Chain Versus Rope Scope ?

[Curmudgeon]

I know the conventional wisdom: 3 anchors (1) a plow (CQR or Bruce) or Manson/Rocna type with a roll bar, (2) a Danforth, (3) a heavy fisherman stowed in pieces in the bilge. Carry as much chain as your boat can stand (extra can also be stored in the bilge). Carry at least one spare rode and if you use all chain a snubber is mandatory. If you are really into ground tackle you can also install a chainstopper on your foredeck (especially if you don't have a windlass) and stow a 25-30 lb. Kellet. (Peter Smith doesn't think Kellets help much either, but sailors have been using them for 2,000 years.)

[Thumbs Up]

I have a 40' cat, I use a 25 kilo Rocna, 50' 3/8 chain spliced to 7/8 nylon three strand. I don't want any more weight on my bows but I still want more chain! The issue for me is that the tighter you stretch rope, the easier it is to cut. 1. Here in the western Caribbean (Guatemala, Honduras, Mexico) we have a lot of "lancha" traffic and a lot of dinghy traffic. Some "lancheros" will motor very close to your bow, sometimes at night. If the wind is up it can even cause them to get blown closer than they intended.
2. If I anchor in more than 15 feet I will have some rope lying on the bottom during periods of dead calm. That rope can get wrapped around coral or junk on the bottom and get damaged when the wind picks up.
3. If it is blowing hard enough to make chain "bar tight", then rope in this same situation at that tension would cut through very easily. If a boat in front of you were to drag into you or drag his chain or prop over your rode you would be set adrift.
4. Using the windlass is a pain when your chain changes to rope

There you have it, I am a rope guy but I want chain, but the fact is, I don't like chain either, It is expensive, it is heavy, it rusts, it is only as strong as it's weakest link, and if you splice it you have to worry about the joining link breaking. I am sure that this discussion is going nowhere but I think the important thing is to understand the characteristics and limitations of whatever you do use and make do accordingly.

[JoeFish]

Originally Posted by Bash

Give us a break! When Peter Smith wrote that, he had a great deal to profit from cruisers believing they should invest more in their anchor and less in chain. HE SOLD ANCHORS! The more you believe that your money should be invested in an oversize anchor than in chain, the more money Peter Smith stands to make.

If we were to believe what Peter claims about the uselessness of chain, why is my chain so muddy every time I bring it up?

(Hint: consider the fact that the chain is actually in contact with the bottom.)

That's a nice rant but as I mentioned before, you have nothing other than your own subjective experience and no tangible evidence to back it up.

I'm not saying you are wrong, what I'm saying is that people who are smarter than both of us disagree for a host of reasons and you have provided nothing from an evidence standpoint that goes beyond opinion. Your experience is all well and good, but you may have an oversized anchor at the bottom of all that chain which would just as easily skew the results.

I'm sure we can all agree a 200# anchor would be secure on most 40' boats, chain or rope aside. What we're after here is real data on rode given a suitably sized anchor.

I am happy to listen to your opinion when you back it up with something we can measure. Part of why Peter's claims have so much more weight than yours is that he actually tested this and provided detailed data and analysis from those tests relating to catenary. These can be read irrespective of the anchor type.

I'm actually trying to get this discussion out of the opinion and insult slinging phase and into a place where we can actually compare data and make judgements based on real fact based evidence.

[JoeFish]

Originally Posted by roverhi

As far as weight in the bow, yes it does make a difference but really only going to weather. Something that a good cruiser avoids like the plague.

Running down wind in steep seas I find I'm far more likely to submarine the bow and load up my rig than I would going to weather. Downwind I fly almost 1000 ft. sq more sail than upwind and can easily hit 12-13 knots if it's blowing in the 30's. Stuffing the bow sucks in these cases and you can hear the runners load up.

Keeping the weight down in the bow in this situation reduces load, strain and wear on a whole host of components from lines to blocks to chainplates and swaged fittings.

[conachair]

Originally Posted by JoeFish

I'm actually trying to get this discussion out of the opinion and insult slinging phase and into a place where we can actually compare data and make judgements based on real fact based data.

The calcs to show what force it needs to lift a chain off the sea bed aren't really that complicated. With 10m between the bow and the seafloor and 50m of 10mm chain out, less than 1/4 tonne will lift the chain clear. Not that much really.

http://alain.fraysse.free.fr/sail/ro...ic/sta_hom.zip

But just as valid is not sleeping soundly because you don't have enough confidence in a short section of thinner chain then you would like spliced to a length of rode which you are sure you can hear chafing. You can throw all the data you like to a setup like that but if instinctivly you don't trust it than that is just as valid reason to go with thicker all chain than any spreadsheet you can come up with.

And the skittish boats dancing around on mostly rope in the anchorage is a fairly strong case against rode as well.

Personally I have 60m 10mm chain which is almost always ample. With another 50m nylon octiplait if it turns scarey.

[sailorboy1]

Originally Posted by JoeFish

I'm actually trying to get this discussion out of the opinion and insult slinging phase and into a place where we can actually compare data and make judgements based on real fact based evidence.

Well then .............. why do you insist in telling people they are wrong when they are expressing real life facts? Those are the only "fact based evidence" worth the weight on the subject!

[zeehag]

i get to watch as the "facts" start to drift thru an anchorage because they cannot anchor with all chain rode in a roadstead anchoraqe because all the info they were given was that "all (they) needed only 30 ft chain with their wtf anchor." DO NOT FORGET TO COUNT CHAFE as a factor in anchoring. real world dictates rope rode isnot sufficient as primary rode in a roadstead anchorage. or on coral or with rocks, or...

goood luck and smooth sailing.

[conachair]

Found my new anchor anyway, never to drag again...



Is there a better site looking into the physics of anchoring than here?
Tuning an Anchor Rode

[RabidRabbit]

If your main concerns are anchors with welds and roncas made in china you are worried about the wrong things. Welding is the best known way to join metals, and the Ronca from china are fine. Some people worry to much or maybe there are trolls among us.

[Bash]

Originally Posted by JoeFish

I'm not saying you are wrong, what I'm saying is that people who are smarter than both of us disagree for a host of reasons and you have provided nothing from an evidence standpoint that goes beyond opinion.

Smarter than both of us? Really, JoeFish?

So what sort of evidence does someone with your level of intelligence need to be convinced that, back when he wrote that article, Peter Smith was in the business of selling anchors?

[zeehag]

those who sell things do not always speak the facts as known in the real world.

[JoeFish]

Originally Posted by Bash

Smarter than both of us? Really, JoeFish?

So what sort of evidence does someone with your level of intelligence need to be convinced that, back when he wrote that article, Peter Smith was in the business of selling anchors?

The article is about catenary, not anchor choice. You don't need any degree to work that out, just basic reading comprehension.

His conclusions are, and remain agnostic when it comes to anchor choice. The only assumption was that the anchor itself was set properly and sized appropriately.

Where in the catenary/rode discussion in that article was there any mention of one anchor or another being a better choice with regards to rode and catenary? There wasn't because he knows as well as most of us that it would have been absurd to assert that.

Why do you keep insisting that because Peter is selling anchors that his tests relating to rode and catenary are invalid?

I as a discerning reader am quite capable segregating marketing fluff from valid test data.

By your logic we would ignore the advice of NOAA because they sell charts.

Now where's that ignore button...

[downunder]

Originally Posted by Strait Shooter

Great discussion!
Thanks everyone!

Would an all chain rode with a long nylon bridle not be ideal? Barring of course the weight distribution issue which is really more about boat design and getting the weight low and back.

Allright if you consider it what many/most experienced cruisers use.

[downunder]

Originally Posted by JoeFish

That's a nice rant but as I mentioned before, you have nothing other than your own subjective experience and no tangible evidence to back it up.

I'm not saying you are wrong, what I'm saying is that people who are smarter than both of us disagree for a host of reasons and you have provided nothing from an evidence standpoint that goes beyond opinion. Your experience is all well and good, but you may have an oversized anchor at the bottom of all that chain which would just as easily skew the results.

I'm sure we can all agree a 200# anchor would be secure on most 40' boats, chain or rope aside. What we're after here is real data on rode given a suitably sized anchor.

I am happy to listen to your opinion when you back it up with something we can measure. Part of why Peter's claims have so much more weight than yours is that he actually tested this and provided detailed data and analysis from those tests relating to catenary. These can be read irrespective of the anchor type.

I'm actually trying to get this discussion out of the opinion and insult slinging phase and into a place where we can actually compare data and make judgements based on real fact based evidence.

In the real world what advise would you give a newby heading to the carrabiean or pacific which many would.

Slightly oversized, new generation, all chain rode.

You site the issue of too much weight in bow in a 30ft vessel using 1000sgft sails doing what 12/15 knots in 30k winds.

For racing you are right

For cruising I would not take your advise. And most of us want advise for cruising not racing.

[JoeFish]

Originally Posted by downunder

For racing you are right

For cruising I would not take your advise. And most of us want advise for cruising not racing.

Well, perhaps I am from the school of cruisers who both race and cruise and sail more than I sit in an anchorage.

I do however anchor about 60-70 times a year, just not for weeks or months on end. That's probably where a difference in anchoring philosophies can be justified.

Because I'd rather sail than sit in an anchorage I'd prefer my boat sail well. Perhaps it's simply a matter of asking yourself where the compromise lies for you as a sailor.