What Anchor Line Would You Get?

[Rakuflames]

Originally Posted by Dennis.G

My boat is 48' ketch, fairly low windage, and 23 tons. I currently have 300' of 3/8" BBB chain with 65# CQR and a Muir 1000W windlass.

I recently wanted to anchor in an area with 105' depth. I think I would have held OK in the current conditions with 300', but I was not comfortable getting off of the boat with that short of scope, so moved on elsewhere.

I want to keep an extra length of anchor line to shackle on to the end of the chain should this situation come up again (plan to revist the area soon). Also want line long enough so it count serve as a back-up anchor rode by its self. Trying to decide between:

1. 250' of 5/8" 3-strand nylon
2. 250' of 3/4" 3-strand nylon
3. 250' of 5/8" mega plait nylon
4. 250' of 3/4" mega plait nylon

The 3/4" size seems an overkill and would add significant bulk, but maybe I should use anyway?

What do you use, and recommend for use based on my boat?

Thanks for your input

I have the megaplait and really like it for a number of reasons. I don't have a windlass and it's easy to handle. It's highly resistant to kinking, so it uses stowage space efficiently. The one thing about it is that it chafes easily, and you do want to put chafing gear on it. It probably won't last as long as stiffer rode, but IMO for ease of handling it can't be beat.

[Gene :^)]

Just get the 3/4 mega plait and not have to worry.

You are accustomed to all chain with good scope. 3:1 made you uneasy.

You say you want this line to also be a back up rode.

Well if the day comes to use it or even add it to your chain and you have saved a couple bucks going with the 5/8... you will probably be uneasy and thinking the whole time that you wished you had just gotten the larger line.

This message board always says anchoring gear is no place to go cheap, our lives are hanging on that gear. Your boat could easily be lost forever by poor gear. Yet here is a thread debating what to use and trying to calculate the minimum requirement??? Saying get the 5/8 because it "should" be "good enough".

Since this is back up gear, will be stowed most of the time, and not heavily used (less abuse) the mega plait will be easier to handle and take less space.
Since you probably won't use this until you really need it, you want the strongest you can handle or else you won't feel comfortable when you really need it.

-----

Gene :^)
http://www.Strathbelle.com/

[jeremiason]

We have 300 feet of 5/16" HT chain with two hundred feet of 5/8" Mega Plait spliced to the chain for a total of 500 feet of rode. On he secondary anchor to save a little weight I went with 200 feet of chain and 300 feet of Mega Plait.

Since we started cruising in September of 2010, we have anchored once in a spot that required putting out more than 300' of rode and getting into our Mega Plait line. It worked well and was easy to retrieve and store.

If I have to replce my rode, I would assemble it in the same configuration. 300 feet of chain will do in almost every circumstance, but it is nice to have the extra rode if needed.

The one thing I would suggest is slicing the line directly to the chain. This makes transitioning from the warping drum to the chain gypsy much easier.

[Jim Cate]

Originally Posted by jeremiason

The one thing I would suggest is slicing the line directly to the chain. This makes transitioning from the warping drum to the chain gypsy much easier.

Not sure that I agree with this for a couple of reasons:

Having the rope lying o n the bottom of the chain locker all the time exposes it to degrading influences like abrasion from mud and sand brought up with the chain as well as generally being beaten about by the chain itself lying on top of the rope. If the ripe is stored in a clean bag below decks for 99% of the time, it will be in like new condition when pressed into service.

And, depending on the size and shape of the chain locker, the big pile of rope may raise the chain pile enough to reduce the chain fall excessively. This can lead to chain jamming in the chain pipe.

I do agree that the splice makes it easier to recover the rode when teh rope part is in use. However, since this will be i n use very seldom, it isn't that big a deal IMO.

Cheers,

Jim

[micah719]

About -%10 for a good splice. Another -%10 to -%15 for nylon when it's wet. The SWL for lifelines is so high because they are shock loaded perpendicular to the line. As the deflection approaches 0 degrees, the load goes to infinite. Good for swigging halyards, bad for lifelines, and immaterial for anchor rodes.

A short blurb on line types:
http://seagrant.uaf.edu/bookstore/boatkeeper/rope.pdf

And a test-to-destruction article.
Used Nylon Three-Strand Rope Faces The Ultimate Endurance Test - Practical Sailor Article

Conclusion

Our test shows that even when you eliminate the effects of chafe, up to 75-percent of the original tensile strength in our sample ropes was lost. Although experts tell us that nylon has great ultra-violet damage resistance and chemical stability, our testing revealed a worrisome trend.

If you are basing your buying decisions on breaking strengths for new rope, you will obviously want to allow a generous safety factor for deterioration, or else plan to replace the rope soon. Keep in mind that the abysmal numbers seen in our testing actually optimized the cordage’s breaking strength because it was a straight line pull, did not include on/off cycle loading leading up to higher strains, and provided minimal chafe generating factors. Even so, the best showing was only 51 percent of the lines’ original tensile strength, and some samples of the dock lines broke at only 25 percent of the original rating!

These findings fly in the face of the conventional rhetoric that views nylon as such a strong material that one should always opt for thinner line due to its better elastic effect. To the contrary, within reason, this overly springy, rubberband-like function is a foe rather than a friend, and a couple of its downsides are significant. The first is that the heat build-up associated with repeatedly stretching the material gets critical as surge stretches the dock lines or gale-force gusts tension an anchor rode. The second is that the acceleration afforded by the springy dock lines actually encourages a vessel to "sail" at anchor or saw back and forth on its dock lines. Lastly, the smaller-diameter line has less sacrificial surface to lose in the chafe process, and damage to the line will jeopardize the vessel sooner rather than later.

Anti-chafe protection must allow rain to cool and lubricate the stretching and contracting fibers. Leather or water-permeable canvas are better than impervious PVC hose. Yes, wet nylon loses some strength, but the trade-off is minor in comparison to melting the filaments at the point of maximum strain.

We left the lab realizing the importance of taking a close look at dock lines and other nylon-line applications, noting the last time they had been replaced and why tropical storms and nor’easters take such a heavy toll.

Check your boat’s nylon lines before the next storm season, and even if they look OK, consider our test results and decide how secure your boat will be with 25- to 50-percent of your line’s original breaking strength remaining. Remember that we tested dry nylon lines and that wet nylon loses even more strength. These lab findings reminded us that a new set of dock lines is cheap insurance, and money well spent.

[foggysail]

I gave up on nylon even for dock lines. I use 1/2 & 5/8" polyester for docking. My anchor rode is 5/18"HT chain. Again, if I had to use some type of rope, it definitely would be polyester.

Just pulling on nylon causes internal heat build up AND IT DOES GET HOT TO TOUCH! I used 5/8" nylon a few years ago with my van to rip out some brush by their roots. I was amazed at what tugging on that rope did to it! It was permanently destroyed by heat.

A few weeks ago I had my dinghy tied to my boat's stern. I started to back up and forgot that one of the 2" belts (nylon seat belt material) that I use with my davit crane to lift the dingy was in the water. The props sucked that hanging belt into one of the propellers and chopped it! I almost lost the dinghy and most likely would have had it not been for the painter attached to a cleat.

But getting back to the nylon belt which I still have, it not only was sheared, IT WAS MELTED AND IT WAS IN SALT WATER! My point, nylon heats when under stress, the higher the stress, the greater the heat.

Foggy

[Rakuflames]

Originally Posted by foggysail

I gave up on nylon even for dock lines. I use 1/2 & 5/8" polyester for docking. My anchor rode is 5/18"HT chain. Again, if I had to use some type of rope, it definitely would be polyester.

Just pulling on nylon causes internal heat build up AND IT DOES GET HOT TO TOUCH! I used 5/8" nylon a few years ago with my van to rip out some brush by their roots. I was amazed at what tugging on that rope did to it! It was permanently destroyed by heat.

A few weeks ago I had my dinghy tied to my boat's stern. I started to back up and forgot that one of the 2" belts (nylon seat belt material) that I use with my davit crane to lift the dingy was in the water. The props sucked that hanging belt into one of the propellers and chopped it! I almost lost the dinghy and most likely would have had it not been for the painter attached to a cleat.

But getting back to the nylon belt which I still have, it not only was sheared, IT WAS MELTED AND IT WAS IN SALT WATER! My point, nylon heats when under stress, the higher the stress, the greater the heat.

Foggy

Yes, that's what the insurance investigators found after Katrina, that nylon failed when the water could not get to it to cool it. They found that the nylon lines melted from the inside out, from the friction, when encased in waterproof chafe protection.

[Jim Cate]

Originally Posted by Rakuflames

Yes, that's what the insurance investigators found after Katrina, that nylon failed when the water could not get to it to cool it. They found that the nylon lines melted from the inside out, from the friction, when encased in waterproof chafe protection.

Hmmm, talk about a double bind! If you keep it dry, it melts from heat buildup, if you keep it wet, it looses much of its strength.

Makes the dacron I suggested earlier look even better to me.

Cheers,

Jim

[foggysail]

Jim--

That seat belt material I just described in my last post was buried in at least 3-4 feet of water when it got hit with a propeller and stretched! That is what got my attention, it was wet but it heated so quickly being wet did not matter one bit. The melted piece is resting in my dinghy as I type. The last 8" of the belt material is as hard as a rock with a permanent curvature that it had when it melted.

I don't know about Dacron, I know polyester does not have the same internal heating problems or at least as great a problem as nylon. If I can figure out how to post pictures, when I get home I post one showing the material in its final condition.

Foggy

[jeremiason]

Originally Posted by Jim Cate

I do agree that the splice makes it easier to recover the rode when teh rope part is in use. However, since this will be i n use very seldom, it isn't that big a deal IMO.

Jim

If I was daysailing it wouldn' be a problem to store 500' of line in two coils down below, but we are cruising. This is our house with spare sails, mooring lines, spare parts, food and the rest of the stuff we carry there is no room below deck.

Our anchor locker is about 4 feet deep and separated into two compartments with no chain pipe, so storage there is no problem.

Every six months or so, I remove the rode, lay it on the dock, power wash it and inspect it.

The Mega Plait is 3 years old now and no sights of chaffe or damage.

Will it last as long as being stored down below, probably not, but for us it works