Enclosed Thimbles

[SV Papillon]

I can only comment on what we had. Our line rode was our secoundary rode and was only set if we were in a particular place for a long time. We sat through a couple good blows where the line rode with the shovel splice was taking the brunt. Our secondary anchor was a aluminum fortress in one instance where it was loaded over night it took about an hour to free the anchor as it had set pretty hard, no visible signs of wear, broken yarns etc. I was reluctant to service the entire splice in an effort to let the yarns work themselves in giving a uniform load, just theory on my part, I have no idea if it was the case.

Jake

[Renoir]

From an idea that I got from Brion about 4 years ago I have eliminated anchor gear thimbles. Dress the end link of your anchor chain so that the zinc coating presents no "pimples" or other mechanism that can cause chafe. Buy a length of double braid polyester (about 20 ft) that has a diameter will JUST fit through the end link of the chain (5/8 inch for a 3/8" chain for example).

Using directions in The Riggers Apprentice (or better yet view Brion's splicing DVD for the dynamic visualization) splice an eye in the end link of the anchor chain.

Splice an eye in the other end of the polyester anchor chain-to-rode interface pendant sufficiently large so as to accept two diameters of your rode.

Splice an eye in the end of your rode sufficiently large so as to accept two diameters of the polyester pendant.

Pass the bitter end of the rode through the polyester eye, pass the bitter end through the other end eye of the rode and snug it up. You then have a "square knot" looking connection formed by the two eyes intertwined together. This is STRONG.

The polyester will not stretch under load at the chain link and, therefore, you will experience almost no wear (other than what can be caused by dirt and grit if you don't keep it clean).

The result will pass through a hawse pipe that a sufficiently strong thimble will not and will be probably much stronger and longer lasting.

[SV Papillon]

Three splices instead of one?

[Renoir]

Yes, absolutely! The result is stronger, more chafe resistant, and will not degrade the nylon as a thimble WILL do when under heavy surge and strain. When that happens you must resplice the eye on the thimble. The nylon literally fuses on the inside of the thimble (not visible to inspection) when that happens. This is because the nylon WILL stretch around the thimble and abraid creating heat.

With the two eyes joined by the nylon and polyester, there is a completely balanced tension in each of the four elements formed by the join (assuming that you followed the splicing directions correctly). Stretch due to the nylon characteristics is absorbed by the polyester in compression and almost no relative movement occurs to abraid the nylon, hence a longer lived tackle.

[SV Papillon]

shovel splice = no thimble

[Renoir]

A shovel splice works, yet does not sufficiently reduce nylon stretch over the steel end of the chain and must be periodically replaced although perhaps not as often as a thimble eye must be replaced. That is why a polyester double braid "interface" between the steel chain and nylon works without the requirement of a periodic replacement.

I realize that many boaters do not experience extreme anchoring situations yet blue water cruisers often do. When that happens one must carefully prepare one's gear so that one can sleep with heavy waves passing beneath the hull and heavy wind blowing the hull around and that is when these types of splices (nylon shovel splice on a steel link or a thimble) must be replaced due to the degradation of the nylon line.

I believe that a shovel splice on the end of a chain would have less than an 80 percent of potential rode strength ultimately. The polyester "interface" solution results in a strength greater than 80% of the potential rode strength (when wet as well as dry) approaching 100%.

[Renoir]

A new shovel splice will probably give close to a 100% strength yet will degrade over time due to chafe and that is why I believe that one must assume around a 80% "ultimate" strength after some abuse. Worse with greater abuse....comments?

[SV Papillon]

After working with poly quite a bit in the fishing industry I am pretty leary of it. The theory is sound. My solution to the chaff worry was to go way oversize on the nylon. 1" 3 strand to 3/8" chain. It sounds ridiculous but it made a very uniform transition with the shovel splice and the line was large enough that it was very easy to pull in by hand. It was for a secoundary rode too. Our primary being all chain 300'. This arrangement was fine for the west coast of us and mx but not great for any depth over 70' or so. I like having as few parts as possible in the ground tackle. The double eyes to eliminate a shackels is nice. Maybe oversized spectra 12 strand instead of the poly.

Jake

[Renoir]

Normally when someone says, "poly" when referring to line they mean polypropylene, not polyester (Dacron in the USA). I know that the fishing industry uses a LOT of polypropylene due to the low cost and floating characteristics compared to the other synthetics. Were you referring to polyproplene here?

Polyester (Dacron) line is stronger and more chafe resistant (due to much lower stretch) than wet nylon, right? So why would you be leary of it?

[SV Papillon]

I re-read your post and had initially read it as polypropylene. Dacron is good but pretty stretchy too. I used it for a snubber. Probably not alot of stretch in a short piece.

Jake