Downsizing chain

[Ventana]

Wondering if anyone here has replaced a larger chain size with a smaller size but more length? I am thinking of replacing the 300’ of BBB 3/8 chain we currently use with 400’ of HT 5/16, and wondering what the difference will be in overall size in the anchor locker. I understand about differences in chain, I have multiple wildcats for the different chain sizes, and have the need for the extra length, but I am pretty maxed out on space in the anchor locker so I want some first hand experience in the differences in overall volume between the two rodes before I place an order.

 

[caltexflanc]

This gives you a rough idea:

https://www.peerlesschain.com/wp-content/uploads/PER199_RETAIL_sm2.pdf

Looks like you could get 400 ft in where you now have 300.

 

[bayview]

BBB is designed not to kink in the locker. You may not be happy with long link chain

 

[rslifkin]

Based on the volume that fits in a standard drum, the 400 feet of 5/16" will take just a tiny bit less space than the 300 feet of 3/8". The 400 feet of 5/16" will also be about 415 lbs compared to 480 for 300 feet of 3/8", so you'll save some weight too.

 

[rslifkin]

BBB is designed not to kink in the locker. You may not be happy with long link chain

G43 windlass chain is still short link. No windlass I know of takes long link.

 

[Ventana]

Thanks guys. When I was in the business I had barrels of chain shipped in regularly, but never paid much attention to how full the barrels were filled. I would assume they would fill them as full as possible for shipping efficiency, but my track record with assumptions isn’t all that great.....

Anyone actually downsized like this and have real world experience?

 

[Tidahapah]

I have upsized from 10 mm to 12 mm but stayed with the same length (110 mts) approx 350 ft. Just have to compensate for the extra weight. Nothing beats chain weight to keep that anchor in place. I would be endeavouring to get in a bit more of the 3/8 chain before downsizing.

 

[rslifkin]

I have upsized from 10 mm to 12 mm but stayed with the same length (110 mts) approx 350 ft. Just have to compensate for the extra weight. Nothing beats chain weight to keep that anchor in place. I would be endeavouring to get in a bit more of the 3/8 chain before downsizing.

Or he could put the weight savings into a bigger anchor and probably come out ahead in the long run.

 

[Nomad Willy]

I’ve always said a pound of anchor is far far more beneficial than a pound of chain. One can effectively use “a few feet of chain” per Chapman’s boat handling book commonly thought of as the boating bible.

 

[Tidahapah]

Or step up to a super high holding power anchor such as a Sarca Excel and have the best of both worlds. Could even go the aluminium version to save weight.

 

[Ventana]

I already have the best anchor, I’m just trying to work out the chain issue now.

 

[foggysail]

BBB is designed not to kink in the locker. You may not be happy with long link chain

Heck with kinking, how about teepee’ing?

 

[foggysail]

I use 5/16 G4 with my Maxwell HW2C2200 windlass (24V) and have thought of going to 1/4’’ providing a gypsy is available. My current chain is in fine condition and that is the only reason that I did not search for a gypsy.

1/4’’ G4 I think has enough strength to rip the windlass right off my deck so strength fears are unnecessary. And using 1/4’’ chain will build a shorter teepee in my anchor locker

 

[Shrew]

The problem I see is that the Krogen 42 specs are:

Length: 42'4"
Weight: 39,500 lbs

That puts you squarely in the 3/8" chain. 5/16" would seem to small for that size and weight boat.

Is less chain and more line a better option? How about wire rope?

 

[foggysail]

The problem I see is that the Krogen 42 specs are:

Length: 42'4"
Weight: 39,500 lbs

That puts you squarely in the 3/8" chain. 5/16" would seem to small for that size and weight boat.

Is less chain and more line a better option? How about wire rope?

I doubt there are many boats out there that would see a 5/16’’ g4 chain fail before its attachment onto the boat proper

 

[Ventana]

The problem I see is that the Krogen 42 specs are:

Length: 42'4"
Weight: 39,500 lbs

That puts you squarely in the 3/8" chain. 5/16" would seem to small for that size and weight boat.

By whose standards? Not saying you are wrong (well, I kinda am) but most things written about anchoring are garbage, so I’m wondering where this recommendation comes from? I’m anchoring a boat with the chain, not lifting the boat out of the water.
In all my years of obsessing over anchors and anchoring, as well as participating in multiple highly publicized anchor tests, I have only seen one person post real world data on anchoring loads. I wish I could find the information again to post it up. If someone can show me real data that proves the high loads most people believe exist, I will gladly rethink my opinions. I’m not picking on you specifically, these misconceptions get posted in practically every anchoring thread on the internet.

 

[psneeld]

Some people think their everyday tackle has to be rated for hurricanes.

Reality is for many boaters, 90 percent of the time you experience X conditions....9 percent you experience 2X for 24 hrs or less and 3X for 12 hrs or less. Rarely do you see even high squall winds and most boaters never anchor in hurricanes.

Pick reasonable numbers to calculate your tackle and happily cruise, knowing that if severe conditions are even remotely possible, plan B is batter up.

 

[MathiasW]

We decided to opt for a thinner but longer chain. The disadvantage is a larger swinging circle, and at the same water depth shock loads on the anchor due to swell will be larger (which, however, you can address with good snubbers), but the advantages are that I can anchor safely in deeper water, at a smaller scope, and be fine. If you halve the chain weight per metre, double the chain length, and double the anchor depth, you have the same geometric situation as before, just scaled up by a factor of 2. But the elasticity of the chain will still be twice compared to the twice as heavy chain at half the anchor depth.

The full analysis can be found here:

https://trimaran-san.de/die-kettenkurve-oder-wie-ein-mathematiker-ankert/

(In English, not in German )

 

[Nomad Willy]

I don’t know what to say.
It’s TMI for me.
I don’t see chain as being “elastic”. No not much of a bungie chord I’m think’in.
I have my own theories on catenary and chain. I’ve posted them and nobody seems to get that and it’s simple compared to this.

Has anybody read more than 5-10 minutes of this? If so what basically is ... or there any recommendations or advice to boaters that anchor.

 

[Westiculo]

I switched from the older 3/8 that was in my locker to 270ft of 5/16HT. Bought a new gypsy. Works great. Can't tell you how much less space it takes up, but it's definitely less.

 

[MathiasW]

I don’t know what to say.
It’s TMI for me.
I don’t see chain as being “elastic”. No not much of a bungie chord I’m think’in.
I have my own theories on catenary and chain. I’ve posted them and nobody seems to get that and it’s simple compared to this.

Has anybody read more than 5-10 minutes of this? If so what basically is ... or there any recommendations or advice to boaters that anchor.

Sure chain is elastic. If it has a good 'sag' and you pull at one end, you will be able to stretch it further away from the anchor. When you reduce your pull, the chain will snap back to its original place. That is elasticity!

Happy to get a pointer to your theories on catenary and chain!

 

[Nomad Willy]

Be careful what you ask for MathiasW.

My theory is to put the chain weight near the anchor.
Try to have no chain on the top half of the rode.
Three to six feet from the anchor use a chain 2 to 3 times the size of the main length of chain.
Ideally one would have chain 25 to 35% of the rode at normal anchoring depth.

Obviously one would need a reel winch to handle the ideal rode. (see pics). With a sized gypsy only one chain size and one line size can be accommodated. Adjust sizes to fit as best as can. And of course a chain/line splice will be required. I see that as 30 to 40' of heavy chain. Probably about 25 to 50% of the chain weight of the weight of a typical all chain rode.

If you’re wondering about my chain placement consider a rode w (for the average depth) w the chain on the upper half of the rode and line to the anchor. Re catenary how do you see that working?

Alaska fishermen frequently have several feet of studded chain from the anchor to the rode. Then a mid sized chain for 20’ or so. Then 50 to 100 or so feet of standard size for them but heavy. And the rest nylon line.

The reel winch is shown in the pics. Most of the time you can't see the nylon line as it's under the chain.

 

[Ventana]

Eric,
I tried to read it, but my eyes glazed over and I have to admit I skimmed quite a bit of the last parts. Not to be mean but it’s about as useful as most of the other opinions people write about anchoring...
It does provide links to two articles that I think DO provide some useful information about anchoring and associated loads. I will repost those links so folks don’t have to wade through the article linked above.

https://www.practical-sailor.com/sails-rigging-deckgear/the-load-on-your-rode


https://www.practical-sailor.com/sails-rigging-deckgear/anchor-snubber-shock-load-test

 

[Ventana]

I believe there is either some translation issues or I am misunderstanding, but I believe they are using the term elasticity in chain to describe the concept of cantenary.
And as far as your ideas on mixed rodes and holding, it’s not that none of us have heard you or that we don’t understand what you are saying, I think it’s mostly that we don’t agree with your conclusions.

 

[MathiasW]

Eric,
I tried to read it, but my eyes glazed over and I have to admit I skimmed quite a bit of the last parts. Not to be mean but it’s about as useful as most of the other opinions people write about anchoring...
It does provide links to two articles that I think DO provide some useful information about anchoring and associated loads. I will repost those links so folks don’t have to wade through the article linked above.

https://www.practical-sailor.com/sails-rigging-deckgear/the-load-on-your-rode


https://www.practical-sailor.com/sails-rigging-deckgear/anchor-snubber-shock-load-test

Thank you for this very qualified feedback! I am not expressing 'opinions' as you put it, but rather have a quantitative model with some maths around it, so you can calculate its predictions and compare it with reality. This is quite different to the unsubstantiated 'opinions' I only hear too often about anchoring. It is called a scientific approach. So, please do not put me into this basket, it is an insult.

It seems I have stung here into a nest of folks who are not really interested in looking at new view points and rather are content with what they already believe to know. Seems to be more and more common in some parts of the world. Sorry about that, I will stop bothering you, except for answering Eric.

PS: I gave an answer to your original question as to whether you should switch to a longer but thinner chain, and this is all you get out of it? Why bother, really, is my conclusion...

 

[MathiasW]

Be careful what you ask for MathiasW.

My theory is to put the chain weight near the anchor.
Try to have no chain on the top half of the rode.
Three to six feet from the anchor use a chain 2 to 3 times the size of the main length of chain.
Ideally one would have chain 25 to 35% of the rode at normal anchoring depth.

Obviously one would need a reel winch to handle the ideal rode. With a sized gypsy only one chain size and one line size can be accommodated. Adjust sizes to fit as best as can. And of course a chain/line splice will be required.

If you’re wondering about my chain placement consider a rode w (for the average depth) w the chain on the upper half of the rode and line to the anchor. Re catenary how do you see that working?

Alaska fishermen frequently have several feet of studded chain from the anchor to the rode. Then a mid sized chain for 20’ or so. Then 50 to 100 or so feet of standard size for them but heavy. And the rest nylon line.

The reel winch is shown in the pics. Most of the time you can't see the nylon line as it's under the chain.

I am not sure I understand this, really.

Are you suggesting the chain should be thickest closest to the anchor, and then get thinner and thinner as it approaches the bow? Is there a model for this that supports this, or is it just a hunch?

Whilst I would tend to agree with you that this could be very efficient in terms of total chain weight that needs to be deployed, it does not appear to be practical for the average sailor to handle.

 

[Ventana]

Thank you for this very qualified feedback! I am not expressing 'opinions' as you put it, but rather have a quantitative model with some maths around it, so you can calculate its predictions and compare it with reality. This is quite different to the unsubstantiated 'opinions' I only hear too often about anchoring. It is called a scientific approach. So, please do not put me into this basket, it is an insult.

It seems I have stung here into a nest of folks who are not really interested in looking at new view points and rather are content with what they already believe to know. Seems to be more and more common in some parts of the world. Sorry about that, I will stop bothering you, except for answering Eric.

I did not mean to insult anyone. Math is fine, equations are good, but as soon as you start admitting that you can’t get real numbers for some of the variables and that you need to use estimations, it means the end results are suspect. None of the equations I have seen adequately solve for the force of either wind or waves on a particular vessel, hence my pessimism. The data from Smith used real number obtained by actual real world testing. I would trust his conclusions over any of the others I have seen that use approximations and guesswork.

I can see you put a lot of time and effort into this, hopefully it will be useful to others.

 

[Nomad Willy]

Ventanna,
I came to that conclusion years ago.
If one drove a truck and saw nothing but trucks the'd probably be delighted to see a car. Or the reverse.

 

[Nomad Willy]

MathiasW wrote;
"Are you suggesting the chain should be thickest closest to the anchor, and then get thinner and thinner as it approaches the bow? Is there a model for this that supports this, or is it just a hunch?".

I'm saying there should be less chain (in length) than line and the chain should be attached to the anchor and upper rode. The line.

As I see it the sole purpose of chain (assuming no coral) is to hold the anchor shank down.

 

[markpierce]

I don't place much reliance on catenary. My boat's three-eights chain stretches pretty straight when there is a two-knot current.