Enclosed Thimbles
 

Had no luck searching so I will ask here. I am trying to locate an enclosed thimble for my anchor rode. I have 3/4" nylon 12 strand going to about 20' of 3/8 chain. The existing thimble was a nylon one of poor quality and did not hold up well. I want to replace the thimble and wish to use an enclosed thimble of either stainless or galvanized steel. I believe an enclosed thimble will prevent the line from slipping the thimble out but do not see them available in the more common chandleries. Is this something you make your self by welding tabs over an open thimble?

Hi there,
We call them "keeper thimbles", and can get them for you, assuming that you come up dry at commercial fishing outlets. A splice, properly done, is better still.
Fair leads,
Brion Toss

My plan was to redo the eye splice in the 12 strand but also to install a thimble that could not come out. I have not seen these in any stores. I have seen enclosed thimbles for sailmakers use but they dont seem to come any bigger than about 1/4". I thought of taking a stainless 3/4" thimble and cutting some 3/4" id stainless tubing to weld straps onto the thimble to make it enclosed but was hoping to be able to buy one. Thoughts?

A loose splice on a enclosed thimble is likely to chaff on the eye. A tight splice over a welded thimble that is served or whipped will hold the line on the thimble and protect the line from chaff.

Jake

Can elaborate on the "welded thimble"? I was planning on making the splice a tight as I can get it. Again I was really hoping to be able to buy a stainless or galvanized 3/4" thimble that was enclosed so it could not pop out.

Options...
 

It sounds like Brion's shop can help you with a keeper thimble -- a metallic version of the nylon ones that are commonly available. I'd give them a call at 360 385 1080. I am sure you find the experience enjoyable and the price fair.

As you said, you want the splice as tight as possible, and service at the throat can help tighten things further.

With that said, Brion and many others have a preference to splice the rope directly to the chain. They have found the chafe to be lower, security to be higher, and the splice runs over windlasses and bow rollers far easier. Brion has covered this well in The Rigger's Apprentice -- though in three-strand -- I am sure Brion or others would be willing to consult on how to perform this splice in 12-strand.

Bob Pingel

Chain to road splice
 

We did the same on our last boat and I liked it quite a bit. We did the Shovel splice. Seperating the strands into quarters and passing through in opposing pairs over about 2' of chain. We used oversized 3 strand that was easier to hold onto and this splice allowed for a clean transition into the chain whereas a tucked splice back into the line wouldn't have.

pg 92 of The riggers apprentice

Jake

I dont have a windlass but it is starting to sound like a splice may be an easier way to go than fabricating an acceptable thimble. My friend who would probably help with the fab work may be able to do the 12 strand to chain splice. If not I can probably find a local rigger to so it. I am just getting started with splicing and don't think I'm quite up to this one just yet...

Splicing
 

Not being one to push goods, however picking up a copy of the riggers apprentice would be worth your money. The shovel splice, line to chain, would be a fine first splice. Other than being time consuming it is very easy to do. The book is a worthy tool for future projects and you can always bring questions back the source, the author is the host.

Jake

shovel splice
 

Has anyone done any load testing on the shovel splice ? I have completed quite a few from braided line to chain that have given fine service (at least as far as I am aware), but never having done it on my own gear I wonder about the longevity and strength. I have always covered the whole 'sh-bang' (what else can one call a shovel splice?) with service of sorts to protect all the individual yarns.

It seems like getting even tension on all yarns in the rope is near impossible with the shovel splice. With a tucked or buried splice around a thimble , a very percise job can be done. This will of course only work if you have a large anchor roller and no windlass, like Ted.

Maybe the shovel splice is just as strong and secure as a large thimble and bury or tuck splice. Anybody KNOW ?

I would call Brion and order one of his 'keeper thimbles' if this were my problem...

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

A strong reliable alternative solution
 

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.

????
 

Three splices instead of one?

Three spliced instead of one?
 

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.

shovel splice = no thimble

The "catch" to a shovel splice
 

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%.

Initial vs ultimate
 

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?

makes sense
 

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

"Poly" line
 

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?

Dacron good
 

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

to thimble or not to thimble
 

Renoir,
I understand your suggestion and see its benefits for minimizing chafe where a thimble wont work. Thanks for speaking up !
I will say that your comment on cleaning up the end link of the chain has a lot of merit. We always polish our thimbles on the bearing surfaces and make sure that all areas are smooth and friendly to the line as they can be.
I can imagine that the polyester line interface will minimize movement, but I often see the friction melting on both nylon and polyester knots after severe loading: such as when I have used various lines and the 'zepplin bend' to lengthen my anchor scope for very high winds or deep anchorages, indicating there is still movement and chafe and damage to lines where they are joined by knots (though obviously because of the relative lengths to stretch, not as much chafe as over a rough large thimble)
I have not done testing on this but still think that a well thought out thimble will provide the most secure, strongest attachment point, if all other considerations in the system allow it.

Brian Duff's good points!
 

You bring out the reality of the continuum in just what damage does occur to nylon under heavy strain. In fact, in the limit, I have seen strands fused together all along the interface (3-strand nylon in this case) between the three strands which become evident only when peeling them apart.

So, I would like to know from your observation where one loop of nylon joined with a loop of dacron under severe strain that has fused some nylon strands if ALSO some strands of the nylon were fused further along the nylon rode itself. Have you looked for that? When I found such an incident I replaced the entire rode, of course.

This condition was caused when anchored bow and stern off Cabo San Lucas years ago (not far from where Bernard Moitessier lost Joshua ashore from not having been anchored really well). I had even dived in the water to check the anchor and watch the boat action in the large swells. The swell would pick the boat up (450 ft of bow line and chain combination with 250 ft of stern line and chain with the stern anchor on 3 ft of water and the bow anchor in 40 ft) and move it back as the rode stretch waaaay out several boat lengths. When the valley of the swell came the boat moved forward back to the original position and everything was smooth but scary.

The boats with all chain would have their bows practically buried in the swell and when the valley came along the boat would fall away from the chain and if the chain was not captured by some bow roller mechanism it would sometimes come crashing down on the toerail damaging various parts of the boat giving a very uncomfortable looking action.

It was after the action died down a few days later and I moved to La Paz that I checked the gear and had to replace the rode. Everything looked O.K. until I began to notice that the eye splice around the thimble would not move at all and it was fused to it. Removing that part I kept pulling the line apart and saw that it was at least slightly fused all along the rode. At least the thimble was stout and did not collapse.