Anchor chain. Change from 8mm to 10mm ?

The OP's idea is crazy.
That amount of weight in the stem of a 32 footer will have a huge effect on the sailing ability. way too much weight in the end.
The difference to my 39 footer when I remove the 30m of chain that I have for racing is very noticeable. 60m of 10mm, just crazy!
 
lw395 said:
The problem is, people can gather data as much as they like, but anchors vary, seabeds vary, boats vary. Then what depth do you pick, and what scope?
Then the big variable is wave motion....
Click to expand...

By this logic, if data doesn't count, then neither do observations. Nothing counts. Let's all throw our hands in the air.
 
Last edited:
Mrnotming said:
Interesting thread here! There is a standard ship test which requires the chain to be deployed in deep water so that the whole lot is suspended from the windlass.Next the tackle is required to be hauled back up again,either by windlass or electrically powered windlass.
I would avoid going to 10mm diameter chain for this reason,that it might be impossible to recover the Anchor,and also the weigh of any decent length of 10mm chain is colossal in terms of the trim (OP's commented) .
I have had the chain jump off the gypsy(10mm) deploying all automatically,the windlass gave up on recovery,and I had to ask assistance from another substantial yacht who kindly used their hydraulic windlass to recover my gear.So I for one will be downsizing to 6/8mm to carry more length in a recoverable fashion.I now have two more house batteries as well so it is surmised that the Lofrans Cayman 1200 watt will be happier with a beefed up supply!
Click to expand...
Amen. I have 8mm chain (I think!) and when I had to deploy it in 20+m of water, with two of us heaving it in with no other load on the chain (it wasn't windy, and we were in good shelter), we were both blowing hard by the time we'd retrieved 50+ m of chain (all we had - I know it wasn't enough, but we'd just had the engine fail). Even 20m of 8mm chain is a pretty fair weight to lift; 10mm chain is going to be correspondingly heavier. I now have an Anchorman winch, which is surprisingly effective as long as the boat can be gently motored towards the anchor totake the strain off.
 
Doris, mon vieux, the details count.

I am looking at an anchor chain of 30m, not 60. And the difference between 30m of 8mm and 30m of 10mm is 25.5kg, using specs from J Green Esqr. That is why as a technical person I am happy to deal with figures to solve a problem, and look at the extremes of possible solutions.

And the chain locker in my boat is approx 7ft back from the stem, and below the waterline and CoG, so whilst there is a small addition to the polar inertia of the vessel, there is also an increase in righting leverage. And I have lost count of the racy boats I've sailed on where the lack of mass at the sharp end prevents the boat from carrying through oncoming waves; usually they are IOR boats with wide beams and bustles. And guess what , mine is a IOR 3 boat.

Yes, keeping mass out of the ends is generally a Good Thing, but sometimes you need the bow to shoulder its way through waves rather than be deflected.

Currently my thoughts for the anchor chain are turning towards 3mm Grade 200 made from a mix of titanium, beryllium, vanadium and zirconium, as used by NASA on the door handles of their spaceships. With a working load of 2.8 tonnes, and resistant to all known forms of electrolysis in sea water between temperatures of -15C to +45C, self-stowing, and with a pleasant golden lustre to impress the natives, I reckon I can save over 72kg even though 30m will cost more than the the boat.
 
sarabande said:
Doris, mon vieux, the details count.

I am looking at an anchor chain of 30m, not 60. And the difference between 30m of 8mm and 30m of 10mm is 25.5kg, using specs from J Green Esqr. That is why as a technical person I am happy to deal with figures to solve a problem, and look at the extremes of possible solutions.

And the chain locker in my boat is approx 7ft back from the stem, and below the waterline and CoG, so whilst there is a small addition to the polar inertia of the vessel, there is also an increase in righting leverage. And I have lost count of the racy boats I've sailed on where the lack of mass at the sharp end prevents the boat from carrying through oncoming waves; usually they are IOR boats with wide beams and bustles. And guess what , mine is a IOR 3 boat.

Yes, keeping mass out of the ends is generally a Good Thing, but sometimes you need the bow to shoulder its way through waves rather than be deflected.

Currently my thoughts for the anchor chain are turning towards 3mm Grade 200 made from a mix of titanium, beryllium, vanadium and zirconium, as used by NASA on the door handles of their spaceships. With a working load of 2.8 tonnes, and resistant to all known forms of electrolysis in sea water between temperatures of -15C to +45C, self-stowing, and with a pleasant golden lustre to impress the natives, I reckon I can save over 72kg even though 30m will cost more than the the boat.
Click to expand...

Add a dash of uranium-235 and you will also have electricity and hot water - oh, and you won't need an anchor light as you will glow in the dark.....
 
sarabande said:
Doris, mon vieux... Currently my thoughts for the anchor chain are turning towards 3mm Grade 200 made from a mix of titanium, beryllium, vanadium and zirconium, as used by NASA on the door handles of their spaceships. With a working load of 2.8 tonnes, and resistant to all known forms of electrolysis in sea water between temperatures of -15C to +45C, self-stowing, and with a pleasant golden lustre to impress the natives, I reckon I can save over 72kg even though 30m will cost more than the the boat.
Click to expand...

Finally, some good sense. Of course, it will cut right through all available bow roller and gypsy materials. Upgrades all around!
 
I think the OP has made a big error here, if he had stuck his 10mm. chain in the for sale section before exposing its uselessness in the responses to this thread he would probably have got a decent price for it, now everyone knows why they do not want it and its value will have dropped almost as fast as the post Brexit £.
 
Sounds like the OP is determined to use 10mm no matter what we all say and that's commendable determination, he'll need that level of determination when he's on the foredeck hand cranking it in ;)
 
I don't recall anyone reacting to the fact that with a 32' boat he had 2 more anchors, which he says are oversized, also on chain. More reason for a tired back. If these are used for secondaries and kedge, for that size boat there is no reason they should not be combination rode.

So I figure he's got at least 600 pounds more than he needs on the bow. Nearly 1000 pounds of ground tackle, if we count the windlass. It's an incurable disease.
 
thinwater, mon vieux, the current anchoring armament is a Delta at 16kg, a Knox at 9kg, a Fortress FX16 at 5kg, 2 x 30m of 8mm chain (say) 90kg, and 25mm of 6mm chain at 20kg, plus assorted warps at 40kg, and no windlass..

Now I know that SI units are foreign waters for our sailing buddies across the pond, but to suggest that my existing setup at 190kg or around 418lbs is anything like the figure you write is exaggerating just a little. I don't know how USA winches are made, but a winch weighing 400lbs or 180 kg or the weight of two men is again carrying hyperbole to its nautical extreme though to good forum effect. :)

And for Colvic W., I am far from determined to go for 10mm. What has arisen from discussion is the use of high grade, smaller size chain as a a satisfactory and practical solution by sailing people from round the forum's world. 6mm Grade 70 looks, to me, like the way to go, despite a natural proclivity on my part to go for heavyweight kit 'because it looks beefy'.
 
sarabande said:
thinwater, mon vieux, the current anchoring armament is a Delta at 16kg, a Knox at 9kg, a Fortress FX16 at 5kg, 2 x 30m of 8mm chain (say) 90kg, and 25mm of 6mm chain at 20kg, plus assorted warps at 40kg, and no windlass..

Now I know that SI units are foreign waters for our sailing buddies across the pond, but to suggest that my existing setup at 190kg or around 418lbs is anything like the figure you write is exaggerating just a little. I don't know how USA winches are made, but a winch weighing 400lbs or 180 kg or the weight of two men is again carrying hyperbole to its nautical extreme though to good forum effect. :)

And for Colvic W., I am far from determined to go for 10mm. What has arisen from discussion is the use of high grade, smaller size chain as a a satisfactory and practical solution by sailing people from round the forum's world. 6mm Grade 70 looks, to me, like the way to go, despite a natural proclivity on my part to go for heavyweight kit 'because it looks beefy'.
Click to expand...

Actually, US engineers are probably the most bi-lingual in the world when it comes to units; both high school and university exams typically alternate units between cgs, SI, and what we call "standard" units.

I lept to the assumption that you had 60m of 8mm chain on each anchor, and that the anchors were all of similar weight. Nothing in your writing suggested anything as efficient as a Fortress. So I was not exaggerating, just working from limited information.
 
Unfortunately 6mm gal G70 is like hen's teeth. In fact like the teeth I do not think it exists.

Peerless make a 1/4" G70 under their ACCO brand but for obvious reasons it is not normally available in Europe. However Peerless make and distribute metric chain and I would not have thought it impossible for them to include some 1/4" G70 in a shipment of the metric from America. If you are buying a 'new to you' gypsy then specifying a 1/4" gypsy should be possible (or it would be if you bought a new one)

Sadly the smallest size of gal G70 for both Maggi and Peerless is 8mm. Peerless sell metric G40, as do Maggi - but it will not fit the bill.

The alternative is to have the chain custom coated, which is how I had my G80 made. My 75m length was based on Gunnebo chain - but there are a number of manufacturers - and maybe its made in the UK (Hacketts?). There are significant sales to the lifting industry now from various Chinese producers and in addition to my 75m length I had 15m of Chinese G80 coated (and its better than the Gunnebo product - if strength is a measure of betterness!). Its a surprisingly cheap option (or it was for me) as G80 is quite common place and it does not have the 'leisure marine' moniker. A major advantage of looking to G80 is that there are a host of off the shelf attachments, hooks and enlarged links made to the same specification that fit the chain. The chain can be purchased to a size standard for which most windlass makers make gypsies (EN 818-2). The downside is - you need to arrange to have it coated, its a specialist coating (not expensive, or not in Australia) and there is only one converter in the UK (Bodycote) but a number in Europe. I believe that Gunnebo have a coating facility in Sweden (but you would need to check).

What's not to like?

Jonathan
 
thinwater said:
Actually, US engineers are probably the most bi-lingual in the world when it comes to units; .....
Click to expand...

I would agree with this.
I have seen real world problems caused by mono-lingual UK engineers who don't realise that 'mil' is American for 'thou' so shouldn't be used on the phone for mealy-metres.
 
sarabande said:
thinwater, mon vieux, the current anchoring armament is a Delta at 16kg, a Knox at 9kg, a Fortress FX16 at 5kg, 2 x 30m of 8mm chain (say) 90kg, and 25mm of 6mm chain at 20kg, plus assorted warps at 40kg, and no windlass..

Now I know that SI units are foreign waters for our sailing buddies across the pond, but to suggest that my existing setup at 190kg or around 418lbs is anything like the figure you write is exaggerating just a little. I don't know how USA winches are made, but a winch weighing 400lbs or 180 kg or the weight of two men is again carrying hyperbole to its nautical extreme though to good forum effect. :)

And for Colvic W., I am far from determined to go for 10mm. What has arisen from discussion is the use of high grade, smaller size chain as a a satisfactory and practical solution by sailing people from round the forum's world. 6mm Grade 70 looks, to me, like the way to go, despite a natural proclivity on my part to go for heavyweight kit 'because it looks beefy'.
Click to expand...

What you're not telling us is how you intend to use your boat.
Are you going to be pottering the English Channel in fair weather, or becoming a hermit in the Scottish Islands?
 
Actually, US engineers are probably the most bi-lingual in the world when it comes to units; .....

Having learned from some expensive errors of translation in the past, no doubt !

http://edition.cnn.com/TECH/space/9909/30/mars.metric/

Throwing ideas around....

JN
What about the use of lifting chain ? Some 6mm G70 from your home country, but little info about abrasion/corrosion resistance of the zinc/dichromate finish.. I know that you have different Grade classifications (e.g. l, M, T etc), plus ISO nomenclature

https://www.1st-chainsupply.com/aboutgrading.htm
and
http://www.nobles.com.au/Products/Chain/Lifting-Chains

and indeed there are some G100 and G120 grades available form Pewag in Austria. If the max SWL: the minimum link diameter is required from my theoretical specification search, then why not use the really high test lifting chains ?


Then consider perhaps the use of alloy chains, e.g. Grade 100 8mm with a WLL of 2.5T ( safety factor 4:1 - that's 10 tonnes breaking strain !) at 2 to 3 times the price of galv steel. If the alloy is inherently corrosion resistant, why do we use galvanised steel ?
 
lw395 said:
What you're not telling us is how you intend to use your boat.
Are you going to be pottering the English Channel in fair weather, or becoming a hermit in the Scottish Islands?
Click to expand...


I think that a week storm-bound in the Isles of Scilly would subject a boat to the same anchoring requirements as a week stormbound in Loch Ewe ? F9 is F9, unless the SNP have re-calibrated the Beaufort Scale.
 
sarabande said:
I think that a week storm-bound in the Isles of Scilly would subject a boat to the same anchoring requirements as a week stormbound in Loch Ewe ? F9 is F9, unless the SNP have re-calibrated the Beaufort Scale.
Click to expand...
A week storm bound is different from 'business as usual'. Storm bound is time to get the heavy gear out of the bilge instead of using your every day lunch hook for some.
Going to Scilly when F9 is likely might be considerd bad planning or bad luck for a boat that rarely strays west of Helford, but F9 in Scotland is as inevitable as frothy beer and greasy food..
I could introduce you to someone who'd probably say you need 10mm chain, and a suitable sized boat to go with it.
 
You must log in or register to reply here.

Share this page

Top