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Old 18-08-2008, 18:21   #1
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anchor sizes and chain lengths

my wife and i just purchased our first boat a 27 ft catalina. we have been out day sailing but are a little concerned about anchoring out. our boat only has i believe a 12lb danforth anchor 30ft of chain and 150ft of line. seems to me to be a little on the light side can anyone shed any light on this for me. thanks
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Old 18-08-2008, 18:28   #2
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16lb = 7kg?! if it's true it's too light; a lot too light; add cca 15kg more; danforth is the best anchor for mud and sand
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Old 18-08-2008, 18:36   #3
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If you want to feel secure get at least 15kg or 33 pounds.
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Old 18-08-2008, 18:43   #4
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did i mention that we dont have a windlass
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Old 18-08-2008, 19:47   #5
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Hinz's "The complete book of anchoring and mooring" (which is a pretty good read) recommends 240ft nylon rode with a chain lead or 135ft all chain attached to a 27lb danforth (for anchoring in up to 30ft).

So long as you're in reasonable shape you shouldn't have too much difficulty raising it but a windlass makes life a lot easier!
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Old 18-08-2008, 20:00   #6
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I am not so good at replying to questions. My old 27' footer very light displacement. I used a 12 lb danforth with a 10' of 5/16 and 150'of 7/16" rode. I also had a Delta 27 with 20' of 3/8 chain and 150' of 1/2". the Danforth served as a lunch hook depending on the bottom and weather I used it as a primary. I would consider a second anchor and think the Danforth is a bit small. your rode depending on the diameter, where you are, the bottom and weather conditions is probably okay.
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Old 18-08-2008, 21:07   #7
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Danforths can be fussy....

It also depends what your bottom type is.

My recollection is that Danforths do well in thin mud or sand. If the bottom is heavy mud then they have trouble setting.

The Deltas look good as a light anchor and should do better in heavy mud. I'm using a CQR clone but the Deltas look better.
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Old 18-08-2008, 21:34   #8
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My questions are: Where are you going to be anchoring, and what type bottom conditions?

What model Danforth is your anchor?
Is it a real Danforth brand? All "danforth" anchors are not created equal.
If your Danforth 12# anchor is a 12H model, it is a very strong anchor and for light conditions should be fine for your boat. Even for a fair blow if it digs in good. You should have 2 anchors aboard at the least. I would get a Delta 22, as a primary anchor, and keep the 12# Danforth as a second hook.
A lot of people advise using monster lengths of chain. In 7 years of full time cruising, anchoring thousands of times, I never used more than 20' of 3/8 chain, for my 35' 14,000# sloop, except for storm anchoring.
The last 3 years I used 15' on each anchor, beacuse I got a deal on 2-15' lengths of ss chain. I carried an extra 20' for each anchor for hurricanes.
I believe the stretch in 3 strand anchor line is very important for anchor holding, by absorbing shock. If you anchor in 10' of water with 5:1 scope, you need to have about 75' of rode out. If you have 50' of chain, that only leaves 25' of line to stretch and absorb shock.
If you have longer chain, you will need to rig a snubber. That gets old when you are anchoring a lot.
My feeling about chain is that it is good for chaft protection, and thats about all. When the wind really picks up, the chain gets tight and doesn't absorb any shock.
Huricane Bob, in Block Island. Anchored with:
40# Danforth/40' 3/8 chain
35# plow/40' 3/8 chain
13S standard Danforth 14# anchor 40' 3/8 chain
200' 5/8 rode on each.
Anchors set equally apart.
135 mph winds
The anchor facing the 135mph winds and held was the 13S Danforth anchor!
All the above is just what has worked for me, and as we know, anchoring opinions are like....well you know, everyone has one!

My cruising was in the east coast, from Maine to FL and the Bahamas. Except for up north, mostly sandy bottoms.
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Old 20-08-2008, 02:12   #9
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My boat (one of them which is close to a Cat 27), 32ft yacht, 7000lb's loaded, no winch only a wench
50ft 1/4" chain to 200ft of 1/2" polyester 8 braid with a Model 60 Spade (in alloy 9lb or 18lb in steel). Sat through 45-50kts and the only problem we had was getting it back, it buried rather too well. I do race occasionally and that is a lightweight set-up. If cruising more I'd go up a size on both. Also those anchors are top end so don't go weight for weight on a plow style (delta included) or it may bite you. I use the alloy version.

There is absolutely no way a 27fter needs anything larger than a 5/16" chain and/or 9/16" warp. The strengths of those is more than enough and piles higher than any matching anchor will hold, even top end ones like the Spades, Supremes or Rocnas. Many cleats will rip out of decks below those loads as well.

Sure you can carry heavier if you like, some do, but all you are doing is spending more money on putting reasonably useless weight exactly where yachts don't like it i.e. the ends of the boat. Don't go silly on G40 (hi-test) or high tensile chains, you will get zero benefit from them on your boat. BBB or Grade 30 is more than enough. Save the bucks and spent them on a bloody good anchor instead.

Some like to carry, say 10ft of 3/8" chain thinking the extra weight is a good thing. In a way it is but you will gain better holding power from your anchor with a 17ft length of 5/16" and save weight at the same time. Chain length counts a lot towards how the anchor will perform. Increase the length of chain by 50% and that will increase it's anchor helping power by 100% (actually more like 92% and just rounding here for the ease).

There is no such thing as a 'must be' length on either the rope or the chain, it all depends on where you anchor. Why carry 250ft when you only anchor in 20ft and equally whay carry 250ft when you anchor in 300ft. Work on 5 times the maximum depth you'll anchor in as minimum, 7 times if the weather can get a bit bad or 10 times if the weather can go real bad. But the rule is 'more the merrier', it's harmless to have to much but dangerous to have too little.

If you have or will get an anchor winch use Nylon, not as slippery and they work far better on that. Hand over hand polyester is equally as good if not better. Don't listen to people saying you get more stretch out of nylon as they obviously intend to use their ropes in an overloaded state and well beyond manufacturers recommendations. At normal working loads the difference in elastic elongation (generally known as stretch even if slighly incorrectly) is not large at all, up near break load it is.

I'd suggest 45ft of 5/16" chain to whatever length warp to sut the depths you anchor in.

Anchor wise a 12lb Danforth pattern is a bit small, a good lunch pick size. General rule is 1lb per foot of boat length then tweak to suit both boat and YOUR happiness level. Big heavy blunt bowed boat with a windage issue go up in size. Lightweight harbour racing flyer you can go down a size. If big makes you feel happier go big and sleep well. Newer designs like the Spade and it's derivatives you can go down a size as they do have far superior holding power. Or get one of those in the same weight and then drink a bottle of rum and sleep just well i.e just take the extra holding power bonus.

So I'm thinking a 10kg delta if racing or a 16 if cruising. Same applies to CQR's and Bruce's as they all hold similar loads depending on bottom type. If you anchor is soft sandy or sloppy bottom types Danforth patterns work well in those. If not like that all the time go for a plow style as they are more versatile. Ideally go for one of the new designs like a 80 Spade, 25lb Supreme or a 10kg Rocna but be aware they may cost more in the short term, it all depends on how much you value you anchoring stability.

Don't get caught up too much by the weight differences between the old and the new style anchors, both work on very differant principals. The old work on weight where the new work on surface area. The new ones are refered to in weights purely as many can't get their head around buying a 600cm2 anchor rather than a 20lber.

Always carry a second anchoring system. You may never need it but do you want too find out the hard way, most don't. The 2nd system can be a bit lighter if you boat in an area replacement gear is easy to obtain. If not make it grunty as well.

And the last big thing - play with your gear and find out the best way to use it. Operator error is a large component of many anchoring issues. We see it almost daily where people blame the gear only to find out they run 2:1 scopes or other stuff which shouldn't be done. Short scoping is a big common issue so the general rule for setting scope is more the merrier but 5:1 minimum on rope and chain rodes. If you have the room to chuck out 10:1, why the hell not? It's only going to increase the holding a pile more and that's what it's all about. A rode set at 10:1 has a massive higher holding capability than one at 5:1 a pile more than twice.

All reasonably simple and once set-up well you will gain confidence and hence sleep better. Sadly it may cost to get it sorted the 1st time but that's just the price you have to pay to keep you and your boat safe. No fun lying in a coffin thinking "****, I should have spent that extra $50 to do it right".

My job is specifying anchoring systems. No you can't come and see me, I'm not in your country but if you enjoy a jet plane ride you can and I'll happily buy you a beer while we yack about anchors and associated gear.

over40pirate - it's no wonder you chain straightens quickly in a breeze, you have next to none. Go all or a fair whack more chain and you'll find it is a very different story. FYI - using such short lengths of chain is pretty much a US only thing. Cruise further afield and you'll find you are in a definite minority if not almost on your lonesome.
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Old 20-08-2008, 04:26   #10
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From the charts, an Anchor assembly for a 27' Catalina should be sized to approximately a 700 Lb (working) to 1,400 Lb (storm) Load, requiring a minimum of " Nylon, and 1/4" chain rode.
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Old 20-08-2008, 18:17   #11
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Who's tables are those Gord?
Someone in the US looking at the unusual numbers and a bit old school looking at the skinny boats.
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Old 20-08-2008, 22:12   #12
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Quote:
Originally Posted by GMac View Post
My boat (one of them which is close to a Cat 27), 32ft yacht, 7000lb's loaded, no winch only a wench
50ft 1/4" chain to 200ft of 1/2" polyester 8 braid with a Model 60 Spade (in alloy 9lb or 18lb in steel). Sat through 45-50kts and the only problem we had was getting it back, it buried rather too well. I do race occasionally and that is a lightweight set-up. If cruising more I'd go up a size on both. Also those anchors are top end so don't go weight for weight on a plow style (delta included) or it may bite you. I use the alloy version.

There is absolutely no way a 27fter needs anything larger than a 5/16" chain and/or 9/16" warp. The strengths of those is more than enough and piles higher than any matching anchor will hold, even top end ones like the Spades, Supremes or Rocnas. Many cleats will rip out of decks below those loads as well.

Sure you can carry heavier if you like, some do, but all you are doing is spending more money on putting reasonably useless weight exactly where yachts don't like it i.e. the ends of the boat. Don't go silly on G40 (hi-test) or high tensile chains, you will get zero benefit from them on your boat. BBB or Grade 30 is more than enough. Save the bucks and spent them on a bloody good anchor instead.

Some like to carry, say 10ft of 3/8" chain thinking the extra weight is a good thing. In a way it is but you will gain better holding power from your anchor with a 17ft length of 5/16" and save weight at the same time. Chain length counts a lot towards how the anchor will perform. Increase the length of chain by 50% and that will increase it's anchor helping power by 100% (actually more like 92% and just rounding here for the ease).

There is no such thing as a 'must be' length on either the rope or the chain, it all depends on where you anchor. Why carry 250ft when you only anchor in 20ft and equally whay carry 250ft when you anchor in 300ft. Work on 5 times the maximum depth you'll anchor in as minimum, 7 times if the weather can get a bit bad or 10 times if the weather can go real bad. But the rule is 'more the merrier', it's harmless to have to much but dangerous to have too little.

If you have or will get an anchor winch use Nylon, not as slippery and they work far better on that. Hand over hand polyester is equally as good if not better. Don't listen to people saying you get more stretch out of nylon as they obviously intend to use their ropes in an overloaded state and well beyond manufacturers recommendations. At normal working loads the difference in elastic elongation (generally known as stretch even if slighly incorrectly) is not large at all, up near break load it is.

I'd suggest 45ft of 5/16" chain to whatever length warp to sut the depths you anchor in.

Anchor wise a 12lb Danforth pattern is a bit small, a good lunch pick size. General rule is 1lb per foot of boat length then tweak to suit both boat and YOUR happiness level. Big heavy blunt bowed boat with a windage issue go up in size. Lightweight harbour racing flyer you can go down a size. If big makes you feel happier go big and sleep well. Newer designs like the Spade and it's derivatives you can go down a size as they do have far superior holding power. Or get one of those in the same weight and then drink a bottle of rum and sleep just well i.e just take the extra holding power bonus.

So I'm thinking a 10kg delta if racing or a 16 if cruising. Same applies to CQR's and Bruce's as they all hold similar loads depending on bottom type. If you anchor is soft sandy or sloppy bottom types Danforth patterns work well in those. If not like that all the time go for a plow style as they are more versatile. Ideally go for one of the new designs like a 80 Spade, 25lb Supreme or a 10kg Rocna but be aware they may cost more in the short term, it all depends on how much you value you anchoring stability.

Don't get caught up too much by the weight differences between the old and the new style anchors, both work on very differant principals. The old work on weight where the new work on surface area. The new ones are refered to in weights purely as many can't get their head around buying a 600cm2 anchor rather than a 20lber.

Always carry a second anchoring system. You may never need it but do you want too find out the hard way, most don't. The 2nd system can be a bit lighter if you boat in an area replacement gear is easy to obtain. If not make it grunty as well.

And the last big thing - play with your gear and find out the best way to use it. Operator error is a large component of many anchoring issues. We see it almost daily where people blame the gear only to find out they run 2:1 scopes or other stuff which shouldn't be done. Short scoping is a big common issue so the general rule for setting scope is more the merrier but 5:1 minimum on rope and chain rodes. If you have the room to chuck out 10:1, why the hell not? It's only going to increase the holding a pile more and that's what it's all about. A rode set at 10:1 has a massive higher holding capability than one at 5:1 a pile more than twice.

All reasonably simple and once set-up well you will gain confidence and hence sleep better. Sadly it may cost to get it sorted the 1st time but that's just the price you have to pay to keep you and your boat safe. No fun lying in a coffin thinking "****, I should have spent that extra $50 to do it right".

My job is specifying anchoring systems. No you can't come and see me, I'm not in your country but if you enjoy a jet plane ride you can and I'll happily buy you a beer while we yack about anchors and associated gear.

over40pirate - it's no wonder you chain straightens quickly in a breeze, you have next to none. Go all or a fair whack more chain and you'll find it is a very different story. FYI - using such short lengths of chain is pretty much a US only thing. Cruise further afield and you'll find you are in a definite minority if not almost on your lonesome.
Though not short this is the best reply to a "What Type of Anchor" question.
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Old 21-08-2008, 01:30   #13
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Though not short this is the best reply to a "What Type of Anchor" question.
Thanks Charlie and by the way that is the short version

There's more to it than just picking an anchor. The more that realise that, the more I'll sleep happy as well. I never quite know who's anchored upwind from me and while I love meeting new people/boats I prefer it doesn't happen at 4am
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