Manson Supreme in Weed

[JonJo]

Originally Posted by Dockhead

I think there's a lot to that. My own background with anchoring is about a decade of cruising with a CQR, considered state of the art at the time. .

You must be very old if the CQR was 'state of the art'. Bruce was 1970; Bugel, I think, 80's (maybe late '70s); Delta 80's, SARCA and Spade 90's - though promotion was probably rubbish then. When we bought anchors in 1989 - all we were offered were CQRs.

[JonJo]

Originally Posted by Bash

This is not necessarily the case. For a working anchor I use the Rocna that is specked by for my size boat, and have never yet dragged. I generally anchor around 75 nights per year, and have used this anchor on this boat for six years. I tend not to anchor in gales or storms, but I carry a different storm anchor for that eventuality. Regardless,

So on the assumption the storm anchor is better

What is it?

[JonJo]

The 'debate' which was about Manson Supreme in Weed' developed into 'big is better', or not. Guilty as charged, size crept into the debate and I think, though its a red herring for the topic, size enjoyed airing.

Its not about weight, as such - so the idea that simply because we have a multi we might have an aversion to weight, is wrong. When on a long cruise, 2,000nm, we spend much of the time, of that say 4 months, at anchor. So carrying weight is not an issue, being relaxed is more important than weight. Equally carrying an anchor the next size up is not an issue, we carry a 16kg anchor - the next size up is 20kg. Its not an issue - but we have not found it necessary.

However carry the concept to its logical conclusion, 25kg, 33kg, 40kg?

The question is why. Why carry a 20kg anchor that no-one can define (I don't mean you feel better, I mean come up with something that the technical people here can say - yes, that's right!) is better. They feel its better - but no-one can define it.

My view is that an overly large (I'm not going to define large) anchor cannot be set properly. The yacht is too small (it does not have a large enough engine to set the large anchor - and real cruising boats have smaller engines, because they sail). So the large anchor sits with half its shank sitting proud, whereas the smaller anchor would be fully buried. (And a fully buried small anchor has a higher 'all round' holding capacity than a half buried bigger one). Wind change, little anchor shuffles round (Noelex will confirm this). Big anchor, my observation is - it falls over, because it was not fully set - the shank has limited holding (because its not deep) and the vertical of the shank allows the anchor to fall pulled sideways and it falls over. I'm like Noelex, I've sat and watched it happen. So if you are fast asleep - confident in that 'big is better' anchor - it needs to reset, itself. Popular anchorage littered with stuff blown of yachts (beach towel?), normal anchorage with coral rubble, old seaweed, waterlogged wood? Any anchor will drag, educated recommendation is - when deploying make sure its well set etc - so who is watching that half buried anchor reset?

And we are not such bigots that we think only convex work. We think Spades fantastic - but extortionate. Get rid of the costly hollow shank (use hi-tensile steel), cast the fluke (cheap) - real winner, technically and commercially. Fortress, great product, works in most seabeds, even some weed. Has limitations (don't they all) but possibly grossly underated. Maybe if Rocna/Manson/Mantus got rid of the roll bar - they would work better, less choking in the fluke, less seabed to carry.

But back to - re-think small.

Much the same in weed, the little anchor, which has a smaller profile can be driven into the weed (not all weed) with the puny engine but big anchor - no chance. Someone will say but the weight of the bigger anchor, get real - the bigger anchor is 10kg bigger than the puny one, we still have (on a 20hp engine) 200kg of potential pull - so weight is not significant, especially for those anchors with non weighted toe - physical increase in size is (significant) - you need to get a bigger cross sectional area through the weed so that it can engage. Its like digging turf, easier with a small spade (or shovel) than a big one.

It might be, for those with a 50' or 20t yachts, that big anchors are better - but most cruisers do not have 50' or over 20t yachts (and many big multis have pretty puny engines) - so we have, by definition - smaller anchors 15kg - 30kg not 40kg to 75kg.

Added to this we have the problem of the concave anchors choking in some seabeds, (its not me saying this - it keeps creeping in from concave owners, see Kenomac above).

[Dockhead]

Originally Posted by JonJo

You must be very old if the CQR was 'state of the art'. Bruce was 1970; Bugel, I think, 80's (maybe late '70s); Delta 80's, SARCA and Spade 90's - though promotion was probably rubbish then. When we bought anchors in 1989 - all we were offered were CQRs.

In the early 90's, the CQR was still considered a top anchor. The genuine CQR with forged shank was also very expensive.

I don't think this really changed until the Delta came out. I don't remember exactly when that was; I wasn't really aware of it. In the 90s I thought chronic failure to set and dragging anytime the wind got up was just a normal part of cruising. The revolution for me came in about 2000 or 2001 when I acquired a Spade, which was newfangled then having come out I think in1999 or thereabouts. When I bought a new boat in 2009, I inherited a Delta which was original equipment, 25kg for a 25 ton (loaded) boat. It was not satisfactory, and in 2010, I replaced it with a 55kg Rocna, which was good if not perfect, and clearly less good than the Spade on the previous boat. So then I replaced the Rocna with a 100 pound Spade, which has been easier to set, especially in weedy conditions, and easier to handle.

That's my story. I guess you could say I've been around the block a few times, with anchors.

One thing I can say in praise of both Rocna and Spade is that I've never once dragged either of them despite years of experience in often difficult conditions. Once set, these anchors don't budge no matter what; a really nice change from old type anchors.

[noelex 77]

There is no problem providing enough force under motor alone to set an oversized anchor.

No matter what the size of anchor, full reverse power in a sailboat is only the equavelent of 30-35 knots of wind.
So if you set in light winds as the wind goes over 30-35 knots (average) the anchor will set deeper, unless it reached its reached its limit then it will drag.

[noelex 77]

Originally Posted by JonJo

The question is why. Why carry a 20kg anchor that no-one can define (I don't mean you feel better, I mean come up with something that the technical people here can say - yes, that's right!) is better. They feel its better - but no-one can define it.
.

The holding power is very dependent on the bottom type as other have said, but its It's well established that a larger anchor of the same type will hold better, when other parameters are unchanged.
Here is a table from one manufacturer (Fortress) that quantifies the effect.

[JonJo]

Noelex,

I could not agree more, with much of what you say - in fact the tables you reproduce underline the problem exactly. The tables might be equally looked at in a number of ducuments, I might suggest Vryhof as a good place to start. But they all say the same thing - larger surface area produces higher holding capacity. The important point is that suface holding capacity is pretty minimal which is why diving anchors are better. A comparison might be the Delta, it does not dive and compared to the newer designs has a low limit of holding capacity - ostensibly similar anchors beat it hands down - because they dive. The Delta has a low finite holding capacity - I do not know anyone who has tested a Supreme or Rocna, for example, to its absolute limit (because most test winches are too small and because it would take an unreasonable amount of time to get the anchor out). We test 10/15kg diving anchors to 2,000kg and then stop - not because they have reached the limit but because it takes longer to dig them out than test, the winch is groaning and what's the point (what would it prove)? The debate is when is enough (capacity), enough.

1 It takes more load to set a larger anchor (such that you are using its real potential - ie you are not using it as a Delta) than a smaller one.

2 It takes more load to set a smaller diving anchor in a hard substrate than a small diving anchor in a softer substrate.

So, trying to simplify the debate (and assuming we are not going to change anchors with every different seabed) are engines in a small yacht (and there are many older 35' yachts with small engines and inefficient props) large enough to set a large anchor in a hard substrate, safely - or would it be better to set a small anchor, properly?

A big diving anchor set just into the seabed is no better than a Delta, what does it do when the wind changes? This all depends on the seabed, obviously, but we can set, with our engines, our puny 16kg, or an equally puny Spade, such that the shank is just showing, if we went to 25kg we could not achieve this level of 'diving'. If the wind builds these anchors continue to dive, until the shank and say 2m of chain has disappeared etc. If the wind changes slowly the 16kg, well set anchor, shuffles. Our testing of less well set diving anchors with the shank not well embedded suggests they tip over when the wind changes, rather than shuffling. The good ones then re-set, by themselves (the CQR being the exception - it just drags, forever - unless you are lucky).

[noelex 77]

Another way to look at it is that when we set our anchor the anchor will bury under the surface untill its holding power matches the force put on it by the engine ( and wind/ tide if there is any, plus perhaps some of the boats momentum as well).
A small and large anchor will have the same holding power at this stage because it is simply matching the applied force.
A very small anchor may be deeply buried, at the limit of its holding power. A larger anchor will be less well buried, but still capable of holding exactly the same force.

When a larger force is applied from a stronger wind the larger anchor will bury further increasing its holding power, untill it too reaches its limit.
The trick is make sure the limit is less than the force applied by the wind and tide etc.

When a storm is coming no one wishes for a smaller anchor.

[Kenomac]

Originally Posted by Dockhead

Any anchor will drag in the right circumstances, but with a good anchor like any of the new ones, and with good technique [edit - and of course a reasonable bottom!], I think the risk is small.

It's worth saying that it's easy to be lazy with a new gen anchor since they bite quickly. It's tempting just to call it a day, but you still have to work the anchor into the seabed, and you still have to back down hard to be sure. It takes some time and effort, but it will reveal if you're in a dodgy, weedy patch where your anchor might not hold. I always finish the whole ritual with two full minutes of 3800 rpms in reverse, which also blows the carbon out of the turbo. Your anchor must hold a sustained full power pull, or it's not set.

I did all the above to set the Rocna, and the boat was right were I'd left it 8 hours earlier when I went ashore. Following my return to the boat, the wind shifted 180 degrees and picked up considerably, which probably pulled out the anchor. The Rocna eventually dragged because the anchor was unable to reset itself properly in the weedy, grassy, hard mud bottom.

This post should be relevant to the OP as the Rocna anchor is very similar to the Manson supreme in that both have the roll-bar design, and the Rocna I was using was one size larger than what was recommended by the manufacturer.

My point: No anchor is perfect despite what the manufacturer says. Always check the weather forecast before leaving the boat for a day ashore, set the anchor properly & return to the boat prior to weather shifts and you'll be OK.

[sailorboy1]

Don't all properly sized anchors in weed hold just fine,..... once set?

[Dockhead]

Originally Posted by Kenomac

I did all the above to set the Rocna, and the boat was right were I'd left it 8 hours earlier when I went ashore. Following my return to the boat, the wind shifted 180 degrees and picked up considerably, which probably pulled out the anchor. The Rocna eventually dragged because the anchor was unable to reset itself properly in the weedy, grassy, hard mud bottom.

This post should be relevant to the OP as the Rocna anchor is very similar to the Manson supreme in that both have the roll-bar design, and the Rocna I was using was one size larger than what was recommended by the manufacturer.

My point: No anchor is perfect despite what the manufacturer says. Always check the weather forecast before leaving the boat for a day ashore, set the anchor properly & return to the boat prior to weather shifts and you'll be OK.

I couldn't agree more about no anchor being perfect, despite the claims of the makers. This is the first time I've heard of a Rocna failing to reset after a wind shift, which is pretty alarming. I would have thought that once well set they wouldn't come out of the bottom at all.

I once rode out a good storm on my father's boat which involved 40 - 45 knot winds, driving rain, and a 180 degree wind shift during the night. Half the night we were off a lee shore - there was no choice. It scared the bejeezus out of me - I kept anchor watch in the cockpit all night with the engine running, with the rain lashing down (my Dad, on the other hand, had a couple of drinks and went to bed, laughing at my nerves). But we didn't budge an inch, even when the wind swung around. The anchor was a Spade. Possibly more importantly - It was a good bottom with clean, hard sand.

[lancelot9898]

For the most part, I agree with JonJo's explaination. All these anchor tests are prefprmed under staight line pulls whereas the real problem comes into effect when a wind shift occurs under storm conditions. Why not test with a 90 degree pull after "set'? Or even 180 degree shift? And while I've replaced my old CQR with a MS, I still think the CQR is and was a good anchor. It allowed a better reset with the hinge design that even the "modern" anchors. I receive an annual brochure from Oyster of all their new yachts and stories about various people taking their Oysters around the world in remote places and all seem to be shown with the good old CQR on these large expensive boats. FWIW

[colemj]

Originally Posted by downunder

Jon Jo is the first I have seen to make the case for at times a smaller anchor.

I haven't read any of his posts as advocating a smaller anchor. I think a 16kg new gen anchor on a 38' 6T boat is a correct size. He hasn't even been distinguishing much between 16kg-25kg anchors for the same size boats. What I have read from him is his disagreement with those who are putting 50kg-80kg new gen anchors on 35'-50' boats.

Weight isn't really the argument in the setting and holding debate - it is just being used as a surrogate for surface area and design. For instance, the Spade comes in equal size aluminum and steel versions. I wouldn't expect a holding debate on those based on weight. Likewise, no one is suggesting a 50kg fisherman will out perform a 16kg Rocna in anything other than a specific specialty condition.

Mark

[foggysail]

Originally Posted by Don Lucas

Don't all properly sized anchors in weed hold just fine,..... once set?

Don, I don't think so based on my ownership and use of Bruces and Delta type anchors. What I found is that pulling on the Bruces in weeds, specifically ell grass, my anchors just pulled out a huge chunk of ocean bottom.

I first noticed this problem using a 33# Bruce in my old 30' Hunter. It had a puny 15HP Kabota that provided enough force to rip the anchor from the bottom. Later after finding my previously trusted 33# Bruce could no longer be trusted, I upgraded to a 44# Bruce with the exactly the same performance.

The 44# Bruce just would not hold my 40' Silverton aftcabin. That experience convinced me to move to a 55# Delta. It held sort of. The forces placed on the rode during 20k+ wind along with maybe 1k of current caused the anchor to slip, slowly but sip just the same. That was when I went to an 88# Delta. It was no better than the 55#.

Each time I set those anchors, I pull back on them with 2000 RPMs, both engines, and then one engine at a time so I could work the anchor sideways while maintaining a strong pull on it. It made no difference. The anchor always slowly slipped. The bottom was mostly mud mixed with sand, some ell grass but limited.

Sure, I possibly could have pulled with over 3000 RPMs. But even at 2000, the chain rode was like a steel rod. I did not want to yank out the boat's cleats.

Foggy

[Kenomac]

Originally Posted by Don Lucas

Don't all properly sized anchors in weed hold just fine,..... once set?

Short answer: No.

With a 180 degree wind shift, they (the roll bar type) simply pull out of the ocean bottom like when you power over to dislodge the anchor during retrieval. If the anchor is one of those with a roll bar like the Rocna and Manson supreme, it basically pulls out with an anchor full of weed and root stuck between the roll bar and anchor spade... I think this is why this type of anchor has some difficulty resetting itself after a wind shift in weed or grass. Try to picture it... My over-sized Rocna just seemed to be skidding along the weedy ocean bottom, never really grabbing & holding after it came out.