Anchor choices

[kmacdonald]

Originally Posted by Dockhead

It's not been done, however. We all use Fortresses and kedges and know that high holding power is possible UNDER SOME CIRCUMSTANCES with light weight, but none of us sleep overnight lying to a Fortress. Because Fortresses are subject to popping out in wind shifts. Probably because they lack weight.

I use my fortress overnight and do have problems in wind shifts. Not because of weight but because of fouling with debris mostly. I always set an anchor alarm. I'm sure my properly size Fortress would rip the cleats out of the boat before dragging when it is set. IMHO the Fortress hates low or no wind anchoring.

[Panope]

Originally Posted by Izikalvo

........Also, Steve's boat is napping, at the moment she will be in the water we will be more than happy to send him one of our smaller size anchors for testing.

To clarify, my "big" boat, Panope (34 foot, sail) is indeed in the shed until perhaps July or August.

However, I have full access to my fathers fishing boat (18 foot, outboard power). I am now conducting all "small" anchor tests (anchors less than 20 lbs.) with this boat.

Note: In my testing area, water clarity degrades in the Summer time as sea life (algae? Plankton?) Increases. This makes my camera footage less than ideal.

Steve

[Izikalvo]

Originally Posted by Panope

To clarify, my "big" boat, Panope (34 foot, sail) is indeed in the shed until perhaps July or August.

However, I have full access to my fathers fishing boat (18 foot, outboard power). I am now conducting all "small" anchor tests (anchors less than 20 lbs.) with this boat.

Note: In my testing area, water clarity degrades in the Summer time as sea life (algae? Plankton?) Increases. This makes my camera footage less than ideal.

Steve

Thanks, Steve, just sent you an email

[Lodesman]

Originally Posted by Dockhead

Show us even one person who says his anchors set poorly because they were too big. Doesn't exist.

No chance of any confirmation bias there

How do you even judge that? Unless in a side by side controlled test, there's no way to compare the set of a large anchor relative to a smaller anchor of the same design.

[Don C L]

As far as Danforths go, one other consideration is that if the chain is allowed to fall straight down on top of the anchor it can easily foul on the stock or crown so that it will upend or twist the anchor as you start to pull on it. It may still release the chain after it has spun and then set, but there is a fair chance it won't. For where I am I love my Danforths. When they are set, I sleep very well. But I always make sure I am drifting back a bit as I lay out the chain. And as one of the few who is always anchored bow/stern I pull both anchors against each other. I always know they are set.
I too doubt weight is the issue with re-setting a Danforth or Fortress. If there is decent scope, and the anchor is not fouled, I think it will re-set ok. Another thing about the Danforth though, it can bury itself REALLY well given enough force. Once it is diving, with a half decent scope, it will break before it drags. So when the boat swings, if there is a strong pull in the opposite direction, it can (probably will) bend the shank before it pulls out, if it pulls out. With a bent shank it won't re-set well at all. Or if you bury the anchor you can bend the shank trying to retrieve it too aggressively and quickly. I go one size larger (in my case a 20H) than I need, but another advantage to that (besides the reserve holding power,) is that it does NOT bury itself too far. The fluke size relative to the force my boat can put on it results in the anchor staying closer to the surface. The 12H for my 29 foot, 8000#, boat will hold just fine in 90% of what I encounter.
As to whether an anchor could be too big for a boat to set it properly, that too is one mystery I'd like Panope to test!

[Dockhead]

Originally Posted by kmacdonald

I have but not because of lack of holding power. The problem is resetting reliably. A lot of you guys are sizing anchors with holding power way greater than your boat attachment points can handle. It's a waste to some degree.

It's not a waste at all.

My own anchor in perfect bottom will break the chain at maximum holding power.

But my anchor is not sized for a perfect bottom -- it's sized for a bad bottom, on short scope, in a storm. In such conditions there is no lower limit on the reduction in holding, compared to holding in a perfect bottom. Under some conditions, actual holding power may be 1/10, 1/50 even 1/100 of the maximum holding power.

So my anchor does not have ENOUGH holding power under certain conditions -- say, 2:1 scope, thin mud, blowing gale. No anchor has enough holding power for every possible situation.

So nothing is wasted, ever. I would upsize my anchor to 200 pounds if I could handle it.

Let me put it another way. You may call it Dockhead's Two Anchoring Theses :

1. If your anchor, properly set, ever failed to hold you, then it's not big enough.

2. If your anchor never failed to hold you, you don't get out enough.

ergo


3. There is no such thing as a big enough anchor.

[Dockhead]

Originally Posted by Lodesman

. . . How do you even judge that? Unless in a side by side controlled test, there's no way to compare the set of a large anchor relative to a smaller anchor of the same design.

A test would be great, of course, but not the only way to have knowledge on the subject. Plenty of us have experience with all kinds of different sizes of anchors.


Have you ever heard anyone ever say that they felt like they were getting worse holding, after upsizing an anchor? Even once?


Not definitive proof -- testing would be GREAT, c'mon Steve -- but a pretty strong indication.


I went through three sizes of Spades on my previous boat over 25 years. Every one set and held remarkably much better than the next smaller one. Remarkably and instantly noticeable.


I've had up to 121 pounds of anchor on this boat. In my experiences with anchors from I guess 20 pounds to 121 pounds, there is no mistaking how effectiveness goes up with size, and seemingly even not in linear proportion to size. I've never meet anyone who had any experience different from that, and this is consistent with all of the writing on the subject, too.



That doesn't prove anything definitively by itself, but I would be very surprised to hear someone say this or that anchor set or held worse, than a smaller version of the same anchor. I'm pretty sure that just doesn't exist. I don't think this is controversial.

[Dockhead]

Originally Posted by kmacdonald

I use my fortress overnight and do have problems in wind shifts. Not because of weight but because of fouling with debris mostly. I always set an anchor alarm. I'm sure my properly size Fortress would rip the cleats out of the boat before dragging when it is set. IMHO the Fortress hates low or no wind anchoring.

You might want to consider using a different anchor overnight, which does not release in wind shifts.

How do you know this behavior is unrelated to weight? "Low or no wind anchoring" is one type of situation where it seems pretty obvious that weight would help keep an anchor engaged with the seabed.

[evm1024]

I would have no problem using a 500 to 2000 pound anchor (or larger), even if it had poor holding compared to modern anchors. The problem with anchors that size is that they are hard to handle and also hard to inspect.

Mostly when we get to that size we just put them in the water once and leave them there.

Oh, nevermind we call them moorings.

There is a point here if you think about it.

[rslifkin]

The low or no wind problem I think points to the issue of getting a Fortress set deeply enough in the first place. When I had one as a primary for a while, my general MO was once it seemed to be set solidly, I'd let the engines run at idle or a little more in reverse for a couple of minutes with a soft bottom to help dig it in further (it would take more throttle on a typical sailboat).

[Dockhead]

Originally Posted by rslifkin

I'm not convinced that one is a weight problem. I think it's a limitation of the Danforth design. If you don't manage to get it buried far enough, it can trip out on the stock when you pull on it sideways, particularly in harder bottoms. If you manage to drag it far enough into the bottom, it's probably going to stay there (as shown by stories of them being almost impossible to retrieve after use in a heavy storm). The issue is that in many cases, particularly with a sailboat, it's hard to bury it far enough in all but a very soft bottom unless you have a ton of wind to help.

You may be right -- I don't know.


My experience is like yours -- the Fortress likes to bury deep -- something about the sharpness, angle, and large area of the flukes. And if the seabed is the right consistency, not to soft, not to firm, you can drag it way under the surface, where it will stay no matter what. 100 Yanmar ponies and a variable pitch prop are QUITE adequate for that task, in my case. And I have experienced the difficulties in retrieving a deeply buried Fortress.



But this doesn't work in all seabeds, or even in most of them. Sand is too hard; thin mud doesn't work. Gravel doesn't work. So the Fortress is not an anchor which is suitable for a wide range of conditions. It is in my opinion, basically, the perfect kedge anchor. Absolutely perfect anchor for Baltic mooring too. I have spent the night lying to mine, but would not do so by choice, not even in good bottom.

[Panope]

Originally Posted by Dockhead

Not definitive proof -- testing would be GREAT, c'mon Steve -- but a pretty strong indication.......

I have now tested 3 designs of different sizes:

1. Bruce anchor in 11lb. and 44lb. Both remarkably similar in the way they set reliably but failed to dive into the seabed - with low resulting holding power.

2 Mantus M1 13lb. and 45lb. (40 on my scale). Big version performed perfectly in all my tests. Small version set perfectly (initially) but became fouled with seabed during resets AND high power strait line pull test.

3. Xxxxx anchor 17lb. and 47lb. Big version performed perfectly in all my tests. Small version was close in performance but needed more scope in high power/pull tests. (This anchor test will be revealed soon)

Note: A mixed rode was used for the small anchors while "all chain" was used for the large.

Note to self: Do back to back test of same anchor with different rodes. Test max holding power to see of chain catenary (if any) has affect.

Steve

[kmacdonald]

Originally Posted by rslifkin

The low or no wind problem I think points to the issue of getting a Fortress set deeply enough in the first place. When I had one as a primary for a while, my general MO was once it seemed to be set solidly, I'd let the engines run at idle or a little more in reverse for a couple of minutes with a soft bottom to help dig it in further (it would take more throttle on a typical sailboat).

I agree but I cant back down long and hard with my boat. Too much prop walk.

[rslifkin]

Originally Posted by kmacdonald

I agree but I cant back down long and hard with my boat. Too much prop walk.

I didn't even think of that issue, but that's another good point on sailboats (and single engine powerboats) having somewhat limited ability to dig in an anchor hard enough for designs that rely on it.

[Lodesman]

Originally Posted by Dockhead

Have you ever heard anyone ever say that they felt like they were getting worse holding, after upsizing an anchor? Even once?

Through the various anchoring threads there have been numerous "my roll-bar anchor A never set properly/dragged frequently; replaced it with anchor B" anecdotes. While not usually stated, it was generally implied that anchor A replaced an older generation anchor, which I have no doubt would have been considerably lighter. All the new gen anchors have sizing recommendations much larger than what would have been recommended in a Delta or CQR. So not an apples to apples comparison, and maybe not worse, but certainly no improvement with an upsized anchor.

I've had up to 121 pounds of anchor on this boat. In my experiences with anchors from I guess 20 pounds to 121 pounds, there is no mistaking how effectiveness goes up with size, and seemingly even not in linear proportion to size. I've never meet anyone who had any experience different from that, and this is consistent with all of the writing on the subject, too.

Are you still using the 121 pounder?

That doesn't prove anything definitively by itself, but I would be very surprised to hear someone say this or that anchor set or held worse, than a smaller version of the same anchor. I'm pretty sure that just doesn't exist. I don't think this is controversial.

For you few who have upsized the same anchor design on the same boat and used it in the same conditions, you may have perceived better performance, but without a quantitative measurement of the performance factors, all you have is perception. How much of the hold of the heavier anchor was due to simple deadweight? And is that achieved at the expense of mechanical hold(set)? Did it bury as deeply as the smaller anchor would have in the same conditions? If it hasn't buried as deep, or if it buried deeper, does that have an effect on its performance? I assume for most of us, we have a binary appreciation of our anchor's performance - it set and held, or it didn't. It's very hard to discern a performance difference between two anchors that held through the night.
Regardless, I'm happy to agree with you, that a larger anchor of the same anchor design provides more hold than a smaller one - that is not controversial. The question remains, is the excess "anchor capacity" necessary or worth the disadvantages?