Anchor Drum Rode Combinations

[MurrayM]

Recently saw a 40' Willard with a hydraulic anchor drum winch that had an interesting rode combination which included 20' 1/2" chain, 130' 5/16" chain, 150' 3 strand nylon and 300' 3/8 Spectra cord for a 600' rode length.

Being able to anchor in 100' of water would be very handy where I live to stay a safe distance from estuary drying flats.

I've never heard of anyone using Spectra in their rode, with its smaller diameter, to gain more length on a drum windlass.

Is this normal/proven?

 

[Lepke]

I can't see 3/8 line, whatever it's made from, for an anchor line on a 40' boat. The anchor and rode is also a piece of safety equipment. It needs to be able to stop the boat if the engine fails.

 

[Xsbank]

3/8" Dyneema has a breaking strength of 20,000#
5/16" grade 43 chain is 3900#

 

[DavidM]

The 3/8" Spectra should hold up fine for deep anchoring. It's tensile strength is about the same as 5/16" G4 chain.


Xsbank: The strength that you quoted for 5/16" G43 chain is its safe working load. Its tensile strength (ultimate breaking force) is four times higher.


See https://www.westmarine.com/buy/west...eZjqUBj19e2GV0wH9e8dZyEUsjVaH5hIaAj5dEALw_wcB


David

 

[cafesport]

I think I get his reasoning but his combined wetted chain weight is 165 pounds for 150’. 150’ of 3/8ths would give him more energy absorption and catenary which he might need with no stretch in his spectra line. That and smaller chain dragging on the seabed will be more likely to burry itself.

 

[Xsbank]

I stand corrected.

I am using a dyneema product on my hydraulic crane and my hand crane, way better than meat hooks on cable and I have 300' of 3/4" braid and 100' of 5/16" chain. The only drawback to Dyneema is its chafe resistance, many boats are using it for mooring and towing but it needs a protective sheath.

 

[MurrayM]

I sent a question to E-Z Anchor Puller about using Spectra, and got an answer back in less than an hour:

Hi Murray,

Thank you for your interest in E-Z Anchor Puller. The rode combination you describe is extremely common. We have a large market in Alaska and Seattle and I would say about 85% of our customers there are doing similar rode combinations in which you describe. The spectra line is 9X stronger than steel so it gives them the strength they need at a smaller diameter but it doesn't have any elasticity to it so they add on the nylon rope toward the chain and anchor to give them the elasticity they need. This is one of the benefits to our drum winches vs the windlass. You are not married to specific diameter rope and chain like you are for a specific size gypsy on the windlass.

https://www.ezanchorpuller.com/collections/anchor-winch

 

[MurrayM]

Aussies & Kiwi's seem to have more drum winches on their boats...any experience with Spectra down there?

 

[MurrayM]

Will try to find research on breaking strength of Spectra when going over a rounded edge (bow roller) as compared to a straight pull. (Chafe shouldn't be too much of an issue as the nylon portion of the rode would be stretching, not the Spectra).

 

[MurrayM]

Will try to find research on breaking strength of Spectra when going over a rounded edge (bow roller) as compared to a straight pull.

Quick hit #1 was testing done for rock climbing:

The cordelette to be tested was placed at the location of the "pivot edge", or the direction change anchor. The force at this point should theoretically be twice the rope tension because of the direction change.

Comparative Testing of High Strength Cord

So...you should account for some loss of strength for going over the bow roller, but that would be true of nylon as well.

 

[DDW]

If using Spectra (or more likely Dyneema) you have to use a drum winch, nothing else will recover uncovered Dyneema as it is too slippery.

The loss of strength of Dyneema over various sheaves and around shackled etc. has been well studied by the sailboat community. A small line going over a roller 10x or more than the diameter of the line will suffer little or no loss in strength. (Your quote refers to force on the roller and has nothing to do with the line). A greater concern is how it is terminated: almost any knot will reduce the strength by at least 50%, and most knots by 60 or 70%. You need to eye splice the line with a method specific to Dyneema. A second consideration is how the line is make fast to the cleats or bits. A standard cleat hitch, even doubled or tripled, will slip all the way to the end under much tension.

 

[Nomad Willy]

Murray,
Probably the important thing is to be able to use the anchor to hold the boat off the beach/rocks should the engine fail.

Lots of rodes in SE Alaska use nylon line (starting on the drum) normal chain, heavy chain and then super heavy chain at the anchor. This way the heavy part of the rode holds the anchor shank down where it does the most good.

The drum winch looks heavy but it’s almost all aluminum.

And the use of the spectra adds even more length to an already long rode. There is often a problem getting a long rode on a typical reel winch. I have oversized (for my boat) 5/8” brait line for most of my rode but it won’t fit on my reel with the 435’ of line. If I had 1/2” line it probably would but I wanted the 5/8”.

I still have the old drum winch I bought in Alaska used from an old fisherman. Seems functional but the old hydraulic motor either needs rebuilding or replacement. New drum winches are 3-4 and probably $5K. The level wind feature is seldom seen in Alaska.

1st picture and second picture too,
Fish boat in Craig. There are three different sizes of chain on the drum. Most have a long length of nylon under the chain that can't be seen. Second picture is of a boat in Petersburg and the boat's name (if you're wondering) is " Honey Willya"

 

[MurrayM]

The loss of strength of Dyneema over various sheaves and around shackled etc. has been well studied by the sailboat community. A small line going over a roller 10x or more than the diameter of the line will suffer little or no loss in strength. (Your quote refers to force on the roller and has nothing to do with the line)

Thanks for that, and good point that going over the roller doesn't decrease strength, but increase force.

Will also have to see about reduction in strength due to heat generated from repeated loading, as happens with nylon. If I were in a really big blow, I'd probably have a length of serious nylon webbing attached with an appropriate constriction knot to go over the roller, just in case.

Also, you apparently don't have to cleat or tie the rode off with the E-Z Anchor Puller...the unit will hold the boat all on its own. Knots can be avoided by using eye splices, as a drum winch can gobble up pretty much anything.

 

[MurrayM]

Murray,
Probably the important thing is to be able to use the anchor to hold the boat off the beach/rocks should the engine fail.

Lots of rodes in SE Alaska use nylon line (starting on the drum) normal chain, heavy chain and then super heavy chain at the anchor. This way the heavy part of the rode holds the anchor shank down where it does the most good.

The drum winch looks heavy but it’s almost all aluminum.

And the use of the spectra adds even more length to an already long rode. There is often a problem getting a long rode on a typical reel winch. I have oversized (for my boat) 5/8” brait line for most of my rode but it won’t fit on my reel with the 435’ of line. If I had 1/2” line it probably would but I wanted the 5/8”.

I still have the old drum winch I bought in Alaska used from an old fisherman. Seems functional but the old hydraulic motor either needs rebuilding or replacement. New drum winches are 3-4 and probably $5K. The level wind feature is seldom seen in Alaska.

Hi Eric,

They also make stainless steel units.

I've read that steering the boat side to side when reeling in a long rode can help.

 

[Nomad Willy]

Murray,
Good one I've not heard of the side to side steering method of "level wind".

SS yes but Ive not seen one in SE.

Hers's my winch.

 

[DDW]

Thanks for that, and good point that going over the roller doesn't decrease strength, but increase force.

Will also have to see about reduction in strength due to heat generated from repeated loading, as happens with nylon. If I were in a really big blow, I'd probably have a length of serious nylon webbing attached with an appropriate constriction knot to go over the roller, just in case.

Also, you apparently don't have to cleat or tie the rode off with the E-Z Anchor Puller...the unit will hold the boat all on its own. Knots can be avoided by using eye splices, as a drum winch can gobble up pretty much anything.

I've not heard of a melting issue on Dyneema due to stretch. This is somewhat unique to nylon because it is stretchy, therefore absorbs a lot of energy, which turns into heat. It doesn't typically happen with Dacron due to less stretch. Dyneema doesn't stretch much at all, so is does not absorb energy or produce heat. It DOES have a very low melting point though (it is just polyethylene), and can melt if it is rubbing hard on something as it is taken in or let out. This has been a problem on sailboat lifelines, often made of Dyneema these days. Dragging the jib sheet over them fast will melt them.

I'd put the nylon in-between the chain and Dyneema, if it's in the water while stretching it is pretty effectively cooled and lubricated. If you are thinking of a constrictor type knot on the Dyneema, forget that - there is no rolling hitch or variation that will hold.

 

[FF]

I wonder about the damage resistance of many of the new line.


The chain wound on the drum can easily scratch or nick line, will disaster follow?

 

[MurrayM]

I'd put the nylon in-between the chain and Dyneema, if it's in the water while stretching it is pretty effectively cooled and lubricated.

Yup, that was the plan. The 300' of chain + nylon would suffice for around 90% of our anchoring. The extra length given by the Spectra/Dyneema would be used in deep water, ice avoidance, or storm.

If you are thinking of a constrictor type knot on the Dyneema, forget that - there is no rolling hitch or variation that will hold.

Good point. I forgot that it's recommended that constrictor knots use a cord at least 1/2 the diameter of the rope it's being used on, so the cord would be freakishly thin, and you're right in that they apparently won't hold anyway.

My hunch is the weakest point in any rode will be where it goes over the bow roller, especially if there is any wave/surge action. Will look into anti chafe strategies...

 

[MurrayM]

I wonder about the damage resistance of many of the new line.


The chain wound on the drum can easily scratch or nick line, will disaster follow?

Look to the commercial fishing fleet of BC and Alaska...apparently not.

 

[ben2go]

It is advised to use a hawse type fairlead instead of a roller with synthetic lines. I believe the idea is that the line could be damaged if it jumped roller and jammed in the roller side. I'm not sure how that would be accomplished with a chain and rope rode. A hawse would get nicked up by the chain and in turn, would abrade the synthetic line.

 

[MiltonP]

Fishing Fleet Question

I like those heavy anchoring rigs the fishing fleet has but I wonder how much anchoring they do as part of their fishing process. Is anchoring for them a daily activity or just for emergencies? Guess I could watch some reality tv show to try and get an answer.

 

[Greg S]

I like those heavy anchoring rigs the fishing fleet has but I wonder how much anchoring they do as part of their fishing process. Is anchoring for them a daily activity or just for emergencies? Guess I could watch some reality tv show to try and get an answer.

Salmon trolling in BC used anchoring almost nightly.

 

[Nomad Willy]

Depends on the type of fishing.
Seiners rarely anchor. Trollers anchor most of the time except those that operate out of a port. Not common these days. And gillnetters basically don’t anchor at all. And the question gets further confused by the fact that there’s so many combination boats that troll and also gillnet.
One of the reasons for the drum winch is that with a heavy rode and anchor it’s super simple. Drop it down in the evening and pull it up in the morning. While talking anchoring with a fisherman he said “we haven’t got time for all that fussy yacht club seamanship show”. And after fishing all day I can see why.

 

[Bkay]

I don't think this thread is too old to revive, is it?

I've not handled Dyneema, but I've thought about adding a section of it to my rode after 3 strand nylon for the reasons mentioned above. But I've never figured out how you would attach a bridle to the Dyneema since it is slick and has a small diameter. Have any of you given thought to a easy method to use a nylon line for the bridle, but use a short section of Dyneema line to tie it off to the Dyneema rode? I'll be using a drum winch, but I still like a bridle to reduce sailing at anchor.

The reality in my set-up is around 20% of the time I'll only have chain out, 60% will be chain and 3 strand, and 20% will be Dyneema. So I'd like a bridle attachment mechanism that will tie into all three if anyone has good ideas.

 

[Greg S]

I don't think this thread is too old to revive, is it?

I've not handled Dyneema, but I've thought about adding a section of it to my rode after 3 strand nylon for the reasons mentioned above. But I've never figured out how you would attach a bridle to the Dyneema since it is slick and has a small diameter. Have any of you given thought to a easy method to use a nylon line for the bridle, but use a short section of Dyneema line to tie it off to the Dyneema rode? I'll be using a drum winch, but I still like a bridle to reduce sailing at anchor.

The reality in my set-up is around 20% of the time I'll only have chain out, 60% will be chain and 3 strand, and 20% will be Dyneema. So I'd like a bridle attachment mechanism that will tie into all three if anyone has good ideas.

Many ways to attach a bridle to a chain, including a hitch. For attaching to 3 strand nylon try a Rolling Hitch. For attaching to the slippery stuff don't use more slippery stuff. Use the same you use on your nylon but use an Icicle Hitch. I haven't tried it yet but you'll experiment and let me know how it works. An icicle hitch can be tied without having to slip a bight over an open end. Work with it and you will find it easy and quick to do.

 

[Fish53]

I prefer wire, way cheaper, less chafe and the weight creates a catenary that absorbs shock. Of course I'm biased in that I've worked with wire rope for forty years, use what you know.

 

[Bkay]

Many ways to attach a bridle to a chain, including a hitch. For attaching to 3 strand nylon try a Rolling Hitch. For attaching to the slippery stuff don't use more slippery stuff. Use the same you use on your nylon but use an Icicle Hitch. I haven't tried it yet but you'll experiment and let me know how it works. An icicle hitch can be tied without having to slip a bight over an open end. Work with it and you will find it easy and quick to do.

Greg S - thanks for your comment. Attaching to chain and 3 strand is easy and I agree with the Icicle Hitch. But the the Dyneema will be so much thinner (I believe 1/4" is spec'ed) that using nylon is not practical. I seem to recall you need to use the same or smaller diameter for your hitch and I suspect 1/4" or thinner nylon won't create a good hitch.

My thought is 1/4" Dyneema formed into a loop using a Figure 8 and attach that to the 1/4" Dyneema rode using a Prusik. Then I can use the eye of my 1/2" nylon bridle to thread through the Dyneema then let out as much nylon as I see fit. I hope that gives me shock absorption from the nylon and uses the Dyneema Prusik to hold me to the rode. Not sure how this will work, but I'll give it a shot. I may resort to some other system with the Icicle Hitch but using Dyneema rather than nylon.

I'll let you know if it works.