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Anchoring a C25/0 redux - part dieu - OK 101

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redviking
Master Marine Consultant

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Initially Posted - 06/30/2008 : 21:11:57

SO, I got a few responses about chain et al offline and while I did respond, Sprint seems to be blocking me from yahoo accounts...

SO, in my opinion 12.5 feet of chain is not enough. 20' maybe. Here's why. If you anchor in 6 feet of water all of the time 20' will hold you no problem. It's all about catenary. This is the angle at which heavy chain keeps the hook firmly planted to the bottom.

So - try to visualize this - you throw down your 13 lb. danforth which has the square footage of less than one square foot, and is half the weight of the length of your vessel. Attached to that you have 10' of chain - standard WM package - with 150' of rode. You are in 14 feet of water, so you play out 70' for a 5 to one... Negative. That's a lunch hook! Not an overnighter. In tight anchorages increase quantities of chain. Think about what catenary means. When it blows the angle of the chain prohibits the shank of the anchor to rise up. As long as the shank does not rise up, the anchor will not move. As previously posted, we used to shackle on additional chain when needed with awesome results. I still dragged in Block Island with 35 or so a blowing.

Now about hauling. OK, get yourself a block and tackle and rig a pick up if you can't or don't want to haul all of that chain. It's easy - think of it this way - if you are in 14 feet of water, you are really only hauling 14 feet of chain and the hook covered in heavy mud albeit! SO, attach a 4/1 to a halyard and attach that to the last portion of the chain. Voila! hook comes up, mind you, you should still break it out by motoring forward.

Lastly - the bigger the hook the bigger the damage. Period. If you are in Maine where there are a lot of rocky places, then a fisherman anchor may be applicable sometimes. Most C25/0 folks needs a good Danforth and a good Bruce as a second anchor in my opinion. Knock yourself out and get the Delta or the CQR - my personal fav - but you'll help yourself more with a lot of chain than you will with anything else. And if you should ever need to storm anchor - have three hooks down. Numero uno for a C25 (was for us in a near hurricane) was the Bruce 13 followed by 20 feet of chain, followed by a 22 lb. Danforthwith 35' of chain, followed by 100' 1/2 inch - chafe guarded - in 8 feet of water. Our second hook was set slightly behind the first at about 30 degrees to port to the wind, such that it would never foul the primary hook, no matter what. If we were to drag during the storm, we would have basically been like a farmer, making one very slow ditch across the bottom. Again, visualize what is going on.

Final product rec.... http://www.cruisingoutfitters.com/kiwi.html the Kiwi anchor rider - which is just a kellet. A kellet helps keep that all important catenary. SO, if you know you can't haul all of that chain no matter what - think about one of these. They glide on the rode on wheels and are only 20 lbs for a C25. I need a 30lb - so mine is for sale

But they really do work. I only used mine twice, but I was very impressed. A kellet is of course not a new idea, someone made it easy to retrieve.

sten

Edited by - on

delliottg
Former Mainsheet C250 Tech Editor

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Response Posted - 06/30/2008 : 23:19:03

How much you want for it, and is it small enough to fit in a USPS flat rate box?

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Dave5041
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Response Posted - 07/01/2008 : 00:27:02

Nobody could ever suggest that more chain doesn't hold better, but incremental improvements eventually lead us to all chain for the best holding power. Can't argue with that, but it may be a little overkill for most of us. 60' of rode tugging at a low angle on 10' of chain will still provide a reasonable catenary in the chain in the conditions most of us are likely to face. How much chain depends a lot on where you sail and how you cruise. On inland lakes, Erie, and the sand bottom of the Fl panhandle I have been well served by 10' of chain, 150' of rode and 150' in reserve for a long time. When I go to the granite bottom of Georgian Bay I will want more chain for shorter scope and chafe resistance. How much weight do you want to haul aboard and store in the bow - every choice is about risk/benefit, and where the likelihood risk becomes so low that the benefit is negligible is a decision we each make based on our assessment of the variables. No arbitrary length, be it 10', 15', 20', or more is safer in mild conditions, and all can be overcome in some extreme condition - its all about how and where you sail. A 5 point safety harness is potentially safer in a car, but I haven't worn one since I quit racing.

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Dave Bristle
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Djibouti
10005 Posts

Response Posted - 07/01/2008 : 09:38:16

Note that an all-chain rode should also have a snubber rigged each time you anchor--the chain doesn't absorb shock like twisted nylon does. Conventional wisdom is length-of-the-boat in chain. High winds can occur anywhere in the country, and the more the rode lifts the shank of the anchor, the more likely it'll break out, even in "good holding."

Sten: The Kiwi looks interesting...... What scope do you use with it? Shouldn't the control line let the weight get as close to the chain as possible? Is 50' long enough? I suppose at some angle, it won't want to slide any further...

Friends of mine gave up on their CQR in New England conditions, including Block--it failed to reset too often on a current or wind change, as also reported in some tests I've read. (Some say the hinge is the culprit, allowing the plow to be pulled sideways.) They switched to a Bruce and are happy. (I'm skeptical.) I picked the Delta, which as you know is sorta like the CQR but without the hinge. I played with it on the lawn, pulling in various ways, and it would turn and bite into the turf immediately. So far, so good. It's an imperfect science!

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redviking
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Response Posted - 07/01/2008 : 11:00:03

Quote: "How much you want for it, and is it small enough to fit in a USPS flat rate box?"

NO - it isn't larger than a bread box, but it won't fit in a USPS flate rate either. It weighs 20 lbs. and is substantive. They are selling for $180. I'm looking for $150 shipping included. I need to buy their $300 all chain model - although we can use this when we run all rode.

Dave5041 - yes every choice is about risk/benefit. if you have already established where you wanna be depending on the conditions - cool. There is no end all solution, just a lot of good answers. The average owner who is asking these kinds of questions wants some relative guidance from someone who has done it. I provided a safe answer. You are correct, you can anchor with only 10 feet of chain. I have. But knowing what I know now, I would never do so again. Even my Zodiac has a small anchor and 10 feet of chain.

The point about too much weight in the bow is correct - which is why I recommend the ability to shackle on additional chain if required.

Dr. Dave - the Kiwi Anchor rider is designed to run down to the bottom and then be lifted up a foot or two and cleated off. 50 feet is plenty long enough.

Our CQR has never failed to reset, although we have experienced a couple of places where I felt like Johnny Appleseed for a few moments while she took her time to reset. We are holding in Newport on our original hook dropped weeks ago with no issues at all. Block is another story, although with my 10 mm chain and a lot of scope I'd be willing to give it a go provided I had a lot of swing room.

I recently met a cruiser with a Manson http://manson-marine.co.nz/SitePages/Supreme.htm and was very impressed with the quality and the approval rating given to me by its owner. They make a 15lb which would be perfect for a C25. I found this video http://www.youtube.com/watch?v=luWJwTRkTUo which shows how rough being on a hook can be.... Been there, seen 55 knots. Not fun!

We do deploy a snubber, but I always have troubles keeping the hook on the chain - so I may go to a full-time shackle that won't let go.

Anchoring is an imperfect science - which is why I like to do it. Some nights I sleep like a baby, and other times I am freaking and on anchor watch.

We have two 35 lb. CQR's, one 45 lb. Delta-ish storm hook. Two Bruce 22 lbs, and a collapsible fisherman on Lysistrata. And I still want a big Fortress collapsible Danforth! Oh and one of those reels mounted on the stern rail for the stern hook! Good golly, does it ever end?

Sten

DPO C25 #3220 "Zephyr", SR, FK
SV Lysistrata - C&C 39 - Newport RI

Edited by - on

JimB517
Past Commodore

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Response Posted - 07/01/2008 : 11:22:52

I use 50 feet of 5/16 chain on my main anchor - a 13 lb danforth, and 40 feet of 5/16 chain on my second, also a 13 lb danforth. My 3rd is an 8 lb danforth on 20 feet of chain. Danforth's hold well around here - usually sand or hard clay/mud bottoms. For east coast cruising I'd want a Delta.

I need to anchor in short scope, crowded, harbors.

Usually anchor in about 25 to 30 feet of water, although at Catalina you sometimes have to anchor in 75 feet or deeper.

Chain is good, but not all chain. All mine are backed up by 150 - 200 feet of 1/2 nylon.

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JohnP
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Response Posted - 07/01/2008 : 12:08:50

On my list of home-made gadgets for the boat is a 2 gallon plastic bottle filled up with concrete and a big screw eye --- a Gypsy Anchor Rider.

Gunkholing around the Chesapeake I try to avoid traffic and anchorages requiring heroic efforts.

But Sten is a true cruiser and he knows about anchoring when it's necessary for survival.

I'd like to make my homemade Gypsy Anchor Rider for those hypothetical times when heroic efforts would be required. Wouldn't 20 lbs of concrete in a plastic bottle hold the rode down just as well? Same principle, but 5% of the cost.

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Dave5041
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Response Posted - 07/01/2008 : 12:46:02

The concrete filled bottle will work fine, as Sten said, it is just a kellet - a weight hanging on the line to keep the angle of pull lower. More expensive ones are denser and therefore smaller for their weight and easier to store. Rollers make them easier to deploy and retrieve and offer substantially less chafe - a real issue when you need one. I'm just not sure of how much 2 gal would weigh, keeping in mind that it would weigh 16 pounds less when submerged and Sten said the 20 pound (probably 17 or 18 pounds deployed) is recommended for us. A sense of security is not necessarily security.

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Nautiduck
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Response Posted - 07/01/2008 : 12:55:24

Anchors are best chosen based on your cruising grounds. For our San Juan trips we use a 16lb Bruce with 30' of chain and 300 feet of 1/2" rode.

My favorite anchors are a slip at a nice marina or a mooring at a marine state park.

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Dave5041
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Response Posted - 07/01/2008 : 13:21:19

As an aside, we are talking about reacting to weather. If you sail like I do - probably 80% is marina/mooring field hopping or day sailing, reading the sky is a skill that helps you avoid many bad situations. Storms do not come up suddenly, there are always indicators in the sky that you should learn to read.
Locally developing storms take time to develop and a moving line of thunderstorms can be seen long before they reach you. More severe storms are taller and can be seen farther away, that doesn't mean you won't get caught, but you have time to prepare. Big water storm systems can last for days, but in the interior we are usually looking at a day or two of transient storms that can be severe. I just want to reinforce for newer sailors that a basic understanding of what different clouds mean can add add a lot to the comfort, safety, and joy of sailing.

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delliottg
Former Mainsheet C250 Tech Editor

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Response Posted - 07/01/2008 : 14:48:54

John,
I did the math, a two gallon jug of concrete will weigh about 38-1/2 pounds. Canceling terms struck out: (8 lbs/<s>gallon</s> of <s>water</s> x 2403<s>kg</s>/<s>cubic meter of concrete</s> x 1 <s>cubic meter of water</s>/1000<s>kg</s> x 2 <s>gallons</s> = (8 x 2403 x 1/1000 x 2) = 38.49 lbs of concrete.

A one gallon milk jug might just do you, it'd certainly be easier to pull up.

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stampeder
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Response Posted - 07/01/2008 : 15:17:48

<blockquote id="quote">quote:<hr height="1" noshade id="quote">I use 50 feet of 5/16 chain on my main anchor - a 13 lb danforth, and 40 feet of 5/16 chain on my second, also a 13 lb danforth. My 3rd is an 8 lb danforth on 20 feet of chain. Danforth's hold well around here - usually sand or hard clay/mud bottoms. For east coast cruising I'd want a Delta.
<hr height="1" noshade id="quote"></blockquote id="quote">
where do you keep all that steel?

For cruising in the PNW, I use two 25LB Kellets.

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JimB517
Past Commodore

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Response Posted - 07/01/2008 : 15:30:59

The main anchor with 5/16 chain is in the anchor locker.

The 2nd anchor and 3rd anchors are home right now because I am racing, but I carry #2 + rode in a big plastic tray which I put under the V berth. The 3rd anchor is really small and I carry it for cruising as a stern anchor in a plastic 5 gallon jug in the cockpit.

For crusing I also carry 2 sets of anchoring stabilizers (those orange cones) with 8 lb mushroom anchors on the bottom of the string. These are carried in the lazerette. They really work when deployed off the spinnaker pole. I think this year I'll only take 1. Capable of reducing 15 degree rolls to 5.

Some of the racers around here don't even carry a main anchor but I think that is foolhardy.

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skrenz
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Response Posted - 07/01/2008 : 16:21:04

I've been thinking about what you said Sten and lets just do what you suggested "try to visualize this". I think we all agree that catenary is the key to keeping the anchor holding. But lets think about how more or less chain is effecting this. Supposes you have 50 feet of 5/16" chain like Indiscipline carries. 5/16" chain weighs about 1 pound per foot. That adds up to 50 lbs. That means that the action of the boat pulling on the chain needs to lift only 50 lbs before the whole rode is acting as if it were all line without any chain at all. Likewise if you have only 20 feet of chain it takes only 20 lbs of force before the whole rode, chain and all, is acting, in terms of catenary, as if it were all line. If you had all chain rode and let out 200 feet of rode you would have 200 lbs to lift, etc. The same holds true for a kellet. If you had a kellet that weighed 50 lbs, you should have the exact same effect as 50 feet of 5/16" chain. So as long as you are in a situation where the force on the boat is less than the weight of the chain or kellet, they will be your friend and keep the catenary flatter. But over that force and it doesn't make a wit of difference what your rode is made out of in terms of effecting the catenary of the rode.
What effects the catenary much more is the scope you set out in the first place. Chain at the end of the anchor protects the rode from sharp objects on the sea bed but depending on its added "holding power" will be limited to only those times that the force on the boat is less than the weight of the chain. This would also mean that the length of chain should be proportional to the amount of force that your particular boat presents for a given wind strength. I'm not sure how you come up with that number. And I suspect it is for this reason that people depend on what others experience to guide them in the length of chain they put on their rode.

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SailCO26
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Response Posted - 07/01/2008 : 16:30:59

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by JimB517
Some of the racers around here don't even carry a main anchor but I think that is foolhardy.<hr height="1" noshade id="quote"></blockquote id="quote">And in a lot of classes illegal.

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skrenz
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Response Posted - 07/01/2008 : 17:00:03

I need to amend the amounts of pull I quoted in my earlier post because I wasn't taking into account the angle of pull. So, if you have a 5 to 1 ratio of rode to depth 50 lbs of chain will require 255 lbs of pull before the rode is straight. 20 lbs of chain for the same ratio will require 102 lbs of pull.
But this demonstrates the importance of the catenary angle even more so. Reduce the ratio to 3 to 1 and still use 50 feet of chain. Now the pull required is only 158 lbs before the rode is straight and acting like it has no chain at all.
Kellets actually will work differently depending upon how far down the rode you set them. This is because if you set them half way down the rode, as the web site for the Kiwi anchor rider demonstrates, you reduce the catenary angle by half to the kellet and so decrease the force needed to lift the kellet because the angle has changed.

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Stardog
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Response Posted - 07/01/2008 : 17:12:20

The assumption that 50' chain weighing 50lbs gives 50lbs of holding force is erroneous. If you're lifting the chain straight up vertically that statement is accurate, but the further the boat is from the chain the greater the force required. At some very great distance from the chain the force required for the boat to straighten the chain become infinite. Chain is not for the sake of chafe, it's there to increase the force required to straighten the catenary. The longer and heavier the chain, the greater the force required to straighten it and that force increases exponentially. Here is little write-up on catenary, if you sort through it you'll find Tension in the equations for towed cables, this tension is the equivalent of force a boat applies on an anchor rode.

http://www.answers.com/topic/catenary?cat=technology

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Dave5041
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Response Posted - 07/01/2008 : 17:29:40

Correct, Stardog. and can easily be demonstrated by tying a 20' or 30' length of line to the bottom of a tree or post, add a 10# weight to the middle and try to pull it straight. But chain is also indicated by chafe potential to keep the line away from abrasives. A nylon rode rubbing on a granite outcrop won't hold you very long

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redviking
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Response Posted - 07/02/2008 : 11:40:34

Aaahh, I forgot - one of the many sailing discussions that exist in the physical universe is anchoring. Everyone has an opinion except for those who don't. I've seen the 35 footer on a rode purchased at walmart with 15' of swag lamp chain from Home Depot. It can be done. The laws of scope are applicable to everything about anchoring. Always has been, always will be. Which is why for those hanging on a lot of rode - the Anchor Rider is a great idea becasue it increases catenary - simulating chain.

In Portsmouth VA, I toured a huge navy ship turned more or less public. The retired guy - rank unknown or forgotten - at the bow knew everything about anchoring the vessel. The anchor was obviously huge as was the chain. They could anchor in 300' of water, but only on a 5/1... They always ran a 7/1 in shallower water. I asked if they "backed down" on the hook when setting the hook. No, they would let it drop and grab and then let more chain out as the ship naturally pulled back. (Side point: This guy was not a sailor. Once his tour of duty was over, he was done with the water.) I've had many a hook fail becasue of the initial load from backing down and since hearing this advice, I now drop a hook similarly.

CQR means "secure" hence the name and they are, knock on boat. The pivot IS helpful as it allows the hook to dig deep while the shank is allowed to move a bit without disturbing the slow process of burying the hook. Delta's have their place, but the majority of cruisers we've met on the east coast run CQR's.

sten

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Dave5041
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Response Posted - 07/02/2008 : 14:18:57

Interesting, but I still back down. I am drifting as I pay out, so I am pretty much in line with the wind. A 1 -2 thousand pound anchor probably digs in a little faster than my 14, but what ever works for you in your environment.

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redviking
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Response Posted - 07/02/2008 : 17:46:43

Oh, I still back down, but really just to test the hold and allow the hook to firm up. But I now wait at least 5 minutes before backing down.

sten

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piseas
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Response Posted - 07/02/2008 : 18:25:44

I do not do a lot a anchoring. But I want to learn as much as I can about it. This post has taught me a lot and I want to thank all of you who have put in your 2 cents.
I have determined what will work best for me in so far the the type of anchor, chain and length of nylon, etc. And my new favorite word, "catenary", which I have found several ways to pronounce and not sure which is correct.
All of you that have contributed have enlightened me. I will take advice from all and use that for my situation. But I can tell you one thing, I will not buy nylon at Walmart or lamp swag chain from Home Depot. Thanks all.

Steve A

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delliottg
Former Mainsheet C250 Tech Editor

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Response Posted - 07/02/2008 : 19:02:52

Catenary: "KAT-in-nairy" Second "n" in my guide is sort of silent and obviously not really there, sort of like "na-nairy".

I used to joke that my calculus teacher could be put onto the middle of the Brooklyn Bridge and asked to point out a catenary curve and she'd be unable to. Same with pointing out a hyperbola while standing in an opera shell, or a parabola while looking into a search light's beam.

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Stardog
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Response Posted - 07/02/2008 : 21:17:57

I always thought catenary sounded like a mythical creature; part cat, part canary.

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Megsskipper
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Response Posted - 07/02/2008 : 21:27:41

Hey Sten...love your posts man...you, Oscar, Hopper and Bumhgart are always a "gotta read"...(where'd Oscar go?).
We do our fair share of hook setting around the Chesapeake...weather gets ugly quick...never been let down yet....(knock on teak)...pardon my ignorance...why do you wait 5 minutes??

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piseas
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Response Posted - 07/02/2008 : 22:27:24

Skip, you are leaving off a lot of names. Better be careful. My apologies to the rest of you and you know who you are.

Steve A

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