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View Poll Results: Direct 3 strand nylon line to chain or to shakel/with themble
Direct nylon line to chain braided in serveral links of chain 10 20.41%
Direct nylon line to chain braided in one link of chain 16 32.65%
3 strand nylon to themble/eye and to shakle 26 53.06%
Multiple Choice Poll. Voters: 49. You may not vote on this poll

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Old 21-05-2006, 17:19   #16
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One thing I have noticed on several boats is rusted thimbles and stained anchor rodes. I purchased a Bruce anchor with chain and rode this weekend at a flea that has this exact problem. Either the thimble is of inferior quality or the action of the shackle and thimble may wear the galvanization and cause the thimble to rust. In either case it is unsightly and most likely compromises the connection. I use the crown knot.
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Old 22-05-2006, 02:18   #17
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I finally get to disagree with Wheels, well a little anyway.

Rope to chain connections are one of our specialties. We have been doing them since Maxwell first came up with the auto rope to chain winch concept. We have done literally thousands of these and do a lot of test work with Maxwell and a couple of others. This is fun, they pay us to build the latest cunning plan from their engineers and then they pay us again to find out whats wrong with the concept... very cool fondling and busting other peoples stuff.

There is 3 basic methods of joining rope to chain in a anchor rode situation. All are equally as strong as each other give or take a few %. Mind you nobody should put themselves into the position they find out. If they do they are using all the gear at loads massively above manufacturers recommendations, it is one very extreme bit of weather and the rode coming apart just adds to all the other failures that will happen first.

We have 'straight pulled' and cyclic loaded many of these over the years. Not to mention seeing hundreds of used ones.

1, A thimble - works fine apart from the fitting the bugger down the chain pipe and on Auto Rope to Chain winches. Maximum strength will be the rope break load less 15%. The 15% is the standard deduction for a good splice be it 3 strand or 8 braid (octiplait). In real life the shackle will probably be the weak spot. Don't be cheap always use a Stainless thimble.

2, Around the last link and backspliced. Note this is not an eye splice around the end link, that is just asking for chafe and the most common we replace. Done right rope chafe is a none issue and the strength is no more or less than a thimble. The problem that 'can' occur with this splice is the chain link eroding under the rope. We have noticed 'in the odd' old one the chain itself is quite corroded. This is why we always cut the end link off when we redo one. All of the rodes we have seen this in are heavily used (usually off charter boats or the extreme fisho's) and at least 3 years old. Notice the use of 'in the odd one' meaning it is not common but has been seen to happen. Issues with the rope are in the less than 1% area.

This splice is easy for the average boaty with a few clues to do well. It is also easy to see problems if they occur.

The key thing is to get the splice as tight as possible onto the end link this way there is no movement between the chain and rope hence no chafe. All the movement is between the 1st and 2nd links of chain.

3, The down the chain splice. A smidgen stronger that the other 2 if done very correctly which is not that easy. In actual use there is no strength differance than the other 2 ways. The problems with this splice are it is not easy to do correctly, you run a high risk of damaging your winch and issues are not as easy to pick up. They should be but it don't seem to happen.

To get this right all the fibres must take equal load or just part of the rope does the work with the possible big decrease in load carrying. This method also has issues when cheaper ropes are used and when they go hard. This makes the splice too long and stiff to work around a winch well. There is the problem with the 'odd' link rotating in the splice and if one rotates enough it could hit your gypsy 'on end' which has blown some gypsies apart, usually causing gearbox damage. On smaller 7/8mm winches repair bills have hit US$700 odd. This method is also a bit visually busy and we have seen the odd one with broken strands which are not easy to pick up from a casual glance. Winch manufacturers are not great fans of this splice due to their products getting beaten up.

In real life all 3 options are viable and can be regarded as equally strong. Anyway the splice is not the weakest part of an average well matched (rope and chain sizing) rode, the chain is.

A common match is 10mm chain to 20mm rope. Break load of the rope 9000kg (average) less 15% for the splice makes it 7650kg. Grade 30 10mm chain (the most common in use) break load 5000kg or on a Grade M (the US call it 'HT') 6500kg, both still below the spliced rope load.

In all the testing we have seen the rodes break at the back of the splice as would be expected with any spliced rope. We have yet to see one rope spliced directly to the chain rode fail due to the connection between them. This excludes rusty thimbles cutting thru the rope, shackles busting or poor splices which just fall out - in that order. Talk chafe in other parts of the rope or knives due to rock grabbing anchors and the list is huge.

In reality any rope to chain connection will still take far larger loads than your anchor will hold, the winch will hold, snubbers will hold, a lot of decks will hold (don't laugh we have seen a deck torn open) and most boaties will allow before they bail out of a nasty spot.

Rick - sexy looking set up but watch your double braid. 1/2 of double braids loads are carried by the cover and the other by the core. As soon as the cover is cut you have a sudden (possibly big) strength loss. Polyester was a better choice than Nylon though, good call.

Gezz another novel but I hope it is of some use to someone.
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Old 22-05-2006, 02:42   #18
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Excellent work Gmac. And I am happy to stand and be corrected anytime. Especially when such an excellent reply is written.
Although, if I may be picky. You will note that what you have stated does cover many of the same comments I made. It's just my accent that make it hard to understand me.
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Old 22-05-2006, 02:54   #19
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I did say 'only a little'.

Yeah you southern folk can be hard to understand at times. To close to the snow I reckon
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Old 22-05-2006, 03:30   #20
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GMAC
Great Post !
Thank you!
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Old 22-05-2006, 04:30   #21
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1994 Rope to Chain Splice Test:
http://www.ussailing.org/safety/Stud...hainsplice.htm
Conclusions (One of 5) : If the chain splice is examined for chafe on a regular basis, we find no objections to the rope to chain splice from a strength reduction standpoint, as it appears close in strength to other components in the system and to commonly available nylon line.

On-line references:

3-Strand Rope to Chain Splice Instructions (New England Rope):
http://www.neropes.com/splice/sp72_3...d_to_chain.htm

New England Ropes Splicing Guides:
http://www.neropes.com/splice/main.htm

How to make a Warp to Chain Splice:
http://www.bluemoment.com/warpchainsplice.html

Braid (Brait) Back Splice (Yale Cordage):
http://www.yalecordage.com/html/pdf/...ain_splice.pdf

Eye Splice 8x3 Strand (Plaited) - Class II Rope (Sampson):
http://www.samsonrope.com/home/pdf/C..._EyeSplice.pdf

“Marlowe Splicing Instructions” (begins @ page 8 of 15):
http://www.marlowropes.com/cordage/y...nformation.pdf

“Animated Knots by Grog”
http://www.animatedknots.com/

“Knots, Splices and Rope Work” ~ by A. Hyatt Verrill
http://www.web-books.com/Classics/No...k/Contents.htm
(for download) http://www.web-books.com/Classics/No...sWork/home.htm

See also references in print:

“The Complete Rigger's Apprentice: Tools and Techniques for Modern and Traditional Rigging” ~ by Brion Toss
(See also his forum): http://www.briontoss.com/spartalk/

“The Splicing Handbook - Techniques for Modern and Traditional Ropes” ~ by Barbara Merry & John Darwin

“Nautical Knots and Lines Illustrated: The Essentials of Smart Line Handling, Knotting, and Splicing” ~ by Paul & Arthur Snyder

“The Complete Book of Knots and Ropework” ~ by Eric C. Fry
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Old 22-05-2006, 06:57   #22
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Warp to chain splice !!!!!

Probably the 'strongest' connection possible.
Better vs. chafe as with an 'eyed' or walled/crown splice.
Thimbles have the notariety of coming loose under heavy cyclical loading even if served, etc.

http://www.bluemoment.com/warpchainsplice.html

I increase the distance of the 'interleaving' by 2X and taper the terminal ends.
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Old 22-05-2006, 13:23   #23
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Southern Folk eh?! yeah, so far south, were beyound marrying our cousins, but the sheep sleep with one eye open
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Old 22-05-2006, 18:48   #24
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Yeah Alan.

I bet the guys down there have their velcro gloves and knee pads at the ready for them sheep. Right?
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Old 22-05-2006, 20:50   #25
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Gmac I truly appreciate your comments and expertise. Please notice that the polyester will chafe through well after any nylon wil under the same circumstances either three-strand or double braid. In addition, the first place that the polyester will suffer damage will be the inside radius of the turn and, at that time, there will not be a 50% degradation of strength, merely some other number less than that until which time the core begins to lose strength (obviously it takes more than a fraction of the cover to degrade before one can claim a 50% degradation of strength even considering the non-uniform loading thereof) , again noticing that the tendency to do so will be WAAAAY less than any nylon fibers under the same conditions.

The main point here is that polyester has been neglected heretofore as a viable improvement for an "interface" between attachments (albeit cleats and fairleads or shackles and thimbles or any other chafe point) and nylon which provides the necessary stretch and shock-loading accommodation for mooring, anchoring, and docklines, etc. that chain alone cannot provide.

Please, further comments....???? Let's tear this discussion apart with illumination of critical thinking!
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Old 23-05-2006, 00:40   #26
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Quote:
Originally Posted by Rick
Please, further comments....???? Let's tear this discussion apart with illumination of critical thinking!
mate..... I'm still trying to get rid of the mental picture of Wheels, velcro gloves and sheep . If anyone catches him wearing short gumboots (Wellingtons to some) be very afraid, a sure sign the wife is away on an extended holiday , it is in Taranaki anyway

back to boat bits:

I'd agree you have a reasonable sound theory there with your polyester. I'd just like to add I've seen polyester chomped up pretty quicky at times but it is a good improvement over the nylon for abrasion. Correct again with the strength loss if you nik the cover, it will not drop 50% immediatly but it pretty much means a replacement will be needed quite quickly, Dbl braid doesn't hold itself togeather to well once it has started to go. At least any cuts to the outside cover should be very visable. I doubt if the inside of the 'interface' will suffer much damage, once the 2 ropes lock tight I'd expect nothing to happen.

I do quite like the theory you have and are just trying to find flaws for interest sake, not to denigrate your plan as such. I hope that came out right.

The connecting between the pendent and main rode could be a issue if it gets caught in rocks. Have you had anything like that happen?

Assuming all you splices are up to speed (more connections means more to go wrong theory here) thats about all I can come up with, so far

Personally all my rodes are Polyesters but then I'm not using a Auto R2C (rope to chain) winch, I've only got a 1 wife-power model, which is a tad unreliable and goes very bad sometimes.

I like the Polyester mainly due to the way it stays softer longer, mind you I swap rodes often to play with some 'cunning new plan' we come up with.

1/2 an hour ago I added a Ross 930 to my stable. A 9.3 mt higher performance leadswinger. A new test bed for us to kit out..... cool. By the time we are done the Americas Cup boys will be jealous. PBOs, Vectrans, SK90 heat-treated Dyneemas.......oh oh.. I think I'd better go and have a cold shower
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Old 23-05-2006, 00:42   #27
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Sorry Rick, I'm approaching with a dull torch.
My opinion is Nylon is the rope of choice. Polyester should not be used for anchor work. Not enough stretch and as you said, poor abrasion resisitance. Plus the stuff floats. You need the rode to sink down. The only time I use polyester is for a stern line to shore when I am 50m or greater away. I don't like it sinking. With it lying on the surface, anyone else can see it if they come around behind you, and it is easier to keep the scope tight and short. If it is in a large arc down to the bottom, you can never get that darn thing tight enough when working that sort of distance.
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Old 23-05-2006, 10:51   #28
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"Polyester should not be used for anchor work. Not enough stretch ...."

It seems some who have done some research in this area disagree.
See http://www.setsail.com/_storefiles/71.pdf
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Old 23-05-2006, 13:55   #29
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Everyones allowed to disagree and I didn't say I was right. I was bringing my dull torch as light to the argument remember. It is my opinion and I stand to be corrected with others views if need be. But my explanation above does state why and what situations I use such material.
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Old 23-05-2006, 21:13   #30
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Hey everybody, wake up!

Polyester (Dacron the brand name manufactured in the USA) does not float! Polypropeline floats and is NOT the point of discussion here!

IN addition, this discussion applies only to a few feet of material to replace the position where nylon might abraid against a fairlead or connect to something that might abraid it. This discussion is about using a few feet of NON-STRETCHING (translation: no stretch, almost no abraision) line to interface between an attachment and the stretch and shock absorbing nylon looooong line that is still utilized.

An amplifying point about using two eyes to join the two different types of line is that this connection has been proven to not degrade the strength of the weakest line as would virtually any other knot. Failure in such a "system" will invariably be at another place.
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