Anchor slipping

[meirriba]

Originally Posted by Tomrob

Depth of 12 to 14’
On the set I held 1800 rpm in reverse for about 30seconds

When I try the anchor, I go up the RPM to the maximum. Do it slowly but up to our engine max (just over 3,000). If boat does not move for that, no wind in the 'normal' range will move us.

[wingssail]

After using a Danforth for years in the PNW we started cruising with a CQR because it looked nice and fit our bow roller. Nice anchor, stainless steel, a real beauty.

But we drug it though every anchorage on the west coast and into Mexico.

Finally I dove down to watch as Judy tried to set that anchor. It just bumped along the bottom like a little bulldozer; it was never going to set.

So we took a bus to San Diego and bought back a Bruce, (same weight) which we thought looked rather nice, and swapped out the stainless steel CQR.

Never have regretted it since then.

[DanielPerry]

Originally Posted by wingssail

After using a Danforth for years in the PNW we started cruising with a CQR because it looked nice and fit our bow roller. Nice anchor, stainless steel, a real beauty.

But we drug it though every anchorage on the west coast and into Mexico.

Finally I dove down to watch as Judy tried to set that anchor. It just bumped along the bottom like a little bulldozer; it was never going to set.

So we took a bus to San Diego and bought back a Bruce, (same weight) which we thought looked rather nice, and swapped out the stainless steel CQR.

Never have regretted it since then.

I will say that my chain has fouled on the stock of my bruce a couple times (its a good thing I reset my anchors when the wind shifts abruptly or after a calm), just a heads up. I could see it happening with tidal shifts too.

[Jim Cate]

After using a Danforth for years in the PNW we started cruising with a CQR because it looked nice and fit our bow roller. Nice anchor, stainless steel, a real beauty.

Umm, Fred, if it was stainless I believe that it was not a genuine CQR, for all of them are galvanized steel, not s/s. So it was a knock-off, and IME those vary a lot in their capablities, and as far as I've seen none are better than the original, many are not as good.

Like you, I had an appropriately sized knock-off CQR when we set out from SF years ago. There were some bottoms where it worked well, some where it held after it finally found a spot it approved of, and some spots where it, like yours, just bumped along the bottom forever.

At first opportunity we swapped for an equal weight Bruce, and like you, found it a major improvement. But, unlike you, we eventually changed to a new gen (Manson Supreme) hook, and it works even better... demonstrably so IMO.

You seem to believe that the Bruce can't be improved upon... I believe that it can, considerably!

Jim

[MathiasW]

Now, I do realise that this is ever so slightly off topic, but it is related to anchoring and safety, and hence might be of interest to some guys in the discussion:

I have used the corona lock down time to develop an app to calculate what the minimal required anchor chain length needs to be. More precisely, the App

- Calculates the required minimal anchor chain length based on vessel characteristics and weather / sea conditions.
- Calculates the anchor load and pulling angle at anchor shaft.
- Works with snubbers & bridles.
- Chain not long enough? The Anchor Chain Calculator will tell you what effect this has.

You can find more information on its home page:

https://trimaran-san.de/anchor-chain-calculator/

For now I have created Apps for iPhone and iPad. The latter needs iOS 13 or more to make use of the screen size and not default to the screen size of an iPhone 5, but both Apps work all the way back to iOS 10. If there is sufficient interest, I might create an Android version as well.

The app was developed whilst anchoring here for 6 months, so I had ample of time to test it...

Cheers

Mathias

[HopCar]

It took thousands of years for farmers to develop a tool that could be pulled easily through the earth. Then someone had the bright idea to use it as an anchor.

[zeehag]

i will also suggest a bruce having watched boats using the new stuff drag anchor--yes even rocna.
bruce anchor oil rigs.. why not be like oil rig, besides in 45 kt winds my 30 kg bruce didnot cause any issues not even slippage- i use all chain rode and the bruce with no issues.
i switched to bruce from genuine cqr when my cqr dragged due to chain falling into a dredged channel p
ulling anchor with it..oops...winds were 25 kts... help arrived as called and w e got the formosa away fromt he rocks 3 ft and closing on my transom... close but was ok.

[wingssail]

Originally Posted by Jim Cate

...You seem to believe that the Bruce can't be improved upon... I believe that it can, considerably!...

Jim

"Can't"?

I didn't mean to say that. But I am not having any problem anchoring, what issue am I trying to solve by changing?

Further, it seems to me a little suspect when the recommendations for the newer anchors are for heavier anchors. Frankly it is not convincing to me that the new anchors are a lot better because of their shape when everyone who has one also has upgraded to a larger size.

What size Bruce did you replace with what size Manson Supreme?

And if an anchor is always holding, what is "demonstrably better"?

I am more interested in your opinion than the guys whom I see and hear who say, "I'd buy the biggest anchor that I can fit, because I like to sleep at night".

Or guys who say, "My new 80lb XYZ really works better than my old 44lb XYZ" Uh?, Yeah.

[Cheechako]

The CQR was the dominant anchor decades ago, but they dont have great holding power. They most often lay on their side and dig one fluke in. Since the 80's I have helped rescue about 6-8 boats dragging with a CQR and all chain rode.

A modern anchor is much better.

A Delta is better than a CQR, but not good in a wind shift.
A Bruce is good in rock but will move along readily in a blow.

[wingssail]

Originally Posted by Cheechako

A Bruce is good in rock but will move along readily in a blow.

My 44lb Bruce moved slowly in 1998 in soft mud in the Bay of Islands in 50 knots of wind. Upon resetting it held.

New Zealand 98-Wings Anchored in Storm-2.jpg Views: 62 Size: 229.0 KB ID: 224565" style="margin: 2px" />

My 66lb Bruce has never dragged in any conditions or bottom.

Setting our anchor has been difficult in thin sand over rock, sometimes taking 2 or 3 tries, or until we snag a rock. I doubt if any anchor would do much better in those situations.

But once it holds, it stays.

[Jim Cate]

What size Bruce did you replace with what size Manson Supreme?

66 lb Bruce, 60 lb Manson Supreme.

The Bruce was pretty successful, but we had some issues in river silt and slow dragging, and with it picking up rocks or coral rubble in its "palm". The Manson has set quicker, especially in harder substrates, doesn't pick up rocks and will usually penetrate weed where the Bruce kinda wadded it up to the point where it would not bury at all. We try to avoid weed areas, of course, but are not always successful in that.

And I didn't mean to imply that you should alter your successful anchoring schemes... rather that most anchor testing shows that the ultimate holding power of the Bruce is less than the newer models, and that my experience has agreed subjectively.

Jim

[JPA Cate]

Originally Posted by Tomrob

I can’t help but wonder why it slipped over 25 to 30 mph winds. Not once but twice in the same day and same anchorage.
Thanks

Hi, Tom,

Anchoring involves dealing with the force of the wind, which increases with the square of its velocity. So, sustained force on the boat is a lot greater at 30 kn, than at 25. That's one part of the interaction, but it is one reason one starts to "slip" when the wind strength increases. The other factors have to to with fluke area and the nature of the bottom.

If the bottom that you call sand and clay is normally good holding (for boats with modern generation anchors), then your plow may be the culprit in this case. But anchorages are not necessarily the same holding over the whole place. Where we are today, the western side of the anchorage has softer mud than the center. (W=anchor comes up clean, center= gooey mucky mud with shell, and requires lengthy washdown.)

One option you have is to carry a 2nd anchor, and an old 20 lb. Danforth (cheap) will do. Motor up and well to one side of your plow, and drop the Danforth, fall back on it, and lie to the two of them, set in a "V" configuration. The additional holding power offered by the Danforth's flukes will allow you to stay located where you were, well past the comfort point if you're on a lee shore. This strategy has worked well for us.

Someone recommended viewing Panope's thread "Videos of Anchors Setting", and I would suggest also looking at noelex77's thread "Pictures of Anchors Setting". In the latter, noelex discusses how the modern generation anchors "shuffle" around to orient themselves in wind direction changes. A CF Custom Google search should also you find a relatively new thread which discusses a mathematical approach to anchoring, with some very involved discussion.

Ann

PS @ wingssail,

Our 44 lb Bruce was genuine, got a bent fluke. Our 66 lb one was a knock off.

A.

[wingssail]

Originally Posted by Jim Cate

66 lb Bruce, 60 lb Manson Supreme.

The Bruce was pretty successful, but we had some issues in river silt and slow dragging, and with it picking up rocks or coral rubble in its "palm". The Manson has set quicker, especially in harder substrates, doesn't pick up rocks and will usually penetrate weed where the Bruce kinda wadded it up to the point where it would not bury at all. We try to avoid weed areas, of course, but are not always successful in that.

And I didn't mean to imply that you should alter your successful anchoring schemes... rather that most anchor testing shows that the ultimate holding power of the Bruce is less than the newer models, and that my experience has agreed subjectively.

Jim

Originally Posted by JPA Cate

Our 44 lb Bruce was genuine, got a bent fluke. Our 66 lb one was a knock off.

A.

Jim and Ann, Your reports carry more weight (no pun) with me than most of the "Anchor tests".

Thank You

[Panope]

Originally Posted by wingssail

Jim and Ann, Your reports carry more weight (no pun) with me than most of the "Anchor tests".

Thank You

Hello wingssail,

I am always trying to improve my testing, so if there is anything you can recommend I do differently, please let me know.

I can report that a 44lb. Genuine Bruce at 5 to 1 scope dragged slowly at 750 lbs. force and released completely at 910 lbs. (sandy mud)

By comparison, numerous "modern" anchors of the same weight held 910 lbs. with no movement at 3.5 to 1 scope. (same seabed as Bruce).

In cobblestone, I found the 44 lb. Bruce had less than 1/2 the holding power of numerous modern anchors.

I used a Bruce anchor aboard Panope for 10 years and never had a problem. I certainly have no bias against a Bruce. In fact, I think it is a brilliant design.

Steve

[wingssail]

Originally Posted by Panope

Hello wingssail,

I am always trying to improve my testing, so if there is anything you can recommend I do differently, please let me know.

I can report that a 44lb. Genuine Bruce at 5 to 1 scope dragged slowly at 750 lbs. force and released completely at 910 lbs. (sandy mud)

By comparison, numerous "modern" anchors of the same weight held 910 lbs. with no movement at 3.5 to 1 scope. (same seabed as Bruce).

In cobblestone, I found the 44 lb. Bruce had less than 1/2 the holding power of numerous modern anchors.

I used a Bruce anchor aboard Panope for 10 years and never had a problem. I certainly have no bias against a Bruce. In fact, I think it is a brilliant design.

Steve

Sorry, I didn't mean to disparage your tests and videos. I just give a lot of credibility to the Cates and their real world experience.

But I have to say that the evidence is becoming overwhelming that the new anchors do pretty well, thanks to people like yourself who test them scientifically.