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Old 26-03-2016, 17:21   #61
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Re: Help me flesh out my ground tackle

A comment on my original question and the answers - I believe I'll stick with the Rocna, and buy either a fx-37 or fx-55. I'll keep the Bruce for now, with an eye to replacement if a good opportunity comes along. I will keep the 20lb danforth for stern/dinghy/kedge, for use when a proper bower is not required.

Regarding rode, I currently have enough for two primary rodes of roughly 100m. The chain plus a bit of polyester line, and then a bit of chain plus most of the polyester line. Prior to going South to MX, I'll likely pick up a third "set". In this way, if I lose the Rocna and rode, I'll still have adequate gear for cruising (More than one decent anchor plus rode).

Thanks again everyone, especially for the active dialog.


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Old 26-03-2016, 17:26   #62
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Re: Help me flesh out my ground tackle

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Originally Posted by El Pinguino View Post
I don't think I really like that idea...may come the day when you want to slip your chain.... the 'bitter end' of the chain on big ships is secured in place by a pin so that it can be slipped quickly ..(edit) from outside the chain locker.. if needs be.

Same. Our bitter end is attached with relatively thin line that can be cut away after attaching a float to the rode if we need a quick get away. Then instead of a chain stopper we (will) have a short, thick line with a chain hook, then snubbers. We always more than one snubber. Probably not necessary in most situations, but I feel better that way.


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Old 26-03-2016, 19:07   #63
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Re: Help me flesh out my ground tackle

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Originally Posted by Jim Cate View Post
DH, there are a number of elements of your argument where the logic fails, but in particular, the above paragraph is flawed IMO. First, in my system, the strengths of all three elements are roughly balanced, ie, they have similar breaking strengths. Second, even if, as you contend, my chain is "overbuilt" in terms of strength (which I do not believe) there are benefits from heavier chain. We've discussed this before, but to reiterate, while the catenary will eventually be lost at high loads, the act of straightening it out absorbs lots of energy, and this energy absorption does not add to the loads on the snubber or cause chafe... it's a good thing, and heavier chain does it better. And of course, there are the advantages of better wear tolerance and ability to regalvanize that accrue with heavier low-test chain... but that's outside the scope of this discussion.

Finally, do remember that many cruisers do attach the bitter end of their chain in a robust manner, so that loss risk is small. And if one troubles to engage the pawl on the gypsy of the windlass, it will absorb a great deal of load ( I don't know just how much, for that is not addressed in the specifications that I have seen). There is risk of bending the drive shaft, and I certainly don't think that this usage is a good one, but again, it would very likely keep the chain from running out if the snubber broke.

I'm not an engineer by trade, so don't feel competent to comment on your judgement of "bad engineering". I'll leave it to the many engineers on board to discuss. But remember, I'm not advocating NOT using an additional chain stopper. I'm saying that failing to use one does not mean conclusively that the system is badly engineered.

Jim
The logic is entirely sound.

And it's actually very simple. It's nothing more than the principle that "a chain is only as strong as its weakest link", something even children understand. A good system for carrying loads, has all parts matched to each other. No point, for example, in having a 100 pound shackle with breaking strength of 100 tons, if the chain is only rated for 10 tons. Is that so hard to understand? By exactly the same principle, there is no point in chafe-proof chain, rated at 6 tons (or whatever), if you are dependent anyway on a chafe-prone snubber which may easily fail at 3 tons of load. If you insist on using only that snubber to connect you to your anchor, then your system would be better if it were all nylon, so that you can at least enjoy the benefits of that material (light, easy to handle and store), since you've anyway condemned your entire anchoring system to its weaknesses. As it is, you've created a system which is the worst of both worlds, and that's what I mean by bad engineering.

Your snubber is exceptionally strong compared to that of the average cruiser, maybe equal to the strength of your chain at its catalogue strength, but if you read Dashew's article, you will see that it's real strength in realistic conditions may only be 40% or so of its catalogue strength. Besides that, nylon is notoriously vulnerable to chafe -- you may get away with it even for decades, but one bad storm and your chafe protection may be out the window, and the snubber chafed through, before you realize it. Why reduce your whole anchoring system to this lowest common denominator? Why did you bother with the chain in the first place, if all of these qualities are good enough for you?


There are different ways to join the chain strongly to the boat, and if you have a pawl on your windlass which is as strong as your chain (?), and if the gypsy wouldn't slip at loads approaching the chain's breaking strength (?), that would certainly be ok. If you use it.

I've never seen a boat with a strong connection at the bitter end, and I'm not sure it's a good idea. What if you have to ditch the chain in an emergency? The strong connection to the boat should be at whatever point you've let the chain out to.

A stout chain lock is best of all, or a stout sampson post with a stout chafe-proof (I use stainless chain) strop. The strop could go to a bow cleat also since, sadly, few of our boats have sampson posts.
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Old 26-03-2016, 20:19   #64
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Re: Help me flesh out my ground tackle

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Originally Posted by ScottMeilicke View Post
Same. Our bitter end is attached with relatively thin line that can be cut away after attaching a float to the rode if we need a quick get away. Then instead of a chain stopper we (will) have a short, thick line with a chain hook, then snubbers. We always more than one snubber. Probably not necessary in most situations, but I feel better that way.


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This sounds like a sensible way to go. Those deck mounted chain stoppers scare me. No way to release them if they are under load. At least a short bit of line can be cut if needed.

Personally I make the line attaching the bitter end as strong as possible, it can take a lot of load if the chain gets away from you in deep water. The strength is limited by what you can pass through the chain. Though I guess these days you could use a soft shackle through the last link, then a nylon pendant to the strong point, ideally long enough to reach the deck.
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Old 26-03-2016, 20:43   #65
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Re: Help me flesh out my ground tackle

Other discussion about "logic" here would seem to have a difference in basic assumptions.

Is the piece of rope a sacrificial link designed for comfort, or is it an integral part of the anchoring with requirement for full strength.

If the former, then lighter stuff or even two pieces of different strengths and lengths seems reasonable. If it is a full strength extension of chain then obviously heavy rode is required.

Different functions.


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Old 26-03-2016, 20:47   #66
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Re: Help me flesh out my ground tackle

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Yes, but if your snubber breaks at night, you're screwed. Your ground tackle will be gone before you can get up on deck.

Your whole anchoring system is only as strong as your snubber, the way you're doing it. You're not "isolating the windlass from shock" -- you're connecting the rode to your boat. With only one little rope which is far weaker than the chain. You might as well downsize the chain two sizes and use rubber bands instead of a shackle -- the same result as relying on a snubber to connect the rode to your boat.

Since you've already got a good way to tie down that chain, my recommendation would be to use it, always. Only then is there any point to the chain, shackle, etc. being as strong as it is.

Snubbers are made to stretch and flex, and chafe is inevitable. You can never quite predict when they're going to break. They're just not good for this purpose -- don't make them do two different completely incompatible tasks.
I understand what a snubber does and the characteristics of chain as well as that of nylon as far as strength and elasticity. BTW, you are wrong about making assumptions that a nylon snubber as strong as chain couldn't have a lot more elasticity than that chain so could be used as a snubber if it were long enough, but in the length and size rope snubber I use, you are correct that it's certainly not as strong as my chain, but I digress. What it comes down to is that stiffness, strength, elasticity, chafe resistance, etc. are all characteristics of chain and various types of rode and are all quite independent of each other. In other words, more elasticity doesn't necessarily mean less strength, though to keep the length of snubber reasonable and still have adequate elasticity, I for normal anchoring conditions I purposely choose one that's much weaker than my chain.

I guess I wasn't clear enough about anchoring in normal, moderate conditions. I wrote this: "For backup just in case my snubber slips or breaks during "normal" moderate conditions, I just snap shackle the short, permanently attached piece of wire rope that holds my anchor in place against the bow roller while underway. It's already in place and easy to use and can be detached easily when it's time to depart."

It's effectively what you are talking about, though not as rugged as my heavier one that is stowed away and I only use when the wind blows really hard. It's about a 18" wire rope lanyard that's permanently attached to a pad eye with a backing plate located right in front of the windlass and has a snap shackle at the other end. It's primary purpose is to be snap shackled to the chain when I am underway to keep the anchor pulled in snug against the bow roller if the windlass clutch slips. But for anchoring in moderate conditions, it's strong enough so I feel comfortable shackling it to the chain as a backup in case the snubber slips or fails. So, I'm confident that if a squall should surprise me some night and my snubber fails, it will hold the chain so there is no danger of all my chain running out before I can get on deck. If I'm anchoring and expect the winds to be more than about 20 knots (extremely rare where I usually anchor), then I have doubts that my little, permanently mounted lanyard would be strong enough so I have to go get the heavier one out of the box on the aft deck where it's kept. I'm very comfortable with this part of my anchoring setup but as I stated before, I do want to get a longer and heavier nylon snubber than I normally use for those time when stronger wind conditions are expected.
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Old 26-03-2016, 20:52   #67
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Re: Help me flesh out my ground tackle

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Originally Posted by stillbuilding View Post
Other discussion about "logic" here would seem to have a difference in basic assumptions.

Is the piece of rope a sacrificial link designed for comfort, or is it an integral part of the anchoring with requirement for full strength.

If the former, then lighter stuff or even two pieces of different strengths and lengths seems reasonable. If it is a full strength extension of chain then obviously heavy rode is required.

Different functions.


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I think you need both functions.

* medium strength line attaching the bitter end to the boat. Strong enough to stop run away chain, thin enough to cut.
* strong short line attaching the boat to the chain, same as a chain stopper.
* strong for the conditions snubber, sacrificial and high energy absorption.

Each has an important but different function.

Oh, and one more line to hold a small basket of beer in the water for the initial cool down. At least in the cold waters of the PNW.


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Old 26-03-2016, 20:57   #68
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Re: Help me flesh out my ground tackle

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Originally Posted by Dockhead View Post
The logic is entirely sound.

And it's actually very simple. It's nothing more than the principle that "a chain is only as strong as its weakest link", something even children understand. A good system for carrying loads, has all parts matched to each other.
***
Hmm... matched strengths are good? Mine: chain 11,000 lbs, snubber 13,500 lbs, bitter end attaching lashing (which is long enough to reach up through the windlass and on to the foredeck) 2x9200 lbs. Seems pretty reasonably matched to me in terms of ultimate strength. Yes, the snubber could chafe through, it isn't as strong as when it was new, and it could get hot and melt, but the chain and the lashing would still likely hold, for they have not suffered those insults.
***
No point, for example, in having a 100 pound shackle with breaking strength of 100 tons, if the chain is only rated for 10 tons. Is that so hard to understand? By exactly the same principle, there is no point in chafe-proof chain, rated at 6 tons (or whatever), if you are dependent anyway on a chafe-prone snubber which may easily fail at 3 tons of load. If you insist on using only that snubber to connect you to your anchor, then your system would be better if it were all nylon
***
DH, that's nonsense! I still have all the advantages of chain. Your proposed all nylon system WILL chafe, has no catenary advantage and would slingshot the boat all over the place! I think the passion of your argument has carried you a bit far here! Need I remind you yet again that the chain is well terminated, and if both snubber and windlass should fail, that attachment will have a good chance of survival, and the boat will still be anchored on chain.
****
, so that you can at least enjoy the benefits of that material (light, easy to handle and store), since you've anyway condemned your entire anchoring system to its weaknesses. As it is, you've created a system which is the worst of both worlds, and that's what I mean by bad engineering.

Your snubber is exceptionally strong compared to that of the average cruiser, maybe equal to the strength of your chain at its catalogue strength, but if you read Dashew's article, you will see that it's real strength in realistic conditions may only be 40% or so of its catalogue strength. Besides that, nylon is notoriously vulnerable to chafe -- you may get away with it even for decades, but one bad storm and your chafe protection may be out the window, and the snubber chafed through, before you realize it. Why reduce your whole anchoring system to this lowest common denominator? Why did you bother with the chain in the first place, if all of these qualities are good enough for you?


There are different ways to join the chain strongly to the boat, and if you have a pawl on your windlass which is as strong as your chain (?), and if the gypsy wouldn't slip at loads approaching the chain's breaking strength (?), that would certainly be ok. If you use it.

I've never seen a boat with a strong connection at the bitter end, and I'm not sure it's a good idea. What if you have to ditch the chain in an emergency? The strong connection to the boat should be at whatever point you've let the chain out to.
****
See above. 12 mm double braid dacron, doubled... on the order of 18,000 lbs breaking strength, less any knotting and unfair lead when in use. If dumping is required, and it is under load one swipe with a knife will see it gone in a flash.
****



A stout chain lock is best of all, or a stout sampson post with a stout chafe-proof (I use stainless chain) strop. The strop could go to a bow cleat also since, sadly, few of our boats have sampson posts.
One final comment: One needs to relate all these putative strengths to the actual loads that my 60 lb Manson Supreme could develop. It's a good anchor, but I rather doubt that, unless fouled on something immovable, it could put a five or six ton load on the chain system without popping out of t he bottom. Don't have data to support that belief, but suspect the truth of it. In that light, the strength of the snubber, even with all the Dashew and DH caveats seems pretty good to me.

Jim

PS Re actually using the pawl on the windlass: I've only done so a few times, in situations when I expected severe winds. I do not know what it's yield load would be... just want to limit the potential loads on the worm gears. And too, I don't know if the chain would slip off of the gypsy. It never has (vertical axis windlass with ~180 degree wrap), but i suppose it could.
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Old 27-03-2016, 04:51   #69
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Re: Help me flesh out my ground tackle

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I understand what a snubber does and the characteristics of chain as well as that of nylon as far as strength and elasticity. BTW, you are wrong about making assumptions that a nylon snubber as strong as chain couldn't have a lot more elasticity than that chain so could be used as a snubber if it were long enough, but in the length and size rope snubber I use, you are correct that it's certainly not as strong as my chain, but I digress. What it comes down to is that stiffness, strength, elasticity, chafe resistance, etc. are all characteristics of chain and various types of rode and are all quite independent of each other. In other words, more elasticity doesn't necessarily mean less strength, though to keep the length of snubber reasonable and still have adequate elasticity, I for normal anchoring conditions I purposely choose one that's much weaker than my chain.

I guess I wasn't clear enough about anchoring in normal, moderate conditions. I wrote this: "For backup just in case my snubber slips or breaks during "normal" moderate conditions, I just snap shackle the short, permanently attached piece of wire rope that holds my anchor in place against the bow roller while underway. It's already in place and easy to use and can be detached easily when it's time to depart."

It's effectively what you are talking about, though not as rugged as my heavier one that is stowed away and I only use when the wind blows really hard. It's about a 18" wire rope lanyard that's permanently attached to a pad eye with a backing plate located right in front of the windlass and has a snap shackle at the other end. It's primary purpose is to be snap shackled to the chain when I am underway to keep the anchor pulled in snug against the bow roller if the windlass clutch slips. But for anchoring in moderate conditions, it's strong enough so I feel comfortable shackling it to the chain as a backup in case the snubber slips or fails. So, I'm confident that if a squall should surprise me some night and my snubber fails, it will hold the chain so there is no danger of all my chain running out before I can get on deck. If I'm anchoring and expect the winds to be more than about 20 knots (extremely rare where I usually anchor), then I have doubts that my little, permanently mounted lanyard would be strong enough so I have to go get the heavier one out of the box on the aft deck where it's kept. I'm very comfortable with this part of my anchoring setup but as I stated before, I do want to get a longer and heavier nylon snubber than I normally use for those time when stronger wind conditions are expected.

I'm not quite sure what you're arguing with. This practice, which sounds different from what you originally posted, sounds fine to me. You are separating these functions (snubbing, on the one hand, and belaying the chain, on the other), and using tools appropriate to each job.


As to elasticity versus strength -- there are two different sides to this question. One is pure strength, and naturally elastic things can be strong. Nylon rope, the material we typically use for snubbers, has to be quite long and quite thick, to be as strong as a corresponding piece of chain -- once you consider the reduction in strength in actual use which results from being wet, and from internal heating (see Dashew). It's theoretically possible, but I'm sure I've never seen a snubber as strong as the chain it was used on.

The other side is chafe. Nylon is very vulnerable to chafe -- it seems to come with its elasticity. So the snubber is a weak point in your system in this sense also, even if it is very strong. Just read about people battling chafe in hurricanes with one snubber sawing right through after another -- there are a number of accounts on CF about that.


But this is not a problem, if you have a chafe-proof means of belaying the chain, as you do. This will keep you off the rocks while you put on another snubber.
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Old 27-03-2016, 05:47   #70
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Re: Help me flesh out my ground tackle

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Originally Posted by Jim Cate View Post
One final comment: One needs to relate all these putative strengths to the actual loads that my 60 lb Manson Supreme could develop. It's a good anchor, but I rather doubt that, unless fouled on something immovable, it could put a five or six ton load on the chain system without popping out of t he bottom. Don't have data to support that belief, but suspect the truth of it. In that light, the strength of the snubber, even with all the Dashew and DH caveats seems pretty good to me.

Jim

PS Re actually using the pawl on the windlass: I've only done so a few times, in situations when I expected severe winds. I do not know what it's yield load would be... just want to limit the potential loads on the worm gears. And too, I don't know if the chain would slip off of the gypsy. It never has (vertical axis windlass with ~180 degree wrap), but i suppose it could.
This is an important point, because of course the anchor is also part of the system. Obviously the rest of the ground tackle should be stronger than the maximum holding force of the anchor. That's because when the system is overloaded, you want something non-destructive to give. And that would be the anchor dragging, not part of the ground tackle breaking. But also, anchors do get stuck in rocks etc. If the force of wind and waves on your boat could be stronger than the maximum holding force of your anchor (which would be the usual case), then the system should be design to deal with that without breaking. The ground tackle must keep your boat attached to the anchor no matter what, so it should be sized with a reserve of strength adequate to make it almost impossible that the anchor could impart loads on it which could break part of it. That is why the rest of the ground tackle has to be stronger, than either the maximum holding force of the anchor or the maximum force of wind and waves on your boat.

The whole system is limited by the strength of the weakest link. And this is the concept which I can't seem to convey to you.


One more twist to throw in is snatch loads. In real life, snatch loads are what breaks anchor chains (because they are all designeded with adequate reserves of strength compared to the static forces). Here's where the snubber comes in -- not just for comfort, but to prevent the destruction that snatch loads can wreak on your boat in a storm with all-chain rode and no snubber.

And in fact that is how, practically, you will end up on the rocks, if you don't do this properly -- snatch loads. In a violent squall, the snubber saws through, or it just breaks unexpectedly at far less than its rated strength (as described by Dashew) -- in the surge created by the storm, the bow pitches up and snatches violently against the chain, creating a dynamic load far greater than the static ones, the windlass gearbox explodes, or the chain jumps off the gypsy, and suddenly your boat is flying towards the rocks.


The reason why I am so conscious of this issue, and yes, ok, passionate, is because this actually happened to me, in real life. For me this is not a theoretical discussion. I was anchored in Studland Bay just N of the Old Harry Rocks, about 5 years ago, and the wind shifted 100 degrees during the night (that was not in the forecast) and piped up to a F8 (also not forecast). The wind shift meant I lost all the shelter from Old Harry Rocks and I found myself anchored off a lee shore in an F8 -- in the surf . The bow pitched up and down in the surf and the snubber -- quite a stout and long one -- exploded with a loud bang. Nylon can only absorb so much energy before it fails from internal heating.

Thank God that was not all there was holding my boat to the ground tackle -- my Father taught me, and I have always without fail used a strong method of belaying the chain, independent of the snubber. You're simply not anchored, without it, he always told me "you're merely casually associated with your ground tackle". So I had time to throw on clothes, crawl up on deck, clipped on, with surf breaking over the bows, tie on another snubber, and veer more chain (VERY carefully, and right in the lull between a set of breakers), and get back to the cockpit, blessing my Father's wisdom all this time. I spent the rest of the night in the cockpit with the engine running, but we rode it out ok. That was when I had my old 121 pound Rocna, which held perfectly and didn't budge an inch despite the huge loads.

If I'd been rigged like you do it, Jim, I would have lost the boat, and possibly our lives.

You and Ann are among my very favorite CFers, so I would sure hate to lose you this way.
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Old 27-03-2016, 06:14   #71
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Re: Help me flesh out my ground tackle

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... Re actually using the pawl on the windlass: I've only done so a few times, in situations when I expected severe winds. I do not know what it's yield load would be... just want to limit the potential loads on the worm gears. And too, I don't know if the chain would slip off of the gypsy. It never has (vertical axis windlass with ~180 degree wrap), but i suppose it could.
Jim, you have been lucky that you haven't been caught out too often with unexpected severe wind resulting in a weakened snubber snapping, resulting in the windlass taking the shock load. I agree fully with Dockhead that securing the chain to avoid load on the windlass if the snubber snaps is a very sensible precaution.

Stay safe .

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Old 27-03-2016, 06:37   #72
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Re: Help me flesh out my ground tackle

Great thread. Thanks all.

Something I don't think has been touched on with snubbers, is the critical effect overstretch has with nylon.

If it stretched over 20%, it permanently loses all stretch capability from then on. It becomes a 'dead' line with no stretch capability (maybe this is where it rapidly starts overheating and goes bang?) and no longer has a shock absorbing effect.

So no matter the thickness of snubber used, to me the critical issue is length - you do not want that snubber to be able to stretch to 120% of its length.

So you have to determine how much movement you want to allow that snubber to have. If you want a total of 8ft of movement, to me, you must use at least 50ft of snubber for a theoretical 10ft of stretch before failure damage can occur (you want a safety margin with that stretch), and so only allow a maximum of 8ft of slack in the chain, so the slack is gone before the stretch closes in on 120%.

Personally, with my penchant for safety margins, I'll be going with a 50ft snubber, of thicker (5/8" 3strand) nylon, so it isn't working so hard, is less likely to overheat, and with possibly a greater damping effect, only have 6ft of slack in the chain.

I say a damping effect, because a shock absorber has two elements - spring, and damping. The best vehicle shock absorbers (competition use) tend to have soft springs with very firm dampers. I think a thin snubber can run the risk of being 'oversprung' very easily, have inadequate damping effect as a result, and possibly run the risk of a dramatic increase in heating effect.

I may be wrong, but in very severe conditions, it's the damping effect we may really want, and not the springing (I suspect over springing could contribute to things going more than a bit wild and out of control - but that is only a suspicion after experience with road shock absorbers that were over sprung and under damped, when rapidly manoeuvring at high speed, though I have also had experience with road testing someone's racing bike that was massively over damped, AND massively oversprung - now that was 'interesting' in a terminally lethal sort of way). Bear in mind, with adequate scope, the catenary in the chain rode itself, may provide all of the springing that is needed (perhaps behaving as a soft spring?).

Lots of 'maybe's' in there, but things to think about, and I suspect that some may be why thicker than 'usual' snubbers are working far better than theorised (I don't think the theory has accounted for damping effect or realised its importance)?

Fair winds and calm anchorages, to us all.
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Old 27-03-2016, 09:01   #73
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Re: Help me flesh out my ground tackle

Okay, hope y'all ready for my pov

The weakest point in the anchoring should be the chain; i.e. all the rest that secures the boat to the seabed, should not break first. This is the anchor, the shackle, the swivel if any, the windlass and the chain stopper.

If you have no chain stopper then stop right here and create one. It doesn't have to be the nice stainless deck-mounted hardware; you can create a chainstopper from anything stronger than the chain which attaches it a point on the bow that is also stronger than the chain, like a cleat.

Do not confuse the chain stopper with the snubber.

The above components are what hold the boat in the worst conditions. Any snubbers and other rope parts have been shredded at that point.

Then the snubber; forget the old mantras and make it polyester 3-strand or nylon 3-strand and test it. For the 40' category of boats, start with 20' of 1/2" and see how you like it. With our 25 tons and 64' length I can't break a 5/8" snubber in any sub hurricane conditions so I doubt many need 3/4" rope. You design the snubber to stretch and absorb shocks so that the anchor sets deeper and deeper instead of being yanked out of the seabed. It also provides comfort at anchor. By the time the snubber breaks, the anchor should be set deep enough for what comes.

Then the bitter end of the chain: it should have two lines attached. One must be same strength as the chain and attached at a strong point. It must be exactly long enough to bring the bitter end of the chain on deck at a point that the line an be cut easily.
The second line must be polypropylene of 1/4" - 3/8" and 100' long. When you cut away the anchor, this line runs out with the chain and as it floats, it is ow you find your anchor back.

Windlass: you need one for any boat over 30' long. Yes you can live without but at much less safety. I'm a big guy but on a 41' plastic boat I could not retrieve the anchor in 30 kts of wind without somebody using the engine at full revs.
Then the pawl: it is for using during manual operation or temporary while working in the chainlocker (freeing the chain, securing bitter end etc.) It is ot to be used instead of a chain stopper. Read the windlass manual if you don't believe

Size/weight of chain: irrelevant. Only the strength of the chain and the length is important. If you want to save weight go ahead and buy grade 40 or 70. This is not opinion but fact: read the papers if you don't believe it.

Size of anchor: determines how safely secured to the seabed you are. Only use manufacturer sizing tables when they state up to which conditions it is valid for. Most are for up to 30 kt winds and you need to use a storm anchor above that, which is 1-2 sizes up. For cruisers who are out there and can't decide to go golfing for the weekend instead, your primary anchor must be that storm anchor.

Type of primary anchor: many will start screaming but do get a Manson, Rocna or Spade made from solid steel. Don't get the aluminium Spade with hollow stock that rips apart during storms or other such nonsense. Remember it must be stronger than the chain.
Do not get Danforth style or anything else that becomes too unreliable during big windshifts. Forget CQR and knock off Bruce anchors. For original Bruce it must be 1-2 sizes bigger than a Rocna to equal holding power.

You can't have two anchors on the bow of a monohull, because if sized right, only one will fit.

Get a big/huge Fortress as 2nd anchor. If you want 3 anchors, get the next bigger Fortress as well. Use short chain leader plus very long octoplaid polyester rode for the secondary. Think 400'.

The sheave diameter of the anchor roller should be as big as possible. Have a machine shop turn one from delrin as big as will fit your boat.

Create a very long snubber, 1.5 times the boat length and one size smaller diameter than the normal snubber. You use this as a snubber that goes outside the railing all the aft to a primary winch. You can then let out more chain to lay at an angle to the wind, all the way to stern to the wind if you like. Do this to put the bow into the swell instead of into the wind. When right, add the normal snubber as well and tune using the primary winch.
When weather gets ugly this ling snubber should break to get bow into the wind, or you take it off the winch and bring it forward. You can also retrieve chain to achieve this more safely.

With bad conditions we put the dinghy in the water, ready for use. When really bad (50+ kts) we start the main engine just to be prepared. When all is okay and the storm lasts at same strength you can shut it off again. We take the dinghy and go help others at that time.

Good luck
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Old 27-03-2016, 22:01   #74
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Re: Help me flesh out my ground tackle

I'm rather impressed that my simple comment

'Moving right along... the deeper the water the less scope you need and the less need for weight except down near the anchor. Cray boats anchoring out near the 100 fathom line off the west coast of Tasmania lie to pot line....

And in those cases you don't need a snubber but it is still good to take all load off the capstan.'

has generated such a debate.
Getting back to my original post..see above... if you are lying in 100 fathoms to a mulligan and pot line the windlass is not involved in the operation so snubbers and snatch loadings and broken chains and all the rest have no relevance in that situation.
I'm done...
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Old 27-03-2016, 22:46   #75
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Re: Help me flesh out my ground tackle

No need to get all worked up about it; I did not even read your post so mine had nothing to do with you or your post

Quote:
Originally Posted by El Pinguino View Post
I'm rather impressed that my simple comment

'Moving right along... the deeper the water the less scope you need and the less need for weight except down near the anchor. Cray boats anchoring out near the 100 fathom line off the west coast of Tasmania lie to pot line....

And in those cases you don't need a snubber but it is still good to take all load off the capstan.'

has generated such a debate.
Getting back to my original post..see above... if you are lying in 100 fathoms to a mulligan and pot line the windlass is not involved in the operation so snubbers and snatch loadings and broken chains and all the rest have no relevance in that situation.
I'm done...
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