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From: (no name) (no email)
Date: Tue Sep 28 2004 - 22:54:09 EDT
In a message dated 9/28/04 6:27:28 PM Eastern Daylight Time,
writes:
> I would disagree with Brian Fagan, but I disagree on a number of issues
> with him.
> Using tandem anchors is not a common practice in experienced cruisers.
I would agree that it seems to be uncommon. But I'm not sure whether that is
because it as you claim doesn't work well or as I have found many people have
never even heard of the technique.
>
>
> It is difficult to deploy or retrieve two anchors on the same chain (Fagan
> refers to cable?).
Has worked well for me. You can put a buoy on the back anchor and break it
free first.
How can you set a Danforth and CQR with 10 feet of chain between them? I
would
> say that it is very difficult.
Hasn't been so far. But your mileage may vary.
Of course a lot depends on the bottom. If you are using a combination of a
plow
> and a Danforth because you think that it will cover the bottom types for
> what each is designed; this is not a good idea. It is better to use two
> anchors which are designed for that bottom type.
Of course you can use two of the same type of anchors. But as you've stated
it's better to carry a couple of different types. And since that's what most
people do that's why I mentioned using two different types. Also many types of
anchors overlap in the types of bottoms they can handle.
>
> The chance of fouling one of the tandem anchors is very high.
Perhaps. But have actually you seen this accur often?
I have considered tandems as a possibility and rejected it because of the
negitaves.
> Using the appropiate anchors I have rarely drug. Where I have, it was
> because of a very unsuitable bottom--such as round stones (both in Yugoslovia
> and in British Columbia)--also before the Fortress, I had drug several times in
> very soft mud--and this is out of thousands of nights at anchor in many
> types of bottom and wind conditions--up to over 90 knots. Actually I have to add
> over 125 knots, with the last hurricane Ivan. During Hurricane Georges a
> boat had anchored as you desciibed with a 70 lb Danforth first and a 75 lb CQR
> second in Bayou Chico.
Perhaps the CQR should have been first. :-)
The boat drug all over the Bayou and was dammaging other boats and docks.
>
> The owner refused to come to his boat, so we boarded it and pulled the
> anchors. After removing the COR we did get the Danforth to set. The wind
> velocity was about 85 knots at that time. The problem with any anchor in that
> velocity is to avoid the anchor skating over the bottom--and we had to use full
> power to keep the boat in place to bring the drift down to a point where we
> could slow the drift enough to allow the anchor to settle. The CQR appeared to
> be interfering with the Danforth digging in.
Of course no one system is fool proof in all cases. And for all we know the
anchors were never set properly in the first place.
>
> When you attatch an extra chain to the throat of the plow or the cross bar
> you are signifantly altering the characteristics of the plow and making it
> more diffiuclt to set.
>
> As for "lots of fouled or twisted second anchors" I would say that you had
> used the wrong anchors for the bottom.
I said I had SEEN over the years lots of fouled or twisted anchors. Luckily
for me it has only happen to me a couple of times over the years.
I have had situations where an anchor seemed to set, but later in the night
slowly
> drug and the boat came to ride to the second anchor which had been properly
> deployed--since these were set at an appropiate angle--no twists or tangles.
> An example. I anchored in Minorca during a 60 knot storm. The only anchor
> I could get to set well was a large fisherman anchor. I also deployed a 75
> lb also. I had tried to set it several times to no avail, but in the
> morning we had drug the Fisherman back about 75 feet and the CQR had worked in and
> now was firmly in the bottom.
The twist and tangles happen when there is a lot of wind direction change.
Not of course every time double anchors are used.
> There may be places for doubled anchors, but using only 10 to 15 feet of
> chain is not a good technique. If it works for you, fine--but I would not
> recommend this as a regular practice.
Like I said people are free to add any length of chain they wish.
The places where I
> had considered it were such poor holding, that I moved and anchored
> elsewhere.
Some times we don't have that luxury. :-)
>
>
> Finally I will include a quote from our Captain Will--the ex list member who
> was doing a lot of anchor testing:
> This is from his post of May 19 1998 on T W L.
>
>
> "I have heard no discussion about putting two anchors in series with one
> >connected to the other. This seems to me to make some sence. What about
> >it, Capt Will?
>
>
>
>
> Just when I had returned from the latest Max test ready to write that
> report, the matter of two anchors in series comes up! It's an interesting
> subject, and I'll try to handle it before the Max test result.
>
>
> *************************************
>
>
> Theoretically two anchors in series can increase the holding capacity of an
> anchoring system if they can be properly deployed and the load does not
> change more than 90-degrees. Please note that these two conditions are
> serious and more far reaching than appear upon first inspection. I haven't
> made any tests on two anchors in series and can give no definitive
> information on the results. I do see some potential problems and the
> following discussion will try to help you think through some of them.
>
>
> 1. If the load shifts more than 90 degrees you are left with just one
> anchor. I don't know what havoc that causes.
>
>
> 2. The general scheme is to deploy each anchor on its own rode for a
> short distance and attach both to a single rode leading to the boat.
> Normally the rode on each anchor would be chain or cable (wire rope), as
> well as some length of rode after the individual anchor rodes had been
> joined. After that, the normal rode would lead to the boat -- nylon or
> chain.
>
>
> 3. Getting the whole mess off the boat and to the bottom without the
> individual anchor rodes wrapping around each other is the first problem. If
> they do wrap, each wrap effectively makes each rode shorter.
>
>
> 4. Setting each anchor is the second problem. The problems are different
> for penetrating and non-penetrating anchors, but this problem is something
> like:
>
>
> You have arranged the anchors so you can set the first one before you deploy
> the second one -- I'm not sure how, but assume you did. When the second
> anchor is deployed, you must set it, but the first anchor is already set, so
> if you move the boat to set the second anchor, the first anchor must also
> move.
>
>
> 3.1 If the first anchor moves, it has been overloaded and likely no
> longer has any holding power -- pity! You are now dependant on the second
> anchor alone.
>
>
> 3.2 If the first anchor doesn't move, you can't set the second one. You
> are now dependant on the first anchor alone.
>
>
> 3.3 But 3.1 and 3.2 are the good news. The bad news is that you don't
> know if 3.1 is so, or 3.2 is so, or you lucked up and both anchors set.
>
>
> You'll likely find the answer to 3.3 when the wind blows hard. The problem
> is you might not like what you find.
>
>
> *************************************
>
>
> Since I am very concerned with hurricane protection, I have spent a lot of
> time thinking about this issue of anchors in series. I am unable to come up
> with a good way of making it work reliably -- I really wish I could come up
> with a satisfactory system.
>
>
> Among the problems of storm protection is that most anchor manufacturers
> don't make anchors large enough to do the job in hurricane-like storms.
> You can get single anchors with enough holding power to hold most trawlers
> in less than hurricane conditions -- 60+ knots. Many manufacturers make
> such anchors which will work in good bottoms, and two make anchors which
> will work in both good and soft bottoms.
>
>
> At least one manufacturer makes a single adjustable anchor large enough for
> hurricane protection on boats of about fifty feet or less. I suspect that a
> second manufacturer will make one for you on special order.
>
>
> ***********************************
> It is always preferable to have one single anchor large enough to do the job
> than trying to arrange a system of two or more anchors in some series
> fashion. When the big blow comes, "There are no Second Place Winners."
>
>
> **********************************
> See the upcoming Super Max report on reversal of load.
>
>
> CaptnWil"
He makes some valid points. But in the end it comes down to:
"I haven't
made any tests on two anchors in series and can give no definitive
information on the results."
>
> There have been some articles in Passagemaker on the tandem anchors--and a
> very few internet postings. We discussed this on several anchoring seminars I
> have participated in--and the concensis was that it is controversial--so I
> stick with my anchors--it is controversial.
>
> I am not aware of any valid tests done with single anchor vs tandem
> anchors--and this would be a very difficult test to do.
> (just dong valid single anchor tests are difficult because of bottom
> inconsistancies)
>
>
>
I agree, no tests have been done. But I don't agree that it would be much
harder to do than single anchor test. Other than I doubt you could get an anchor
manufacturer to sponsor it. :-)
In the end, it's just another technique that people can try or reject.
Capt. Bill
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