Ok. Not all chain, what do you use?

[Talbot]

I have 50m of 10mm chain and then 200m 0f 18mm Octoplait. Octoplait is much easier to stow in the anchor locker and readily splices to chain. The splice doesn't like the gypsy although the rest of the octo will work with it. I prefer to use the winch on my windlass for the rope.

I chose the combo so that I had all chain in my normal anchor scenario thus reducing my swinging circle to most other boats. I have the rope for those Oh sh*t moments where it is really deep but you need to anchor.

The deepest I have anchored is in 60m (in another boat during a race) on that occasion we used every bit of spare rope onboard and had a nightmare getting It back onboard.

[mikedefieslife]

Originally Posted by Talbot

... The splice doesn't like the gypsy although the rest of the octo will work with it. I prefer to use the winch on my windlass for the rope.
...

Hmm. In which case considering that is already spliced to the chain, when you know you are going to need the octo do you let the chain out with the windlass, then manually pull all the octo out and then rewind it around your drum?

[ZULU40]

Originally Posted by mikedefieslife

Hmm. In which case considering that is already spliced to the chain, when you know you are going to need the octo do you let the chain out with the windlass, then manually pull all the octo out and then rewind it around your drum?

good question, I like his set up tho

https://www.youtube.com/watch?v=h99Qh4mAQ8A

[p435]

My cat is 13.5 m and weighs at the crane hook 11t. I have a rocnan anchor of 40kg (maker states good for 20m boats of up to 40t) attached to this is a 10mm stainless steel chain. A rope can be attached, but with 100m of chain I don't expect a need for that.


I recently had twice the anchor down at about 8-9m in sand when I got hit by strong winds. One time, 6bft fully hit the boat for the entire night. Another time, different bay, wind varied between 5-7Bft for a whole day.



In both cases the chain was a wonderfully buffering the blows. I tracked the boat movements at my chart plotter. No slipping of the anchor observed.



I always favor a long chain over a rope knowing that I have a bit more weight at the bow. But safety first.

[ZULU40]

Im working on the theory that rope can extend the weight u can deploy in chain (thicker) and anchor, yet still have plenty of scope

[thinwater]

Originally Posted by ZULU40

Im working on the theory that rope can extend the weight u can deploy in chain (thicker) and anchor, yet still have plenty of scope

That was not very clear to me.


If you mean using some rope means you can use heavier diameter chain, then the math says you are incorrect. The farther the weight is from the anchor the more effectively it creats catenary. It is about leverage. Thus, a longer length of higher grade chain is better.



The corollary is that there is no sense I can derive for a mixed rode to use anything other than G43; lower grade (heavier) is not effective use of weight, and higher grade is difficult to splice at strength (chain links too thin) or manage through a windlass (the chain will be strong, but the rope will be under strength for the chain it is spliced to). G43 is the sweet spot. G30 is OK for boats less than 30 feet because it is strong enough at 1/4". The other exception is if you want to use very little chain (<10 feet) to avoid handling it; then heavier makes some sense.



Anyone, please present math why either of these statements might be incorrect.

[thinwater]

Originally Posted by p435

My cat is 13.5 m and weighs at the crane hook 11t. I have a rocnan anchor of 40kg (maker states good for 20m boats of up to 40t) attached to this is a 10mm stainless steel chain. A rope can be attached, but with 100m of chain I don't expect a need for that.

I recently had twice the anchor down at about 8-9m in sand when I got hit by strong winds. One time, 6bft fully hit the boat for the entire night. Another time, different bay, wind varied between 5-7Bft for a whole day.

In both cases the chain was a wonderfully buffering the blows. I tracked the boat movements at my chart plotter. No slipping of the anchor observed.

I always favor a long chain over a rope knowing that I have a bit more weight at the bow. But safety first.

I like chain, but...


The problem with the story is that it offers no hint as to whether rope would have been better or worse. In fact, chain catenary and nylon rope would probably have been very similar. But no information.

[KiwiKen]

Originally Posted by Benz

I have used 3-strand spliced to a boat's length of chain as a primary rode on a small, lighter displacement boat than I have now, and my current kedge is set up the same. The chain does most of the dragging around the rubble on the bottom, leaving the nylon pretty unscathed. Boats on nylon rodes tend to 'sail' around on the anchor quite a lot, which can look alarming viewed from the nearby seawall when it's blowing hard.
If I were to do it again, I'd use Anchorplait or one of the other 8-strand nylon braids. Those are a huge improvement over 3-strand.

As a rule of thumb the more chain the better, but one should not have less than a boat length of chain.
The problem with chain is the weight, particularly if one does not have a windlass.


The chain provides two vital elements in anchoring.
It will not be frayed or damaged by being in contact with sharp rocks or other material on the sea floor that could damage a rope.
The chain aids the set up of a catenary and acts as a shock absorber for the anchor - changes of load due to sea motion are absorbed by lifting part of the chain thus removing snatch loads coming on the anchor that could break it out.


Nylon is a preferred use for a rope part of the anchor warp due to it's inherent stretch which reduces snatch loads on the anchor and chain element.

[ZULU40]

Originally Posted by thinwater

Anyone, please present math why either of these statements might be incorrect.

nobody should have to
50m of 8mm chain 150lb, 10 mm chain 250 lb

who here has a winch for tackle best suited to a boat 2x their length

yet you can easily have an anchor 2 sizes plus to your length if you forgo some lighter chain and not overburden the winch. A heavy anchor, heavy chain makes sense suspended from a nylon rode because it is ultimately the anchor and nearest chain that grips where it counts. Not to mention more common shallow anchoring.

[Talbot]

Originally Posted by mikedefieslife

Hmm. In which case considering that is already spliced to the chain, when you know you are going to need the octo do you let the chain out with the windlass, then manually pull all the octo out and then rewind it around your drum?

Happy to deploy using the gypsy as it seems to cope without problem. I have a Lofrens Airon and the Privilege 37 has excellent access to capstan and anchor locker. I have a cleat right next to the cable run, and a chain stopper. I normally operate the capstan using a wireless remote.