Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 06-08-2016, 13:03   #1
Registered User

Join Date: Oct 2013
Posts: 31
How much working load does my anchor chain need?

Hi
Im about to buy about 40 meters of extra chein for my Vancouver 25 that weits 3.2 Tons before extras such as food and people. im now in colombia and planing to sail around south pacific so iv been told to expect some strong winds and deep anchorages.
At the moment i have 15 meters of 5/16 which i dont no the spesification about but i think its good qwality becouse of how it looks.

Any body knows what should be the working load of the chein that im about to buy?

Thank you all
__________________

gal ecker is offline   Reply With Quote
Old 06-08-2016, 13:15   #2
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 20,343
re: How much working load does my anchor chain need?

I would think 1/4" chain would be plenty strong for your 25.
__________________

__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 06-08-2016, 14:21   #3
Registered User

Join Date: Oct 2013
Posts: 31
re: How much working load does my anchor chain need?

Thank you very much for the reply. But i askd for the minimal workng load and not for the caliber. There are diffrent kinds of 1/4 inch. Some can hold only 500 Kg As working load and some hold more.
Thanks agein
gal ecker is offline   Reply With Quote
Old 06-08-2016, 14:29   #4
Senior Cruiser
 
Sailmonkey's Avatar

Cruisers Forum Supporter

Join Date: Sep 2009
Location: Houston
Boat: '76 Allied Seawind II, 32'
Posts: 6,402
re: How much working load does my anchor chain need?

Heres a table of some standard rhode loading based on boat and windspeed.

http://www.mantusanchors.com/mantus-...e/rode-sizing/


Sent from my iPhone using Cruisers Sailing Forum
Sailmonkey is offline   Reply With Quote
Old 06-08-2016, 15:01   #5
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 20,343
re: How much working load does my anchor chain need?

Quote:
Originally Posted by gal ecker View Post
Thank you very much for the reply. But i askd for the minimal workng load and not for the caliber. There are diffrent kinds of 1/4 inch. Some can hold only 500 Kg As working load and some hold more.
Thanks agein
I understand, but if you can get on here why don't you look it up on line?
PS: I've used 5/16 hi test on boats over 40 ft.
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 06-08-2016, 15:16   #6
Senior Cruiser

Cruisers Forum Supporter

Join Date: Aug 2009
Location: between the devil and the deep blue sea
Boat: a sailing boat
Posts: 17,478
re: How much working load does my anchor chain need?

5/16 is good for your boat. You want g4 grade for regular use.

b.
barnakiel is offline   Reply With Quote
Old 07-08-2016, 01:10   #7
Moderator
 
noelex 77's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Boat: Bestevaer.
Posts: 10,952
re: How much working load does my anchor chain need?

It is a good question and surprisingly not an easy one to answer. The ABYC give the expected load for your boat in 60 knots as 2100 lb. The ABYC are felt by many to overestimate the forces, or be a worst case scenario. Prof Knox came up with an alternative formula. I have crunched the numbers for your boat and in 60 knots it is 920 lbs.

There is obviously a large discrepancy in these numbers. This comes about because the dynamic loads, especially from wave action can be very high. Anyone who has anchored with significant wave action when being on a lee shore or anchored on a coral reef at high tide will realise the dramatic effect. It is difficult to know what allowance for these dynamic loads is reasonable. It also needs to be remembered that the forces go up roughly with the square of the wind speed. I have given the figures for 60 knots but higher wind speeds are certainly possible and the force rises substantially.

1/4" G30 chain has a SWL of 1300 lb. In my opinion this is too low (although it is not unusual to buy G3 chain and find it is actually G4). 1/4" G43 chain has a SWL of 2600 lb. Unfortunately 1/4" (or metric 6mm chain) is not available in G7 as far as I am aware. Some have suggested buying 1/4" G8 lifting chain and having it galvanised as a way around this problem.

1/4' G43 is getting close to the limit that is acceptable, but I think it is fine for your boat. 1/4" chain will enable you to carry a much longer rode and/or a heavier anchor than going up to 5/16" G43. I think for a similar weight of ground tackle (and this is generally the limit especially on a small yacht) the lighter chain will be ultimately safer given that you will be able to carry more chain (important in coral waters) and possible a heavier anchor.

If you do go for 1/4" G43 make sure the chain is in good condition with no corrosion and pay particular attention that the connecting shackles/swivels are suitable and not the limiting factor, especially with some side loading.

One difficulty with this advice, is that traditionally yachts carried heavy chain with relatively poor anchors. We are entering a new era where cruisers are using lighter chain with heavier and higher performing anchors. Historically chain breakages are exceedingly rare (unless due to corrosion), but it is difficult to know if this still be the case in the future.

I assume you do not have a windlass. For those that do check the availability (and cost) of a new gypsy if you order different sized chain.
noelex 77 is online now   Reply With Quote
Old 07-08-2016, 03:50   #8
Registered User
 
Snowpetrel's Avatar

Join Date: Jul 2012
Location: Hobart
Boat: Alloy Peterson 40
Posts: 3,550
re: How much working load does my anchor chain need?

^^Very good post Noelex, though I once saw a 28 footer snap g30 1/4 inch chain during a nasty night with 40 knots and 1 meter seas plus a swell rolling into a bay. But I don't think he had much in the way of a snubber, and the holding was very good hard sand. So I think g43 chain plus a long snubber would have been fine in this case on his larger boat.

I used 5/16 on my old 26 footer. Now I would probably go g4 1/4, but she was pretty light, about 2 tonnes. I think given the weight of the vancouvers id rather probably go the 5/16 chain at this stage until g7 1/4 is available. But its a hard toss up between the sizes in your case and either would probably work fine. Is there a way to get the chains weight further aft and lower?

Sent from my SM-G930F using Cruisers Sailing Forum mobile app
__________________
My Ramblings
Snowpetrel is online now   Reply With Quote
Old 07-08-2016, 06:57   #9
Senior Cruiser

Cruisers Forum Supporter

Join Date: Aug 2009
Location: between the devil and the deep blue sea
Boat: a sailing boat
Posts: 17,478
re: How much working load does my anchor chain need?

It is all a sweet banana discussion and an interesting one too.

Just PLS allow for what can be actually handled when there is no anchor winch (this is quite often on small boats).

Hence my experience: 8/9/10 mm chain works best. Smaller and bigger sizes are TOO DIFFICULT on the hands of the human winch.

This is imperial 5/16 to 3/8 range. (?) I think.

If you are your own winch, ;-), avoid chains of smaller or higher size.

PS I downgraded from 10 to 8 mm here to get MORE (=longer) chain.

Cheers,
b.
barnakiel is offline   Reply With Quote
Old 07-08-2016, 08:16   #10
Moderator
 
noelex 77's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Boat: Bestevaer.
Posts: 10,952
re: How much working load does my anchor chain need?

Quote:
Originally Posted by barnakiel View Post
Just PLS allow for what can be actually handled when there is no anchor winch (this is quite often on small boats).

Hence my experience: 8/9/10 mm chain works best.
An intereresting point.

Certainly with rope rode as it becomes thinner it becomes too difficult to grip, so you need to be careful going too thin even if the extra strength is not needed. But I have never noticed this with chain. Chain is "lumpier" so getting a grip on even thin chain with a hand or glove is less of an issue, at least for me.

At one stage I owned a 26 foot yacht with no anchor winch. We cruised coral waters, so all chain was essential. We carried 60m of 6mm chain. Some of the anchorages were quite deep (20m). When hauling it up, I cannot say I ever wished for thicker chain .

The weight you are hauling up goes up considerably as chain becomes thicker.
20m (60 feet) of 6mm weighs (in air)= 17kg, 8mm= 29kg and 10mm= 46kg. In water the weight will be about 10% less, but there is friction around the bow roller and for the last part of the lift you also need to include the anchor weight.

You also need to consider the total weight at the bow. With 60m of 6mm chain the chain weighs 51 kg, about as much as our lightly built little yacht would tolerate, otherwise I would have installed more. 60m of 8mm = 87kg 10mm= 138 kg.

The OP has only mentioned 15m of chain, but if cruising coral waters he will need much more.
noelex 77 is online now   Reply With Quote
Old 07-08-2016, 09:02   #11
Senior Cruiser

Cruisers Forum Supporter

Join Date: Aug 2009
Location: between the devil and the deep blue sea
Boat: a sailing boat
Posts: 17,478
re: How much working load does my anchor chain need?

Yes.

It will be as you observed.

There are many factors and we do differ physically - I have relatively small hands and I am super fit yet not very strong (I am 6ft tall and less than 150 pounds heavy, which limits me quite a lot).

So, with 6mm chain I bet it will be G7 stuff?

As for desired length of the chain, I always say longer is better. We had about 60ft of 10mm which I have swapped for 100ft of 8mm.

So to say I swapped for more length while holding on to roughly the same weight (about 120 pounds total, boat 26 ft).

I think I could manage more than 100ft of this (8mm) chain except this would be quite a lot weight in the bow of our very fine entry boat. I think this could be no problem on many US boats that tend to be very full in their bow sections. But it is already way too much for our specific design.

I am actually considering moving all chain to the bilge for our passages. I could remove the 33 pound anchor too, except it does not fit into the bilge.

Cheers,
b.
barnakiel is offline   Reply With Quote
Old 07-08-2016, 10:38   #12
Registered User

Join Date: Nov 2014
Location: Puerto Montt
Boat: Perry 47 Ketch 1981
Posts: 119
Send a message via Skype™ to surazo
Re: How much working load does my anchor chain need?

Gal,
Im sailing in south pacific and you are right expecting anchorages no less 10 m deep due the tides ,over 6 m, and winds up to 30 knots as common .sometimes over 40 knots
regards Surazo
surazo is offline   Reply With Quote
Old 07-08-2016, 11:49   #13
Marine Service Provider
 
O_salt's Avatar

Join Date: Sep 2010
Location: Bellevue, Wa.
Boat: Beneteau, First 47.7, 48.5', Flyer
Posts: 33
Re: How much working load does my anchor chain need?

Hi, thought I would throw some information into this discussion;

The chain has three number for its strength, working load, proof load and breaking strength. Working load is the pounds pull it can handle without any damage to the chain and can handle day in and day out. Proof load is the force it takes to elongate a link, this function works a excess force indicator, at any time, if you have a elongated link, this means the force on the chain has exceeded it's proof load. It is time to replace this chain. Breaking strength is the force that will break the chain. Proof load is typically double the safe working load, and breaking strength is double proof load. What this all means that there is a large safety margin built into chain and it has built in indication when chain has been overloaded.

In regards to G3, G4, and G7; besides higher loads the higher the number the more brittle the chain is, with G3 being the most malleable and G7 being the brittlest. Their is a reason that G7 does not come galvanized from the factory, the process of Hot dip galvanizing changes the properties of the metal with the high temperatures the Hot dip galvanizing.

G4 or High Test chain is the best choice for a type of chain for anchoring. It is the balance between strength, size and durability. SS is not a good choice for anchor chain, it is to brittle.

ABYC's chart is a good guideline for sizing the safe working load for your ground tackle, use the storm anchor column.

When using HT G4 chain, always use shackles rate at or higher than the safe working load of the chain. Most galvanized shackles are Proof coil type ratings.

Hope this info helps, let me know if you have any questions.

O_salt
O_salt is offline   Reply With Quote
Old 07-08-2016, 11:59   #14
Registered User

Join Date: Apr 2016
Posts: 178
Re: How much working load does my anchor chain need?

The discussion about which of many options is the correct way to anchor will go on and on. In the end each skipper must make their own decision.
There is however an aspect of this problem which is not negotiable.

Never anchor in a fashion which might destroy coral.

I would've thought that everyone who sails in the tropics understands the coral is an endangered species. 50 percent of the coral in the Caribbean has irreversibly been destroyed. This destruction is one of the strongest proofs for the reality of global warming.
The message is clear: if you have set your anchor so that the movement of your chain will destroy coral, move to an other anchorage. Never ever drop the hook in coral, live or seemingly dead.
In the Florida Keys, the destruction of even a little bit of coral is a federal crime. Punishable by huge fines and in some cases confiscation of the boat.
In my estimation the destruction of coral in any jurisdiction is a crime.
Pdenton, marine biologist
pdenton is offline   Reply With Quote
Old 07-08-2016, 12:17   #15
Moderator
 
noelex 77's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Boat: Bestevaer.
Posts: 10,952
Re: How much working load does my anchor chain need?

Quote:
Originally Posted by O_salt View Post
Their is a reason that G7 does not come galvanized from the factory, the process of Hot dip galvanizing changes the properties of the metal with the high temperatures the Hot dip galvanizing.
Depending on how it done the galvanising process does reduce the strength of hi tensile chain. However, this is taken into account in the final specification.

There are a couple of marine providers that produce galvanised G7 chain "from the factory" such as Maggi.

https://www.jimmygreen.co.uk/product...qua-7-grade-70
__________________

noelex 77 is online now   Reply With Quote
Reply

Tags
anchor, loa

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Working load for anchor shackle Palarran Anchoring & Mooring 16 27-04-2014 04:59
How Much Weight Can I Load My Freaking Boat Up With?!??!! NOMN Monohull Sailboats 32 06-06-2013 22:15
How Much Load on Halyards ? rhr1956 Deck hardware: Rigging, Sails & Hoisting 6 09-02-2012 05:42
Working Load of Chain PyotrBee Anchoring & Mooring 2 14-01-2012 14:29
Does Chain Stopper Wear / Damage Chain ? nitpik Anchoring & Mooring 29 25-02-2010 11:51



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 22:31.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.