Is 5/16" BBB Large Enough?

[colemj]

Originally Posted by skipmac

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

I'm actually a 14yr old girl using my grandmother's Pentium box in her basement rec room...

Mark

[skipmac]

Hi Jim,

Thanks for the comments. Of course I always have another question back.

Originally Posted by Jim Cate

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!

Since this is my first boat with all chain rode I've been experimenting. Max I've seen at anchor so far in this boat was 25-30 kts with maybe some higher in gusts. A nylon snubber did very well to dampen the pitching so I'm satisfied with that aspect.

As far as sailing at anchor that brings up another question. The boat has a short, heavy sprit with the anchor rollers fairly close in. If I run the snubber over the roller the boat doesn't sail at all, a first for me on all the boats I've owned. If I run the snubber through the chocks on the side of the bow then the boat takes off. Haven't yet tried a snubber that runs through both chocks to see how that works. So I like running the line over the roller but wonder if it will stand up to a really bad blow?



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.

I'm a cheap SOB myself which is one of the reasons I'm looking at 5/16 HT instead of 3/8" BBB. Would save over $1.00/ft for stronger chain. And by the way, don't have and don't think I could get a gypsy to fit 3/8" HT so I'm stuck with these two options.


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.

For a 300' rode the difference is almost 200 lbs. Overall not a lot but right in the bow? My last boat due to storage locations and such I had a lot of wt in the bow and stern and in a steep choppy head sea it would hobby horse pretty badly. How much was due to the weight in the ends vs the design? Don't know but made me think about the issue.

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!

Fair question. After all, I asked you first. Chain is the original that came with the boat (1984) and a couple of sections were well beyond surface rust, as in fairly large flakes of iron oxide chipping off the links. The bad parts were the end by the anchor that got all the wear and the bitter end in the locker. Not sure if the PO end for ended the chain or if the bitter end rusted just being in the bottom and wet all the time. The middle isn't too bad but after chopping off the bad I only have about 100' left and even that could use regalvanizing. So at this point I'm chain shopping.

[skipmac]

Originally Posted by colemj

I'm actually a 14yr old girl using my grandmother's Pentium box in her basement rec room...

Mark

Photos?

[scoobert]

Originally Posted by skipmac

Photos?

no you didn't...

[bobconnie]

Skipmac and colemj yall always make us laugh! Thanks

[Jim Cate]

Originally Posted by skipmac

Hi Jim,

Thanks for the comments. Of course I always have another question back.

Skip, we have run our snubber (16 mm double braid nylon) over the roller for years and not had chafe or wear problems. If you have a bobstay on your sprit that can be a chafe point, though.

And yeah, I see that depending on exactly which chains are involved there is about a half pound per foot difference in weight... but still, on a boat your size and weight I doubt if it would make a big difference. I believe hull shape and LWL are big factors in pitching... don't know what yours looks like.

I agree that you old chain sounds like it has reached its use-by date!

Cheers,

Jim

[skipmac]

Originally Posted by Jim Cate

Skip, we have run our snubber (16 mm double braid nylon) over the roller for years and not had chafe or wear problems. If you have a bobstay on your sprit that can be a chafe point, though.

And yeah, I see that depending on exactly which chains are involved there is about a half pound per foot difference in weight... but still, on a boat your size and weight I doubt if it would make a big difference. I believe hull shape and LWL are big factors in pitching... don't know what yours looks like.

I agree that you old chain sounds like it has reached its use-by date!

Cheers,

Jim

Thanks.

No bobstay so good there. Sprit is very short and forestay runs to the stem so don't need one. However, I did always want a bobstay with a dolphin striker just because I like the name.

I might keep a piece of the old chain for the lead on the Fortress I keep on the pushpit.

[scoobert]

i do not really see a big difference between a QCR and an ultra.
same holding principle. dig deep, use the weight of the substrate to dig more.
once set, they are not coming out unless your scope is too far off, or you drive over it.
if i was going to do a second anchor, it would be a different design.
i have a traditional for my stern.

[Stu Jackson]

Originally Posted by scoobert

i do not really see a big difference between a QCR and an ultra.
same holding principle. dig deep, use the weight of the substrate to dig more.
once set, they are not coming out unless your scope is too far off, or you drive over it.
if i was going to do a second anchor, it would be a different design.
i have a traditional for my stern.

Then you haven't read the link I provided earlier.

[scoobert]

Originally Posted by Stu Jackson

Then you haven't read the link I provided earlier.

you posted a link to a forum discussion.....

[sailorchic34]

Just a little note that on my dinky little 6 ton boat, I use a 44 pound anchor with 5/16" chain. If I could lift a 66 pound, I would have one. On a 45' Tayana somewhere north of 80 pounds will get you sleeping when the wind blows. 45# is a lunch hook at that size boat.

When the wind is blowing 50-60 knots or more, no one ever says the anchors too big.

[scoobert]

Originally Posted by sailorchic34

Just a little note that on my dinky little 6 ton boat, I use a 44 pound anchor with 5/16" chain. If I could lift a 66 pound, I would have one. On a 45' Tayana somewhere north of 80 pounds will get you sleeping when the wind blows. 45# is a lunch hook at that size boat.

When the wind is blowing 50-60 knots or more, no one ever says the anchors too big.

i know. its amazing to me it shipped with a 35# setup. not sure how much bigger i can go on the roller. the 45# is hard to get into the slot. thou it looks like the shank could be about 12" longer.

[Stu Jackson]

Originally Posted by scoobert

you posted a link to a forum discussion.....

Yes, I know. I'm not quite sure what you meant by this reply. That discussions has a lot of information that pertains to your particular issues. I simply thought it might help you.

You could, should also read this by Lin Pardey, just posted:

http://www.cruisersforum.com/forums/...ml#post1347196

[scoobert]

according to this:
Independent Anchor Performance Testing
the fortress is the way to go.
and what is a fortress, but a alloy danforth.
so i guess my two should be a QCR and a danforth.
i need to try and get 3/8 chain.

[bobconnie]

Darn Ive been useing anchors for a lot of years, And back in the good old days I had Danforth, and CQR, and tryed a bunch of orhers, but Ive never seen or heard of a QCR is this something new ??