Anchor chain question...

M

mixmaster

Well-Known Member
Joined
19 Feb 2007
Messages
528
Visit site
Ok. Close to everyone's favourite topic, anchoring.
I need to buy some new chain as the old one is rusting to bits. Here's the dilemma: I have a Lofrans windlass with an 8mm gypsy and a 20kg (45lbs) bruce anchor. I plan to upgrade to a 25kg (55lbs) delta anchor, keep the bruce as a kedge and was going to upgrade to 60 meters of 10mm chain and and matching 10mm gypsy. Now, looking at Bradney chains website (http://www.bradneychain.com/products_search.htm?product=Windlass Chain) I see that you can get grade 40 8mm chain which has just a slighly lower breaking strength than grade 30 10mm. So, do I keep the 8mm gypsy and buy the grade 40 8mm chain which is lighter, cheaper and almost the same strength or go with the grade 30 10mm stuff?

The boat is an 11,000kg, 45 foot Grand Soleil and I'm equipping her for long distance crusing and lost of anchoring out.

If anyone has any different ideas regarding anchor weight (but not type!) and anchor chain then by all means...
Thanks.
 
I'd take the gypsy off, make sure it matches the 8mm chain and go for that. Less weight, and you could then afford to take a bit longer chain if you want, but what you're suggesting sounds fine.

Take care of the right shackle rating for the chain size and you'll have no probs. Look at Crosby shackles G209A series and all their info on chain / shackle ratings. You can often go one size up on shackle with a Crosby G209A series.

This is worth a read - bookmarked from a helpful forumer on YBW, it's what I've followed http://www.morganscloud.com/techniques_tips/ttqaanchoring.htm
 
You are looking at the wrong chain parameters nobody ever breaks anchor chain, though there have been cases of links between chain and anchors failing, the 8mm grade 30 has plenty of strength. The reason for upgarading to heavier chain/anchors is that the extra wt helps stop the anchor dragging. The diff in wt between 8 and 10mm chain is about 1.5Kg so you add about 90kg, the difference in anchor wt is an insignificant 5kg but the slightly bigger flukes will give more resistance provided the chain wt keeps the pull along the bottem.

A well balence anchor/cable combinations means that the anchor will start to drag before all the chain has lifted from the seabed allowing an upward pull which whould break out the anchor. To achieve this generally 8mm chain is matched to anchors up to about 15kg, 10 mm to about 30kg.

While the anchor sounds OK 60m chain on a boat that size sounds rather short unless you are deffinatly only going to be in shallow waters with small tied ranges and have shollow draft. Even on a 7:1 scope allowing for about 1.5m freeboard at the bow this only gives you 7m max depth, allow another 1.5m for swell and even a moderate tide and you could find youselt uncomfortably close to the bottem or in the surf. I would think about either going up to 100-120m for an all chain rode or going for 50m 12mm chain plus at least 100-150m 25mm rope so that you are able to put out at least a 7:1 scope on 10m but preferably 10:1. Once the depth is over 10m scope ratios can be dropped so you actually need very little more cable even in 20m. As a rule of thumb I work on min 3:1 scope but then increase it to matchthe wind force so 5:1 in F5, 8:1 in F8, above that I just put out everything I can!
 
Nauti and Roly. A longer cable is the one of the reasons I'm considering the 8mm chain.

I agree with you on the weight issue Roly but a lot of people argue that the weight is better put into the anchor not chain (steve Dashew, the Morgans Cloud folks on the link above etc..). Ideally I would go with the heavier chain as well but I'm concerned that if I up the length and diameter the chain will stack too high in the anchor well (so many variables!). Should my bower be heavier than 25kg?

Anyone have experience with the Bradney chain people? I notice they quote "tested to" strenghts (1650kg in the case of the Grade 40 8mm). Is this the same thing as "safe working load". Is 1650kg enough? I understand that the faults usually happen with poor shackles, inappropriate strop etc..
A part of me is still thinking, bigger anchor!
 
However. 10:1 is a bit excessive in normal use no? For extreme cricumstances I carry 60 meters of 18mm anchorplait as well (but is not part of regular set up as a pain with the way the cable goes past the gypsy).
 
[ QUOTE ]
A well balence anchor/cable combinations means that the anchor will start to drag before all the chain has lifted from the seabed allowing an upward pull which whould break out the anchor.

[/ QUOTE ]Unless the anchor is entirely inadequate, that statement is utterly incorrect.

[ QUOTE ]
I agree with you on the weight issue Roly but a lot of people argue that the weight is better put into the anchor not chain (steve Dashew, the Morgans Cloud folks on the link above etc..). Ideally I would go with the heavier chain as well but I'm concerned that if I up the length and diameter the chain will stack too high in the anchor well (so many variables!). Should my bower be heavier than 25kg?

[/ QUOTE ]The likes of Dashew and Harries (Morgan's Cloud) have a huge amount of experience and know what they're talking about, and one can do worse than listen to their advice.
On size, If you're selecting a new gen type then 25Kg will be about the right size, anything else I would want to be quite a bit larger. You could oversize further yet if you think you need to regularly anchor on low scopes.

[ QUOTE ]
Anyone have experience with the Bradney chain people? I notice they quote "tested to" strenghts (1650kg in the case of the Grade 40 8mm). Is this the same thing as "safe working load". Is 1650kg enough? I understand that the faults usually happen with poor shackles, inappropriate strop etc..
A part of me is still thinking, bigger anchor!

[/ QUOTE ]I don't think 8mm G40 is adequate for your boat; you're thinking down the right lines to save weight, but you would need to go to high tensile G70 at 8mm. The better G40 match for your boat and a 25Kg new gen anchor is 10mm. This is a strength issue and weight is not relevent.

[ QUOTE ]
However. 10:1 is a bit excessive in normal use no? For extreme cricumstances I carry 60 meters of 18mm anchorplait as well (but is not part of regular set up as a pain with the way the cable goes past the gypsy).

[/ QUOTE ]While scope is the most important factor, there is little benefit in more than 8:1 - the decreasing angles past that point are trivial.

On all the above, please read the following:
www.rocna.com/boat-anchors/catenary.php
This is probably the article Sybarite was referring to.
 
10mm G30 is the call. Using 8mm on a 45ft distance cruiser is silly light.

Chains are there for a reason and one is the weight of them. In a well balanced system the anchor does next to nothing below 15 knots of wind, approximately. 95% of boats don't actually need an anchor until the wind gets up to that area, the chain alone will hold them fine, assuming a half decent length deployed.

Use too small a chain and the anchor and the small bit of dirt it's into has to do all the work. Spread the love between anchor and rode for vastly improved performance.

I agree with Craig (we do occasionally /forums/images/graemlins/wink.gif ) that if the anchor moves without the chain being lifted 1st something is out of balance or the anchor is just crap.

Interesting reading the Bradney stuff. I wonder why the 'tested to' load (also know as the Proof Load) of the G40 8mm is only that of a G30. A G40 8mm's proof load should be 2000kg minimum. By industry standards what they are calling G40 is called G30 by everyone else. The 10mm G30 'tested to load' should be 2500kg. The 10mm number they have listed means it should only be a G23.

'Proof load' is the load it is tested to in the factory before shipment. It is 1/2 the rated break load and twice the Working load.

[ QUOTE ]
Windlass chains need to be calibrated to ensure consistent dimensions. Furthermore, the same chain is rarely interchangeable between different makes of windlasses. Even if the chain diameter is the same they are likely to require links of different dimensions to ensure a good fit.

[/ QUOTE ]
1st sentence - all reputable manufacturers calibrate their chains as standard. Many chains from the east are not calibrated or are very poorly done. Many have killed winches or at least caused big buck repairs.
2nd sentence - pretty much just bull pooh.
3rd sentence - correct, the chain you buy must fit the gypsy you have fitted. There are physical size differences between some Standards i.e. the DIN766/A 10mm is 2mm per link shorter than the EN818-3 Standard and both of those will not fit the same gypsy but all big winch manufacturers have gypsies to suit either.

[ QUOTE ]
You are looking at the wrong chain parameters nobody ever breaks anchor chain,

[/ QUOTE ]

I sorry but Rubbish. Chain failure is on a big upswing, noticeably so. To much cheap stuff from the east being sold as 'reliable'. Sadly most is being sold by people who don't know what they are selling.
 
Good quality 8mm G4 will be fine.
The 8mm is heavy enough to keep the anchor shank down, provide shock resistance, tolerate coral and rocks and has a breaking load that vastly exceeds the holding power of any anchor you are likely to use in any bottom.
The 10mm adds significant and unnecessary weight in the wrong place.
All IMHO, as usual..
 
One of the issues here is the strength of the Windlass. Which Lofrans have you got? I have 60m of 10mm chain with 100m of 16mm octoplait attached.[I anchor a lot]. You need the thicker rope with 10mm to "bite" on the gypsy. This should allow most situations anchoring in 10-20m.
If you are planning on going long term cruising your main peace of mind is when you leave the boat or sit inside with the wind howling. Good heavy tackle, with plenty of spare capacity and also other anchors to use in conjunction with the main anchor is what you need. I have had 3 anchors out with plenty of scope and still stayed awake all 24hrs.
 
GMAC - I don't know where you're located but it seems to me that here in the UK none of the chandleries talk of tensile strength and where the chain comes from. Regarding calibrated chain, they all sell "regular" and chain they claim to be calibrated for your brand of windlass. What's the story? Does it sound to you like the Bradney chain is of a funny spec?

Craig, I've never seen G70 chain sold anywhere...?
Mudisox, I have a Lofrans Leopard mounted horizontally (11 years old).

Salty, you seem to fall in the lighter chain, put the weight in the anchor school.
I think I am veering towards that way of thinking, partly because I can fit more chain that will stack lower in the anchor locker (whereas a bigger anchor on the bow shouldn't make much practical difference).

Just need help on all these tensile and calibration issues...
 
Having just gone down this route, you may find it worthwhile to talk to E C Smith who are the UK agent for Lofrans.

We looked at Bradney but couldn't get what we required to fit our new Lofrans windlass, i.e. 10mm G40. We did manage to get some from E C Smith, calibrated for our Lofrans.

For what it's worth, your requirements should be looked at in terms of where you're planning to sail to some degree - if you are planning to visit higher latitudes, for example, it might be worth going for 10mm G40, as well as a bigger bower anchor.

G70 doesn't seem to be available in Europe readily, although there is an Italian manufacturer that apparently lists it as lifting chain, although from what I could glean it wasn't galvanized. ACCO chain (US) is the thing, but how to get it here at reasonable cost was the main downside.

Much of the chain available in the UK is now from the far east, and as some of the other comments here suggest is fairly questionable in terms of quality. We found it very difficult to get the people offering it to give us specific details of SWL or breaking load, and when we did, the results appeared to be very poor.
 
Had a chat with EC Smith the other day actually. Seems like the stuff and my local chandlery deals with them as well. In terms of plans, currently just sailing English Channel/Biscay but have more ambitious plans. Not planning to go any further north.
Nice boat by the way. What set up did you go with? I know you went with 10mm Grade 40, how long. What anchor?
 
If you galvanize G70 chain it will damage it and reduce its strength considerably.

I did visit Bradley chain about 30 years ago when I worked for a company in the UK designing electric chain hoist in the lifting industry and they made good products at that time.
 
I found ECS were very helpful, for what it's worth. We have 3 cables, one mainly chain (70m) with spliced 18mm anchorplait, a second with 30m chain + 100m anchorplait and third with 10m chain and 130m anchorplait. If and when we're in sight of the US we might very well go for some ACCO G70 on an all chain rode - we hope so.

We have a 33kg Rocna backed with a 25kg, an FX 37 Fortress and a 65lb fisherman. We do hope to be heading further N though, so we do need the mix, and you can never have enough anchors!

Glad you like the boat - like yours too, we've just sold a similar Frers design, and wish you every success with your plans.
 
Yes, I prefer a lighter but higher grade steel chain to give me lower weight and greater flexibility at the same working load limit.

Be careful, though. My experience is with US chain where the load difference between G3 and G4 of the same diameter is double; I don't know what the equivalent of grade 4 is called in Europe. Grade 3 corresponds exactly but WLL for G4 is only given as 50% more in some cases.
US G3 is made from grade 30 steel and G4 from grade 40; why it should be different here I can't imagine.

You must forget using American chain on a European windlass, or vice versa. Here’s the reason: American 5/6” chain, or 0.313”, is actually made of wire 0.34” thick. This is because all American chain is made with a wire size 1/32” bigger than the nominal size. So, although 5/16” (0.313”) is damn close to 8mm (0.314”) an American 5/16” chain will not fit an 8mm gypsy. Better to forget American chain except for an American windlass.
 
It's not just a bit rusty. Bit of a mess a at this stage and at 8mm of unknown standard on a 45 foot boat, would prefer to change it.
 
[ QUOTE ]
GMAC - I don't know where you're located but it seems to me that here in the UK none of the chandleries talk of tensile strength and where the chain comes from. Regarding calibrated chain, they all sell "regular" and chain they claim to be calibrated for your brand of windlass. What's the story? Does it sound to you like the Bradney chain is of a funny spec?

[/ QUOTE ]
Not by you, I know that for sure, it's still summer here, just /forums/images/graemlins/smile.gif

Basically all reputable manufactures calibrate their chain as standard. As far as I know this includes all EU, US and even the Aussie makers do. Many from the east don't or do so poorly. Generally winchmakers don't like un-calibrated chain as it has been known to blow up winches, this is on the increase. Buying an un-calibrated chain for your winch could very easily void warranty so if it does do damage it's your wallet that suffers.

A 'regular' short link chain can very easily be calibrated depending on manufacturer. Our everyday 'regular' short link chain is Italian made a G40 and very highly calibrated. So it is possible to have a 'regular' short link chain that is bloody good but sadly these days the chances are it maybe dodgy.

Just be careful you don't order and get a 'regular link' chain, also know as Mid link somethimes. It is a completely different measurement to short link and won't fit any new winch. There is also 'long link' chains but again they won't fit winches.

As for some chains fit some winchs and not others, that's just pure crap 95% of the time. All gypsies are built to take a certain sized chain. The DIN766/A standard is a common one. Every winch maker I know has gypsies to suit DIN766/A. So if they say it's made for Lofrans it probably is but that same chain will fit a Maxwell, Quick, Sth Pacific, Lewmar, Anchorlift and many more AS LONG AS YOU HAVE THE RIGHT GYPSY TO SUIT DIN766 (not shouting just emphasizing)

Yes, there is something not quite standard with the Bradney numbers. They maybe they are using some old British system, old numbers or something like that but by normal worldwide industry standards something doesn't stack up. That's not to say it is a crap chain, it maybe bloody good but something just doesn't appear quite right on their site.

[ QUOTE ]
Craig, I've never seen G70 chain sold anywhere...?
Mudisox, I have a Lofrans Leopard mounted horizontally (11 years old).

[/ QUOTE ]
G70 is very common, look on any truck passing you, that's more than likely a G70. But galvanised it is not. I only know of 3 places worldwide that make it galvanised to finish at a G7.

Some do like the idea of a G7 anchor chain but we just don't see the point really. It's a fragile chain meaning it hates shock loads, it will not give you any warning of impending failure (a G3 or 40 will if you're looking), can't be regalvanised without a serious lose of strength, approx. 30-40% maybe a lot more if the galvaniser is sloppy. It also cost approx 3-4 times more than a G40. It's no lighter than a standard chain. It will also hold piles more than anything it is attached to or you attach to it, generally just like a G40 on most boats. Personally I think using a G70 is just a complete waste of money as I tell the people who come to me wanting some. Yes I do sell a galvanised G7 but have a habit of being a crap salesman as I tell it as I see it but then I also sleep straight in bed.

Not to mention by downsizing all you are doing is making the anchor work a lot harder than it has too, which maybe fine in 20kts but what about 40 or more?

WHATEVER YOU DO DON'T BUY A LENGTH OF G7 AND GET IT GALVANISED (again for emphasis). The chances are all you will end up with is a G40, maybe a G50 if the guy is real good and know what he's doing. Equally you could very well end up with a steel reinforced bit of zinc with next to zero load holding.

And how many anchors do you think that usually go on the end of an 8mm chain can hold 7000kg, absolutely none come even close in anyones dreams. Don't waste you're money but if you really want too I will take it /forums/images/graemlins/wink.gif

[ QUOTE ]
Be careful, though. My experience is with US chain where the load difference between G3 and G4 of the same diameter is double; I don't know what the equivalent of grade 4 is called in Europe. Grade 3 corresponds exactly but WLL for G4 is only given as 50% more in some cases.


[/ QUOTE ]
Sorry but miles from factual. A G30 will break at XX kg beit made in the UK, EU, Aussie or the US (note 'asia' has been excluded from that list on purpose). Exactly the same applies to G40, they ALL will break at the same XX kg, approx 25% higher than a G30.

The difference is people fall for the good old US Corp marketing ploy of tweaking the WLL. Had a bloke today bitching the loads on some Swedish G40 we sold him was miles lower than the US G40. Very completely wrong as he, like most inc Salty, look at the WLL not the break loads. 90% of the world use a safety margin of 4:1 i.e the WLL is 1/4 of the break. The cunning US marketing machine came up with 'G40 HT' which means grade 40 High Test, not high tensile as many think. What they do is use a safety margin of only 2.5:1 hence they show a lot higher WLL. No matter what WLL is published a G40 will break at XXkg no matter where it is made, again excluding asia often.

OK so why am I bashing asian made chains? Firstly then are more often than not poorly calibrated if at all. They are built to assorted specifications but most of the time come no-where near them. We buy a regular link chinese made chain to the Aussie standard and we also buy Aussie made chain to the Aussie Std. Put both chain side by side and they measure completely different. Put them side by side on a test bed and again not even close. The same applies to some asian made 'DIN' standard we saw last week. a 10mm should measure 28mm ID with a tolerance of +2.5/-0.5mm per 11 links. The asian made measured 30mm +/-1mm per link. Hence you can see why winch makers don't like asian made. Also they are 'soft' chains. By that i mean the stretch very easily. The 10mm I mentioned above we put on the test bed. At 650kg it was stretching. We did some Italian which didn't budge until 3100kg and some Aussie went to 2700kg. The DIN Standard says nothing should move before 2500kg. See why now?

And one bit more to finish this novel - 90% apporx. of the worlds cruising fleet are using a G30 chain even the superboats. The number of chain failures of a reputable made G30 is infinitesimal. Chain failures of asian made is noticable and growing.

Ok now the last bit - If in doubt ask for a Test Certificate and read it well. It should have alsorts of good info including the Proof Load and country of manufacture, if it doesn't don't buy the chain.

Over and out /forums/images/graemlins/cool.gif
 
You must log in or register to reply here.

Share this page

Top