General consensus on Ultra Anchor

[rslifkin]

Pin through the shank should be fine, just requires use of 2 shackles, rather than 1. That way you still follow the convention of pin through the chain (and have the bow sides of the 2 shackles joined together).

[Panope]

Originally Posted by Dockhead

Oh, sorry. Not paying attention! But a round hole of sufficient size should be ok, no? Is the hole simply too small?

Originally Posted by Panope

Yes, hole was much too small for the boss of a 7/16" shackle to pass. I use 3/8" BBB chain so I suppose I could try a "high strength" 3/8" shackle (crosby 209a). I'll check this at the next opportunity.

Steve

OK, I have confirmed that a 3/8" shackle's BOSS will NOT pass through the hole of the 46 pound ULTRA.

Steve

[Lodesman]

Originally Posted by rslifkin

That way you still follow the convention of pin through the chain .

Surely this is only "convention" when using bulk chain - if a proper anchor chain with an oversize link at the end is used, that second shackle needn't be required.

[rslifkin]

Originally Posted by Lodesman

Surely this is only "convention" when using bulk chain - if a proper anchor chain with an oversize link at the end is used, that second shackle needn't be required.

Oversize end links aren't necessary except for G70 chain. For G30 and G43 chain, running a 1 size up shackle of the correct grade (such as a Crosby G-209 for G30 and G-209A for G43) will give plenty of working load. For example, 5/16" G43 has a WLL of 3900 lbs. The pin of 3/8" Crosby G-209A shackle fits nicely into the 5/16" chain. And the shackle has a WLL of 2 metric tons, or just over 4400 lbs, which is more than the chain.

IIRC, the convention of pin through chain (rather than the shackle bow through chain) has nothing to do with the shackle fitting into the chain, but entirely to do with reducing the risk of binding or side loading the shackle pin against the anchor shank hole, which can cause failure at lower than designed loads. So it's better to put the pin through chain and bow through anchor. And if that can't happen, using 2 shackles is supposed to reduce the issue.

[Factor]

Originally Posted by Muaddib1116

I'm just exploring options for anchors without roll bars. The spade seems well regarded, but many people complain about the chintzy galvanization on it, and suggest that maybe the SS spade is the way to go. Which, incidentally, is pretty close to the Ultra. Also, fit has to be considered for some boats, both with the rollbars and with the shank angles/shapes.

EXCEL, SPADE, ULTRA, VULCAN

Originally Posted by Jim Cate

While I agree with the general implication of this, do note that IIRC none of the comparisons were between Spade and Ultra, and Spade is the only other commonly available non-rollbar modern anchor. I'd be interested in any head to head comparisons between this pair of designs.

Jim

EXCEL, SPADE, ULTRA, VULCAN

For the record, I would never own another Roll Bar scooping anchor. (And I have owned Rocna and Manson Supreme). They suffer from a fatal falw for me in the areas I anchor.

I choose Excel cause they work - and in my case its nice they are Australian.

[rslifkin]

Originally Posted by Factor

EXCEL, SPADE, ULTRA, VULCAN

EXCEL, SPADE, ULTRA, VULCAN

For the record, I would never own another Roll Bar scooping anchor. (And I have owned Rocna and Manson Supreme). They suffer from a fatal falw for me in the areas I anchor.

I choose Excel cause they work - and in my case its nice they are Australian.

The one roll bar anchor I'd consider to be different than the others (and not so prone to the clogging problem) would be the Mantus, as its roll bar opening is far larger than any of the others. But yes, those are pretty much the 4 good choices for non-rollbar anchors. The Manson Boss got some good reviews as well, but I'm not sure if it's still in production, as a lot of places seem to have stopped carrying it.

[Lodesman]

Originally Posted by rslifkin

IIRC, the convention of pin through chain (rather than the shackle bow through chain) has nothing to do with the shackle fitting into the chain, but entirely to do with reducing the risk of binding or side loading the shackle pin against the anchor shank hole, which can cause failure at lower than designed loads. So it's better to put the pin through chain and bow through anchor. And if that can't happen, using 2 shackles is supposed to reduce the issue.

Do you have any reference that says that? It sounds like nonsense - the pin, properly-sized, would have the side load spread over a much larger area of the pin, assuming the hole in the shank is a straight bore (most tend to be IME). Pin over the round of a link would concentrate the side-load on a fine point - if that's at the centre of the pin, it seems more liable to bend the pin with a resultant twist and failure of the threaded lug.

Most of my books are on the boat, but I did get some snips out of Hinz's Book of Anchoring and Mooring that seems to favour putting the pin through the shank.

[rslifkin]

I know practical sailor did some testing on the matter. It had more to do with the shank trying to spread the cheeks than the strength of the pin itself. Leverage on the cheeks loads the threads on the pin, which is the weakest point. The rounded, narrower chain links don't put the same leverage as the end of an anchor shank can.

[Lodesman]

I looked at PS and found this comment and associated article:

https://www.practical-sailor.com/mai...anchor-shackle

in which this claim is made:

All of the shackle failures in that test occurred as loads concentrated at the pin threads as the shackle was pried open.

Looking at the anchor shackle report, it does not indicate how the failure test was set up, but it is clear that in most cases the pin has sheared at the thread where it meets the inner face of the lug. There is one anecdotal example of an unrated (and spindly) shackle that the author refers to being "incorrectly installed with the pin through the anchor shank" - it failed by pulling the pin (intact) out of the lug. It seems to me that what probably happened was the lug expanded under tension, then subsequently a side load opened the jaws of the shackle - failure caused by using el cheapo components and not inspecting them regularly, not by the orientation of the shackle.

https://www.practical-sailor.com/sai...surance-policy

A subsequent test explains the testing procedure, but the author dismisses the valid point from Peerless that the larger-diameter shackles employed in the testing process will skew the results. The author was dismissive of this, even though he can't seem to see that the 'wedging' of the larger shackle into the jaw of the smaller shackle leads to the "necking" he reports as contributing to the failure.
PS would do better to get an engineer to design and conduct a proper test.

https://www.practical-sailor.com/sai...itial-findings

I didn't find any tests that compare the orientations of the anchor shackle, or even test shackles under a side-load. Given that the quality shackles all failed at the same point, it seems putting the point load at the thread-side of the pin (ie. with the chain) would be the likeliest way to failure.

[Dockhead]

Originally Posted by Lodesman

I looked at PS and found this comment and associated article:

https://www.practical-sailor.com/mai...anchor-shackle

in which this claim is made:

Looking at the anchor shackle report, it does not indicate how the failure test was set up, but it is clear that in most cases the pin has sheared at the thread where it meets the inner face of the lug. There is one anecdotal example of an unrated (and spindly) shackle that the author refers to being "incorrectly installed with the pin through the anchor shank" - it failed by pulling the pin (intact) out of the lug. It seems to me that what probably happened was the lug expanded under tension, then subsequently a side load opened the jaws of the shackle - failure caused by using el cheapo components and not inspecting them regularly, not by the orientation of the shackle.

https://www.practical-sailor.com/sai...surance-policy

A subsequent test explains the testing procedure, but the author dismisses the valid point from Peerless that the larger-diameter shackles employed in the testing process will skew the results. The author was dismissive of this, even though he can't seem to see that the 'wedging' of the larger shackle into the jaw of the smaller shackle leads to the "necking" he reports as contributing to the failure.
PS would do better to get an engineer to design and conduct a proper test.

https://www.practical-sailor.com/sai...itial-findings

I didn't find any tests that compare the orientations of the anchor shackle, or even test shackles under a side-load. Given that the quality shackles all failed at the same point, it seems putting the point load at the thread-side of the pin (ie. with the chain) would be the likeliest way to failure.

My personal opinion -- which is just an opinion from a non-engineer who has not done any testing, so take it for what little it may be worth -- is that this is not as big an issue as it sounds like, like side loading of any of these connectors, including swivels. How strong is the strongest anchor shank when pulled sideways? Not strong enough for you to break a shackle or swivel on it, methinks.



Nevertheless, I think where possible one would want to avoid loading any of those connectors in a way which stresses that part of them. We've all seen the anchor swivel/connectors whose jaws have been gradually levered apart. Better put the bow of the shackle through the shank, not the pin, the way our fathers taught us. Where possible.

[Lodesman]

Originally Posted by Dockhead

My personal opinion -- which is just an opinion from a non-engineer who has not done any testing, so take it for what little it may be worth -- is that this is not as big an issue as it sounds like, like side loading of any of these connectors, including swivels. How strong is the strongest anchor shank when pulled sideways? Not strong enough for you to break a shackle or swivel on it, methinks.



Nevertheless, I think where possible one would want to avoid loading any of those connectors in a way which stresses that part of them. We've all seen the anchor swivel/connectors whose jaws have been gradually levered apart. Better put the bow of the shackle through the shank, not the pin, the way our fathers taught us. Where possible.

I'm of much the same mind with regard to side-loading the anchor - in most cases the effort to pull the anchor around will be well below the reduced SWL. If the anchor was trapped, by a rock or something, then again the shank is liable to bend/break. Is it then preferable to have the shackle part, with the chance that you could eventually retrieve an undamaged anchor?

I'm curious why it is your fathers taught you that way, as that goes against the grain as far as I can see from a naval background, and the one yottie book I have at hand. Not only that, it seems to fly in the face of common lifting practice. (source: https://www.ccohs.ca/oshanswers/safe.../shackles.html):

• • Do not allow a shackle to be pulled at an angle. The legs will open. Pack the pin with washers to center the shackle.

  
  

In order to fit through the anchor shank, I know the jaw width must far exceed the chain diameter - do you use spacers or washers to centre the chain on the pin, as code requires for lifting?

[Dockhead]

Originally Posted by Lodesman

. . .I'm curious why it is your fathers taught you that way, as that goes against the grain as far as I can see from a naval background, and the one yottie book I have at hand. Not only that, it seems to fly in the face of common lifting practice. . . .In order to fit through the anchor shank, I know the jaw width must far exceed the chain diameter - do you use spacers or washers to centre the chain on the pin, as code requires for lifting?

I dunno -- that's what I was taught as a lad, like many others of us. Yachtsman practice and navy practice may be different I guess.


Out of curiosity, I just flipped open Dashew's Offshore Cruising Encylopedia and was surprised to see that he has his shackle pin through the shank.




Guess what I was taught is not as universally accepted as I thought. I'll ask my dad where he got this from.

[Simi 60]

Originally Posted by Factor

For the record, I would never own another Roll Bar scooping anchor. (And I have owned Rocna and Manson Supreme). They suffer from a fatal falw for me in the areas I anchor. .

A supposed flaw that other full time cruisers in the same waters you sail never experience?

I choose Excel cause they work - and in my case its nice they are Australian

Never stopped you from buying and selling "made in Vietnam" boats.

[Lodesman]

Originally Posted by Dockhead

Out of curiosity, I just flipped open Dashew's Offshore Cruising Encylopedia and was surprised to see that he has his shackle pin through the shank.

Now you got me looking at Dashew's book. IIRC, CQR and Bruce have round holes, so wouldn't allow the shackle lug to pass through, as Panope found with the Ultra. Dashew's close-up shot was of a D-shackle which seemed to be devoid of any markings - so that's a fail on 2 points: quality shackles should have WLL marked and D-shackles shouldn't be used where there could be side-loads; it should be a bow-shackle, which is also (surprise surprise) known as an anchor shackle.
He has this note regarding chain, which again seems to support my position:

If you’re using a high-strength, small-size chain, have the chain manufacturer affix an oversized link at each end to accept the anchor shackle; the space between the links is generally not large enough to accept a full-strength shackle.

[Lodesman]

Should have also pointed out in the attached pic, that besides the previously-mentioned flaws, this shackle's jaw is too large and should have been sized closer to the width of the shank.