Stainless Steel Shackles on Anchors?

[noelex 77]

Originally Posted by groundtackle

So no shackles/ swivels or anything of bulk would be better?

Yes. This would improve anchor performance, but we also need a secure connection so some form of shackle or swivel is necessary, but try to keep the bulk down for maximum performance.

If we look at a well set anchor such as this Mantus, we can see the anchor has managed to bury all the fluke and shank. All that is visible is the rollbar. To reach this level of bury the anchor has to drag down the connection between the anchor and the chain below the substrate. If this connection is bulky, it will reduce the anchor's ability to bury and reach this stage.



Even if we look at anchors that struggling to set or have only managed a poorish set with just a small portion of their fluke buried, such as this convex plow anchor, it is apparent that in many cases the anchor forces the anchor chain connection under the substrate quite early in the setting process. Anchors typically try and bury the shank end and the fluke together.






There are exceptions. If the anchor is set on a short scope the upward pull on the chain end of the shank is much greater and the anchor has more difficulty forcing the connection under the substrate. The anchor will still set, but it will not set as well.

The more streamlined the anchor chain connection the easier it is for the anchor to set deeply. This theory has been tested with some practical experiments. One test looked at the depth of set with bulky chain versus a thin wire strop. The anchors with reduced bulk next to the shank set deeper.

A swaged streamlined wire strop rather than chain has been suggested as a means improving anchor performance. One manufacturer (XYZ) has even incorporated this into their design. I am not a great fan of this approach, as there are practical problems ensuring the long term reliability of this method of securing the anchor. The reliability of the connection should take priority, but if this can be achieved in a more streamlined design then there are benefits to anchor performance.

So the ideal anchor chain connection is strong, but is also streamlined. The effect of adding something like an extra shackle, or even with an extra Dyneema security line will not be great, but if it can be avoided the anchor performance will be better with a less bulky connection. This does not rule out swivels. Some of the swivels such as the Ulta swivel are quite streamlined.

Originally Posted by groundtackle

I am going to test some shank lube tomorrow.

What, exactly, do you want to do with the anchor?

[Panope]

Originally Posted by UNCIVILIZED

I absolutely, & utterly DO NOT understand this mindset that Spectra is seemingly invincible, & is fully viable for connecting an anchor to chain. Never have, never will. Not since my 3rd post here on CF 3yrs ago.
The reason. There's not a knife I own, including the tiny 1.8" Buck minibuck on my keychain, that has any trouble cutting 1/2" Spectra in one stroke. Cleanly. So no, I do not trust 10mm, 20,000lb BS cordage to secure steel to steel (anchor to chain) at the ocean floor. How can others? It does pretty much defeat the purpose of having a chain leader, or "all chain" rode.

+ 1

Steve

[UNCIVILIZED]

To be clear, I earlier stated that my opposition to the use of Spectra as an anchor connector was my 3rd post because then, as now, I thought the idea silly at best.
Here's the original wording (which some members really loved, idue to it's factuality & comical nature):

Re: Dyneema anchor shackle
I'd say thumbs down. As you'd be purposefully connecting two pieces of metal, with sharp corners & very rough finishes, essentially with string. And then asking said piece of cordage to hold up in an environment where all of the bits are extremely highly loaded, & endlessly drug through; rock, coral, sand...
I'm a BIG fan of Dyneema/Spectra, but not for use in environments which resemble a cross between my knife & a belt sander. And my knife's yet to meet ANY cordage which it can't cut in less time than it takes to draw it from my sheath.

Is there actually a company marketing these shackles?

Stick with a standard shackle, check it's mousing wire/cotter pin regularly, & call it good. Besides, I can't say as I can recall of any time when I heard of a standard shackle failing.
Plus, & here's the bonus, down near the hook's where you want weight anyway... and Dyneema floats, so...

It's posted in this thread --> http://www.cruisersforum.com/forums/...ml#post1610475 Where pretty much everyone weighing in on the topic, including some VERY experienced & professional hands, give Spectra the thumbs down for this app.

[thinwater]

Originally Posted by noelex 77

Yes. This would improve anchor performance, but we also need a secure connection so some form of shackle or swivel is necessary, but try to keep the bulk down for maximum performance.

If we look at a well set anchor such as this Mantus, we can see the anchor has managed to bury all the fluke and shank. All that is visible is the rollbar. To reach this level of bury the anchor has to drag down the connection between the anchor and the chain below the substrate. If this connection is bulky, it will reduce the anchor's ability to bury and reach this stage.

Even if we look at anchors that struggling to set or have only managed a poorish set with just a small portion of their fluke buried, such as this convex plow anchor, it is apparent that in many cases the anchor forces the anchor chain connection under the substrate quite early in the setting process. Anchors typically try and bury the shank end and the fluke together.



There are exceptions. If the anchor is set on a short scope the upward pull on the chain end of the shank is much greater and the anchor has more difficulty forcing the connection under the substrate. The anchor will still set, but it will not set as well.

The more streamlined the anchor chain connection the easier it is for the anchor to set deeply. This theory has been tested with some practical experiments. One test looked at the depth of set with bulky chain versus a thin wire strop. The anchors with reduced bulk next to the shank set deeper.

A swaged streamlined wire strop rather than chain has been suggested as a means improving anchor performance. One manufacturer (XYZ) has even incorporated this into their design. I am not a great fan of this approach, as there are practical problems ensuring the long term reliability of this method of securing the anchor. The reliability of the connection should take priority, but if this can be achieved in a more streamlined design then there are benefits to anchor performance.

So the ideal anchor chain connection is strong, but is also streamlined. The effect of adding something like an extra shackle, or even with an extra Dyneema security line will not be great, but if it can be avoided the anchor performance will be better with a less bulky connection. This does not rule out swivels. Some of the swivels such as the Ulta swivel are quite streamlined....

This has been discussed and quantitatively tested in Practical Sailor. Interested readers should subscribe!

https://www.practical-sailor.com/issues/37_38/features/Anchor-Rode-Report_11321-1.html

The anchor flipper is another way to turn the anchor on the roller that is streamlined. Although it looks big, it is slim like a knife in the setting direction. Personally, I'm happy without a swivel. I anchored several more times the last few days. As usual, it came up straight because of proper chain alignment and because I was slowly drifting backwards.
Yes, a slender rode and no or minimal swivel

I've been using a 20' Dyneema leader on my kedge/secondary for 3 years. This is not for deeper setting as much as to make it easy to handle. However, there are caveats:
1. I anchor in sand and mud, although there are shells and isolated rocks.
2. A kedge or secondary (set in a V) does not see side-to-side yawing.
3. The leader is covered with a free-floating chafe guard. I rock cannot cut through this easily because the chafe guard rolls and slides with the rock, and because the guard is not under tension. In 3 years, the chafe guard is not even fuzzed. The guard also makes handling and cleating Dyneema safer.

Is there some increased risk? Not the way I use it. Additionally, ease of use is so improved I am more inclined to use it when I should. There is less chance of falling because I do not have to carry the chain--I can let the Dyneema drag along behind. So overall, safety is improved. It is so nice not have to drag chain on deck and into the kayak or dinghy.