Chain Versus Rope Scope ?

[webejammin]

I have noticed lots of CQR copies that I would not have, I think those are what is giving CQR the bad name.

[delmarrey]

Originally Posted by webejammin

I'm afraid if I go to 50 lb my arthertic back can't lift it if my windless was to go out.

That's where a pair of lines with a chain hooks comes in. You rig it back to the main sheet winches and pull a little at a time. until you can get it on deck. Then fix your windlass.

[wolfenzee]

This is not a questioned that can be definitively answered, both have advantages and both have people that believe their preferance is without a doubt the the best method.
I personally prefer all chain, it keeps the pull closer too hoizontal and I have see too many boats end up on the rocks because their rode had been ct by another boat. I put a good long snubber on my chain, not just to reduce the jarring effect chain would have if I happened to anchor in a place/time you shouldn't be anchoring, but mainly because the brake on a windlass should not be relied on to hold the boat. I have my boat set up for both, rode is easier to handle and you can tell your scope without looking at the depth sounder.

[s/v Jedi]

Originally Posted by wolfenzee

I personally prefer all chain, it keeps the pull closer too hoizontal

I'm sorry that I keep busting this but you are wrong. It only keps the pull closer to horizontal when conditions are calm and you don't need top performance. When conditions go bad and we need all it can give us, the pull is the same.

The reason for chain is chafing resistance. And that is where we get into more misconceptions. Users of nylon rodes will often state that it isn't a problem because hey never anchor on coral etc. like if boats with chain do that. But the buggest chafing is internal, inside the nylon line, and caused by heat that will melt the core and thus lead to failure.

cheers,
Nick.

[s/v Jedi]

Originally Posted by webejammin

I have noticed lots of CQR copies that I would not have, I think those are what is giving CQR the bad name.

That is only part of it. When you get to hard sand, they just skip over the bottom without ever setting. People used to think it was as good as it was gonna get, until the Bruce came long and it did set. Delta, Kobra, Spade, Buegel, and Rocna followed and did even better.

When cruisers are very happy with their CQR, it is because they only used it in seabeds that work well with about any anchor. For your boat, ditch the CQR, get a Rocna or Manson Supreme of around 50 pounds, find a Kobra that can be taken apart as a spare, and a Fortress as kedge anchor and you will be okay no matter where you go. Well, you need some very long lines like others suggested. To tie to palm trees on beaches or around rocks in fjords etc.

ciao!
Nick.

[s/v Jedi]

Originally Posted by delmarrey

That's where a pair of lines with a chain hooks comes in. You rig it back to the main sheet winches and pull a little at a time. until you can get it on deck. Then fix your windlass.

Yep. I have modified it a bit: when you have hauled the anchor up to the surface, attach a spinnaker or jib halyard to the chain and haul it up to deck with that. I did this with a manual Lewmar 44 winch and my 176 pound anchor without a problem. The first part with the bigger primary winch and he anchor still submerged is much easier (the anchor weighs 15% less while submerged).

ciao!
Nick.

[Dockhead]

Originally Posted by s/v Jedi

That is only part of it. When you get to hard sand, they just skip over the bottom without ever setting. People used to think it was as good as it was gonna get, until the Bruce came long and it did set. Delta, Kobra, Spade, Buegel, and Rocna followed and did even better.

When cruisers are very happy with their CQR, it is because they only used it in seabeds that work well with about any anchor. For your boat, ditch the CQR, get a Rocna or Manson Supreme of around 50 pounds, find a Kobra that can be taken apart as a spare, and a Fortress as kedge anchor and you will be okay no matter where you go. Well, you need some very long lines like others suggested. To tie to palm trees on beaches or around rocks in fjords etc.

ciao!
Nick.

+1

I spent ten miserable years anchoring with a genuine CQR. I never did find a seabed which it liked. And I learned to sleep with one eye open at anchor, even in benign conditions -- a habit I still have, much to the detriment of my sleep

[wolfenzee]

Originally Posted by s/v Jedi

I'm sorry that I keep busting this but you are wrong. It only keps the pull closer to horizontal when conditions are calm and you don't need top performance. When conditions go bad and we need all it can give us, the pull is the same.

The reason for chain is chafing resistance. And that is where we get into more misconceptions. Users of nylon rodes will often state that it isn't a problem because hey never anchor on coral etc. like if boats with chain do that. But the buggest chafing is internal, inside the nylon line, and caused by heat that will melt the core and thus lead to failure.

cheers,
Nick.

A friend of mine, who is still rebiulding his boat, had all the "proper" ground tackle for far worse weather and bottom conditions than here. 40' of chain and 1" rode with a good amount of scope, 45lb CQR, nasty storm hit everything held.....but another boat dragged anchor so they fired up thier engine and left, cutting my friends rode with thier prop as they disappeared into the darkness (someone from out oof town, never identified), he ended up on the beach, his rudder destroyed and an old piling stub punching a hole in his boat (a very well constructed Italian made boat) . Last winter alot of boats ended up on the rocks in Port Hadlock (one marina over) mostly because one unattended boat dragged anchor on to he others starting a chain reaction.
The second owner of my boat has alot of world wide cruising experience as well as being skipper of several 100''+ schooners under his belt...he put all chain on this boat so I will trust his choice (besides the 500lbs o ballast make her handle better in heavy seas).

[roverhi]

With an all chain rode, you can get by with less scope in normal situations. We routinely anchored with 4-1 scope, 45# CQR, 3/8" chain, 20,000# displacement and never dragged anchor. If we were expecting strong winds or conditions looked a little dicey would go with 5-6-or 7 to 1 scope but we only did that a few times in over a year of 24-7 anchoring. We always used a 40' length of 5/8" nylon 3 strand attached to the lower bob stay fitting as a snubber.

Nothing quite so much fun as a group of boats anchored on chain that get joined by a boat using a rope rode. A nice compact group of anchored boats turns into a CF as the rope rode boat wanders all over the ground on it's light weight 7-1 scope.

[cal40john]

Originally Posted by webejammin

I bought an origional 35 lb CQR but don't know where to get data on sizeing, I just guessed when making our purchase. Should I melt lead and attach it to the anchor ?

As others have said on this thread, while the increased weight helps, especially in setting the anchor, the primary purpose of getting a heavier anchor is that you are getting much more fluke area.

Look at moorings. They all used to be things like 1000 lb concrete blocks. Adding more weight here helps. Now moorings are going to helical coils screwed into the bottom. Adding weight to this is pointless.


The Fortress anchor, made of aluminum, has a huge amount of fluke area for its weight. Look at any anchor test and they hold something like double of other anchors. They're so lightweight that Fortress recommends a little chain to help them do the initial set. Since all modern anchors rely on digging in I think a closer or more realistic comparison of anchors should not be based on weight, but on fluke surface area.

And before everyone gets excited, I was using the Fortress as an example, yes there are a variety of reasons that people have for not wanting it as their primary anchor.

John

[klem]

Originally Posted by webejammin

Ok so on my 34 ft 10,000 lb cataman what weight of anchor do I pick ?

Webejammin,

I think that you need to define a lot more before you can pick the weight. Nick has been doing a great job of suggesting a good setup and it is a great start.

As an engineer, I would start by saying that you need to define exactly what an anchor will do for you. If you answer is that you like to anchor for lunch occassionally in calm weather, you end up with a very different anchor than if it is your hurricane plan. At a minimum, I would argue that most cruisers need an anchor that will work for severe thunderstorms with the bottoms in their cruising area.

Once you have defined the worst case operating perameters, you should define all of the specifications that it must meet. These include bottom types the anchor will work in, minimum reliable holding power in those bottoms, how the anchor works in a veering situation, weight, size, bow roller config, etc. To get an idea of loads, you can see the ABYC guide and look at manufacturers recommendations and then compare them to holding power tests to get an idea of what size anchor you need. Remember, you want some safety factor.

It sounds like you are very weight sensitive so I would lean toward a new generation anchor which have better holding power to weight (ignoring fortress which doesn't do well in veering) and then something like 50lbs if you are looking for it to work in a severe thunderstorm situation.

[s/v Jedi]

@wolfenzee : see, we agree. All your arguments are about the chafing resistance of chain compared to nylon. I find a 100% chain rode the best for the primary anchor; I just don't agree with the myth of the better holding with chain when the wind gets high enough to pull the rode tight.

@roverhi : yes, short scope in calm conditions is a big advantage of chain rodes. If you would teade up to a modern design anchor of the same weight, you could keep a 3:1 scope even a 20-25 knots without a worry. I have been at 3:1 in 35-40 knots but was a bit worried then... as I stood watching it from ashore in Cartagena!

cheers,
Nick.

[Ex-Calif]

Originally Posted by s/v Jedi

No, you don't throw anything away. Please try to follow me. You keep the chain at the same length and strength. You only make it lighter by selecting a smaller diameter made from a stronger steel. The weight saved you put back in the anchor. This is not difficult to imagine I thought.

Now in real world example because I sense people don't understand this yet. Lets say we have 250' of 3/8" G43 chain which weighs 382.5 pounds and a 66 pound anchor, total weight is 448.5 pound so let's make that 450 pounds for easy math.

Now we anchor with all 250' of chain out and measure holding power. We call that number "x".

Next step is new anchoring gear. We take 250' of 5/16" G70 chain which weighs 250 pounds. 450-250=200 pounds. So we buy the same type of anchor we had before but now a 200 pound model instead of the 66 pound one used in the previous test. Our total weight is the same 450 pounds. Our total rode length is the same 250'

Now, my statement is that with this lighter chain and 200 pound anchor, your holding has increased to 10x - 100x.

Go try it out if you don't believe it

cheers,
Nick.

Nick - thanks for putting it in practical terms. I am not disagreeing with you in any way. Perhaps the fault is in being an engineer.

At the end of your exercise you state holding is improved 10-100%. so, what is it 10 or 100? Of course the question is hypothetical but as an engineer this sticks in my craw. To get a 100x improvement in any system is extremely difficult from an engineering standpoint.

There should be no argument that bigger anchor weight is better. There should be no argument that chain is prefereable to rope.

However, Almost everyone has to make trade offs. It is understanding what you are trading that is important.

[s/v Jedi]

Originally Posted by Ex-Calif

Nick - thanks for putting it in practical terms. I am not disagreeing with you in any way. Perhaps the fault is in being an engineer.

At the end of your exercise you state holding is improved 10-100%. so, what is it 10 or 100? Of course the question is hypothetical but as an engineer this sticks in my craw. To get a 100x improvement in any system is extremely difficult from an engineering standpoint.

There should be no argument that bigger anchor weight is better. There should be no argument that chain is prefereable to rope.

However, Almost everyone has to make trade offs. It is understanding what you are trading that is important.

I don't mean 10-100% ... I really mean 10-100x (times) as much. Your statement about the impossibility to improve a system 100x is correct. But between some weight tossed on the bottom, or that weight used to create an anchor that burries itself into the seabed... those are different systems, not just an improvement.

I am sorry that I can't explain it more clearly. Others did understand and even posted similar calculations; may be they can explain it better?

Also, your asking for either is it 10x or 100x, I already answered.

cheers,
Nick.

[Ex-Calif]

Originally Posted by s/v Jedi

I don't mean 10-100% ... I really mean 10-100x (times) as much. Your statement about the impossibility to improve a system 100x is correct. But between some weight tossed on the bottom, or that weight used to create an anchor that burries itself into the seabed... those are different systems, not just an improvement.

I am sorry that I can't explain it more clearly. Others did understand and even posted similar calculations; may be they can explain it better?

Also, your asking for either is it 10x or 100x, I already answered.

cheers,
Nick.

Please dont mistake inquiry for lack of understanding. Yes I should have stated 10-100x with your measure of hold as the initial x.

Lets say the first system in your example had 400lbs of hold. 10-100x means 4000-40,000lbs of hold.

I might buy 10x but nowhere near 40,000lbs. The chain is only like 5k working load so 100x improvement in holding is impossible.