General consensus on Ultra Anchor

[rslifkin]

Practical sailor mentioned use of a D shackle when you have to put the pin through the shank. Maybe they're harder to spread when side loaded?

[Lodesman]

Originally Posted by rslifkin

Practical sailor mentioned use of a D shackle when you have to put the pin through the shank. Maybe they're harder to spread when side loaded?

I don't trust the opinion of that particular author - much for the reason seen here where he has made an arbitrary statement without any reasons or qualifiers. I will trust the makers of the shackles when they say

Also commonly called a D-shackle due to its “D” shape, screw pin chain shackles are intended for use in straight line pulls or lifts only. Side and racking loads run the risk of twisting or bending a chain shackle.

https://www.uscargocontrol.com/shop/...les-Galvanized

[thinwater]

I don't know what D-shackle vs. bow shackle discussion is being referenced. An issue and page would allow us to put it in context. But D-shackles on anchors are not that unusual.


CQRs use D-shackles. Large anchors nearly always use D-shackles. The original Danforths used D-shackles.

[Lodesman]

Originally Posted by thinwater

I don't know what D-shackle vs. bow shackle discussion is being referenced. An issue and page would allow us to put it in context. But D-shackles on anchors are not that unusual.

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

4th para down.

The same author indicated the use of a D shackle in a couple of the previous links. Notwithstanding the common D-shape of anchor rings in CQRs and large-ship anchors, I think it is worth noting that the makers of D-shackles specify they are only for inline loads, whereas bow shackles can take a side-load albeit at reduced limits. Those large anchor rings are a lot beefier than what is typically used by the yottie-set to attach anchor X to small-diameter chain.

Given the common failure point being the threaded pin, I'm thinking of switching to a bolt-type anchor shackle.

[thinwater]

Originally Posted by Lodesman

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

4th para down.

The same author indicated the use of a D shackle in a couple of the previous links. Notwithstanding the common D-shape of anchor rings in CQRs and large-ship anchors, I think it is worth noting that the makers of D-shackles specify they are only for inline loads, whereas bow shackles can take a side-load albeit at reduced limits. Those large anchor rings are a lot beefier than what is typically used by the yottie-set to attach anchor X to small-diameter chain.

Given the common failure point being the threaded pin, I'm thinking of switching to a bolt-type anchor shackle.

You have inferred something that was never written. Just as posted earlier, the author related historical information, offering no opinion or evaluation regarding whether it was good or bad. From the historical information, a common sense person might deduce that smart engineers had calculated that a D-shackle was appropriate and the that operational experience validated their decision. Few people would judge the original CQR or US Navy Danforth to be weak.

This is the only mention of D shackles in the article (the below is PP 4 in its entirety).



"The typical anchor shackle is a galvanized bow shackle, with the bow (not the pin) passing through the oversized slot in the anchor shank. In some cases, a D shackle is used, but only when there is no slot in the shank. Examples of slot-less anchors include the CQR, Guardian, and the Manson Ray."


Personally, I am very curious why CQR and others use D shackles. As far as I know (and I would very much like to see examples) all of the anchors with fixed shackles use D shackles. It could be because they are simpler to fabricate. It could be because they specify shackles that are considerably oversized for the application and thus strong enough. It could be--and I think this is the real reason--because a D shackle gives less burying resistance and will thus, in some tiny way, increase anchor holding capacity. Swivels, for example, reduce chain burying.



I do not know the reason these manufacturers used D shackles. But they did so very successfully, which no one will argue.


You can use a bolt-style shackle. The only advantage is improved resistance to unscrewing in certain applications, but anchoring is not one of them.

[Muaddib1116]

If the pin of the shackle is closely fitted to the hole of the anchor shank, then it shouldn't be much of a problem. Side forces on the shackle will introduce a couple bending moments to the pin and some to the bow, but there will not be a significant force prying the bow apart.

If the pin is smaller than the hole, but the opening of the bow is tightly fit against the shank, then a side low could create a prying force, using the anchor shank to pry open the bow, where only the threaded pin is holding it closed.

[boden36]

Apart from the relative merits of the anchors, how much of a theft risk is such a valuable piece of gear sitting on the bow roller?
Do they get pinched or am I just being paranoid?

[rslifkin]

Originally Posted by boden36

Apart from the relative merits of the anchors, how much of a theft risk is such a valuable piece of gear sitting on the bow roller?
Do they get pinched or am I just being paranoid?

I'm sure it's happened, but in most places it doesn't seem to be a big issue. If you're worried, back into slips when possible, as that would make it harder for someone to get their hands on the anchor (as it's over water and typically not within reach of a dock).

[Ultra Marine West]

I didn’t want to make further comments on the ULTRA Flip Swivel here not to change the ULTRA Anchor subject, but after all, it looks like the anchor chain connection hole on the ULTRA Anchor looks as its downside for some of you.

I must say that I am happy to see that it is kind of the only downside discussed in our ULTRA Anchor design, but I also have to note that I find this an undue criticism.

There are two types of anchor chain connection designs in anchors, slots, and holes. Anchor manufacturers using slot design ideally preferred their anchor used with D shackles. The original way to use D shackle is by putting the pin through the slot. Here slot lets the D shackle slide in it which should eliminate the need to use a swivel. The problem is there are many low-quality D shackles out there. So in practice, they started to fail from their pins, thus passing the bow of the low-quality D shackle helps it last longer, so that became a general acceptance for some sailors of how to use D shackles with anchors. That is okay. You cannot pass the bow of the schackles from ULTRA shank’s hole, but you can still pass their pin and use them how they ideally designed. If the D shackle you are using is more reliable than the chain, you won’t have any issues. However, there is no slot the shackles will move in, so we recommend you to use your ULTRA Anchor with a swivel having a breaking strength of more than the chain connected not to add a failure point to your system.

Here as I experienced this in the other forum, we discussed the ULTRA Flip Swivel; you may come back to me saying, but the swivels have issues at side loads. Once we put a D shackle passing its bow through the slot, it will never take a sideload.

I will then tell you in maritime; there is no side load terminology for anchors and swivels. Llyods don’t test the side loads of the anchors and the swivels because the only way the sideload takes place if the anchor gets stuck under rocks—however, neither anchors nor swivels designed to work under big rocks.

We should see anchors under rocks as an accident situation so instead of encouraging people to make accidents. I take the shackles passing their bow through slots don’t take side loads in that category. We should encourage people to stay away from accidents or at least take better precautions such as using the ULTRA Anchor Ring for a recovery option for instance. https://www.ultramarinewest.com/prod...ra-anchor-ring

I will finally tell you that there are stronger swivels such as ULTRA Flip Swivel available for you to use with your ULTRA Anchor. My last words will be we don’t market the sideload strength of ULTRA Flip Swivel as it is not in maritime terminology but the sideload breaking strength of the ULTRA Flip Swivel matches with its pulling load.

[Lodesman]

Originally Posted by thinwater

You have inferred something that was never written.

I've not inferred anything. The discussion started with a discussion about Panope's anchor ring on the Ultra, which led me to ask "why do yotties put the bow of the shackle through the shank and the pin through the chain?" The answer that came back was the (unsubstantiated) belief that putting the pin through the shackle puts that shackle at risk if subject to side-loads. Personally I doubt that there would be that much of a side-load applied in turning an anchor around, but admit if the anchor was pinned by a rock or something that this might be possible. If side-loading is a concern, and the anchor has a hole instead of a slot, necessitating the pin-through-the-hole orientation, then it makes no sense to use a D shackle instead of a bow shackle. The shackle makers tell us that D shackles are not suitable for side-loading, whereas bow shackles can be side-loaded. Regardless of the author's intention in mentioning the use of D-shackles, the tacit endorsement of their use would seem ill-advised.
Yes, I acknowledge the D-shape of the anchor rings commonly seen - for all I know this is designed intentionally. Dockhead suggested the anchor shank would bend or break with the sort of side-loads that would imperil the shackle, so maybe the anchor-makers use a D-ring with the intention that it fails first, and the user could subsequently retrieve their anchor with the shank intact.

[Lodesman]

Originally Posted by Muaddib1116

If the pin of the shackle is closely fitted to the hole of the anchor shank, then it shouldn't be much of a problem. Side forces on the shackle will introduce a couple bending moments to the pin and some to the bow, but there will not be a significant force prying the bow apart.

If the pin is smaller than the hole, but the opening of the bow is tightly fit against the shank, then a side low could create a prying force, using the anchor shank to pry open the bow, where only the threaded pin is holding it closed.

I agree. It seems to me that side-loading the shackle, in effect turning a rectangle into a parallelogram could impart a twisting moment on the pin at the lugs. The natural failure point at the base of the thread - ie. being pried off like a bottle cap, seems the most likely concern. Perhaps a snug-fitting D-shackle has an advantage over a bow-shackle, as it might reduce the chance of this type of failure. This is where it would be nice to have test data to refer to, or at least some authority giving a logical reason for using a particular item in a particular way.

[Ultra Marine West]

Originally Posted by boden36

Apart from the relative merits of the anchors, how much of a theft risk is such a valuable piece of gear sitting on the bow roller?
Do they get pinched or am I just being paranoid?

As disincentives against theft risk, we put a unique serial number to each ULTRA Anchor. We note that anchor serials into your Invoices, as well. I haven’t heard of any ULTRA stolen from a bow of a boat.

[Ultra Marine West]

Originally Posted by rslifkin

I'm sure it's happened, but in most places it doesn't seem to be a big issue. If you're worried, back into slips when possible, as that would make it harder for someone to get their hands on the anchor (as it's over water and typically not within reach of a dock).

That is so true, it is not easy to steal it from a bow of a boat, and it is also not easy to sell it with its unique serial number.

So far, the only stolen ULTRA story I heard is that they took if from inside of a boat with a TV and some other items. The boat owner was selling his boat, and he took his ULTRA from bow to use in his new boat and put it inside of his boat and tied his boat to a fishing harbor for a couple of days. A theft stealing everything from that boat took the ULTRA with him, too.