Deadeyes vs just lanyards with HM materials
 

Hello all...

Background:

I am going to be re-rigging my gaff cutter with Dux (9mm) and am currently embroiled in how to terminate the shrouds at deck level. The current setup is traditional(ish) deadeyes and lanyards, but the upper deadeyes are made from boxed heart wood (not sure on the species) and has some decent checking. I would like wither make or buy a replacement. One of the option is just to buy some lignum/ipe/locust and mill them up myself, but then I got thinking on the possibility of raw lashings through very beefy, cast SS thimbles.

I know that the new 12-meter gaffer Kate is rigged with SS shrouds, terminated with stay-lok eyes onto big shackles. They are then lashed to deck with (presumably) HM lanyards through the rounded end of the shackle. This method seems for work well enough for a 12-meter racer... I wonder of its applicability to much smaller craft? My boat (October) is a ~10 ton gaff cutter with 750 sq ft of working sail.

The actual question:

Given the use of HM lanyards and beefy, cast thimbles (such as these ), what are the engineering differences between using just lanyards (lashings) for shrouds and deadeyes and lanyards?
Is the main difference the chafe of the lines against themselves within the heart? If so, one might assume that the very tough HM lines would alleviate much of that problem...
Is it that, generally, stamped thimbles are not strong enough to support the rigging loads of lager craft, and thus traditionally one would need a beefy chunk of wood to take the compression strain? (Leather seems make this point in the Gaff Rig Handbook limiting simple lashings to craft of less than 300 sq ft of sail)

So, I am thinking heavily of using an oversized thimble like the ones linked above (with enough radius for a ~5 x diameter bend for the shroud), and lashing through that at the end of my shrouds with a HM line with a cover (dyneema, amsteel, vectran, dynex, something...). any thoughts on what I am missing what why it may be a bad idea?

Eric, I can't speak for the old timers or anyone else for that manner but one major reason for individual holes in our line terminators is to maintain line separation and therefore put a lateral force on the half hitches that we recommend using to tie them off. If you use a traditional thimble, half hitches won't be as secure. With our system the lashing forms a very distinct hourglass shape which means that you are putting a lateral force on the lashing and that helps make it more secure. As long as tension is on it the system the lateral force is maintained. When tied off correctly with the half hitches on the lower half of the lashing the hourglass shape also helps keep the knot from slipping down and loosening the system. Alot of people just use thimbles, including Francis Joyon on his roundy round record run where he complained of loosing trust in his lashings. I believe using line terminators with good line separation probably would have helped him. See our lashing guide here to better understand what I am saying. http://www.colligomarine.com/docs/mi...ie_ver_1_1.pdf

John Franta, Colligo Marine.

Eric, here is an article that is a bit dated( he uses SK-75 Dynex instead of the far stronger Dynex Dux) of a guy who used SS Thimbles. I have seen some photos of his set up but do not recall where the photos are. He beefed up the SS thimble with as piece of pipe welded across the fat end to facilitate the lashings. It turned out bad as the thimble "capsized" as the load came on one side or the other of the now flat thimble end.
I have lashed smaller stuff through regular SS eyes and found it will bind up as it gatherers on top of itself.
There is a report from Australia of a boat rigged with SS eyes that has had deformation of the eyes due to the loads.
Turns out the old fashioned dead eye is a Superior design after all! Here are some shots of my 34' Trimaran rigged with 7mm and 9mm Dynex Dux and dead eyes from Colligo Marine.com

http://s30.photobucket.com/albums/c3...ner/?start=all

So far so good on all of it. The fittings are also designed with an eye so you can use turnbuckles if you like instead of the lashings, dead eye set up.

Thank you for the info, both Jack and John...

Was this the article you were talking about Jack? http://www.hampidjan.is/Products/YachtRigging/

One follow up:

If one wanted to use more traditional deadeyes and lanyard materials (more like polyesters instead of HM line), would anyone expect adverse affects from the cow hitch (ring hitch, larks head) across the top of the upper deadeye (the "standard" tie-off method) pushing down on or crushing the Dux between the lanyard and deadeye?

I imagine one could/should be prudent and put a cover on the dux for chafe down there, but is the compression on a flat face something to watch for?

Thanks again.

Yes that is the article I failed to post Bott.

As far as your question goes, If I understand you, you wonder if you can make off the lashings in the traditional manner, on top the Dead Eye?. I would say "sure why knot?" I would not worry about chaff if I understand what you are talking about. Dynex is used for butchers gloves because the material is so chaff resistant.
I would question using a different lashing material though. If you get most anything else you will have stretch and creep to deal with. After using Dux on the shrouds, you have the makings of a very strong no creep no stretch set up. If you lash it with with something else you may loose all the advantages of the Dux (except weight saving)
Also a traditional lashing hitch may not work with Dynex as it is very slippery. We have found multiple hitches or turns are required with Dynex where you could use much less with a poly or nylon line.

on all the dux riggs we have put together with deadeyes we tie off in the traditional manner, for both dymeema lashings and polyester lashings.

Ain't nuttin' wrong with tradition, most of the stuff was worked out long before I was born!

I would love to see some wood deadeyes combined with Dynex Dux. I believe it is going to be the next wood/epoxy combination. The way wood was "converted" and rediscovered for boat building in the last 30 years, when used with epoxy, we will see rope replacing wire with the new materials!

http://voyageundersail.com/_wsn/page4.html

one lousy photo here, the photo of sean macleod, knida shows that rig with the dux and trad deadeyes...