3/8 BBB or 3/8 G4 HT dilemma

[s/v Jedi]

Originally Posted by Training Wheels

We have used G70 ACCO chain, the problem is it seems the galvanizing isn’t as good. After 3 years I’m having to replace it because it’s so rusty. I’m replacing it with G43.

I’m at anchor right now, using my G70 ACCO chain that I bought in 2004. No rust.

Here’s the trick: when you’re done anchoring for a while (to marina or haul out), rinse the chain with fresh water. I do this in the chain locker... until clean fresh water runs out. For good measure I sometimes spray a good amount of wd40 over it as well

Edit: okay, I must admit that I turned it end for end a couple years ago ;-)

[chrisr]

Originally Posted by s/v Jedi

Edit: okay, I must admit that I turned it end for end a couple years ago ;-)

this is a good point that many forget. end for ending your anchor chain will extend the useful life by several years.

cheers,

[joelhemington]

Originally Posted by skipmac

Although the Maxwell docs say it works I don't think they make a gypsy for the 2200 that will work with G4 chain. Been working on boat with a 2200 that has 3/8 G3 chain. G3 link dimensions are almost identical to 3/8 G4 and it jumps badly in the gypsy.

Just ordered a 2' piece of 3/8 G4 to test on the off chance that the old chain is stretched out enough to make a difference but I'm not optimistic.

Apparently what happens is that the chain links chafe against themselves thereby lengthening the chain links slightly which results in the jumping. So the metal is not stretching longer, it just the length of the internal links that get longer due to the chaffing over time.

[Ron Bailey]

Originally Posted by Clipper4730

Greeting ye denizens Of the Oracle of empirical knowledge.

Time to replace our anchor rode. We currently have 350 ft of 3/8 BBB chain on a Maxwell 2200 HWC. Most of the old chain is unusable due to the fact that the PO had propylene line weaved into the links to mark the chain, unfortunately it rusted badly so we have about 5 links every 25 ft rusted badly except for the first 120’ boo. Trying to decide on the chain replacement and am having a hard time deciding between the BBB or G4. Does the weight of the BBB make it a better choice for the catenary aspect or is a lighter stronger chain more preferable. Our chain locker is quite large and fits the 350’ of BBB fine however with all that chain the boat does ride a bit down at the head. Oh and as far as anchors we have a 80lb Manson supreme as our primary, cqr as a backup and a big fortress stored in the fore peak for emergencies. Anyway thoughts one way or the other would be appreciated. One other thing currently we cruise West coast of Fl and the Bahamas (shallow) but may move the boat to California next spring if that makes any difference (lighter weight rode and more of it say 400’ for deeper water)

Anyways thanks in advance
Will

Will your windlass take both types of chain as normally they are calibrated to a certain pitch of chain, Ron

[Mickeyrouse]

Anchor chain gets replaced because it looses the galvanize and gets gets rusty. Try to find someone in your area that is set up to hot dip chain. They likely will charge a minimum, so try to get a few other boaters with similar re-zinc’ing needs on chain and anchors to make it practical.

[sv Stella Maris]

I can't believe what I'm reading...disregarding centuries of hard learned experience that chain weight is equally important to anchor weight. I dive my anchor almost daily when I take my morning swim. When the weather has been especially blustery I'm always very curious to observe my chain's sand pattern versus my neighboring boats. My chain is relatively 'oversized' at 12mm for a 18T 46' catamaran, but I would not downsize in favor of more chain (I carry 60 meters and additional rode). Normally what I find is that my 6:1 or more scope is so heavy that the meter or so after the anchor is rarely disturbed.

The chain provides a massive dampening to the shock load that is applied to the anchor. Even if I doubled my anchor size from 39kg to 78kg that still akin to a paperclip holding back a kid in a Radio Flyer wagon ! Physics people...shock loads magnify the force by huge amounts. Making the boat stretch out 6:1 scope of very heavy chain retards that shock load and allows the anchor to remain set.

My current neighbor replaced his 10mm chain in favor of trying more length of HT 8mm chain for time spent in the Med. He now swings all over the place as a result of the light weight chain and add a kedge in tight anchorages as a result !

350 feet ??? Are you anchoring in a fiord ? Thats some serious chain for a pleasure boat, wow wow ;-)

[NSboatman]

Oh boy. Here we go.

Sorry Stella maris; but things have moved on a bit... yes, believe what you’re reading, and do look up the background behind it.

You are not wrong at all when you say that shock loads are the killer, and yes- your chain weight helps I moderate conditions. But-

When you dive on your anchor of course the chain weight looks good and does a great job at absorbing the surge loads- it’s relatively calm conditions. Evidenced by the fact that you are diving on it! I challenge you to dive on it in 55 or 60 knots. I guarantee you will not see your heavy chain giving you that same lovely shock absorption then. It will be essentially bar tight and for all intents and purposes straight.

In these situations, the shock absorption of your chain is now essentially zero. Your ‘bounce’ comes from your snubber now. You have a good one, right? Because you’ll need one! And your best friend at this point is a god combination of a nice long stretchy snubber and a meaty, heavy, new-generation anchor well buried in thick mud.

The theory of the chain weight being a major factor in serious weather has been well debunked.

Most anchoring conditions less than gales - sure. It is a great help (which let’s admit is 99% of the time- so I do agree that for most of the time, chain weight helps).

But once that chain goes tight, it doesn’t matter what it weighs anymore. And believe me- it goes tight, and at lower tensions than you might think!

Ymmv... just my experience.

[Icarus]

Originally Posted by Clipper4730

Greeting ye denizens Of the Oracle of empirical knowledge.

Time to replace our anchor rode. We currently have 350 ft of 3/8 BBB chain on a Maxwell 2200 HWC. Most of the old chain is unusable due to the fact that the PO had propylene line weaved into the links to mark the chain, unfortunately it rusted badly so we have about 5 links every 25 ft rusted badly except for the first 120’ boo. Trying to decide on the chain replacement and am having a hard time deciding between the BBB or G4. Does the weight of the BBB make it a better choice for the catenary aspect or is a lighter stronger chain more preferable. Our chain locker is quite large and fits the 350’ of BBB fine however with all that chain the boat does ride a bit down at the head. Oh and as far as anchors we have a 80lb Manson supreme as our primary, cqr as a backup and a big fortress stored in the fore peak for emergencies. Anyway thoughts one way or the other would be appreciated. One other thing currently we cruise West coast of Fl and the Bahamas (shallow) but may move the boat to California next spring if that makes any difference (lighter weight rode and more of it say 400’ for deeper water)

Anyways thanks in advance
Will

Depends if the chain is DIN or ISO, they have a different pitch.
A Safe Working Load is about 1/5 of braking strain.
So your 1000kg rated chain will rip out your bow fitting before the chain breaks.
I had my BBB 3/8" chain tested and it broke at 5.6 t (metric)

I have 80m of chain and about 50m of 16mm nylon rope...seems to work ok.

[sv Stella Maris]

Thanks for the reply BoatMan,

You'd be correct, I don't swim during the active blow...well I did once but for a fouling issue...not fun, but a calculated risk taken.

The bottom doesn't lie and in the right conditions the evidence is often still present to the discerning eye after a good blow; once the water clears. I can see where the anchor pivoted, reset, dragged or not, and at what rate the chain disturbed the bottom. Not all bottoms provide this story, but I've found myself in either good bottoms or terrible muddy mangroves for storms...the mud doesn't tell much of a story, but my boat doesn't move lashed by a dozen lines ashore either.

Regarding your claim of 'straight as a rod' I'm sorry this is not realistic. With proper scope, up to 9:1 for winds you chose, the chain will not pull straight and is fighting to lay back down at every moment...gravity never ceases.

In physics we studied tension bridges, and being in California it was the Golden Gate Bridge. Depending on the material tensile strength and liner weight used, an optimal length could be easily calculated for the anticipated load. Too short and live load shocks were more likely to find a defect and fail, while too long would see the cable sag under its own weight and give up its tension properties as it became over stressed.

But in all situations with any material calculated it is never possible on Earth to make the cable straight; and shock-loading-stress became a mute point and gave way to more complicated calculations for wave-length-frequency transmission that might vibrate fixed-fittings to the point of deflection and ultimately failure.

When I learned structural rigging, we were taught an anchor called the 'multi wrap' in which no knot is ever tied at the final anchor. Instead the running rigging media is wrapped around the block so many times friction does the work, and it will never come undone, but is easy to remove after massive loads are applied.

I have observed this to be true regarding vessel anchors. The 'multi wrap' knot-less principle would translate to using very long sections of chain only, or shorter sections of larger relative chain, but either way no final anchor. The weight and friction on the ocean floor become the anchor.

But to sleep at night I do have a modern anchor...it works great. My bridle (catamaran) is adequately sized to properly stretch and fail before a structural component does. And my scope is managed with consideration to my neighbors needed swing radius.

Just had a Pan Pan on the radio for a vessel run aground. I hailed him and they are safe, but needed a calm voice to remind him that the tide is rising and he's his best resource. Stay safe out there everyone.

[svbravo]

Regardless of chain size or grade, be sure to always specify with an “oversized link” at each end. This will allow you to use a shackle which better matches the strength of the chain. If you don’t do this, the largest shackle size which will fit in the end link becomes the assembly’s weakest link. We order with an oversized link at each end so we can end for end the chain when it starts to get rusty, as has been described above. Most of the better chain manufacturers can supply chain spec’d this way.

[Clipper4730]

Hey folks thanks for the great info! Knew I could count on a lively thread with lots of great info. Going to order a few lengths of the G43 and G70 to try on the windlass. It is a dual Gypsy horizontal Maxwell and actually never used the port side as the primary anchor is on the starboard side. Maybe it’s for a different size not sure. To be honest I would love to have a rope Gypsy on that side to be able to have an easily deployable rope rode for fishing and diving in deeper water. Anyway 350 ft is probably overkill boat came with it. Original owner wanted to sail to Mars I think. Boat has almost 200 gal of diesel and 200gal of freshwater plus a 20kw genny and a watermaker not sure where he was going but hey I’ll take it. Anyway thanks for the info it’s much appreciated.

Will

[GordMay]

Stella Maris:
Tugboat Hitch - Is this Tensionless Hitch (or the Lighterman’s Hitch) an analogue for your “multi wrap knot-less principle”?
➥ https://www.animatedknots.com/tensionless-hitch-knot
➥ https://www.animatedknots.com/lightermans-hitch-knot

[chrisr]

Originally Posted by svbravo

Regardless of chain size or grade, be sure to always specify with an “oversized link” at each end. This will allow you to use a shackle which better matches the strength of the chain. If you don’t do this, the largest shackle size which will fit in the end link becomes the assembly’s weakest link. We order with an oversized link at each end so we can end for end the chain when it starts to get rusty, as has been described above. Most of the better chain manufacturers can supply chain spec’d this way.

not bad advice, however personally i always secure the bitter end of the chain with half a dozen turns of dyneema - not a shackle. plenty strong enough if it comes to it, BUT importantly, we can cut it if need to slip the cable in an emergency

you never know...

cheers,

[s/v Jedi]

Originally Posted by chrisr

not bad advice, however personally i always secure the bitter end of the chain with half a dozen turns of dyneema - not a shackle. plenty strong enough if it comes to it, BUT importantly, we can cut it if need to slip the cable in an emergency

you never know...

cheers,

The enlarged link is for attaching the anchor shackle, not securing the inboard end. You want the enlarged link at both ends so that you can turn the chain end for end for double life span.

[chrisr]

yep...fair enough. i'm a strong believer in end for ending chain !

fyi at the anchor end we used an 8mm G70 shackle on the 8mm G40 chain as an alternative. this shackle has much the same SWL as the chain (around 1.2mt by memory)

cheers,