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04-02-2025, 06:21
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#1
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Registered User
Join Date: Sep 2021
Posts: 246
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Opinions on going from 5/16 g4 to 1/4 g4 anchor chain.
Hello I've got a downeaster 32"17000lbs displacement ( fully loaded for cruising i'd add 2000lbs more so likely 20k lbs). I have 5/16 g4 chain now and and oversized excel anchor.i always use my snubbed too.. 8000 miles bahamas to nantucket and all in between I've ridden out 60knots at anchor and I've never once felt my chain was undersized.However now my bows getting heavy ( plus I can only carry 100' of 5/16) so I'm trying to shave off all the lbs i can at the bow.
5/16 g4 is 1.21lbs per ft and breaking strain at 11700lb
1/4 g4 is .74lbs per ft and breaking strain at 7800lb
Most of the formulas are general and I'm right at the cut off between 1/4 and 5/16. However I do need to be able to ride out major storms on this chain and don't want to skimp.
Does any one have a similar boat with 1/4 chain that could testify real world if they regret the 1/4 or if I'm asking for trouble by going down to 5/16?
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04-02-2025, 06:35
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#2
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Registered User
Join Date: Jun 2019
Location: Rochester, NY
Boat: Chris Craft 381 Catalina
Posts: 6,975
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Re: Opinions on going from 5/16 g4 to 1/4 g4 anchor chain.
If you're concerned about the strength of 1/4 G43, you could always step up to 1/4" G70. Rated working load of your existing 5/16" G43 is 3900 lbs. For 1/4" G43 it's 2600 lbs, but 1/4" G70 gets you 3150 lbs from what I can find.
Weight-wise, your spec for the 5/16" is a bit off. Most I've seen are listed as about 1.04 - 1.09 lb/ft.
Keep in mind, a boat of this size would likely have used 3/8" G30 or BBB chain historically. And that's rated for 2600 lbs working load just like the 1/4" G43. However, working load is rated differently between the different chain grades (IIRC G30/BBB use a more conservative rating), so the 3/8" BBB would still have a higher breaking strength (not that you'd want to load it beyond rated working load anyway).
Personally, I think any of the chain types would be adequate for your boat. Based on some of the data about actual measured anchor forces found on Alain Fraysse's website (see link below), even if we add some extra load to account for some sea state, it's unlikely you'd exceed the working load of even the 1/4" G43 chain until you're dealing with better than 80 kts of wind.
EDIT: forgot the link. http://alain.fraysse.free.fr/sail/ro...ces/forces.htm
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04-02-2025, 06:42
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#3
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Registered User
Join Date: Sep 2021
Posts: 246
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Re: Opinions on going from 5/16 g4 to 1/4 g4 anchor chain.
Music to my ears. I didn't see a link?
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04-02-2025, 06:47
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#4
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Registered User
Join Date: Jul 2007
Location: Toronto, Canada
Boat: Luders 33 - hull 23
Posts: 1,842
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Re: Opinions on going from 5/16 g4 to 1/4 g4 anchor chain.
Regardless of the specs differential bt the two sizes you do have a heavy boat with a high freeboard, and you need to determine if saving 50 lbs. will have that much of an impact, and what it will do to your peace of mind when its blowing hard out there. Just saying.
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04-02-2025, 06:48
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#5
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Registered User
Join Date: Jun 2019
Location: Rochester, NY
Boat: Chris Craft 381 Catalina
Posts: 6,975
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Re: Opinions on going from 5/16 g4 to 1/4 g4 anchor chain.
Quote:
Originally Posted by Mg451
Music to my ears. I didn't see a link?
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Good catch, I forgot to paste it. It's fixed in the previous post now.
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04-02-2025, 08:15
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#6
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Marine Service Provider
Join Date: Dec 2009
Location: Around
Boat: Woods Vardo 34 Cat
Posts: 3,920
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Re: Opinions on going from 5/16 g4 to 1/4 g4 anchor chain.
I got some 1/4" Lacede brand G70 transport chain. Links about the same length as 5/16" hi test. Comes in a 135' length. Galvanize not the greatest/ about the same as new Acco.
Heavier chain dies work better. In my case my 5/16" was quite rusty and even thin on a few links. I've since added about 4m of 12mm chain at the anchor and this helps the anchor (Manson 35) set and reset much better. My windlass is well behind the roller so I only have about 1.5m of chain and anchor over when I get to the shackle between the 1/4" and 12mm. Pull that by hand.
__________________
@mojomarine1
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04-02-2025, 09:01
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#7
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always in motion is the future

Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 20,114
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Re: Opinions on going from 5/16 g4 to 1/4 g4 anchor chain.
I recommend you stay with the 5/16” chain. The weight will not differ because you say you would fit more chain in the locker with a smaller chain.
For more length I would simply extend with rope rode. If there is no room for that in the locker, then create a system where you can shackle it on when needed. A Dyneema lashing would work as well because you can prepare that when you know you will be anchoring in deep water.
My recommendation isn’t so much as for breaking strength even though it provides for much better sleep, but rather for abrasion resistance, weight for catenary and absorbing shock loads and having a very common size chain that you can buy anywhere
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“It’s a trap!” - Admiral Ackbar.
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04-02-2025, 11:45
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#8
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Registered User
Join Date: Jun 2015
Location: Monterey, California
Boat: Westsail 32
Posts: 890
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Re: Opinions on going from 5/16 g4 to 1/4 g4 anchor chain.
Stick with the 5/16". I just traded in my 3/8" BBB for 5/16" G4 and I think that made sense, but I would not feel comfortable going down to 1/4", and our boats are similar in displacement and freeboard.
The extra weight of the chain does help keep the angle presented to the anchor down too, probably not so much at 60kts, but certainly for anything < 45kts. Anything above that, scope matters far more.
I also don't know what your anchor locker situation is, but on our boat, ours is split into a rode side and a chain side. The chain side is bottomless and has a path all the way down to the bilge area under our floor boards. If we're on a passage, we'll pull the chain down there so it's low and away from the bow. It might be worth considering if there are any modifications you can make to achieve something similar.
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04-02-2025, 12:01
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#9
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Moderator
Join Date: Mar 2008
Location: Rhode Island/Florida USA
Posts: 3,376
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Re: Opinions on going from 5/16 g4 to 1/4 g4 anchor chain.
A large portion of the holding power of the anchor is in the weight and catenary of the chain. Less weight means more force is being placed on the anchor for the same relative length.
G70 might have higher breaking strength, however it is also more brittle. You're better off with 5/16 G40. IMHO you're playing with other variables which are more important than the relatively insignificant weight difference of 5/16 vs 1/4.
also, if you use the Rocna sizing for chain, you are solidly in the 5/16" g40 size for chain for your boat size and weight
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04-02-2025, 12:13
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#10
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Registered User
Join Date: Jun 2015
Location: Monterey, California
Boat: Westsail 32
Posts: 890
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Re: Opinions on going from 5/16 g4 to 1/4 g4 anchor chain.
Quote:
Originally Posted by Shrew
A large portion of the holding power of the anchor is in the weight and catenary of the chain. Less weight means more force is being placed on the anchor for the same relative length.
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This is true up until a point. At storm force winds though, both chains will be nearly taught and the anchor experience the same force at almost the same angle. But adding scope at this point will still help.
Heavier chain buys you a little more room before you hit that threshold, but because wind force scales by the square of velocity, and chain weight is almost linear with size, it doesn't buy you as much as you might want.
In other words, if the choice is between 300' of chain of a smaller size, and 200' of a chain of a larger size, and you think you'll have the room in places to deploy all your chain, and you want to ride out storm force winds, then 300' might make more sense. But if it were me, I'd stick with the 200' of slightly larger chain and add sufficient rode, because in those conditions the centenary weight isn't helping much anyway.
Another thing to consider, and I have not tried, is that leaving a large loop of
your chain hanging off the bow (obviously not touching the bottom), might help from keeping the bow blowing off the wind as easily during gusty conditions, and larger chain is better in this application. The idea is that the chain adds resistance at the bow, making it easier for the stern to swing over more quickly compared to the bow. If your bow gets blown off the wind, then the amount freeboard area presented to the wind greatly increases and thus the force on your chain/anchor.
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04-02-2025, 12:44
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#11
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Moderator

Join Date: Jul 2007
Boat: Bestevaer.
Posts: 15,354
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Re: Opinions on going from 5/16 g4 to 1/4 g4 anchor chain.
I agree with the other responses. 1/4 G4 is a little light for your boat, especially if you anchor frequently and want to be able to cope with 60+ knots.
The other drawbacks are:
The Excel anchor can struggle to set in difficult substrates. The lighter chain will further hurt the anchor’s ability to obtain the initial grip necessary to set correctly.
You will likely need a new Gyspy. These are not cheap.
Lightweight chain moves around on the seabed more. The bearing surfaces between the chain links are also smaller. The overall result is more mechanical wear and tear of the galvanising resulting in a shorter chain life.
You will swing differently in response to windshift changes than neighbouring yachts on more typical chain weights for their size.
To save less than 50lb this does not seem a worthwhile tradeoff. Most cruising yachts can save more bow weight than this with a tidy-out of the junk, valuable equipment that is stored under the V berth  .
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Why worry.
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04-02-2025, 13:12
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#12
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Registered User
Join Date: Jun 2009
Location: Annapolis, MD
Boat: Gozzard, 44CC, 50'
Posts: 575
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Re: Opinions on going from 5/16 g4 to 1/4 g4 anchor chain.
Will your gypsy handle 1/4" chain?
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04-02-2025, 14:56
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#13
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Registered User
Join Date: Sep 2021
Posts: 246
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Re: Opinions on going from 5/16 g4 to 1/4 g4 anchor chain.
I can get a gypsy to handle the 1/4. My excel has set first time every time over 1000 times in all bottoms I've come across from new England to bahamas Never drug an inch either never fuss with it or really even back down on it.. I always thought it was the anchor but maybe the chain is helping to don't want to mess that up. So tempting to try.
I'm crunching the numbers and if I make my bowsprit in aluminium rather then the ss it is now and drop my chain size down to 1/4. I could save about 100plus lbs up front. Problem.is now I cant jam my vebirth full of junk bc my gear is using up all the allocated weight.🤣 looks like even 3/4 triple braid nylon is way stronger then 1/4" g43.
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04-02-2025, 16:20
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#14
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Registered User
Join Date: Jun 2019
Location: Rochester, NY
Boat: Chris Craft 381 Catalina
Posts: 6,975
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Re: Opinions on going from 5/16 g4 to 1/4 g4 anchor chain.
Quote:
Originally Posted by Mg451
looks like even 3/4 triple braid nylon is way stronger then 1/4" g43.
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Keep in mind that maximum working load for nylon line is no more than 20% of breaking strength. So while the breaking strength of 3/4" 3 strand nylon is listed as 17,150 lbs (using New England Ropes as an example here), you'd never want to load it past 3430 lbs. So while it's stronger than the 1/4" chain, it's not as big a difference as the breaking strength sounds. Loading the line past 20% will give it a very short life and risk it failing in use.
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05-02-2025, 10:20
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#15
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Registered User
Join Date: Sep 2021
Posts: 246
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Re: Opinions on going from 5/16 g4 to 1/4 g4 anchor chain.
So would you say if your comfortable using 3/4 triple braid nylon as an anchor rode. ( not assuming the chafe and canterary) you should be more comfortable with 1/4 g43
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