Photos of Anchors Setting

[sanibel sailor]

Trip line up or down work better with an unset anchor?

[noelex 77]

This was a Delta. It was dropped by a charter boat. They only let out a short scope of 3:1 in 8m of water.

This was taken at a similar time to the Delta in post #2277 and has behaved in a similar way. You can see this Delta has also broken out in response to the wind shift.

At 3:1 the Delta is not a great performer. Its modest ability to remain set in response to a change in wind direction is one of the first areas that suffers.

Did anyone notice the swivel? It is one of the few swivels I have seen correctly installed with a few links of chain between the anchor and the swivel. This reduces the side loading on the swivel.

[hoppy]

Originally Posted by noelex 77

Did anyone notice the swivel? It is one of the few swivels I have seen correctly installed with a few links of chain between the anchor and the swivel. This reduces the side loading on the swivel.

My Ultra swivel is correctly installed, as per manufacturers instructions ;-)



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[noelex 77]

It is claimed that swivels with a ball and socket, like the Wasi Power Ball and the Ultra swivel, by virtue of their articulation are fine connected directly to the shank. Of course the Ultra swivel if you buy the flip version has to be directly connected to the shank for the flip function to work.

I have never heard of any failures, but I have some reservations that the articulation of approximately 30° afforded by this design is enough to prevent problems or even to make much practical difference.

Have a look at the next series of photos showing our Mantus anchor and it seems obvious to me that 30° is a long way short of enough articulation to prevent side loading.

The Wasi Power Ball is a massive thing. The Ultra model is a bit smaller. They both look beautifully made. The Ultra flip model is a very clever solution to the problem of the anchor coming up backwards, but are these models strong enough with a side load that exceeds the articulation range to eliminate the normal advice of adding a few chain links between the anchor and swivel?


I don't think we need to get too worked up about this issue. If you look at my photos, 99% of anchors have the swivel directly connected to the shank and many of the swivels are of rather dubious "no name" quality. Even with these problems, reports of swivel failures are not common. I have personally seen only one failure in the last eight years. Compare this to the multitude of boats I see dragging and it becomes clear that the emphasis needs to be on having a good anchor and good technique. You are far more likely to have problems from a dragging anchor than the very remote chance of swivel failure.

The only caution with this advice is that if the swivel, chain or shackle break, the resulting drag is very rapid. The chance of taking control before damage occurs is considerably less than the more conventional and slower drag when the anchor is still attached.

Photos to come.

[noelex 77]

Well, with all the swirling wind, how did the Mantus fare?

If you remember, this is how it looked just after we dropped:



Most of the wind changes were much too light to have any effect on our anchor. If the anchor sets well and buries its fluke, then it takes a reasonable amount of wind before the anchor does anything at all. The boat will drag the chain around so you might be at the other side of swing circle, but often the anchor will sit unchanged.

However, when we arrived at this anchorage there was an onshore wind. So the anchor was set facing the beach. When the wind swung around this was the initial result. You can see the boat is now 180° away from the original direction with the chain leading backwards. The anchor at this stage has just started rotating. It has moved about 25°:



We watched the Mantus for some time like this. I find it fascinating watching anchors rotating. I think how anchors perform this vital task is important for their performance in the real world.


The Mantus has been rotating exceptionally well. Not only "shuffling" but rotating with very little list, maintaining most of the fluke burial and therefore grip throughout the rotation. Anyway, we got cold and missed most of the actual rotation, although the marks in the sand enable us to deduce what has happened.


This was the result after the rotation. Not a bad result. The Mantus has rotated 180° without otherwise moving and maintained most of its fluke buried under the substrate. It has on this occasion developed a moderate list. This is actually the worst rotation I have seen the Mantus do, but it still a pretty good result for a 180° shift. The anchor is a long way from breaking out.





Have a look at the chain angle in the second photo. The thirty degrees of articulation that the ball and socket swivels can manage is not going to be much help reducing the side loading in situations like this.

[Fortress]

I think that it is fair to point out that this Mantus weighs 125 lbs (57 kg), and obviously one might expect an anchor of this size and weight to perform superbly, particularly in an ideal bottom condition as pictured.

Additionally, the weights of other anchors in this thread are not known, which along with the setting technique of the boater, can have an effect on their performance.

[motion30]

Originally Posted by Fortress

I think that it is fair to point out that this Mantus weighs 125 lbs (57 kg), and obviously one might expect an anchor of this size and weight to perform superbly, particularly in an ideal bottom condition as pictured.

Additionally, the weights of other anchors in this thread are not known, which along with the setting technique of the boater, can have an effect on their performance.

I believe the weight of the anchor is all relative to the size And weight of the boat. except of course for your aluminum anchor

[noelex 77]

An interesting anchorage.

We have become so accustomed to the Mantus holding the first time that it is an enormous surprise when it does not. Not only did it not hold, but it did not do so on the first three attempts at this anchorage. The grip was very poor on occasions with the boat moving backwards with only a small amount of reverse applied.

In the end we moved further out, away from shore, hoping to find some better substrate. In this location the Mantus held our standard setting force of full reverse for 30 seconds. Even here it was obvious from the bow that the anchor was not completely happy. It was not the nice smooth progressive bury that we normally get from this anchor.

This was the underwater result of the final drop. Not a terrible set, but there are lots of clues that the Mantus is not doing as well as it normally does. The setting distance is about 3m. Still respectable, but double or triple what is normally seen with this anchor. Very importantly note that after the first metre or so the setting mark is not getting much deeper. If you look at the setting marks of anchors like the Delta this is very common, but the excellent anchors normally rapidly bury deeper and deeper as they are pulled back.

A setting mark that is getting progressively deeper implies that the anchor will bury further as more force is applied. A setting mark that is staying the same depth implies the anchor has dived as deep as it is going to go in that substrate. With more force the anchor might pile up a bit more sand in front of fluke, but it has reached, or is close to reaching its depth limit. If you look at the photos of anchors like the Delta you will see a lot of setting marks that stay the same depth.

Finally, as well as the list, a lot of the fluke bury is a heaping up of the sand rather than the fluke digging in well. Once again this is very common with anchors like the Delta, but is generally minimal with excellent anchors like the Mantus.

Here is our track:






The final set. 8m @ 6:1:





So what went wrong? Why did the Mantus fail to hold even modest reverse force in the first three attempts and why, while the set was OK on fourth drop, did the Mantus suddenly exhibit signs associated with much lesser anchors such as longer setting distance, much more heaping up etc.

The answer is rock. No anchor can penetrate rock. The first two locations were solid smooth rock with no or minimal sand on top. The final location had a thin layer of sand, but with rock below this. Photos to come.

[kas_1611]

Originally Posted by Fortress

I think that it is fair to point out that this Mantus weighs 125 lbs (57 kg), and obviously one might expect an anchor of this size and weight to perform superbly, particularly in an ideal bottom condition as pictured.

Additionally, the weights of other anchors in this thread are not known, which along with the setting technique of the boater, can have an effect on their performance.

Agree that setting technique is a variable that one can not judge but a good anchor should perform well regardless of weight assuming it is correctly sized to the vessel using it.

Obviously using an oversized anchor will have an impact on the overall holding power but the actual setting performance of the anchor is design not size critical.

[noelex 77]

This was a Delta. It belonged to yacht that anchored midway between our second and third drop points. 5m 4:1

You can see this area is just large sheets of solid rock. The Delta has managed to jam in a fissure that is between two of the plates. "Best set I seen from a Delta in ages" joked my Mermaid when we first saw the anchor. In many ways she is right. With the fluke jammed under the rock like this, the grip can be exceptionally good, but the hold is also very unpredictable. A change in wind direction could see the anchor break free and then the grip drops down to nothing.

There is also some risk of jamming the anchor and finding it difficult to retrieve. Finally this sort of terrain bends and damages the tips on anchors very easily. A very fine sharp tip improves anchor performance considerably, but unfortunately in this sort of substrate there is a risk of damage.

I think there are a couple of lessons:

* If you don't set and test the anchor say with reasonable reverse force you have no idea if the substrate is reasonable.
* Even if you set and test the anchor there is no 100% guarantee that the substrate is reasonable. An anchor alarm is a good backup.

[noelex 77]

A large Hallberg Rassy arrived with a Manson Supreme and dropped a little further out relative to our first two attempts. 6m @ 4:1.

It was obvious watching the drop that the anchor was not holding, but they dragged the Manson back and left it. They only stayed a couple of hours so they did not require the greater security for overnight anchoring that we required.

You can see the Manson Supreme is totally unset. I suspect the Mantus would have looked similar on our first drops. The drag Mark is difficult to see, as it such a shallow scrape but was about 15m long.

Diving down the reason was obvious. It was solid rock or solid rock with a very fine layer of sand in some spots.

Notice the swivel is once again separated from the anchor by a few links of chain.

It is just not possible to anchor in all substrates. Solid rock is the worst. no anchor will penetrate solid rock.











You can just see the long "setting" mark here:



The location:






This is my attempt to poke a hacksaw blade into the substrate. A metre back from the anchor it was solid rock. I could not push the blade in more than a mm or so and I tried multiple locations. Where the anchor settled there was a very slight covering of sand but it was still solid rock only 4-5 millimetres below the surface.

[Tayana42]

Noelex and mermaid, at the risk of being redundant, here is another big thank you for this continuing series of photos. It is the best information most of us have about the real behavior of anchors as they are deployed and the real result of setting technique (or lack) Together with Panope's videos it is a wonderful contribution to cruisers worldwide.


S/V B'Shert

[SVNeko]

A big stainless Manson - quite an expensive bit of kit. As to the Ultra swivel side loading, you can address this by oversizing. My 1/2" Ultra has cheeks as thick and strong as my 5/16" chain.


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[noelex 77]

This was a Rocna dropped by a small private yacht. They only stayed for a couple of hours. 6m @ 4:1.

It was photographed by my Mermaid and I did not get a chance to see this anchor. I watched the drop and they only put a mild amount of force on the anchor, but it was enough to produce a very shallow scrape mark extending 3-4m.

It is very poor, or nonexistent set. I did not have a poke at the substrate, but I suspect it was similar to the bottom consistency around the Manson Supreme, which was a very thin layer of sand over rock. The very shallow, but long (for a Rocna) setting mark also suggests this. It difficult to tell from these photos alone, but the anchorage had this type of bottom in a long line parallel to shore.

At this anchorage we had a Mantus, Delta, Manson Supreme and Rocna. Unfortunately, the variable rock substrate means comparisons between the performance of these designs is not possible.

I think the take home message is how rock can severely effect the ability of even top class anchors to set. I think my photos in this thread have shown there is a vast difference in performance between the best anchors and the next tier down, but even excellent anchors used with sound technique are not foolproof, although not much else will defeat them other than rock.

[NornaBiron]

Originally Posted by noelex 77

An interesting anchorage.

We have become so accustomed to the Mantus holding the first time that it is an enormous surprise when it does not. Not only did it not hold, but it did not do so on the first three attempts at this anchorage. The grip was very poor on occasions with the boat moving backwards with only a small amount of reverse applied.

In the end we moved further out, away from shore, hoping to find some better substrate. In this location the Mantus held our standard setting force of full reverse for 30 seconds. Even here it was obvious from the bow that the anchor was not completely happy. It was not the nice smooth progressive bury that we normally get from this anchor.

This was the underwater result of the final drop. Not a terrible set, but there are lots of clues that the Mantus is not doing as well as it normally does. The setting distance is about 3m. Still respectable, but double or triple what is normally seen with this anchor. Very importantly note that after the first metre or so the setting mark is not getting much deeper. If you look at the setting marks of anchors like the Delta this is very common, but the excellent anchors normally rapidly bury deeper and deeper as they are pulled back.

A setting mark that is getting progressively deeper implies that the anchor will bury further as more force is applied. A setting mark that is staying the same depth implies the anchor has dived as deep as it is going to go in that substrate. With more force the anchor might pile up a bit more sand in front of fluke, but it has reached, or is close to reaching its depth limit. If you look at the photos of anchors like the Delta you will see a lot of setting marks that stay the same depth.

Finally, as well as the list, a lot of the fluke bury is a heaping up of the sand rather than the fluke digging in well. Once again this is very common with anchors like the Delta, but is generally minimal with excellent anchors like the Mantus.

Here is our track:






The final set. 8m @ 6:1:





So what went wrong? Why did the Mantus fail to hold even modest reverse force in the first three attempts and why, while the set was OK on fourth drop, did the Mantus suddenly exhibit signs associated with much lesser anchors such as longer setting distance, much more heaping up etc.

The answer is rock. No anchor can penetrate rock. The first two locations were solid smooth rock with no or minimal sand on top. The final location had a thin layer of sand, but with rock below this. Photos to come.

We know this anchorage very well, having spents lots of nights there. The anchor never digs in but the shelter from the north is excellent so, with enough chain out and the anchor alarm set, we've always slept well here.

We normally manage to get half a shovelful of sand on top of the anchor after dragging it back for a while.