Is 5/16" BBB Large Enough?

[scoobert]

Originally Posted by Stu Jackson

You should, WADR, buy a book about anchoring.

lol, my wife would kill me if i did. i have too many books now.
and besides, how can you write a book on something that is mostly preference?

[Stu Jackson]

There's a great deal of difference between technique and preference. Most all anchor books do NOT talk about the selection of a particular anchor, but rather about the techniques of how to use the gear you have. Given the limited time you have had your boat, unless I'm way wrong, you haven't practiced a whole lot. Hope I'm wrong.

And if you don't want to buy a book, then read this and other material on the internet:

Anchors & TEST Results of New Generation Anchors EXCELLENT & Important

Good luck.

[psneeld]

While I usually defer to Jim Cate on subjects like this...his suggestion about world cruising is appropriate and upping to 3/8 chain would be appropriate.

Me being more of a coastal guy...my 5/16 is plenty because 99 times out of a 100 my anchor will probably break free prior to breaking the chain...that said...after a good blow...my chain should be inspected and fixed/replace if any link elongation is noted.

[cheoah]

Originally Posted by scoobert

i have been considering adding a second anchor, maybe a danforth 65#. but i would only keep 100' of chain, then 200' of rode.

my idea would be to drop the anchor in very deep water, long before a storm blows me close to shore. then even if i drag, and i am sure i will, i have time to do something about it.

Keep your eyes open for a used big fortress. You can take it apart and stow it and set it along with your CQR with a blow in the forecast. Or a big danforth if you prefer. It does not have to be all chain. If you're on us east coast you can get by with chain and rope mix and save some $

Whatever you do in your storm strategy, make sure you reduce windage, increase scope to up to 10:1, and try to set yourself up so you have protection from fetch so that your boat doesn't get tossed too much. And chafe protection. If you do all that, and set your anchors in a good bottom, your should be fine. Not so sure about the deep water and time to adjust strategy. Best to be setup well ahead; screwing around with your ground tackle in a blow with everything under a load takes a lot of care. Good way to lose a finger or three. Learn to tie a rolling hitch if you haven't yet.

[scoobert]

yes, i always use maximum scope.
on the 4th i had to warn boaters to stay away. they kept getting close to my anchor chain. i had 150' set in 15' of water.

[colemj]

Originally Posted by skipmac

Hi Jim,

First, I've read lots of previous threads on this and still feel a little confused/conflicted/uncertain so wanted to hear your opinion. My boat is about 10 ton displacement and currently has 3/8" chain. It's original 25 year old and unmarked but based on the link dimensions I'm pretty sure it's BBB.

After hours looking at specs and recommendations and am thinking about 5/16" G4/HT. Compared to 3/8" BBBIt's rated higher WLL, higher breaking strength, lighter AND it's cheaper. So what's not to like?

By the way, that's not a rhetorical question, I'm actually asking, what's not to like?

Also, I do have gypsies for both sizes so that's not an issue.

Our boat is a bit lighter than yours (9T fully loaded), but being a catamaran has much more windage. We use 5/16" G4 with a 55lb Rocna. 7 years cruising and no issues with that choice.

Mark

[Jim Cate]

Originally Posted by skipmac

Hi Jim,

First, I've read lots of previous threads on this and still feel a little confused/conflicted/uncertain so wanted to hear your opinion. My boat is about 10 ton displacement and currently has 3/8" chain. It's original 25 year old and unmarked but based on the link dimensions I'm pretty sure it's BBB.

After hours looking at specs and recommendations and am thinking about 5/16" G4/HT. Compared to 3/8" BBBIt's rated higher WLL, higher breaking strength, lighter AND it's cheaper. So what's not to like?

By the way, that's not a rhetorical question, I'm actually asking, what's not to like?

Also, I do have gypsies for both sizes so that's not an issue.

G'Day Skip,

I don't claim expertise here, and the chain gurus may dump on my opinions, but this is my thinking...

I prefer the heavier 3/8 or 10 mm over the lighter and equally (approximately) strong 5/16 or 8 mm for a couple of reasons. First, while I know that the extra weight in the catenary does not help with ultimate holding power in extreme situations, it does help dampen out some pitching and sailing about in more normal anchoring. This improves comfort somewhat and helps avoid awkward situations in crowded anchorages, things that loom large in normal cruising!

Second, being the cheap bastard that I am, I don't want to have to replace chain very often, and I worry less about wear in the links when they are thicker to start out with. The chain on our previous boat was over twenty years old when we sold her, had been regalvoed 4 or 5 times (can't remember exactly) and was still in pretty good nick. I don't think that this is an unreasonable expectation.

Third, it is easier to get adequately strong shackles to fit the bigger links (without the difficulty of obtaining oversize end links). Of course one can get strong 5/16 shackles but it isn't always easy.

I don't think that the additional weight in the bow is significant, BTW. Folks rattle on about this, but in a cruising boat I think it is an vanishingly small factor.

Finally, anchor chain breaking is a pretty rare event in our experience - only two that I know of personally in 27 years cruising and a lot of previous years weekending and coastal cruising in California. Honestly, I wouldn't worry about either of your choices from that standpoint. While it is certainly good practice to not exceed SWL, the disaster that we all worry about (breakage under storm conditions) means exceeding the breaking strength which is a hell of a lot higher and likely can not be reached with an anchor that is merely stuck into the bottom.

So, while I would personally go for 3/8, there is nothing wrong with your proposed 5/16... IMO! Hope that this helps with your decision.

Cheers,

Jim

PS Why are you abandoning your old chain? Rusty? Worn? just curious, and it isn't really any of my biz!

[colemj]

Originally Posted by Jim Cate

I worry less about wear in the links when they are thicker to start out with.

Jim,

All of your reasoning was very good, except I don't understand this one.

If a smaller chain had the same strength, and each wore equally as a % of material, then there is no difference in worry.

Mark

[boatpoker]

[QUOTE=Jim Cate;1347013]G'Day Skip,

I don't claim expertise here, and the chain gurus may dump on my opinions, but this is my thinking...

I prefer the heavier 3/8 or 10 mm over the lighter and equally (approximately) strong 5/16 or 8 mm for a couple of reasons. First, while I know that the extra weight in the catenary does not help with ultimate holding power in extreme situations, it does help dampen out some pitching and sailing about in more normal anchoring. This improves comfort somewhat and helps avoid awkward situations in crowded anchorages, things that loom large in normal cruising!

Second, being the cheap bastard that I am, I don't want to have to replace chain very often, and I worry less about wear in the links when they are thicker to start out with. The chain on our previous boat was over twenty years old when we sold her, had been regalvoed 4 or 5 times (can't remember exactly) and was still in pretty good nick. I don't think that this is an unreasonable expectation.

Third, it is easier to get adequately strong shackles to fit the bigger links (without the difficulty of obtaining oversize end links). Of course one can get strong 5/16 shackles but it isn't always easy.

I don't think that the additional weight in the bow is significant, BTW. Folks rattle on about this, but in a cruising boat I think it is an vanishingly small factor.

Finally, anchor chain breaking is a pretty rare event in our experience - only two that I know of personally in 27 years cruising and a lot of previous years weekending and coastal cruising in California. Honestly, I wouldn't worry about either of your choices from that standpoint. While it is certainly good practice to not exceed SWL, the disaster that we all worry about (breakage under storm conditions) means exceeding the breaking strength which is a hell of a lot higher and likely can not be reached with an anchor that is merely stuck into the bottom.

So, while I would personally go for 3/8, there is nothing wrong with your proposed 5/16... IMO! Hope that this helps with your decision.

Cheers,

JimQUOTE]


I agree with everything JIm says ,,,, but I also believe in sleep and to sleep comfortably I want the biggest anchor and chain that I can physically handle.

[Kenomac]

A better plan would be to ditch the CQR or use it as a secondary anchor, and get yourself a 60-75 pound new generation anchor with all chain rode 3/8 inch or larger. Then you could anchor with 1:3, 1:5, 1:10 when appropriate like in a crowded anchorage. You won't always be able to anchor using 1:10 without making a total mess, and upsetting others. In light winds, crowded anchorage, most will be on no more than 1:5 scope. 1:10 will just piss everyone else off when you bash into them.

Spending time at anchor is all about getting along with the boaters next door.

[Jim Cate]

Originally Posted by colemj

Jim,

All of your reasoning was very good, except I don't understand this one.

If a smaller chain had the same strength, and each wore equally as a % of material, then there is no difference in worry.

Mark

Reasonable point, Mark!

Actually, I don't know anything much about how chain wears itself out. That is, the wear is generally where the two links rub together under load, but I don't know if that would mean that there was loss proportional to size or to load. I can see arguments for both cases, and haven't the knowledge to choose between them.

My seat of the pants thoughts were that it would be less for the bigger chain link, but I'd be happy to hear from someone who actually knew something about the realities.

Cheers,

Jim

[bobconnie]

Soobert, Im begining to wonder why yall ask questions! You never seem to listen when folks with many miles under there keel give ya good solid answers! First off they have told ya that your anchor is to small, and your chain is a tad small and your sure useing way to much scope in shallow waters! It would be nice if yall would maybe use a little of the sugestions that folks give ya! or at least don't argue with folks that are trying to help Ya!! I just hope you get your boat really ready before ya go offshore!

[Jim Cate]

Originally Posted by Kenomac

A better plan would be to ditch the CQR or use it as a secondary anchor, and get yourself a 60-75 pound new generation anchor with all chain rode 3/8 inch or larger. Then you could anchor with 1:3, 1:5, 1:10 when appropriate like in a crowded anchorage. You won't always be able to anchor using 1:10 without making a total mess, and upsetting others. In light winds, crowded anchorage, most will be on no more than 1:5 scope. 1:10 will just piss everyone else off when you bash into them.

Spending time at anchor is all about getting along with the boaters next door.

This is a good point to ponder, Scoobert. Anchoring on very long scope is often not feasible, and can be distinctly antisocial in today's crowded anchorages. Under normal conditions it is simply not necessary, especially if you have a properly sized anchor.

And again I say that the 45 lb CQR is not a properly sized anchor for your boat.

Jim

[scoobert]

Originally Posted by Kenomac

A better plan would be to ditch the CQR or use it as a secondary anchor, and get yourself a 60-75 pound new generation anchor with all chain rode 3/8 inch or larger. Then you could anchor with 1:3, 1:5, 1:10 when appropriate like in a crowded anchorage. You won't always be able to anchor using 1:10 without making a total mess, and upsetting others. In light winds, crowded anchorage, most will be on no more than 1:5 scope. 1:10 will just piss everyone else off when you bash into them.

Spending time at anchor is all about getting along with the boaters next door.

you can make up for a short scope. by adding a weight. i will have to experiment to see what size weight i need.
moving the QCR and 150' of chain to a quarter of the locker, should not be that hard. looks as if i have room for about 800-1200' of 3/8 chain.

[skipmac]

Originally Posted by colemj

Our boat is a bit lighter than yours (9T fully loaded), but being a catamaran has much more windage. We use 5/16" G4 with a 55lb Rocna. 7 years cruising and no issues with that choice.

Mark

Must have worked out OK since you're still posting here.