Mixed chain/rope idea....

[MedSailor]

So I've got this idea and I wanted your opinion before I don't take your advice and go ahead and do it anyway...

I'm trying to design a system to have an anchor I can pull up by hand for my new boat.

I used to have a 31ft sloop which did not have a windlass. I pulled up my fortress FX-16 and 55ft of 1/4"HT chain by hand and after anchoring 100times or so I got very comfortable with the process and gained a great deal of trust in the Fortress itself and the system I had.

Now I have a 41ft Formosa Ketch that displaces 28,000lbs before loading on the beer. I have a manual windlass and a primary anchor system I trust, but I hate having to rely on the slow mechanical (ie prone to breakage) system to pull up and lower the anchor.

The utility of a hand anchor came in handy not long ago when our engine died at the same time as our depth-sounder. We had to sail into an "anchorage" in 3 kts of wind and anchor somewhere that had a steep underwater profile and was only 300ft or so off the beach. (did I mention the depthsounder was broken?) I quickly improvised a rode from sheets and hand-launched a secondary.


So here's what I have in mind. I have an FX-37 which is adequately sized for our boat (I love swap meets) which weighs 21lbs. I figure 40lbs is probably as much as I or my crew can reliably pull off the ocean floor all at once. So I was thinking of a rode which would look like this:

The FX37 with 10ft 3/8 chain and swivel (40lbs) followed by
50ft of 3 strand or 8 plat 5/8 rope with spliced thimbles at each end then,
25ft of 3/8 chain (38lbs) followed by
300 or so ft of 5/8 rope.

This would allow me to have an adequately sized anchor with enough chain to help it set and have some caterery effect (50lb worth), and still allow me to pull it up in depths of less than 50ft and only pull up 40lbs at a time.

I recognize that adding the 50ft of rope into the middle of the chain segment adds 2 splices and 2 shackles to the total hardware count and thus that many more failure points but I figure that shackles and splices are trustworthy yes? Much like through-hulls, some have 2 some have 12.

What do you think? Good idea? Too complicated? Is there a better solution out there? I await your thoughts.

Cheers!
Medsailor

[soulesailor]

Originally Posted by MedSailor

So I've got this idea and I wanted your opinion before I don't take your advice and go ahead and do it anyway...

truer words have never been spoken

I like your idea. original. I think your angle of pull might be a little higher with the rope in between the lengths of chain. That might be a concern with regards to pulling the fortress out unintentionally.

[sailingdog]

IMHO, it is a really incredibly stupid idea. The 50' of rope is going to get chafed against the bottom in very little time, especially if there is any rock, coral or other sharp hard objects on the bottom. That would leave you without an attachment to the anchor without any warning or way to inspect it while in use. The whole purpose of having chain in an anchor rode is to protect the more vulnerable rope from chafe and abrasion.

I've hauled my 33 lb. Rocna and 30' of 5/16" G4 high-test chain off the bottom by hand. If you can't handle hauling up the 75 lbs or so that the ground tackle I have weighs, IMHO, you've got no business being on a boat that damn big.

Any rode should have at least one boat-length of chain, unless the manufacturer recommends you use less. BTW, the Fortress anchors manufacturer recommend only about 12-18' of chain on their anchors, as too much chain will hinder them setting properly IIRC.

I would also recommend that you not use an anchor that has very little chance of resetting if the wind shifts 180˚. Most fluke-type anchors, like the Fortress or Danforth, generally don't do very well if the current or wind shifts 180˚.

What would probably work better for you is to have a chain pawl setup on the deck. With a chain pawl and a rode that is say 50' of chain and 200' of 5/8" rope, you can pick the rope up pretty easily, and then use the chain pawl to help you haul up the chain.

[MedSailor]

SD, thanks for your input, though I feel as though you are holding back.

I should probably clarify that this anchor will be my secondary bow anchor setup. My primary is currently a 66lb genuine bruce on 300ft 3/8chain though will probably be switched in the future to a 66lb spade. (how do you like your rocna btw?)

The purpose of the fortress is to be able to easily weigh a second anchor when the wind picks up or to use in stressful situations such as the anchoring unexpectedly under sail incident. I might also use it as the only anchor I weigh if I'm in the PNW and I know it's a nice sandy or muddy bottom that the fortress will love. I'm not worrying about wind-shifts and resetting based on my experience and intended use as a secondary-directional anchor.

I'm not sure I follow your logic on the length of chain posing a deadly chafe issue. Anyone who has a mixed chain/rope rode has rope along the bottom. Also some folks (not me) anchor entirely on rope. I checked my rode for chafe every time I brought it up and never worried about it chafing through in the middle of the night as I knew that if the wind really picked up and we were pitching at anchor (the kind or motion to create chafe) that the rode was entirely off the bottom at that point anyway.

Are you suggesting that it's more of a hazard than a regular mixed rope/chain rode because the second length of chain would weigh down the 50ft section of rope allowing it to get caught on something? I suppose that could happen in coral though I'd hate to use a fortress in coral at all....

I'm also not tracking on the "boat length of chain" part. I could have a boat length of 1/4HT chain for the same weight as my 3/8 chain but I thought that initial length was for weight to set the anchor not for chafe as rope is always touching the bottom on mixed systems. I figured that the more weight and chain the better, hence my creativity.

Thanks for the thought on the 12-18ft of chain for the Fortress. I haven't heard that but I'll check on it. If that's the case I can just put 12ft of chain on and skip the extras. Sounds light on catenery and weight to me but I'll definitely look into it.

Medsailor

[arf145]

Medsailor, I'll help interpret because sometimes Sailingdog dances around the issue and hides his true feelings behind a gauzy veil of diplomacy: He doesn't like the idea.

[chris_gee]

The difficulty may be getting the anchor to set with that amount of chain on the bottom. The anchor is relatively light, and probably needs considerable chain like 50' plus on the bottom.
For that size boat Rocna advise a 55lb anchor. That would normally need about the same weight in chain.
The type of bottom, wind strength, depth and windage also come into play. I guess it depends on how much you want the anchor to hold versus be easy to pull up by hand. If you have someone to motor the boat to the anchor your maximum weight is the chain weight of the depth of water plus the anchor.
What you are proposing is a variation on the anchormate type system of an additional weight which can be let down the warp but not as effective, because the weight is not concentrated at the depth you want.
Rocna has a page looking at this and concludes it doesn't add to holding power but may reduce swing. Kellets or Anchor Angels / Sentinels - Uses and Applications
I realise that the Fx anchor is lighter weight and very good on some bottoms but not all.
On a boat that size it seems hazardous to rely on an anchor you can pull up by hand unless you absolutely have to.

[JohnRPollard]

Originally Posted by MedSailor

Are you suggesting that it's more of a hazard than a regular mixed rope/chain rode because the second length of chain would weigh down the 50ft section of rope allowing it to get caught on something? I suppose that could happen in coral though I'd hate to use a fortress in coral at all....

I can't speak for SD, but I'll suggest that.

I'm with SD on this one: not a good idea. Chafe on the intermediate span of line is the biggest issue. Usually with a mixed rode, the chain is on the bottom taking the beating, and the line is merely suspended in the intermediate depths, hopefully well away from anything that could cut it.

I would suggest simply using the maximum amount of chain weight that you can manage, altogether in one single length. Since this is not your primary anchor, maybe you could use a smaller size chain link and get a longer span of chain for the same weight?

[sailingdog]

Even on a non-coral bottom, like the ones found here in New England, where the occasional rock or piece of sea junk is found on the bottom, having a piece of rope between two sections of chain is going to leave it very vulnerable to chafing through with little or no warning. This would be especially stupid if the rode in question is for your "storm" anchor and is designed to maximize holding power when you need it most. This is especially true in a storm condition, where the rode will be under high tension and stress, and the elasticity of the nylon portions will have it sawing back and forth along the bottom.

A single length of chain, attached directly to the anchor, will do far more to help the anchor set properly IMHO, without the risk of chafe or other problems that having a four-part rode is going to introduce.

Another point, which I didn't mention previously is that the rode will now have far more points of failure, since the shackles are usually the weak points in a rode, and the rode, as you've designed it, is going to have three or four shackles, compared to the one or two that are found in a standard chain-rope rode. Most of the better chain-rope rodes I've seen have the rope spliced directly to the chain to avoid the need for a shackle and thimble at that location—since a shackle and thimbled eyesplice won't fit through a windlass gypsy safely.

The chance of the rode fouling is also probably going to increase, since there are two weights pulling down on the rode, not just the single weight at the end.

As pointed out previously, the rope in a combination chain-rope rode, if the chain is of a decent length, is generally not all that subject to chafe.

As pointed out in several books and tests, having the majority of the weight concentrated at the terminal end of the rode is far more effective, especially when the rode is under high loads—where the chain's catenary curve doesn't come into play.

[knothead]

Originally Posted by sailingdog

IMHO, it is a really incredibly stupid idea.

What does IMHO mean?

[sailingdog]

In My Humble Opinion.

Originally Posted by knothead

What does IMHO mean?