is because of maldistribution of tension between the cords, I have tested this, and so have rigging makers. The efficiency is a little better using LFRs (50%) and closer to 70% using proper rigging terminators, but it is NEVER 100%. Just sayin', the lashing needs to be considerably fatter than the line.

That 8-pass 2mm Dyneema lashing will hold about 8 x 880 x 0.5 = 3500 pounds. The 7mm Dyneema will hold more than twice that. It will also degrade more rapidly due to UV because it is thin, so really, it will be only 1/3 the strength of the main line within a few years. So I would cut off the french whipping, get heavier cord, and use more passes. Sorry for the bad news, but google lashing efficiency or read the links below.



https://www.practical-sailor.com/sai...g-for-strength

https://chainsropesandanchors.co.nz/...es-what-to-use


To repeat, a lashing must be 2x line strength to be equal.

[alaskanviking]

Originally Posted by Davidhoy

I'm getting ready to replace the old coated stainless steel lifelines on my boat with dyneema, and looking at the hardware I need I see there are open-bodied and tubular turnbuckles available. For standing rigging I think that open-bodied are best, but for lifelines I think it's a wash in terms of functionality. Can anyone suggest a good reason for choosing one over the other? I'm inclined to go with the tubular style for my lifelines...



Regards,

David

I changed my lifelines over to dyneema in 2013. At the time there wasn't much hardware, available and what was was expensive. I was able to reuse enough hardware to get a good working solution, without fancy turnbuckles. I used stainless thimbles and small shackles for the lashings.

To decide on turnbuckles vs lashing with frapping knot, depends on the dyneema. My lower line is 5mm dynice dux. Super strong, stiff, low stretch. I've never had to retighten, and just replace the lashing every couple years. The top line is 5/8" Amsteel. It stretches enough that I have to take off the lashing and retighten every year-2 years. I should take better notes on this stuff, but regardless it's noticeable. Maybe my stanchions are loosening which is a disturbing thought in itself. Technically I should take off the lashing once a year and move the part that's touching the thimbles...

That means a turnbuckle would have worked well for the lower line. I feel it a turnbuckle would use up all it's slack to fast with the Amstel, and you would have to re-splice that end, so my vote is lashing for Amsteel. However the lashing looks so damn nice, adds to my nautical air like a salty old sea captain. I see people look the lashings and lifelines a lot, which makes me feel like a million bucks.

The thicker upper line is awesome if you can fit it. You probably don't need 5/8" but 3/8" would work if you can swing it. Makes a comfortable easy to grab line, thinner lines don't feel as nice when used in demanding situations.

As to the why's... I can have a coil or two sitting in a locker that could replace all my lifelines or act as emergency stays or rigging, and weighs barely anything. Splices are so simple a 12 year old can do them (not saying that I would trust the splice of a 12 year old for a life line or safety item). No rust or corrosion. And that big 5/8" line is Soo much more grab-able than the wire it replaced. If price is your thing I did it at about the same cost as wire in 2013, and stuff is cheaper now. Once you have splice something like this your brain will explode from all the possibilities you can use your new splicing skills for. Look up "whoopie sling" and other tree climbing spliced slings for even more brain explosions.