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Old 08-10-2005, 09:56   #1
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CQR Anchor

I have a 31' boat, 11,200 displacement and a 25 lb. CQR primary anchor (came with the boat). From what I read, we should have a 35lb. They cost $500.- I want to understand the risk in an undersized anchor. I am assuming it is the size of the flukes limit holding capability and the result would be to "drag" in some conditions. Yes ? No ? Comment !
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Old 08-10-2005, 10:13   #2
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The main problem with an undersized anchor is sleep deprivation.
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Old 08-10-2005, 11:25   #3
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we did a very windy overnight in mud with this anchor and the next day when hauled it was really dug in deep - seems to keep burying as long as bottom will allow. i have never had a problem with anchoring except in rocky bottom where it can "pop" free.
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Old 09-10-2005, 04:59   #4
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Re: CQR Anchor

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capt lar wrote:
I have a 31' boat, 11,200 displacement and a 25 lb. CQR primary anchor (came with the boat). From what I read, we should have a 35lb. They cost $500.- I want to understand the risk in an undersized anchor. I am assuming it is the size of the flukes limit holding capability and the result would be to "drag" in some conditions. Yes ? No ? Comment !
For your boat we would be recommending a 15Kg / 33lb version of one of our anchors. So, your CQR should be at least 35lb. 25lb is too small. If you are doing any kind of serious cruising, upgrade ASAP.

Yes you are correct. Any given size anchor in any given substrate will support X newtons of force in terms of pulling before it lets go and starts to drag. You therefore do not want your boat to be putting more than X newtons of force in any foreseeable weather conditions. Once set, the main factor that affects the level of force sustainable is fluke size and configuration.

Fluke size: equals pure resistance. In the design of the anchor, consider aspects that affect the amount of fluke area, such as the presence of dedicated tip-weight (that lead insert in your CQR). This is inefficient use of material (required to encourage the anchor to orientate itself correctly). The weight might be better put to use in more fluke surface area.

Fluke configuration: determines how effective the present fluke area is. A convex shape offers the least resistance (e.g. any plow such as a CQR), a flat blade offers moderate resistance (e.g. Danforth-style), and a concave blade offers the greatest resistance (e.g. Rocna). Here's a thought: consider what a plow in a farmer's field is intended to do.

So:
  • For serious cruising you need an anchor of approx 35lb, and that is assuming you have the optimal arrangement as discussed above
  • Consider a design other than a plow. Find a design that maximizes fluke area by avoiding inefficient use of weight
  • And, find a design that has either a flat or concave fluke configuration
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Old 09-10-2005, 14:22   #5
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Anchor size is only a part of the system. If you have a smaller anchor, but are using much heavier chain than is recommended, this would enable the anchor to provide the holding power required, but you are dicing with disaster. I always reckon that the anchor should be AT LEAST one size larger than the calculators recommend for a boat size, and I also use a heavier chain (10mm) - result = no worries when at anchor
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Old 09-10-2005, 15:20   #6
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I agree, with Talbot, that bigger anchors are better anchors, but in a smaller boat (like our former C&C29), longer but lighter chain might be more practical than oversized chain.
My lighter chain, was actually stronger - I like 1/4" - G70 “Transport” chain, with a Working Load Limit (WLL) of 3150 #, and weighing only 61#/Ft.
This compares favourably with 3/8" G30 “Proof Coil” at 2,650# WWL (133#/Ft), and also with 1/4" G40 “HT” at 75#/Ft (2,600# WLL).
I often use a “sentinel” weight as well.
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Old 09-10-2005, 19:22   #7
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Can't argue with success!

Capt Lar,
No question that the CQR is one of the most successful all-around anchors. Regardless of all calculations and theoretical arguments promulgated by competitors the CQR is the best reseting anchor to lay to with shifting tides, currents and winds. Any anchor design is a compromise and, to be sure, other anchors should be carried in addition to a CQR for radical bottom conditons. I have 5 anchors aboard and love every one of 'em but the CQR is my favorite way, in general, to get sleep.

High tensile strength Danforth designs are superior in short scope single-direction pull conditions (I would never be able to sleep well on only one of them, tho, if the boat is swinging around in a tide or wind shift...you need two anchors to prevent swinging out a Danforth.

Here's where critical thinking is important: "Here's a thought: consider what a plow in a farmer's field is intended to do." The implication of that statement is that if an anchor is like a plow that a farmer uses to make a large furrow in a field that a plow anchor will move. The falacy of the implication is that it does not consider the fact that given enough horsepower ANY anchor will move, plow or not. The REASON that a farmer doesn't use a different design is because he WANTS to move a large amount of dirt and IT TAKES a lot of horsepower to do it.
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Old 10-10-2005, 03:14   #8
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Rick your argument may be something of a fallacy too.

The basic premise is a convex shape offers less resistance than a concave one. Parachutes are shaped as they are for a reason.

A plow is actually shaped as it is to deflect material to the sides. A farmer's plow is designed to dig a symmetrical trench. A road-plow shifts snow off the road. Such plows are NOT designed to offer reverse resistance as the idea is NOT to push all the material in front of the tractor, horse, or whatever.

So, my parallel works like this: you do not want your boat anchor basically designed to deflect soft substrate up and to the sides as it moves through the seabed.

Plow anchors arose as the shape naturally tends to bury well, and either no one had figured out how to make a concave fluke set, or just hadn't bothered trying (there never has been a huge amount of resources applied to small boat anchor design).

Yes any anchor will drag if sufficient force is applied. But your wording ignores that the amount of force required differs according to design.
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Old 10-10-2005, 11:47   #9
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The whole anchor

Craigsmith:

The fact IS that the CQR is the best compromise for the widest anchoring conditions of all the products on the market. One OVERWHELMING performance feature is the ability of the CQR to most RELIABLY reset when it has been removed from a set by a huge wind or current shift. No other anchor has demonstrated this ability. One reason (not the only one) is the hinge that allows the point to remain on the bottom when reversing a pull.

Now of course the CQR is not the best in any or all conditions. For example, the Bruce is my favorite for throwing into my inflatable to take out in order to kedge or secure a second anchor. The Bruce is one of the worst in sand, in that it pulls through it too easily as compared to any Danforth type (again, assuming that one is not swinging on it). I know many people who only have a Bruce yet I believe that they haven't yet been able to do an "A versus B" comparison in many conditions like I and others have. The Bruce is unbeatable in heavy mud yet will not reset as reliably as a CQR.

I (and others) have had a CQR shank bent like an "S" from having terrible strain under emergency conditions in a rocky bottom with huge waves pushing the boat around off a lee shore without failure. This strength one gets from the metalurgy and forging.

Northill anchors work well to set in some hard bottoms. Fisherman anchors have to be oversized weight-wise yet hang on rock edges well without having to "bury".

Whenever conditions permit I dive on my anchor and wander over to look at the anchors set by other boats and have done this when hurricanes have approached with heavy wind and swells noting what works and what doesn't. When I note an anchor not set or continously pull through the bottom I have replaced it with a different type to note any improvement and that is why I now have a jaundiced eye when viewing some of the types with overly marvelous claims other than the ones that I KNOW work and under what conditions.

One such jaundiced view that I have is the one of the anchor shown in the drawing of your message. I can only "see" the arch as being a design flaw that merely presents unnecessary object that might look "cool" yet would prevent the rest of the construction from burying well and leave the anchor on the surface under some conditions when other types (like the Bruce) would bury well and set. In addition, from an engineering perspective, it would offer leverage when the boat swings around on it and flip it out of the bottom when other designs would remain set. I'm sure that the anchor will work under some conditions, just not as many as other designs do (I'll stick my neck out on this one).

One time another cruising boat demonstrated just how a skipper might be fooled into thinking his anchor was a "good" design by dumping a rather large pile of chain into a depression on the bottom and backing down (with more chain veered) with a LOT of pull (the water was clear and I dove down and watched). Once the veered chain was straightened the boat did not move and there was NO anchor on the end of the pile of chain. My point is that most of us are not anchoring under conditions sufficiently adverse so as to prove or disprove a particular anchor design as being "good" or "better than the other brand". The truth is that with sufficient chain and almost ANY weight on the end of it a boat can safely "anchor" under non-adverse conditions. So, anyone can come out with any kind of a design and offer it with wonderful accolades to the public and it WILL work anyway most of the time period. The flies don't move until the beard gets pulled on the lion.
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Old 10-10-2005, 15:48   #10
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Further to Rick’s closing anecdote:
The truth is, that most sailboats (auxiliaries & motor-sailors) can only exert a force roughly equivalent to that of a 25 - 30 kt wind - when in FULL reverse.
Backing down on an anchor (or just a rode ), proves very little. “Look” your anchor at every opportunity.
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Old 18-10-2005, 22:02   #11
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Quote:
GordMay once whispered in the wind:
I agree, with Talbot, that bigger anchors are better anchors, but in a smaller boat (like our former C&C29), longer but lighter chain might be more practical than oversized chain.
My lighter chain, was actually stronger - I like 1/4" - G70 “Transport” chain, with a Working Load Limit (WLL) of 3150 #, and weighing only 61#/Ft.
This compares favourably with 3/8" G30 “Proof Coil” at 2,650# WWL (133#/Ft), and also with 1/4" G40 “HT” at 75#/Ft (2,600# WLL).
I often use a “sentinel” weight as well.
Chain strengths are very rearly an issue but the weight of it is when anchoring.

Lighter chain is good if anchored in a good depth but in shallow areas you're missing out on lots of holding unless you have a huge amount of swing room.

The load required to get 8mm chain to just lift off the bottom so only the anchor is left touching/buryed in the bottom takes:
a 5mt length 12kg at 5:1 scope.
a 7.5mt length 19kg at 5:1 scope and
a 10mt piece at 5:1 and it takes 35kg.
As you can see the loads increase dramatically with only smallish length increases.

7.5mts at 3:1 Scope:
8mm takes 13kg to get it 'just lifting' off the seabed and it takes 23kg to do the same with 10mm.
Again a big differance in loads with only a small change in size.

When using small very high tensile (brittle) chains you must ensure there will NEVER be any shock load put on them. They do not stretch just snap without warning. Grade's 30 and 40 (HT) will stretch before break. Even Grade 50 will a small amount.

'Proof Coil' is not a grade as such, it is the load put on it in the factory before it is send out. The 'Proof' load is 2 x WLL or 1/2 the break load. Hence the term 'Proof Coil'. All chains are 'proof loaded' before leaving the factory no matter what the grade. Of course this refers to reputable chain manufacturers products.

It appears US citizens like shoping from US manufacturers (which is bloody great, I wish my countrymen/women did the same) but they do miss out on a huge range of other chain sizes and grades which are available around the world. All good winch makers have US sized gypsies as well as the world standard sizes as well.

Here endth chain 101. Safe sailing all.
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Old 19-10-2005, 11:02   #12
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corrosion susceptibility

Does anyone know what is the comparison between HT chain and proof, etc regarding corrosion susceptibility? I would think that corrosion susceptibility would increase with brittleness and HT grade, yet do not know that for sure.
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Old 19-10-2005, 12:25   #13
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As far as corrosion resisitance goes, it's the galv that protects the chain, not the hardness of the parent metal. So a equally galved HT and proof chain will perform the same in regards to corrosion. Of course, the trick in the real life aspect, are both Galved equally AND well.
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Old 19-10-2005, 13:03   #14
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Re: corrosion susceptibility

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Rick once whispered in the wind:
Does anyone know what is the comparison between HT chain and proof, etc regarding corrosion susceptibility? I would think that corrosion susceptibility would increase with brittleness and HT grade, yet do not know that for sure.
Both will rust, no surprise.

If you had a bit of both high and a lower grade chain with no galvanising the lower grade will rust worse fastest. The higher the tensile the slower it seems to it. Either way there will be a mess.

NB: Galvanising chain does reduce the strength. The higher the grade the trickier it is to galvanise. Grades 50 odd and higher must be done by a very good operator or you can lose an awful lot i.e 20% or more, done badly it may get to 50% . It is also recommended you only re-galavanise chains once.
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Old 19-10-2005, 14:39   #15
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GMac

So, would grade 30 HT chain be relatively "safe" to galvanize and then be a good choice over proof for durability, strength, and life? Would it be, in your opinion, a better chain to use, assuming that the cost difference is tolerable?

What do you use?
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