How much working load does my anchor chain need?

[O_salt]

Hi Nolex,

Went and looked at the Aqua 7 you linked too; They listed 10mm as 4850# Safe working load. G70 Acco galvanized 3/8" has safe working load of, 6600#, G43 has safe working load of 5400#. Why would you pay extra for G70 or Aqua7 when G43 gives you better performance?

The link confirms what I stated, 7 series chain when galvanized does not perform as well a 4 series chain galvanized.

O_salt

[mitiempo]

I went back and forth about anchor size and chain size/length for my CS27. In the end I bought an electric windlass and 200' of 1/4 G4 chain for my Rocna 15 (33 lbs). 200' of G4 is about 150 lbs and the max I want forward. No swivel.

If the op has a windlass I think this is a good combination. Plenty strong enough as the load should never be totally on the chain with a good snubber that can be adjusted from short to about 30'.

If the op doesn't have a windlass I would go with about 60' of 5/16 G4 and the rest 3 strand nylon.

[SV Bacchus]

Originally Posted by Cheechako

I understand, but if you can get on here why don't you look it up on line?

I've wondered that very same many times on many threads over the past several months..

[noelex 77]

Originally Posted by O_salt

Hi Nolex,

Went and looked at the Aqua 7 you linked too; They listed 10mm as 4850# Safe working load. G70 Acco galvanized 3/8" has safe working load of, 6600#, G43 has safe working load of 5400#. Why would you pay extra for G70 or Aqua7 when G43 gives you better performance?

The link confirms what I stated, 7 series chain when galvanized does not perform as well a 4 series chain galvanized.

O_salt

G7 chain is stronger than G4. You need to compare like with like. Maggi use a conservative relationship between SWL and break strength. For 10mm chain they list the SWL of G7 as 2200 kg and G4 as 1600 kg.

Acco use a more liberal relationship between SWL and break strength but as I would expect still list G7 as considerably stronger than G4. 6600 lbs for G7 and 5400 lbs for G4 according to your figures.

I see no evidence that "7 series chain when galvanized does not perform as well a 4 series chain galvanized." The figures suggest the opposite.

[O_salt]

Hi Nolex, I was comparing SWL for both chains, from their published data, and both chains where the ISO version of the chains, so the measurements should be according ISO standards, also both chains offer proof test certificates if required.

The ACCO Series 70 chain is stronger before Galvanizing, it is also stronger than the AQUA 7 that is galvanized. The G43 from ACCO has a higher SWL than the AQUA 7 in their published data, both using ISO measurement standards.

I have had this discussion many times over the past 30 years selling anchor winches and chain. From small boats up to vessels that used 32mm studlink chain. It would be great if their was a series 7 or higher chain that would give us the same SWL galvanized as un-galvanized.

O_salt

[Mike Banks]

Old timer rule of thumb for small craft--the safe working load of your chain should be the weight of your vessel.

This supposes it is fastened to the vessel in such a way that it will not rip the securing cleats out of your deck--because these fittings ultimately determine your safety in a blow at anchor if your anchor itself is secure in the sea bed..

Put out plenty of short linked chain and use a kellet as well--and with a decent anchor such as a Manson Supreme or something similar you should be able to ride out most storms. If you are using nylon rode in addition to your chain--make sure the kellet is fitted back in the chain and not where it joins the nylon. Many people believe if you use nylon which has a lot of stretch one need not use a kellet--but they are different--the kellet improves the holding of the anchor and nylon just allows for the vessel take surges with less shock (as does a kellet also)

[knockabout]

6 mm short link /15-20 lb plough / the wind doesn't read the marine engineering specifications and may vary


25ft boat /50kg drum of 6mm short galv or stainless / possible option for deep anchorage 300 mtrs 8mm silver rope 3mtrs 6mm short link galv chain 15lb plough
we carry both / we weigh 7 ton and 21ft waterline length / we are on the other side of the pacific behind the great barrier reef

[reed1v]

Not sure you, the OP, are using the term correctly. Think you are asking what size chain to use? Anyhow work load, breaking strength, percent of breaking strength are all different things. Any good reference book dealing with anchoring and chains will give you all the info you need. By asking the question would indicate you need to learn a lot. Not bad mouthing you, just advising.

[Bulawayo]

Does anyone have experience of using German manufactured cromox stainless steel Grade 60 plus anchor chain? I have read a couple of positive experiences but not actually communicated directly with anyone using this.

[Jim Cate]

Originally Posted by Mike Banks

Old timer rule of thumb for small craft--the safe working load of your chain should be the weight of your vessel.

That is just silly, mate! By that standard, I would need 20 mm G-8 chain on my 46 foot light displacement boat. Dunno what "old timers" you got that from, but they may be suffering from Cruzeheimers disease.

Jim

[sailor Martin]

Thank you all for the advice
I will go with the g4 1/4.
Now i just need to find where to buy it here in colombia or in panama

[Olddave]

possible option for deep anchorage 300 mtrs 8mm silver rope f[/QUOTE]

Hi knockabout
I was suprised to see Silver Rope recommended for anchoring. I have a fair bit of experience with rope, however, I don't like to go off half cocked so I googled it to see what the manufacturers say.
Silver rope is made from polyethylene and floats, that's a negative when anchoring because it can easily be picked up by the prop of a passing vessel. I imagine that floating rope does not help with the catenary of a chain either.
Polyethylene is quite strong but does not have the elasticity of nylon. Elasticity helps to protect the rope from breaking & the anchor from breaking out when shock loads are experienced in the worst conditions. That is when you need all the helpyoucanget from your gear.
Finally 8mm is very light rope for anchoring any vessel. I have seen 6mm anchor rope on a jet ski cause an amputation when it formed a loop and pulled tight due to a snag and swell action.
For anchoring I have always used nylon, either 3 strand or 8 plaited. My choice for a 25 footer would be 12mm, however, I understand stowage problems so maybe 10 would be OK. If the chips were down, I would rather have 12mm

I hope this info is helpful. Dave

[noelex 77]

Originally Posted by O_salt

Hi Nolex, I was comparing SWL for both chains, from their published data, and both chains where the ISO version of the chains, so the measurements should be according ISO standards, also both chains offer proof test certificates if required.

The ACCO Series 70 chain is stronger before Galvanizing, it is also stronger than the AQUA 7 that is galvanized. The G43 from ACCO has a higher SWL than the AQUA 7 in their published data, both using ISO measurement standards.

I have had this discussion many times over the past 30 years selling anchor winches and chain. From small boats up to vessels that used 32mm studlink chain. It would be great if their was a series 7 or higher chain that would give us the same SWL galvanized as un-galvanized.

O_salt

O_Salt you are falling for a common trap of comparing SWL using different criteria. Acco calculate the SWL by dividing the ultimate failure load by a much smaller number than Maggi. From memory Acco use 2.5:1 and Maggi 4:1.

Galvanised G7 chain of the same diameter is always considerably stronger than galvanised G4

Ungalvanised G7 is slightly stronger than galvanised G7 (if conventional hot dip galvanising is used),but of course ungalvanised chain is not suitable for marine use. It has been suggested Maggi actually use G8 and after the galvanising process call it G7, due to the slight loss of temper.

[mako]

Originally Posted by Olddave

I was suprised to see Silver Rope recommended for anchoring...
Silver rope is made from polyethylene and floats, that's a negative when anchoring because it can easily be picked up by the prop of a passing vessel. I imagine that floating rope does not help with the catenary of a chain either.

On my small boat I use polyprop extensively in this area where we don't have any live coral but we have lots of sharp limestone. I use a double heavy anchor and just a short length of double heavy chain. Keep the scope as short as possible especially with all the idiots blasting too close by.

In the future on a larger boat I would switch to carrying a spool of Lugger line or something similar that is 50/50 mix of polyester and polyprop, for use in coral areas. Then switch back to nylon for "normal" anchoring. These mix formulas are either neutral or very slightly positive buoyant, just enough to keep your rope off the coral on the bottom but not enough to become a hazard for passing by idiots .

[mako]

Originally Posted by pdenton

Never anchor in a fashion which might destroy coral.

In my estimation the destruction of coral in any jurisdiction is a crime.
Pdenton, marine biologist

I don't know what the emoji is for "applause" but I would use it. Everyone keeps talking about anchoring in coral but never about just NOT doing it in the first place. That's a great excuse for installing even a cheap downscan sonar on your boat, even if all you need is a depthsounder, because then you can try to get a feel for the sand areas versus rocks/coral.