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Old 30-05-2017, 03:59   #166
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Re: Anchor types and General questions

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Originally Posted by JPA Cate View Post
Don, we still have a trusty 20# Danforth HT. It is not our primary anchor, but it was on our 30 footer, and has made the changes to the new boat each time. We'd probably buy a Fortress if we were starting out, these days, but we already have the Danforth, and it still does what we ask of it. And if we went where Evans used to go, with the impenetrable bottoms, why, we might have a look at the Ray, too. A whole lot of what anchor is determined by the bottoms you'll encounter.



Ann
I had good experiences with my Danforths. Similar performance to Fortress, but Fortress has sharper flukes and possibly better geometry, so sets more aggressively. But heavier Danforth worked better in some bottoms, and was actually the only old-timey anchor I had that worked really well in a variety of bottoms. In my opinion it's a perfectly usable anchor.

Danforth had a reputation (like Fortress) of failing to reset after a tide change. I can't say whether this is deserved or not; never experienced this either with Danforth or Fortress. But I have long avoided using either of these anchors overnight.

I also had a fisherman for a while. It was very easy to set -- toss it overboard -- but wouldn't hold in anything soft because of the very small fluke area. I still think a fisherman can be good for rocky bottoms, but I don't carry one. Like you I was intrigued by Evans' comments on the Ray.
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Old 30-05-2017, 04:40   #167
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Re: Anchor types and General questions

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Danforth had a reputation (like Fortress) of failing to reset after a tide change. I can't say whether this is deserved or not; never experienced this either with Danforth or Fortress.

I suspect it's more anecdotal myth than actual factoid.

We did have a Fortress unscrew itself from the dirt once when a squall came through. The boat made a 360° in about 1 minute; can't say I was surprised, and I also expect almost any anchor design may have unscrewed itself in those conditions.

But otherwise, we routinely used a Danforth and then a couple different Fortresses for many years without any problem with tidal shift.

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Old 30-05-2017, 05:40   #168
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Re: Anchor types and General questions

A tide change will often cause the boat to move to the other side of the swing circle, but it is usually is too little force to rotate the anchor.

Hence, this usually does not cause problems with Danforth/Fortress anchors. The concern is when there is enough force to require the anchor to rotate. This needs a reasonable amount (if the anchor is well set) and this is usualły only seen with a change in wind direction, although a combination of wind and current can be enough, particularly on a small boat.

In my opinion, you need to be more careful with Danforth/Fortress anchors if the anchor needs to rotate. In many cases it will do this successfully, but the incidence of problems is higher in my view. The reputation did not develop for no reason.

In most cases of a tide change (or more correctly a change in current) or a light wind change, a reasonably set anchor will look something like this. The boat will move to the other side of swing circle but the anchor remains in the original position and orientation.

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Old 30-05-2017, 05:50   #169
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Re: Anchor types and General questions

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Originally Posted by noelex 77 View Post
A tide change will often cause the boat to move to the other side of the swing circle, but it is usually is too little force to rotate the anchor.

Hence, this usually does not cause problems with Danforth/Fortress anchors. The concern is when there is enough force to require the anchor to rotate. This needs a reasonable amount (if the anchor is well set) and this is usualły only seen with a change in wind direction, although a combination of wind and current can be enough, particularly on a small boat.

In my opinion, you need to be more careful with Danforth/Fortress anchors if the anchor needs to rotate. In many cases it will do this successfully, but the incidence of problems is higher in my view. The reputation did not develop for no reason.

In most cases of a tide change (or more correctly a change in current) or a light wind change, a reasonably set anchor will look something like this. The boat will move to the other side of swing circle but the anchor remains in the original position and orientation.

I have always thought that there must be some reality behind the reputation, so have always been cautious.

But these anchors are particularly good at setting themselves - wouldn't that greatly mitigate the problem, if it exists?
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Old 30-05-2017, 06:42   #170
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Re: Anchor types and General questions

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It is fair to say that anchors which do not have a deep burying capability are better able to turn during wind and tidal shifts.

As an example, in the image above of the Mantus anchor, the shank is still visible, as it is in the videos I have seen, which indicates that the fluke is not deeply buried into the sea bottom.

Practical Sailor pointed this out in a recent article, which delved into a discussion about the "effective fluke angle" and this anchor's lower angle of attack with the sea bottom.

This difference might allow the anchor to "stick" and set faster (even on hard dense wet beach sand), but since its deep-diving capability is then limited, its ultimate holding power will be as well.


I believe that the "bottom" line, if you will pardon the pun, is that feature and performance trade-offs among all anchors are commonplace.
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Old 30-05-2017, 06:52   #171
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Re: Anchor types and General questions

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. . . I believe that the "bottom" line, if you will pardon the pun, is that feature and performance trade-offs among all anchors are commonplace.
The truth of this statement should be obvious, but very much worthwhile repeating
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Old 30-05-2017, 07:24   #172
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Re: Anchor types and General questions

Is the Mantus able to self-launch?

The shank seems completely straight, except for a very small angled section at the very front. I cannot see how that would self-launch except if the roller assembly is itself pointed downwards, and having to push a 30kg+ anchor off the bow presents its own challenges.
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Old 30-05-2017, 07:38   #173
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Re: Anchor types and General questions

I have a Danforth It resets on the changing tide with no problems,
Untill it gets a rock stuck in the cleavis pin,

Then it will just slide along the bottom with the points in the air, and wont reset,
Dragging an anchor amongst other yachts on swing moorings with no propulsion is not a good place to be, Especially on an outgoing tide in a River,

As for my Chinese Bruce, I could not get that to set no matter how I tried to set it,
It just slid along the bottom, Mud and sand, It did work in coral reefs and rocks,

If you have a back up Bruce anchor, Test it to make sure it works before you have to rely on it in a storm,
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Old 30-05-2017, 08:26   #174
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Re: Anchor types and General questions

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Originally Posted by Fortress View Post
It is fair to say that anchors which do not have a deep burying capability are better able to turn during wind and tidal shifts.

As an example, in the image above of the Mantus anchor, the shank is still visible, as it is in the videos I have seen, which indicates that the fluke is not deeply buried into the sea bottom.

Practical Sailor pointed this out in a recent article, which delved into a discussion about the "effective fluke angle" and this anchor's lower angle of attack with the sea bottom.

This difference might allow the anchor to "stick" and set faster (even on hard dense wet beach sand), but since its deep-diving capability is then limited, its ultimate holding power will be as well.


I believe that the "bottom" line, if you will pardon the pun, is that feature and performance trade-offs among all anchors are commonplace.
The image you posted is a Rocna Anchor, not a Mantus Anchor
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Old 30-05-2017, 11:58   #175
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Re: Anchor types and General questions

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I have always thought that there must be some reality behind the reputation, so have always been cautious.

But these anchors are particularly good at setting themselves - wouldn't that greatly mitigate the problem, if it exists?

In most cases if an anchor rotates poorly and pulls out, or partially pulls out, it will reset itself. However, an anchor design that rotates well and remains engaged with the seabed is much more reliable.

Once an anchor breaks out there is a risk that the anchor will encounter an area of unsuitable substrate (such as weed or rock), pick up some debris (man made such a towel blown from a boat rail, or natural such a log, rock, or just a big clump of weed). In addition, anchors that are moving at any speed find it much harder to grab intially. They will be moving at a higher speed in strong wind so the risks of the anchor not setting increases substantially, just when it is needed most.

I have not found the Danforth/Fortress anchors set initially as reliably as designs such as the concave roll bar anchors, or Spade for example. Especially if setting at speed where the Danforth and particuarly the light weight Fortress tends to "fly" or "plane" along the bottom. In addition the flukes of these anchors sometimes get jammed in one position meaning they cannot set if they break out flip upside down.

The Danforth/Fortress anchors have exceptional holding power in a softer substrate. This makes them great as a kedge anchor, especially the lightweight Fortress, but personally I would not use these models where there is a risk of significant change in the direction of pull.
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Old 30-05-2017, 12:10   #176
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Re: Anchor types and General questions

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It is fair to say that anchors which do not have a deep burying capability are better able to turn during wind and tidal shifts.

As an example, in the image above of the Mantus anchor, the shank is still visible, as it is in the videos I have seen, which indicates that the fluke is not deeply buried into the sea bottom.
As Cotemar has already said, it is a Rocna anchor rather than Mantus. For the harder substrates in this area, the photographed anchor is set reasonably. If you look at my photographs in a similar substrates you can get a better idea of the average.

I would be extremely surprised if a Danforth/Fortress could set more deeply than a Rocna in this substrate. The Danforth/Fortress design is not very high so there is no tall roll bar to see, but the depth of bury of the fluke would likely be less in this harder ground, in my experience.

From memory this small Guardian anchor (a simpler version made by Fortress) was photographed at the same anchorage and did not manage to bury very well at all. It was a fairly firm bottom and of course is only one example.

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Old 30-05-2017, 13:16   #177
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Re: Anchor types and General questions

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Is the Mantus able to self-launch?

The shank seems completely straight, except for a very small angled section at the very front. I cannot see how that would self-launch except if the roller assembly is itself pointed downwards, and having to push a 30kg+ anchor off the bow presents its own challenges.
LongRange,

It appears that the Mantus shank has undergone a redesign sometime during the last year and a half.

This is a picture of the 45 lb. Mantus anchor that I purchased from the factory in January 2016. Note that the shank is "completely straight" as you describe:



This is a picture from the current Mantus website of their 45 lb. model. Note that the shank now has an "angled" portion right where one would expect for self launching from a roller.



To me, this looks like a fine improvement.

Steve
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Old 30-05-2017, 13:19   #178
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Re: Anchor types and General questions

I know it's been discussed, but for new folks perusing here, I love my Danforths but I wouldn't recommend them unless you know they won't be pulled 180. The chain can swing around the shank and help pull it out. It will probably re-set ok but I don't like to put my trust in "probably." With a harder substrate of course they won't dive as well, but in sand or mud I've buried mine pretty deep at times.
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Old 30-05-2017, 13:42   #179
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Re: Anchor types and General questions

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As Cotemar has already said, it is a Rocna anchor rather than Mantus. For the harder substrates in this area, the photographed anchor is set reasonably. If you look at my photographs in a similar substrates you can get a better idea of the average.

I would be extremely surprised if a Danforth/Fortress could set more deeply than a Rocna in this substrate. The Danforth/Fortress design is not very high so there is no tall roll bar to see, but the depth of bury of the fluke would likely be less in this harder ground, in my experience.

From memory this small Guardian anchor (a simpler version made by Fortress) was photographed at the same anchorage and did not manage to bury very well at all. It was a fairly firm bottom and of course is only one example.
My apologies for this error. For the sake of accuracy, I have included two images of the Mantus from a video which will illustrate my point.

As you will note, the shank is still clearly visible:



image hosting 12mb

I suspect that the Guardian anchor in the image you provided could have weighed in the range of 100 lbs (45 kg) or so LESS than the 125 lb (57 kg) Mantus anchor. I think it is fair to say that such a comparison is not fair or realistic.

Additionally, we have no idea if this Guardian anchor was set at a proper scope or speed to allow it to engage the bottom.


But all of that said, let's imagine that a Fortress did not bury as deeply in this harder soil as you mentioned, and the shank was still visible and the back end of the anchor was sticking up and the flukes were only minimally engaging the bottom.

The Fortress would still have a better capability of deeper penetration and holding power from its wider angle of attack / two larger flukes once it was loaded from a wind force, as compared to an anchor with only a low angle of attack / smaller fluke surface area.
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Old 31-05-2017, 00:07   #180
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Re: Anchor types and General questions

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LongRange,

It appears that the Mantus shank has undergone a redesign sometime during the last year and a half.

This is a picture of the 45 lb. Mantus anchor that I purchased from the factory in January 2016. Note that the shank is "completely straight" as you describe:



This is a picture from the current Mantus website of their 45 lb. model. Note that the shank now has an "angled" portion right where one would expect for self launching from a roller.



To me, this looks like a fine improvement.

Steve
Thank you Steve. I see what you mean, and it does seem like a worthwhile improvement.

Now if only I could get Italian suppliers - whom I mostly do not understand because despite being in Italy I do not speak Italian - to tell me whether their stock of Mantus anchors has "that new bent bit at the front?"

By the way, have you tested the Rocna perhaps, and if so could you maybe point me to the results? I appreciate your methodical test technique, and the effort you invested to share that information with the yachting community.

Andre
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