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Maiximum, Average, or Minimum?

If we are talking about rope or chain, we report the minimum breaking strength (3-6 sigmas, depending...) and the safe working load (20-33%, depending...). But in anchor test reports we tend to see the maximum holding reported.

Should we instead...
* Minimum holding in X trials, with some maximum setting distance.
* Allow one throw-out, or not? Any anchor can have the misfortune of landing on trash. Any anchor can display super holding when it hooks a tree trunk or submerged tire.

In the Solmons Island testing, Fortess was the clear winner based upon maximum holding, but Manson, Ultra, and Mantus had better minimum hold. I can see a case both ways: if you are setting anchors for a major storm, taking the time to repeat the set may be fine. Once a Fortress begins to dig, complete setting is really quite dependable, more than most. On a daily basis, though, our engine set power is only a fraction of the max load; we don't want to risk a false set. I also suspect that a reliable minimum set correlates to ability to track through veers, or at least that is what the data seems to suggest.

Of course, this is all herding cats, since the variability of the bottom is enough to make you tear your hair out by the roots. I'm glad I didn't have much to begin with.

(I'm working on some anchor testing)

(when asked how he reached the starting holds on a difficult rock climbing problem that clearly favored taller climbers - he was perhaps 5'5")

"Well, I just climb up to them."

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Re: Maiximum, Average, or Minimum?

I just don't find anchor testing to be all that informative.
When my CQR failed to set the first time (several times), but others around me seemed to have no trouble, I jumped in the dink and asked them what anchor they were using. That was a real world test that made an impression on me, not some company set up "testing" (bragging?) or even some independent testing.
Every boat and skipper does things a bit differently and I can't for the life of me see what this mythical figure, "holding power" has to do with real life. Is this figure going to insure that such and such an anchor is going to hold my 77,000# boat in X number of knots of wind with X amount of X size chain out? If not, then what good is it to me?
My Rocna sets within it's own length about 90% of the time and has not dragged at all in something over a thousand nights of sitting on it. Now that's a set of numbers I should think anyone seeking an anchor would want to know.

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Re: Maiximum, Average, or Minimum?

Since we are running numbers...here's what I want to know: If one generally anchors in 10 meters of water, the roller is 1.5 meters above the water, it's a new-gen anchor and one wants 5:1 scope so one can sleep at night...how many acres of coral are damaged per year?

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Re: Maiximum, Average, or Minimum?

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Originally Posted by aloof View Post
Si de we are running numbers...here's what I want to know: If one generally anchors in 10 meters of water, the roller is 1.5 meters above the water, it's a new-gen anchor and one wants 5:1 scope so one can sleep at night...how many acres of coral are damaged per year?
Solomons Island is deep mud in a temperate area. Off topic.

(when asked how he reached the starting holds on a difficult rock climbing problem that clearly favored taller climbers - he was perhaps 5'5")

"Well, I just climb up to them."

by Joe Brown, English rock climber




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Re: Maiximum, Average, or Minimum?

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Originally Posted by capta View Post
I just don't find anchor testing to be all that informative.
When my CQR failed to set the first time (several times), but others around me seemed to have no trouble, I jumped in the dink and asked them what anchor they were using. That was a real world test that made an impression on me, not some company set up "testing" (bragging?) or even some independent testing.
Every boat and skipper does things a bit differently and I can't for the life of me see what this mythical figure, "holding power" has to do with real life. Is this figure going to insure that such and such an anchor is going to hold my 77,000# boat in X number of knots of wind with X amount of X size chain out? If not, then what good is it to me?
My Rocna sets within it's own length about 90% of the time and has not dragged at all in something over a thousand nights of sitting on it. Now that's a set of numbers I should think anyone seeking an anchor would want to know.
A strange reply, but I'll count that as a vote in the "minimum holding" category.

Yes, some tests are slanted by manufacturers. Yes, bottoms are extremely variable, such that any claim of holding power is only relevant or repeatable on fine sand. And since we invariably drag when the bottom is not good, such figures are basically unusable for most purposes. We agree. In fact, testing worst-case holding on bad bottoms is by definition, nearly impossible, since these tend to be variable.

In this case, isn't the honest minimum holding just a few hundred pounds? And look at the setting distances!



But really, I'm kind of getting at the same thing. In the referenced tests the data was completely honest and it showed some howling failures by most anchors. No anchor (mostly about 45 pounds) held more than 450 pounds every time, which aint' a lot; to me, that made it the more believable. I've repeated some of the tests in the same mud and got very similar results and patterns.

So yes, the question is should we look at the best run in sand or the worse run in soft mud? Even more troubling, how would you define soft mud (sand is much easier to define)?

(when asked how he reached the starting holds on a difficult rock climbing problem that clearly favored taller climbers - he was perhaps 5'5")

"Well, I just climb up to them."

by Joe Brown, English rock climber




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Last edited by pdqaltair; 1 Week Ago at 09:30 AM.
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