# Caternary & Chain...



## Maine Sail (Jan 6, 2003)

Just read an interesting piece on anchor snubbers in the latest Practical Sailor. What really jumped out at me was not about snubbers but rather just how little load was required to lift the last link of chain off the bottom of the ocean and affect the anchor shank angle.

If the chain is laying on the bottom, as people often assume it is, the anchor shank is parallel to the bottom or in optimum holding orientation. When the last link of chain lifts it can change shank angle to match that of the scope being used. If on short scope.......

PS used a 100' section of 5/16" chain set to a 5:1 scope to test how much load was needed to lift the last link off the ground..

To apply the load they used a chain-hoist / come-along and measured it with a calibrated load cell. They physically pulled the chain to see how much load was required to lift the last link of chain eg: the anchor shank, off the bottom.

The shocker for me was that it took just 190 pounds to lift 100' of 5/16" chain at a 5:1 scope off the ground _out of the water_. The in water load calculation to do the same, when taking the density of the chain into consideration, would be just _158 pounds to lift the last link off the bottom_...

Seeing as I own a digital load cell and have physically measured the loads of our 36' sloop at 140 - 218 (218 was peak loads) pounds of load in 17-19 knots the idea of chain holding your anchor on the bottom is really considerably less than where I and many books and experts suggest it would be....? Just 17-19 knots on our boat is enough to lift our chain at 5:1 !!!!! 17-19 knots is not even a stiff breeze.......

I actually just ran the numbers through an anchor load calculator and it does not show the chain lifting until a load applied of 242 pounds yet based on the PS actual test data it takes just 158 pounds of load to do this... Does this mean that all the _theoretical_ data we've been using for years has been skewed???? It would be one thing if it was skewed in the _safer _direction but it has been skewed to the _unsafe_ direction....

This means the wind conditions to affect anchor shank angle, with all chain, seem to be considerably lower than originally thought...

So if I am anchoring at 5:1 with 100' of 5/16" chain in approx 17' of water it will take just 17-20 knots, on our boat, based on actual measurements, to begin to lift the chain so the anchor shank angle is affected.

Interesting stuff to say the least and certainly some interesting data to ponder........

*Quote: Practical Sailor

"We fixed one end and then tensioned the chain with a come-along until the last links at the lower end had lifted free of the ground. Lifting this required a load of 190 pounds, which translates to 158 pounds in the water. Based on data from last year's test (PS, May 2012), this would be the equivalent of about 15 knots of wind on a 40-foot boat anchored in about 15 feet of water with 100 feet of 5/16-inch chain."*

We've all heard the old axiom that 5:1 on chain is okay but 7:1 on rope/chain rode is needed. With this physically tested & measured data it appears that this is simply not entirely true..

It seems prudent that scope should be set irrespective of all chain or rope/chain rode because chain alone really will not help shank angle _when you really need it most,_ in high winds...??


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## manatee (Feb 27, 2013)

Now we know what doesn't work. 

What *does*?

Kellet?
Heavier chain?
More scope?
Better anchor?
Longer snubber?
All the above?


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## Maine Sail (Jan 6, 2003)

manatee said:


> Now we know what doesn't work.
> 
> What *does*?
> 
> ...


I think the bolded items will be the most beneficial. A kellet can help prevent sailing at anchor etc. but in a storm the only things that will reasonably work IMHO are:

*Buy the best performing anchor your money can buy (there are lots of great anchors out there today compared to just 10 years ago)

*Use proper setting technique

*Know your bottom and choose the correct ground tackle

*Be prepared to quickly deploy back up tackle

*Use an anchor alarm

* Use GPS cookie trails as PROOF you stayed put when that other clown hits you and then tries to claim it was you who dragged!! (never know when you might need them for insurance purposes) Our GPS is ALWAYS on & laying trails when at anchor!!!

*Use proper calculations for scope and don't forget tides and bow height

*Check your set/setting technique with a strong power set by backing down at full throttle. If your sailboats engine can drag or un-set your anchor, by backing down hard, YOU ARE NOT SET....

*Recheck/power-set again before you go to bed

*If the wind shifts power-set in the new direction to re-test your new set direction. Some anchors are very poor re-setters..

*Use as much scope as you can for the swing room you have

*If you don't feel comfortable with how much scope you can lay, a kellet can certainly help, _in moderate winds_.

*Get where you are going earlier in the day not later.....

*If you don't feel comfortable with the scope you can lay & swing to, move on......


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## chucklesR (Sep 17, 2007)

Funny, I just read an interesting letter in Practical Sailor about batteries. 

Written by some guy who owns Compass marine 

Nice article MS.


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## capecodda (Oct 6, 2009)

This data is interesting. 

Even if the last link is off the bottom, I would think that the angle at which the chain meets the anchor shank would be more horizontal with a weighty rode like chain than rope. So I'm postulating that even though the chain is "off the bottom" it is just barely off the bottom at the shank and therefore pulling mostly horizontally. 

What would be of interest is what that angle is. You could then calculate the horizontal (good) and vertical (bad) components of force on the anchor.

All that said Maine, I'm surprised at this data. When I look down over the bow in a blow and the chain is bar tight, I'm getting even less sleep than before. And to argue against my hypothesis, I guess if it's bar tight, it's a straight line down to the anchor, so the angle is the angle no matter what the rode.

Maybe the real benefit is that in real life, it's not a straight even pull like a come-a-long. And as you swing back and forth, yanking on everything, the chain absorbs the shock before jerking the anchor out?


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## denverd0n (Jun 20, 2008)

Didn't read the article. Were they lifting the chain straight up? If so, I would think that the dynamics of a boat pulling on the chain would be different. I would expect it to take more effort to lift the last link when pulling at a 5:1 angle (11.5 degrees).


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## denverd0n (Jun 20, 2008)

capecodda said:


> What would be of interest is what that angle is.


Easy enough to figure out...










When a=1 and c=5 (a 5:1 scope), the angle at A is 11.5 degrees. Given that a link of 3/8" chain is about 1.75" long, that means that the last link would be lifted less than 3/8" off the bottom. At least, until the shank of the anchor also starts lifting.


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## Maine Sail (Jan 6, 2003)

denverd0n said:


> Easy enough to figure out...
> 
> 
> 
> ...


The important part is that this "lifting" starts at just 158 pounds at 5:1 with 5/16" chain, a very common size on 30-40 boats. On our boat, a 36 footer, we see peak loads of 218 pounds in 17-19 knots and the loads vary up and down between 140-218...... Get above 25 knots and these loads escalate, rather dramatically....

I have never believed, based on my own all-chain experience, that chain gave the caternary one desired when the winds get blowing or when you really need it...

I did not however believe the loads were so small as to when you began to affect shank angle. I find it rather shocking, and reassuring, that I have always believed in scope first before caternary, when you really need it most......

I think this, and the previous data conducted by PS, really points to longer scope and longer and more elastic snubbers...

We know from the previous data that the shock loads increase dramatically as scope is shortened.....


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## pdqaltair (Nov 14, 2008)

Note that the article was writen by a multihull sailor. There are several reasons why that happend:
* The lighter the boat, the more you feel the chain snap tight. Not that force is greater, but you are more aware of it.
* Multihulls commonly anchor in shallower water, because they can. Perhaps the only free spot in a crowded anchorage is thin. Perhaps there is cove no one else can enter. Either way, multihulls often have less chain out.
* Shallow water gets rough first; some cats have been lost because the owners forgot this. It doesn't matter if you have 2' draft, if the water is <10' it will start breaking fast. 
* Multihulls use a bridle/snubber EVERY TIME, even lunch breaks. Thus we tend to be rather obsesed about the best answer. It is also very reasonable for multihulls to use long bridles.
* We tend to like G43 chain to save weight. We have good anchors but would rather not get rediculous on weight as a solution.

The math is the same, I'm just saying the subject is more interesting to cat sailors. A 2' chop in 5 feet of water with only 50' of chain out gets pretty jerky. NO catenary. A 25-30 snubber really takes the sting out.

I too have started running bridle lines down the side decks when in an exposed anchorage; it allows for a long bridle in shallow water. Not always needed, but I often anchor in dubious holding ground and the less the ahchor is horsed around, the better.

Sail Delmarva: Long Bridles


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## GeorgeB (Dec 30, 2004)

Now I’m really confused. If it takes so little of a force to lift chain off the bottom, what is the advantage of chain over rope rode? I have a 34’ boat weighing 15,000# and was considering ¼ BBB coil all chain rode for the west coast of Mexico. Can I get by with a chain/rope combo and save the weight on my bow?


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## Faster (Sep 13, 2005)

GeorgeB said:


> Now I'm really confused. If it takes so little of a force to lift chain off the bottom, what is the advantage of chain over rope rode? I have a 34' boat weighing 15,000# and was considering ¼ BBB coil all chain rode for the west coast of Mexico. Can I get by with a chain/rope combo and save the weight on my bow?


Anchoring in the presence of coral can make short work of any rope rode... I think that alone would push me to all chain in those areas..


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## JimMcGee (Jun 23, 2005)

GeorgeB said:


> Now I'm really confused. If it takes so little of a force to lift chain off the bottom, what is the advantage of chain over rope rode? I have a 34' boat weighing 15,000# and was considering ¼ BBB coil all chain rode for the west coast of Mexico. Can I get by with a chain/rope combo and save the weight on my bow?





Faster said:


> Anchoring in the presence of coral can make short work of any rope rode... I think that alone would push me to all chain in those areas..


Point taken about the coral, but George raised an interesting point.

I have a 22lb Danforth and 20' of chain, the balance of my ground tackle is rope. If it takes so little force to raise the chain off the bottom, am I actually better off with this setup as the rope will act as a shock absorber in rough conditions?

ex. anchored in 10 feet + 3ft to the bow roller at 7:1 is 90 feet of rode out, 70 feet of which is rope. That's one long snubber.

My boat is a 30 footer rated at 10,300 lbs, probably over 11,000 fully loaded and all tanks topped off.


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## GeorgeB (Dec 30, 2004)

As far as I know, there are no coral reefs on the Pacific side of Mexico. Rocks yes, coral no. So if I don’t have coral and I do have 50-100’ feet of chain for chafe protection on rocks, then, by Maine Sail’s calculations, and 7:1 scope (and a Rocna or Manson anchor). I should be o.k. without the weight of all chain?


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## smurphny (Feb 20, 2009)

Maine Sail said:


> I think the bolded items will be the most beneficial. A kellet can help prevent sailing at anchor etc. but in a storm the only things that will reasonably work IMHO are:
> 
> *Buy the best performing anchor your money can buy (there are lots of great anchors out there today compared to just 10 years ago)
> 
> ...


Nice list! I'd add - oversize the anchor by a considerable margin. Don't go with minimum advertised weight for your boat.

The triangle example shows a right triangle which is actually 3-4-5 a 5:1 triangle with anchor line as the hypotenuse would look a lot different if trying to picture the chain and caternary. Using a 3-4-5 triangle, a 12' depth would only require a 20' anchor line. Showing a scaled graphic would accentuate the point that the actual lift at the end of the chain is quite small, not as if the anchor is being yanked out.


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## tdw (Oct 2, 2006)

I know this will sound somewhat flippant and it is typed with a smile on my face but how is that the Womboat doesn't simply drag all over the anchorage every time we drop anchor ? 

You are free to consider that question rhetorical.  but .... 

Seriously though. I take anchoring very very seriously indeed. Even dropping a lunch pick I take great care but even so in the three keel boats that I have spent the most time on the first had some fifty feet of chain plus rope on a Danforth, the second fifty metres of chain plus rope on a CQR and then later a Rocna while the third has ninety metres of chain plus rope on a Bruce.

Yes there have been plenty of times when we've had to re anchor after failure to set but once set we've very rarely had any problems and in almost every case of dragging it has coincided with my failure to deploy the snubber. 

Yes, I know, preaching to the converted but the efficacy of a snubber cannot be underrated.


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## Stumble (Feb 2, 2012)

Frankly I have never bought the heavier chain argument. The weight of chain just isn't enough to matter in heavy conditions. I have swapped to smaller chain but higher test, and a much larger anchor.

With anchors today generating multiples of their own weight in holding power, the best place to put that weight is in the anchor not the rhode. See Steve Dashew's 120lbs anchor on a 64' boat as an example.


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## mitiempo (Sep 19, 2008)

Stumble said:


> Frankly I have never bought the heavier chain argument. The weight of chain just isn't enough to matter in heavy conditions. I have swapped to smaller chain but higher test, and a much larger anchor.
> 
> With anchors today generating multiples of their own weight in holding power, the best place to put that weight is in the anchor not the rhode. See Steve Dashew's 120lbs anchor on a 64' boat as an example.


I agree. One theory is that catenary provided by the chain disappears when it is needed most - but that is a very small load in PS's test. Dashew agrees with this as does someone named Smith.


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## Minnewaska (Feb 21, 2010)

While I believe the data from this test and some good points have been made, I think it fails to continue up the curve.

The force necessary to lift the last link at the shank is one thing and very telling. However, keep going. What is the comparable force to full straighten a rope rode vs. 5/16 chain? 

To further make this point, if 7:1 all rope rode will theoretically hold, what force is necessary to get 5:1 chain to pull to this same angle? I think that would reveal the value of chain.


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## Maine Sail (Jan 6, 2003)

Minnewaska said:


> While I believe the data from this test and some good points have been made, I think it fails to continue up the curve.
> 
> The force necessary to lift the last link at the shank is one thing and very telling. However, keep going. What is the comparable force to full straighten a rope rode vs. 5/16 chain?
> 
> To further make this point, if 7:1 all rope rode will theoretically hold, what force is necessary to get 5:1 chain to pull to this same angle? I think that would reveal the value of chain.


This was approx 30 knots at low tide with very, very heavy mooring chain, IIRC 3/4" long link mooring chain. This chain weighs 5.3 pounds per foot, the mooring ball and swivel & shackles weighs another 20-25 pounds.......










This anchor roller was folded like a pretzel by the shock loading of an all chain rode. The owner lost power on a lee shore and did not have time to deploy his snubber. He no longer uses 2 micron primary fuel filters...









Yes it takes lots of strength to fully straighten chain or attain infinite scope but to change shank angle, or to impart shock loading, that certainly can and does happen.,

I always liked this photo by Peter Smith:

_"*What catenary?* Anchored in 50-60 knots wind at Deception Island, Antarctica - even in 8 m depth, this 12 mm chain at 6:1 scope is nearly bar-tight and any apparent benefit from catenary to the Rocna anchor at the end of the rode has long since disappeared."_









Typical anchor chain has numerous benefits, but providing adequate caternary, in storm conditions, is not one of them....

I suppose if you want to use chain like this then you would have some caternary, but most sailors don't want to anchor with this stuff. Hell most mooring owners would balk at the per-ft price on this stuff... I use 30 feet of this stuff on my "everyday" mooring. My storm mooring uses significantly larger bottom chain with the bar across the link. Still, in a hurricane or bad Nor' Easter, there will be little to no caternary even on my storm mooring....


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## denverd0n (Jun 20, 2008)

smurphny said:


> The triangle example shows a right triangle which is actually 3-4-5... Showing a scaled graphic would accentuate the point...


True, but that was the only picture that I could find easily to illustrate the calculations I was doing. I calculated the angle at A based on a 5:1 ratio. That is, a triangle where length of "a" would be 1, "c" would be 5, and "b" would be 4.9. That angle, when the chain is straightened out, would be 11.5 degrees.

Of course there will be some catenary, so in reality the angle at A would be somewhat less. Still, the point remains that the angle at A, even at "only" a 5:1 ratio, is pretty small.


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## Maine Sail (Jan 6, 2003)

I did this a while ago to attempt to illustrate what scope looks like. It was done to scale using the shank length of my CQR as the shank in the illustration....

*Anchor Scope Illustrated*


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## smurphny (Feb 20, 2009)

denverd0n said:


> True, but that was the only picture that I could find easily to illustrate the calculations I was doing. I calculated the angle at A based on a 5:1 ratio. That is, a triangle where length of "a" would be 1, "c" would be 5, and "b" would be 4.9. That angle, when the chain is straightened out, would be 11.5 degrees.
> 
> Of course there will be some catenary, so in reality the angle at A would be somewhat less. Still, the point remains that the angle at A, even at "only" a 5:1 ratio, is pretty small.


I just thought your valid point needed a better illustration to clarify. Mainsail's link shows it well. The real crux is the design of the anchor as it pertains to angle of the flukes to ground. If the scope with 0 caternary reaches the upper limit of the anchor's ability to keep digging, then the anchor starts to detach the flukes from their design angle but this angle would be very large. Danforth and Fortress type anchors have the pivot point to make angle of rode even more secondary once the flukes are digging in. I know my Danforth can get REALLY buried over time, more so than my CQR or Bruce. With a straight pull on a 5:1 scope, a good anchor should bury deeper even if the chain is not dragging along the bottom. The actual "caternary effect" may be next to 0 as Mainesail is saying. I guess the real question is at what angle does an anchor begin to stop digging in and rise out of the bottom.


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## Minnewaska (Feb 21, 2010)

I get the impact of a gale and 4 ft seas in the anchorage. However, the impact of wind on rope v chain over the entire scale, not just when the first link is lifted, is going to be more applicable for the everyday cruiser in sheltered anchorages.

Without looking above, i think it was shown it takes 19 knots of wind to lift the first link of chain. However, the rope would be pulled taut by then. That must be two different angles on the shank for identical conditions.


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## Omatako (Sep 14, 2003)

It's hard to argue with reputable test results but common sense appears to be my problem.

So the fact that the test showed that 190 lbs of pull will lift the chain to it's end should come as no surprise - after all, 100 feet of 8mm chain only weighs about 120 lbs.

In my case I use 10mm chain which weighs about 156 lbs so on a direct extrapolation my boat would have to impose a pull of about 270lbs before the end of the chain begins to lift.

What I don't know is what windspeed it takes for my boat to impose a 270lb pull on the chain. Neither do I care.

What I do know is that on a 7 to 1 scope, I have more than once sat through 45 knots without a drag of the anchor. But it was not a lee shore so there were no waves.

What I also know is that boats around the world have anchored millions of times using the above chains with scopes of 5-1 and 7-1 without dragging - they didn't know about this test. Up to now neither did I.

Will it change the way I anchor or my ground tackle? Not a chance. And I will continue to find places to anchor in places where the waves are not 3 feet and the wind speed is less than it takes to lift my anchor out of the ground.


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## mitiempo (Sep 19, 2008)

What I understand from this (and I have had this opinion for quite a while) is that for a given boat/anchoring system the weight is much more effective in the anchor than the rode. As long as there is enough strength in the chain extra weight means nothing. While the chain is needed in many locations for abrasion resistance the anchor weight is more important.

Some (Steve Dashew for one) use grade 70 chain coupled with a custom Rocna anchor. Their current Rocna is 250 lbs on a lean 83' powerboat named Windhorse. A Sundeer 64 weathered a hurricane in Grenada a few years ago without dragging while lying to a 176 lb Bruce anchor. Steve regularly anchors with short scope - 2.5 to 1, often less and hasn't dragged. Here is a link to a blog article by Steve on anchor sizing. SetSail» Blog Archive » More on Anchors and Sizing

My current setup is (for a 27' CS) 80' of 5/16" grade 30 plus rope and a 25lb CQR, which will be changed to a 33lb Rocna. I would use lighter chain but already have the 5/16. Were I to replace the chain it would be to 1/4" G40, and maybe reduce its length to 40' or 50'. I do not have a windlass.


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## mitiempo (Sep 19, 2008)

Forgot to add this.

Here is a list of anchors used by Steve over the years:

Intermezzo (50' ketch)...........100 lbs
Intermezzo II (62' cutter).......150 lbs
Sundeer (67' ketch)...............180 lbs
Beowulf (78' ketch)................225 lbs
Windhorse (83' unsailboat).......250 lbs

To quote Steve "when people start to laugh at the size of your anchor you're off to a good start"


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## blt2ski (May 5, 2005)

There was an article in Pacific Yachting based in Vancouver BC a year or so ago. It showed that an all chain rode in shallower water was not as good as a combo chain/line rode! As shown, a 5-1 chain will lift such that the anchor will pull out, meanwhile a line roade at 7 or even 10-1 will still pull straight. 

Where an ALL chain rode did seem to help, was deeper anchorages at lower scopes. Here the chain wt would help. Otherwise, the article pretty much showed that an all chain setup was not as good as a chain/line setup. Anchors were the same size in this test/article!

Marty


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## mitiempo (Sep 19, 2008)

Marty, I read that article as well. Basic conclusion was that when catenary is needed the most, as in a strong blow, it didn't exist as whatever rode is used it is bar tight.


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## casioqv (Jun 15, 2009)

mitiempo said:


> To quote Steve "when people start to laugh at the size of your anchor you're off to a good start"


great quote!


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## smurphny (Feb 20, 2009)

What seems to be missing from the discussion is the fact that there is a widely variable amount of pull. Wave action, gusts, calms, the boat sailing at anchor: all these make the stress go from 0 to X pounds of pull. There is never a steady load on the anchor system. That's where the use of some sort of shock absorber in the line from boat to anchor raises a whole new set of parameters. Don't underestimate the pounds of stress a 35-40' boat can exert when swinging in a 30 knot wind. Nigel Calder's _Cruising Handbook_ has a good chart of anchor stresses that shows 5/16" chain to be VERY marginal for this range of boats. I highly recommend that book.

Aside from the coral abrasion issue, there is a lot to be said for a rope/chain rode. Not only that but it is MUCH easier to "feel" the anchor set when using rope/chain. With all chain it is almost impossible to feel the anchor grabbing and work it in by hand because the chain wants to go straight down and create so much caternary that there is little indication on the boat end as to what the anchor is actually doing.

Last year I went to mostly all chain (120' of 3/8" G4) which doesn't get to the rope in most anchorages but I'm seriously considering shortening that again to maybe 40' of chain as I had before. It would eliminate the pita of having to deal with a snubber contraption and make it a lot easier on the hands (no windlass).


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## pdqaltair (Nov 14, 2008)

smurphny said:


> ... it is MUCH easier to "feel" the anchor set when using rope/chain. With all chain it is almost impossible to feel the anchor grabbing and work it in by hand because the chain wants to go straight down and create so much caternary that there is little indication on the boat end as to what the anchor is actually doing....


This is a good point that is seldom stated. When I switched from line to chain I felt I had gone blind. I could no longer "see" the bottom material through the line. At the same time I had switched from a Fortress to a "new" anchor and understood why folks where so wild about it; it was less necessary to feel it in. In shallow water and tight anchorages (common for cats) we like to "feel" the initial set. In deeper water this difference is probably noticeable.

No obvious solution, since most of us chose chain for abrasion resistance and ease on the windlass.


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## blt2ski (May 5, 2005)

mitiempo said:


> Marty, I read that article as well. Basic conclusion was that when catenary is needed the most, as in a strong blow, it didn't exist as whatever rode is used it is bar tight.


That was the other thing in the article, was in 60 mph plus winds, an all chain was pulling straight from teh bow of the boat to the anchor, and as such, the angle of pull was greater than a 10-1 with partial chain and rope rode. So the angle the anchor was getting pulled on was less, hence better. If one did chain at 10-1, it might be a bit better than rope, but reality, either would be pulled straight! The rope having some give/stretch was the better option.

Marty


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## mitiempo (Sep 19, 2008)

blt2ski said:


> That was the other thing in the article, was in 60 mph plus winds, an all chain was pulling straight from teh bow of the boat to the anchor, and as such, the angle of pull was greater than a 10-1 with partial chain and rope rode. So the angle the anchor was getting pulled on was less, hence better. If one did chain at 10-1, it might be a bit better than rope, but reality, either would be pulled straight! The rope having some give/stretch was the better option.
> 
> Marty


But the results of the PS testing show that it takes considerably less than 60 mph to straighten the chain and lift the last link off the bottom at 5-1 - 15 knots. With that proven even at 10-1 the last link should be off the bottom well before 60. And who really has swinging room for 10-1 anyway?


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## Don L (Aug 8, 2008)

What am I suppose to do with this new knowledge of how little pull it takes to lift the chain?

I was feeling safe and happy before, am I suppose to be scared to anchor now?


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## Maine Sail (Jan 6, 2003)

Don0190 said:


> What am I suppose to do with this new knowledge of how little pull it takes to lift the chain?
> 
> I was feeling safe and happy before, am I suppose to be scared to anchor now?


Just use more scope when it gets snotty. 5:1 can be adequate under many conditions, with many anchors, but some really need a shallower shank angle to continue to hold...

I think this data only serves to confirm what Peter Smith has been saying for years, put the weight in the anchor, not the chain....

The less scope you have the easier it is to lift the rode and minimize or nearly eliminate caternary...... The less scope you have the easier it is to shock load deck fittings. The less scope you have means the more elastic your snubber needs to be...


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## Bene505 (Jul 31, 2008)

IMHO, one easy way to think of chain catenary is this: When you need it, it won't be there. With enough wind, the angle of pull on the anchor will be the same for chain and rope.










If you are concerned, then anchor with enough scope (chain or rope) so the "lifted shank angle" is still significantly less than the shank-to-fluke angle. That way the flukes aren't getting torqued out of the bottom sand or mud.

Where we anchor in 10 feet of water (roller is 5' over the water, sand bottom), I really like 115 feet of chain on one anchor (60 lb Manson Supreme), 75 feet of rope & 30 feet of chain on the second anchor (40 lb Bruce), snubber on the chain, and a riding sail to keep the boat from tacking (5 degrees versus 120 degrees). Winds have hit 70 mph in a passing storm. I use the second anchor if we are going to be away from the boat for awhile. The Manson is set at 1,500 rpm for 10 minutes. (We previously used a 60 lb CQR. 1,200 rpm would set it, but 1,300 rpm would break it out every time.)

The one time this past summer when the Manson didn't set, having all-chain and an electric windlass meant it took less than 10 minutes to easily raise the anchor, motor forward, and try again. When soloing, it also means I don't have to leave the helm after departure, to coil the rope back into the anchor locker.

Regards,
Brad


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## SVAuspicious (Oct 31, 2006)

Maine Sail said:


> I think this data only serves to confirm what Peter Smith has been saying for years, put the weight in the anchor, not the chain....


Agreed. It also supports Alain Fraysse's point that kellets don't help in heavy air, only in light air.


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## lancelot9898 (Dec 30, 2008)

While there is no doubt that a static analysis will show that there is little difference between an all chain rode vs all line rode under higher wind conditons, I question the conclusions under dynamic loading. For example, the boat will "hunt" and even with a rather mild 150 pound pull from an all chain rode, that will cause the boat to move toward the anchor until the next wind gust hits. Does this help or hurt the loading assuming that an adequate snubber is involved?


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## Minnewaska (Feb 21, 2010)

mitiempo said:


> ......And who really has swinging room for 10-1 anyway?


If we know it's going to blow, we will anchor further out so we have the room. We sleep at anchor almost every weekend. Love it. We have 200ft of 1/2" chain and usually find a 15' anchorage with 5' of freeboard and drop it all, if wind is going to be above 15kts. That's our rule of thumb. I have no problem taking a longer dinghy ride.

Anything under 10 kts and I practically don't even have to set the hook. Just lying chain on the sea floor and we swing around the catenary, not the anchor. I've seen on the iPad anchor alarm that we've swung 180 degrees and have not even dragged the catenary back to the anchor itself. Really interesting to see. All should get one of these to really understand what's happening down there.

We sat outside of Menemsha this past summer, where you do not want to be in anything from the West through any Northern sector. It was forecast to be SW at 15 overnight. Naturally, it swings to the NW and picks up to 20kts, which pushes 2 to 3 ft seas into the anchorage. We had all the chain out and never moved an inch on our POS CQR. More scope or no stop.


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## SVAuspicious (Oct 31, 2006)

Minnewaska said:


> Just lying chain on the sea floor and we swing around the catenary, not the anchor.


Vocabulary is important. Catenary doesn't have anything to do with what you describe. Catenary is the sag due to weight in a structural element under tension. What you are describing is a combination of the weight of chain and friction of the chain on the bottom.

What you have experienced absolutely happens in light air, with "light air" depending on the weight of the chain, length of the chain, weight of the boat, and windage. This is the scenario where a kellet will actually provide some value.


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## pdqaltair (Nov 14, 2008)

We seem to be all over and around the point here.

We are only discussing one senerio: when dragging is due to wind strong enough and consistent enough that all of the chain is well of the seabed. Testing demonstrated that this starts at ~ 15-20 knots and by the time it's blowing hard (>40kn) the chain has effectively no centenary to absorb shock. Thus, we need enough scope and an effective snubber.

The reason for making the point is that this dragging senario is particularly bad in that it is often...
* too strong for us to make any changes,
* re-anchor or move,
* if we hit shore we may loose the boat, and 
* sudden. One minute the chain was helping, the next it is not.
It is also bad because most of us don't experience it often and thus don't get to practice. Practice is high-stakes.

Strategies that have worked for many years in lighter airs and in protected spots fail. They means NOTHING regarding success in stronger winds, since the rules change. The angle of the shank is up and shock absorption fails, both at the same time and with little warning. This is the point.

If you are dragging due to tide shift or in lighter winds, there are more serious problems. Lotsa chain isolates us from basic unsound anchoring practices, since it will sink in the mud and that helps. There local places I go that have terrible holding but work find if I use a lot of chain. But I know that chain means nothing when it blows hard... I will be off and drifting, so I make other plans if wind is expected.


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## mitiempo (Sep 19, 2008)

In this area (west coast of B.C.) we cannot rely on shallow depths in most cases and rarely have the room for 10-1 scope. Many bays are small, crowded or both. Often there is 15' or 20' of depth close in where there is not much swinging room, move out and the depth is very quickly over 100'. 

To quote Steve Dashew regarding anchoring in B.C.'s Desolation Sound 

"...surrounded by a lot of 40' to 50' yachts. Water is 55' deep at half tide.We set the big Rocna at 2.5 to 1 scope and then with a firm bite shorten scope to 1.6 to 1 scope. If you calculate the angle off the bottom, combine the chain length with Wind Horse's length, we need about 150' of swinging room. Compare this to a 40' yacht anchored with a normal sized anchor. They will need at least 4-1 and probably 5-1 scope. Take their length and add to it 240' of chain, allow for angles and you have a radius of at least 220' at a minimum. The smaller boat with its undersized (by our standards) anchor takes a lot more room than the bigger boat with its oversized anchor. Is there a lesson here? Not only does it work in crowded anchorages, but it benefits you in secluded spots which might otherwise be too tight with a normal anchor. The anchor, regardless of design, will set faster, being bigger. This means it drags less before it digs in. This reduces the risk of fouling debris."

From another Dashew post: How big should the anchor be?
Yachts in the 30'-40' range - 60lbs
Yachts in the 40'-50' range - 80lbs


A large bay with 10 - 15' depth and lots of swinging room - I wish! I think from this and the PS test anchor weight is everything. Forget the catenary that will quickly disappear in a blow and keep the rode - whether all chain or a combination of chain and rope - light as long as it has adequate strength. This is probably most important for those without a windlass as they (me as well) have to limit the overall weight to something manageable. With a windlass an all chain rode and an oversized anchor is not as much of an issue.

Steve Dashew is very concerned with overall weight and its effect on performance, whether sail or power. His chain has been Grade 70 for many years.


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## Don L (Aug 8, 2008)

Maine Sail said:


> Just use more scope when it gets snotty. 5:1 can be adequate under many conditions, with many anchors, but some really need a shallower shank angle to continue to hold...
> 
> I think this data only serves to confirm what Peter Smith has been saying for years, put the weight in the anchor, not the chain....
> 
> The less scope you have the easier it is to lift the rode and minimize or nearly eliminate caternary...... The less scope you have the easier it is to shock load deck fittings. The less scope you have means the more elastic your snubber needs to be...


Well yes, but we knew (at least most of should have) this already.

All that we really have learned with this "new" info is that the bad habits we have talked ourselves into because we were on all chain are just excuses to not follow the old rules of anchoring.


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## Minnewaska (Feb 21, 2010)

SVAuspicious said:


> Vocabulary is important. Catenary doesn't have anything to do with what you describe. .......


Then look it up in Webster. 

A catenary is not only a dip in a line but also something in the form of a catenary. I was referring to the latter and you clearly understood what I meant.


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## SVAuspicious (Oct 31, 2006)

Minnewaska said:


> Then look it up in Webster.
> 
> A catenary is not only a dip in a line but also something in the form of a catenary. I was referring to the latter and you clearly understood what I meant.


Sorry - that I figured out what you meant when you misused a word doesn't mean your usage is okay. That simply isn't what a catenary means, particularly in a discussion relating to structural strength. Vocabulary IS important. Language is all we have to communicate with and if we don't use it properly we don't communicate effectively.

What (I think) you were describing is a valid and applicable factor in where a boat lies at anchor in light air. The word you used is not appropriate.

A catenary is:


> the curve assumed approximately by a heavy uniform cord or chain hanging freely from two points not in the same vertical line. Equation: y = k cos h ( x / k ).


The four dictionaries I checked concur. I did not find any definition that uses the terminology "similar."

Of course dictionaries do track common usage no matter how misleading. I'm still wound up over considering 'presently' and 'currently' as synonyms so maybe it's just me.


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## Minnewaska (Feb 21, 2010)

SVAuspicious said:


> Sorry - that I figured out what you meant when you misused a word doesn't mean your usage is okay. That simply isn't what a catenary means, particularly in a discussion relating to structural strength. Vocabulary IS important. Language is all we have to communicate with and if we don't use it properly we don't communicate effectively.
> 
> What (I think) you were describing is a valid and applicable factor in where a boat lies at anchor in light air. The word you used is not appropriate.
> 
> ...


Come on professor. Looking this up took 5 seconds. Note 2.



> Definition of CATENARY
> 
> 1: the curve assumed by a cord of uniform density and cross section that is perfectly flexible but not capable of being stretched and that hangs freely from two fixed points
> 
> ...


Catenary - Definition and More from the Free Merriam-Webster Dictionary


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## SVAuspicious (Oct 31, 2006)

Minnewaska said:


> 2: something in the form of a catenary


What you describe is most assuredly not in the form of a catenary beyond third order issues. Catenary is simply not relevant to what you describe and insisting on an inappropriate word simply takes away from what is otherwise a a valid point about the behavior of ground tackle in light air.

Clearly you don't like that. Fine. I won't belabor the point any further.


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## SkywalkerII (Feb 20, 2008)

I can't find the reference right now, but Rod Stephens of S&S is on record discouraging the use of a chain rode. If I recall, he believed chain stresses fittings and does not add to holding strength. 

Hard to argue with Rod or his brother!

Skywalker


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## mitiempo (Sep 19, 2008)

SkywalkerII said:


> I can't find the reference right now, but Rod Stephens of S&S is on record discouraging the use of a chain rode. If I recall, he believed chain stresses fittings and does not add to holding strength.
> 
> Hard to argue with Rod or his brother!
> 
> Skywalker


Hence the need for a snubber.


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## jrd22 (Nov 14, 2000)

I think what is missing in this discussion about all chain or chain/rope is that the lighter chain/rope will be a straight line to the anchor, and therefore starting to lift the shank, in much less wind than the all chain. If it takes 160 lbs of force to lift the chain in PS's test it would take a small fraction of that to lift a length of nylon line and 30-40' of chain. So it would seem to follow that the same dynamics on the anchor would happen sooner (much lower wind speeds) than with all chain. Increasing the scope would lower the angle of pull somewhat but would not add weight (catenary) at all compared to all chain. No argument that when the wind speed increases to the point where the chain is bar tight there will be no catenary, but 300' of 3/8" chain is going to keep the pull on the anchor horizontal at much higher wind speeds than an equivalent length of nylon line. So I would assume that the same anchor wouldn't start dragging until the wind maintained enough force to lift the chain. 
We use a 66 lb Bruce with 300' of 3/8" BBB as our main anchor on a 40' 24,000lb boat.


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## Bene505 (Jul 31, 2008)

jrd22 said:


> I think what is missing in this discussion about all chain or chain/rope is that the lighter chain/rope will be a straight line to the anchor, and therefore starting to lift the shank, in much less wind than the all chain. If it takes 160 lbs of force to lift the chain in PS's test it would take a small fraction of that to lift a length of nylon line and 30-40' of chain. So it would seem to follow that the same dynamics on the anchor would happen sooner (much lower wind speeds) than with all chain. Increasing the scope would lower the angle of pull somewhat but would not add weight (catenary) at all compared to all chain. No argument that when the wind speed increases to the point where the chain is bar tight there will be no catenary, but 300' of 3/8" chain is going to keep the pull on the anchor horizontal at much higher wind speeds than an equivalent length of nylon line. So I would assume that the same anchor wouldn't start dragging until the wind maintained enough force to lift the chain.


Yes, but it's a bit like having breaks on your car that work on flat terrain but suddenly fail on hills. The false sense of security outweighs any real benefit.



> We use a 66 lb Bruce with 300' of 3/8" BBB as our main anchor on a 40' 24,000lb boat.


Nice.

Regards,
Brad


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## mitiempo (Sep 19, 2008)

"We use a 66lb Bruce with 300' of 3/8" BBB chain."


3/8" BBB chain weighs 1.65 lbs per foot, working load 2750 lbs, coupled with a 66 lb anchor. In lighter breezes there isn't a problem, but when it really blows any catenary disappears and you do or do not drag based on the 66lb anchor alone. If you were to use either a lighter chain or a chain/rope rode with a heavier anchor when it blows you would be relying on a heavier anchor that will not only hold better without the lost catenary but would set better and faster all the time.

G43 chain has a working load of 3900 lbs and weighs just over 1 lb per foot. 300 ft of 5/16" is 198 lbs lighter than 3/8" BBB of the same length. One could use an anchor 50 lbs heavier and still save 148 lbs overall, and have a working load that is 40% larger. Would set faster and give much better holding when that catenary has disappeared due to wind strength. 5/16" G43 is about a dollar less expensive per foot than 3/8" BBB as well for a dollar saving as well based on Jamestown Distributors on line price. 

Were one to really get carried away G70 chain of 1/4" size weighs .66 lbs per foot for a chain weight savings of 300 lbs but still has a working load of 3150 lbs, 400 lbs more than the BBB in use currently. Then the size of the anchor can be whatever is desired and there is an even larger total weight savings. 

The larger the anchor for a given boat size/displacement the shorter the scope can be if it is necessary in tight places that do not have the swinging room necessary for a 5-1 or larger scope. Of course on a normal basis scope can be 5-1, 7-1 or 10-1 if desired.


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## Minnewaska (Feb 21, 2010)

Bene505 said:


> Yes, but it's a bit like having breaks on your car that work on flat terrain but suddenly fail on hills. The false sense of security outweighs any real benefit.......


I'm having a hard time seeing it this way. A better analogy would be that all chain is like having superior brakes in 95% of circumstances one drives in.

Put a snubber on chain and use the same scope as rode and you have the other 5% covered too.


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## MastUndSchotbruch (Nov 26, 2010)

mitiempo said:


> "We use a 66lb Bruce with 300' of 3/8" BBB chain."
> 
> 3/8" BBB chain weighs 1.65 lbs per foot, working load 2750 lbs, coupled with a 66 lb anchor. In lighter breezes there isn't a problem, but when it really blows any catenary disappears and you do or do not drag based on the 66lb anchor alone. If you were to use either a lighter chain or a chain/rope rode with a heavier anchor when it blows you would be relying on a heavier anchor that will not only hold better without the lost catenary but would set better and faster all the time.
> 
> ...


What about corrosion resistance? If you lose 1/8" to rust, it would be a much bigger deal on a 1/4" chain than on a 3/8" chain.

Are there data on this for the different chain grades? (honest question, I don't know the answer)


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## Stumble (Feb 2, 2012)

MastUndSchotbruch said:


> What about corrosion resistance? If you lose 1/8" to rust, it would be a much bigger deal on a 1/4" chain than on a 3/8" chain.
> 
> Are there data on this for the different chain grades? (honest question, I don't know the answer)


I have never seen significant enough rust to feel it was endangering the chain itself. Because of its nature the working limit of chain is much higher than the max load of it. The normal failure mode is for one of the links to stretch slightly (plastic deformation) which is an indicator that the entire length has been over stressed and needs to be replaced.


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## mitiempo (Sep 19, 2008)

Here is a link to a great article on chain strength, galvanizing, and re-galvanizing - which is not recommended.

Facts About Anchor Chain Strength and Grades

It is from MorgansCloud


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## Don L (Aug 8, 2008)

Anyone ever seen a rating from an anchor manufacturer saying what scope their anchor was designed for?


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## jrd22 (Nov 14, 2000)

I think Minne's example of having better brakes 95% of the time is spot on. If you have an oversized anchor and all chain then you have the advantage of the catenary in all situations except when there is enough pull to have all the chain completely straight. In the PS test the values given were only to raise the last link off the bottom, which still gives a horizontal pull on the shank of the anchor and a good deal of catenary. The pull needed to make 300' of chain bar tight would be significantly higher than to just raise the chain off the bottom. Nylon line on the other hand would be a straight line (pulling the anchor upwards) in a light breeze.


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## Bene505 (Jul 31, 2008)

The "bad breaks on a car" anology is for chain with little scope. You think it's great until you find out your anchor is getting lifted up and pulled out, in the exact (strong) wind that eliminates your catenary.

Ample scope cures a lot of ills.

Regards,
Brad


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## PCP (Dec 1, 2004)

I don't know about you guys but none of the boats I had (light boats) stayed quiet at anchor on strong wind. Both tended to sail forward on one side than another (and backwards in the middle) using as sail the lazy bag. That diminished the pull on the anchor but made the boats move a lot (forward/Backwards and laterally).

I always used on strong winds two big rubber shock dampeners but I think that the 70 meters of heavy chain play an important role in making this movement a soft rocking one. I don't think that should be soft or agreeable with a textile line instead of chain and I believe that the anchor would be subjected to a lot more violent pulling.


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## mitiempo (Sep 19, 2008)

A riding sail set on the backstay is effective to eliminate sailing at anchor. Need not be very large.


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## blt2ski (May 5, 2005)

The riding sail is probably a good thing to a swag of 30-40 knots, after that, it might very well propel the blinking boat forward at a reasonably significant speed per say. Under this amount it might work to calm the ride per say....... this is a guess on my part too!

If I was in 50-60+ knot winds, I would swag as noted by many, that more scope, BIG anchor etc is best.

Marty


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## Stumble (Feb 2, 2012)

This whole issue is one that has gotten some conversation on another forum, and I still stick by the fundamental premise I came to there which is that. "Pound for pound, additional weight in the anchor increases holding power faster than weight in the chain." Assuming this premise is true, and there is a lot of justification to believe that it is, then best practice would be to move as much weight from the chain to the anchor as possible. 

In reality most cruisers carry anchoring systems that were designed decades ago when electric windlasses were expensive and very rare. With modern handling equipment the small anchor + lots of chain model, is incredibly inefficient requires carrying a huge amount of excess weight and provides minimal holding power. All in all this system is really due for a rethink.

Modern anchors generally create 40lbs of holding power or more for every pound of dead weight they have. While chain generates about 1lbs of holding power for every pound of weight. This massive difference is because modern anchors are incredibly efficient at converting their weight into holding power, while chain really adds nothing but dead weight. 

So when we consider the 'average' anchoring system on a 40' cruiser what do we find? Typically a 60lbs primary anchor and 300' of 3/8BBB chain weighing in at 1.7lbs/foot. Then a secondary anchor of a slightly smaller size and the same amount of chain used to increase holding power in storms. A perfectly reasonable and reliable system... Until you consider that when it's all added up this system comes out to 1,070lbs of chain and 120lbs of anchor. Even while we know that anchor weight is much more important that chain weight. 

Instead of this, my recommendation is to 
1) get rid of the second anchor entirely, saving over 500lbs in weight alone
2) switch from 3/8BBB to 1/4 Grade 70 chain which will save 290lbs
3) Get rid of the 60lbs anchor and get a 120lbs one

All in all this saves 725lbs of weight from the bow of the boat, puts the weight where it matters the most, and puts an anchor on the boat that will hold thru anything. Heck it's heavy enough that it could work as a deadweight anchor in calm conditions. The only trick to this is that it pretty much requires an electric windlass, without one you would need to stick with a traditional system. But amazingly enough not a huge windlass, the Lewmar 1000 would easily handle this system. 

Evan assuming you wanted to keep a completely separate anchor for some reason, switching to 1/4 G70 chain alone would save enough weight that you could switch to twin 120lbs anchors and still save weight. 


Just as a btw, Steve Dashew on Windhorse (a 78' powerboat uses a 120lbs Ronca on 3/8 G70 chain).


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## mitiempo (Sep 19, 2008)

Stumble said:


> This whole issue is one that has gotten some conversation on another forum, and I still stick by the fundamental premise I came to there which is that. "Pound for pound, additional weight in the anchor increases holding power faster than weight in the chain." Assuming this premise is true, and there is a lot of justification to believe that it is, then best practice would be to move as much weight from the chain to the anchor as possible.
> 
> In reality most cruisers carry anchoring systems that were designed decades ago when electric windlasses were expensive and very rare. With modern handling equipment the small anchor + lots of chain model, is incredibly inefficient requires carrying a huge amount of excess weight and provides minimal holding power. All in all this system is really due for a rethink.
> 
> ...


I agree with everything you posted except that Steve's main anchor on Windhorse was a custom 250 lb Rocna. "Was" because Windhorse was sold and he is working on a 97' powerboat currently. His ideas are worth listening to because he has more "real world experience" than anyone on this or any other forum.

Most boats out there above 40' or even smaller have a windlass in any case and all that is required is changing the gypsy to fit the lighter stronger chain.


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## jrd22 (Nov 14, 2000)

I'd love to see a picture of that 40 footer with two 120 lb hooks hanging on the (hopefully heavily modified) bow roller )


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## mitiempo (Sep 19, 2008)

jrd22 said:


> I'd love to see a picture of that 40 footer with two 120 lb hooks hanging on the (hopefully heavily modified) bow roller )


He posted " get rid of the second anchor". As far as looks, remember the quote "when others start laughing at the size of your anchor you are getting close".


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## Stumble (Feb 2, 2012)

mitiempo said:


> I agree with everything you posted except that Steve's main anchor on Windhorse was a custom 250 lb Rocna. "Was" because Windhorse was sold and he is working on a 97' powerboat currently. His ideas are worth listening to because he has more "real world experience" than anyone on this or any other forum.
> 
> Most boats out there above 40' or even smaller have a windlass in any case and all that is required is changing the gypsy to fit the lighter stronger chain.


WOOPS, good catch, thanks. I am leaving as is for posterities sake.


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## Classic30 (Aug 29, 2007)

jrd22 said:


> I think what is missing in this discussion about all chain or chain/rope is that the lighter chain/rope will be a straight line to the anchor, and therefore starting to lift the shank, in much less wind than the all chain.


Late to this party, but I think what's missing in this discussion is that the moment you back down hard on the anchor to set it, you've got *all *the chain off the bottom and are lifting the shank already.

All this "new research" seems to indicate to me is that with all-rope rode or with little scope, the anchor *might* break out at lower wind forces than might have otherwise been assumed due to the shank starting to lift earlier than expected.. but again, if the anchor is breaking out because the shank is starting to lift, then maybe it wasn't set (backed down on) properly in the first place?


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## Bene505 (Jul 31, 2008)

Stumble said:


> ...The only trick to this is that it pretty much requires an electric windlass, without one you would need to stick with a traditional system.


Love your post and have a question...

If the system weighs less, why would it require an electric windlass more than the traditional (heavy chain) system?

You are lifting less chain weight as it hangs off the roller and down to the bottom, which makes up for the heavier anchor, unless you are in shallow water.

Regards,
Brad


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## Stumble (Feb 2, 2012)

Bene505 said:


> Love your post and have a question...
> 
> If the system weighs less, why would it require an electric windlass more than the traditional (heavy chain) system?
> 
> ...


Huge anchors quickly outstrip the ability of someone to lift without assistance. Most of us can manhandle a 60lbs anchor into a roller if we had to, not many of us can lift a 120lbs anchor without significant mechanical advantage.


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## jrd22 (Nov 14, 2000)

Stumble said:


> Evan assuming you wanted to keep a completely separate anchor for some reason, switching to 1/4 G70 chain alone would save enough weight that you could switch to twin 120lbs anchors and still save weight.
> .


Like I said, I'd like to see a pic


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## mitiempo (Sep 19, 2008)

jrd22 said:


> Like I said, I'd like to see a pic


I think he was making a point about weight more than anything else. I would put the second anchor down below, in the bilge ideally.

However a friend owns a Maple Leaf 50. The bow can be seen here http://snow-goose.net/images/001_MikeonthePulpit.jpg 
Click on the pic for a larger image.

You will note there are 3 bow rollers, all substantial. Only 2 anchors are shown in this pic. There are now 3, the main one a large Rocna, not sure of the weight. Note also 2 windlasses - she was previously owned by a retired United Airlines pilot who believed in redundancy. Even with 3 anchors in place, more weight than I would want up there, it looks fine - people who see her only laugh a little.


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## Don L (Aug 8, 2008)

mitiempo said:


> I think he was making a point about weight more than anything else. I would put the second anchor down below, in the bilge ideally.


For the anchors you are talking about that would be a pretty big bilge (I couldn't put my 60# anchor into my bilge).

Gong to be a lot of pain and damage getting it down there and back out.


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## Minnewaska (Feb 21, 2010)

I think I will keep my chain. Granted, one must have a windlass and, should it break, that's a downside.

While unrelated to the OP, it eliminates concern over chafe and I don't have to scratch my head over the splice/thimble and whether it's going to hold either.

Scope is clearly your friend, so in anything over 15 kts, it all goes out. At least the same as one would use for rode. I always hand tie 3/4" 3-strand as a snubber in these conditions. 

However, 90% of the time, the winds die at night and the chain is clearly superior. Even at 10 kts, the chain is just lying on the bottom and it's very unlikely that one would drag, even if not set deep. If I swing around, its probably not going to drag the chain itself fully around, let alone require the anchor to reset itself. The rope rode is taught at 10 kts, so the set better be pretty good and better be able to reset itself, while your sleeping.

If I was cruising full time, I would have a big honking next-gen anchor and 300 ft of chain.


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## eherlihy (Jan 2, 2007)

I posted on what I use for ground tackle, including the rode, a while back. Some of you may have seen it, some may not care to, so here is a link instead of the whole post. http://www.sailnet.com/forums/gear-maintenance/100243-ground-tackle-oday-35-a.html


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## eherlihy (Jan 2, 2007)

Also, for an EXCELLENT analysis of anchor and rode, see this link;TuningAnchorRode (Alain Fraysse has done the analysis, and researched the formulas, and captured it all here)


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## mitiempo (Sep 19, 2008)

eherlihy said:


> I posted on what I use for ground tackle, including the rode, a while back. Some of you may have seen it, some may not care to, so here is a link instead of the whole post. http://www.sailnet.com/forums/gear-maintenance/100243-ground-tackle-oday-35-a.html


Just read your post as well as the rest of the thread. As far as retrieval goes I think a stainless or galvanized welded ring around the anchor rode makes for the easiest way to pull an anchor up when it will not break free. This is used on the halibut anchoring rigs that we make for fisherman. The ring can stay on the boat with the rode going through it, if large enough it can live around the anchor roller and out of the way. A light line of 1/4" size is attached to the ring. If the anchor gets stuck the ring is allowed to travel down the rode to the anchor and a pull from the opposite direction will unseat the anchor easily.

The Rocna 15 (33 lbs) is my choice for a 27' boat, currently with 80' of 5/16" g30 chain because that is what I have followed by nylon. Were I to replace the chain it would be to 1/4" G43 of 40' or 50' and nylon after that. My rig, like yours is geared for using without a windlass.

If my boat was the size of yours I would certainly have a windlass, manual or electric. I would choose a Rocna 20 (44 lbs) or a Rocna 25 (55 lbs) for a 35' boat.


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## Don L (Aug 8, 2008)

I have 350' of all chain rode. I have never considered the all chain having any real advantage as far as holding at anchor. I do believe that it helps in normal wind shifts as the chain has to drag across the bottom. And I also believe the chain is a plus as far as chafe on rocks etc.

The real reason I have all chain is because I got tired of dealing with the rope/chain transition though the windlass.

So in the end t doesn't really matter much to me how much wind it takes to straighten the chain, I'm more interested in the anchor.


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## mitiempo (Sep 19, 2008)

Many windlasses have a combination rope/chain gypsy and with a rope/chain splice have no problem with the transition, though I realize Don that yours is probably not this type.


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## Don L (Aug 8, 2008)

mitiempo said:


> Many windlasses have a combination rope/chain gypsy and with a rope/chain splice have no problem with the transition, though I realize Don that yours is probably not this type.


Mine has both a chain and a rope gypsy and the rope would run in the chain section. But it never liked to turn into the hole and drop and this always seemed right about when the anchor would come off the bottom. So it just just to the point that it was better to just have chain.


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## pdqaltair (Nov 14, 2008)

Don0190 said:


> Mine has both a chain and a rope gypsy and the rope would run in the chain section. But it never liked to turn into the hole and drop and this always seemed right about when the anchor would come off the bottom. So it just just to the point that it was better to just have chain.


Same reasoning, same solution.


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## PCP (Dec 1, 2004)

mitiempo said:


> A riding sail set on the backstay is effective to eliminate sailing at anchor. Need not be very large.


Not completely. I have one on my previous boat just diminish the movement but I am not sure that is detrimental to safety, I mean the movement. If you go forward and look to the chain you can see that in fact the "sailing" diminishes the pressure over the chain and therefore the pulling force on the anchor.

Regards

Paulo


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## eherlihy (Jan 2, 2007)

mitiempo said:


> Just read your post as well as the rest of the thread. As far as retrieval goes I think a stainless or galvanized welded ring around the anchor rode makes for the easiest way to pull an anchor up when it will not break free. This is used on the halibut anchoring rigs that we make for fisherman. The ring can stay on the boat with the rode going through it, if large enough it can live around the anchor roller and out of the way. A light line of 1/4" size is attached to the ring. If the anchor gets stuck the ring is allowed to travel down the rode to the anchor and a pull from the opposite direction will unseat the anchor easily.
> 
> The Rocna 15 (33 lbs) is my choice for a 27' boat, currently with 80' of 5/16" g30 chain because that is what I have followed by nylon. Were I to replace the chain it would be to 1/4" G43 of 40' or 50' and nylon after that. My rig, like yours is geared for using without a windlass.
> 
> If my boat was the size of yours I would certainly have a windlass, manual or electric. I would choose a Rocna 20 (44 lbs) or a Rocna 25 (55 lbs) for a 35' boat.


When I bought the boat it came with a 25lb Delta. 








That anchor was a bad joke on the bow of a 35' boat...


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## Faster (Sep 13, 2005)

PCP said:


> Not completely. I have one on my previous boat just diminish the movement but I am not sure that is detrimental to safety, I mean the movement. If you go forward and look to the chain you can see that in fact the "sailing" diminishes the pressure over the chain and therefore the pulling force on the anchor.
> 
> Regards
> 
> Paulo


 Agree that a riding sail doesn't eliminate 'sailing' on the hook, but it can lessen the arc, and more importantly soften the 'turnarounds'.

Our Caribbean cruising friends started using a riding sail that we gave them.. and it's still the first thing that goes up after the hook goes down. Their Bene 36.7 sailed so hard on the hook that the 'fetchup' on one end of the swing actually broke the anchor free in one instance. The boat would spring back after stretching the rode (all chain), then turn and almost sail downwind before being snatched back around.

The riding sail makes those 'fetchups' much more gentle, the bow doesn't blow as far off and they sleep better for it.


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