Anchor Setting Comparison (Video)

Craig Smith · Oct 8, 2009

It may well not, Danforth styles are horribly unreliable at setting. They should be used with great caution in a situation that might require self-resetting or as a primary bower anchor. Maine Sail's use as a stern anchor where it is only subject to a uni-directional pull is a more appropriate safe usage when wind or tidal shits are expected.

"The closest I've come to disaster was when my anchor dragged over a mile across a bay, towards rocks and a wall of concrete at Seaview, Isle of Wight. It was 0300 and everyone aboard was asleep when a windshift, aided and abetted by a change of tide, caused the Fortress FX-16 anchor to break out and drag... Though renowned for superb holding power, Danforth types can break out if the pull changes direction and they don't always regain their grip..."

— Editor's Log, Yachting Monthly December 2006

jibes138 · Oct 9, 2009

It seems like the weak link in an anchor would be the hole drilled for the shackle in the shank. A hole causes a high K factor (stress concentration) and the area around the hole resisting the tensile pull is not very large. What is the strength relationship between the cross sectional area around the hole and the shackle or rode strength? The Mason Supreme with that slot and hole just looks weak to me but looks can be deceiving.
From Maine Sails photos the CQR looks inferior (despite their lifetime guarantee against breakage, who ever hear of an anchor breaking?) just because the fluke area is drastically smaller than all the others. I remember when the Spade first came out, I gave up sliced bread.
Hey Maine Sail, with all those anchors on board how can you win any races? Your water line must be a foot lower offset by your wallet a lot lighter..

Ross · Oct 9, 2009

Jibes, Figure 50,000 pounds per square inch of cross section for the breaking strength. It is much higher than that but this way there is a safety factor. So if the shank is a half inch thick and 2 inches wide with a 3/4 inch hole in it, the remaining material is 1 1/4x1/2 equals .625 square inches times 50k psi equals 31,250 pounds breaking strength.

jibes138 · Oct 9, 2009

Ross another view of the cross section

Unfortunately I don't have any dimensions to work with but metals in shear are about half as strong as metals in tension. The forces on the shank from the pull are top and bottom cross section in tension, but the slug trying to be sheared out from the front of the anchor to the hole would be that cross section times two since there is a top and bottom to the slug trying to be extracted. So if we assume uniform distribution of metal around the hole it will be about the same cross section than the tensile cross section. So I would only use half the strength so in Ross' example at 31,000 pounds in shear it would only be 15,500, not much stronger than a 5/8 triple braided line. The shackle is still probably the weakest link? Anyone have any real numbers for all this conjecture?

Ross · Oct 9, 2009

Re: Ross another view of the cross section

I think that all anchors wiill drag long before they break.

John · Oct 9, 2009

experience?

Maine Sail said:
I own two, one aluminum & one steel. I would not invest your money in the aluminum version. The nice thing with them is they can be broken down.
Maine Sail: So what is your experience with the spade as far as holding, setting, resetting, etc.?

John · Oct 9, 2009

Actually, I was thinking of the "Sword" anchor. See here:
http://images.google.com/imgres?img...S325US208&sa=N&um=1&ei=EfPPSuH2B5n4tAPrwtDvCw

Ross · Oct 9, 2009

The manufacture and sale of anchors is very much like the manufacture and sale of plumbing faucets. About 15-20 year ago the technology changed and washer less faucets flooded the market. In the case of anchors or plumbing faucets each maker wants to believe that his product is best. the question comes down to the criteria we are measuring, Holding, stow-ability, weight, marketability, durability. remember cream rises and the best will be found. I think that the CQR WAS the best new anchor developed after the fisherman. There have since been many improvements and we are seeing them now and discussing their merits. Bruce was and is a fine anchor but improvements have evolved and should be acknowledged. There will be many attempts to develop the next "best" anchor and there will be many that don't make the cut.

Stu Jackson · Oct 9, 2009

It seems to be a lot more by now

I agree, Ross, with the concepts you mention and the criteria for anchor selection. But what we have to put into perspective are two new things, new in that they are recent and until now "unpublished":

1. Most of us anchor in either mud or hard sand. I think having one anchor that fits on a bow roller that can properly set in both of these "standard" conditions is very important, combined now with the proof that the "past" generation's "best" anchor just isn't so "best" anymore. If I had a CQR and I learned these facts, I would serriously reconsider my anchor gear.

2. All the literature in the world from manufacturer's is much what you claim it is. However, what we now have, in addition to claims and sailboat magazine tests, is "an independent test laboratory": our very own Maine Sail. Please guys, let's not shoot the messenger. He did all the hard work setting up and filming and uploading. Thanks, Maine Sail! So, just shoot me for wondering out loud why folks would attempt to "defend" a piece of equipment that simply has shown to have it's (severe) limitations.

Maine Sail's been doing these tests for quite some time, as I learned as I discussed on page 1 of this topic and from our earlier discussions here: http://c34.org/bbs/index.php/topic,2705.45.html and popsted elsewhere on the internet by Maine Sail.

jibes138 · Oct 10, 2009

Another Perspective

Let's face it. The new anchors are great, just a question of spending more money on something that isn't very attractive (as opposed to spending it on my wife who is). Frankly what we need out of this team of sailboatowner participants is some inventors to step forward and invent an inexpensive, disposable anchor, that is guaranteed to work in all conditions, all bottom types, with minimal weight. The highest rating will go to the anchor design made out of common recyclable materials that will not harm the environment. I think what we need is an anchor made out of beer cans.

Or how about this. New moorings are typically put in with a machine that screws a long screw into the bottom, the wide threads of the screw provide the surface area to resist pulling out. just like the devices used to hold an umbrella in the sand at the beach. So why can't an anchor be designed that you screw into the bottom and be as secure as a mooring? Maybe it will only work in shallow water, but frankly I have only anchored in shallow (uder 25 feet) or water in 35 years of sailing. Might need a long wrench type device that can be broken down in sections for stowage.
Let's go inventors, I invented the worlds greatest splicing tool and shared it with the team here, how about some new anchor ideas from the rest of you.

Ross · Oct 10, 2009

Re: Another Perspective

Stu, I wasn't disparaging any of the work that Mainesail or anyone else has done. Simply reviewing the progress being made in anchor design and the fact that some of the new designs will be 'also rans" and will never be successful in the market. There is no doubt in my mind that the anchor that will succeed the CQR and the Bruce will be the Rocna. The progress has been Big rock tied to a sharp stick, Iron Fisherman , CQR, Bruce and now the Rocna. all of the other modern styles are valid attempts at improvements but they fall short in some regard. The Navy anchor seems to work in very large sizes best measured in tons.

Ross · Oct 10, 2009

Part of the cost reflected in the Rocna prices is development and research expense and large marketing expense. The claw is a copy of the already well known and tested Bruce. Therefore the costs are only for tooling and material. Lewmar has a respected name. The same held for the Delta plow it is a modified CQR. There was no great advertizing campaign to introduce the Claw or the Delta plow. Anchor makers are in business for a profit and are entitled to make one.
Imagine how many small changes were made in the initial prototype Rocna anchor before they got the plow just the right shape, the point at just the right angle, the shank just the right size and shape and just the right angle for the pull, the roll bar and how high it needed to be and how strong , how wide do we make it? And what is the proper weight distribution? What grade steel do we choose?

Craig Smith · Oct 10, 2009

Quite right, and it's about fabrication costs also. The claw is a cheap single piece casting made from low grade steel. You would barely purchase the raw steel for a Rocna for the retail price of the claw. David, the genuine Bruce from which your claw is copied was heat treated and finished to very high specifications, and cost a lot more. After its patents expired, they were unable to lower their costs to compete with the knock-offs, and, unwilling to compromise the product, simply ceased producing it.

Moreover, re 316 stainless. Cheap stainless is one of my big bugbears. Stainless is relatively weak compared to galvanized steel; 316 possesses even less strength than the mild steel we would consider inadequate for the shank on any anchor. Nevertheless you will frequently see it advertised like it's a good thing. High tensile stainless is extremely expensive. Ultimately, if a stainless anchor doesn't cost 3-5 times its galvanized equivalent, a shortcut's been taken somewhere. The cheap stainless claws you see looking shiny in chandleries are junk.

Not to mention, comparing the price of the genuine Rocna against a cheap knock-off is hardly fair. Try looking up the price of a genuine CQR.

rpwillia · Oct 10, 2009

OK, I am a little late to the game, but ...

Maine Sail, I did not see the video till this morning and was just blown away. Very simple test and actually pretty shocking. At the risk of sounding outdated, I have two Danforth anchors. Have you compared the Rocna to the Danforth? I would like to see that video!

I sail in the Potomac River and we have nasty black/dark green mud just about everywhere and I normally get the Danforth so stuck in that I have to shorten the scope up and use the boat/engine to break it free (and then vainly try and swish it around as I bring it up to get all the mud off).

All things being equal, that video makes it look like the Rocna is just amazing.

Stu Jackson · Oct 10, 2009

Ross and Dave

Ross said:
Stu, I wasn't disparaging any of the work that Mainesail or anyone else has done. Simply reviewing the progress being made ...

Ross just so you know I never took your message that way, I was just responding to the overall and very good summary you provided.

dserrell said:
Now that we've talked about the different anchors lets look at cost.

Prices from West Marine:

Lewmar Horizon 11# galvanized claw anchor $39.99
Lewmar Horizon 16.5# galvanized claw anchor $54.99
Rocna 9# galvanized anchor $229.99
Rocna 13# galvanized anchor $269.99

These are just a few examples from one marine equipment supplier! Are the "new technology" anchors over priced? You bet they are! However, if they are that much better, they may be worth their high cost, because after all anchors save our sailboats and ourselves.

David,

Cost? C'mon, please, please get real. How many times is it necessary to, first, deal with the cost of anchors that are heavy enough to work and second, to compare the cost of anchors to the cost of the boats they are protecting? And to take your comparison even further, the DIFFERENCE in cost between anchors then makes that comparison even more applicable.

Like this: "OK, for $200 more, instead of $400, you can have a better anchor that will hold your boat in both hard sand and mud. Your boat costs $75,000. Is that an issue for ya, skipper?" I guess this approach would always work with folks who are fitting out new boats.

You kind of answered your own question there. Save our boats! Pound wise and penny foolish.

Stu Jackson · Oct 10, 2009

Late to game

rpwillia said:
Have you compared the Rocna to the Danforth? I would like to see that video!

Seems he's already done the heavy lifting for us. But if you want an answer to your question, then read the link I provided twice, the one in reply #92. In it, Maine Sail discusses previous test results.

OK, here's the link that Maine Sail provided, (reply #33 on page 3 of that link) which includes tests of Danforths in it: http://www.rocna.com/press/press_0612_wm_ym_testing.pdf

Understood it was done by Rocna. But I think most if not all of us are convinced by the multiple operational tests of anchors provided by anchor vendors as well as the many, many marine publications (Practical Sailor, Sail, etc.) that Danforths do not reset (very well if at all) and are perfect for the intended purpose if you can assure that the direction of pull will not change. Heck, I used our old Danforths on our old boats and they always held because where I anchored the direction of pull did not change. Period. I trust them for that and for stern anchors.

PS -- Did Maine Sail test Danforths? Don't know if he did. Ya wanna pony up the gas and for his time to do it?

PPS -- Many of us provide links to earlier posts to avoid having to retype a lot of stuff. Many people, like me, tend to repeat themselves, sometimes right in the same topic!

But given links to earlier posts, it sure would be nice if folks read 'em, although I'm sure most of you do...

Ross · Oct 10, 2009

Re: Ross and Dave

I grew up during the transition from mechanical brakes to hydraulic brakes and then to vacuum assisted hydraulic brakes and then to fully fledged power brakes all still on drums. The disk brakes became an option on some cars and today they are practically standard and anti-lock brakes are available. all of these are improvements and they all added cost to the car. A good parking brake on a car is demanded by everyone and so it should be with boats, the anchor is your brakes and you want them to be completely reliable.