Anchors - Bigger is Better ?

[JonJo]

Originally Posted by Cotemar

Like most things. Cruisers are a bit tight with a buck.
They buy many of those Kobra anchors, not because they are a great anchors.
They buy a Kobra because it’s the cheapest anchor you can buy.

As the Kobra advertisements say
"Similar in performance to the Delta, but much more economic"

Is this something you and Delfin are proud to own?

I know they are French but Voile et Voileur gave the Kobra a good rating. I own one and have tested it - it is cheap and cheerful but the Kobra works, it sets quickly and develops good hold. Its draw back is a cheap (and weak) shank and for this reason is not a model I could get excited about. You obviously know better, I take my hat off to you.

Jonathan

[noelex 77]

Originally Posted by Delfin

The Kobra, problem bend and all, beat out other convex anchors, and the Fortress, neither convex nor concave, beat them all. The Kobra outpulled the Delta by 3x.

The Kobra is a good anchor and is especially good value for money, but it is important not to get too excited by one isolated (French) test. Other tests have rated it as very similar to the Delta. This test rated it a little worse than the Delta:
http://manson-marine.co.nz/Anchor%20...0Ankertest.pdf

In the real world I would rate its performance as slightly better than the Delta, but it is below the top tier of anchors.

[DumnMad]

Yup noelex 77. World of difference between these tests and the real world.

That wind graph was about unreal conditions. The boat length in anchor charts is about wave load on the boat and to a lessor degree wind load.(Ever wondered why weight and length are mentioned but no comments on mast height and rigging or launch vs yacht.)
Anchor tests I've read about are probably OK for benign conditions but unreal for life threatened storms where the rode is constantly jerked about by a bucking vessel.

[JonJo]

Originally Posted by Kenomac

If I need to set two anchors during a significant blow, they will be set in tandem on the same rode, not using two separate rodes. Less chance of tangling and much greater holding ability when both dig in, in a straight line. Think tug o' war with the big fat guy anchoring the end of the rode/rope. I've done this before, it works great.

The idea of setting 2 anchors in a 'V' is not specifically to gain extra holding capacity, there is extra hold - but it is obviously not 2 times. The idea of the 'V' is to stop the yacht veering from side to side as a result of wind gusts that develop either side of the average wind direction. Veering can result in snatch loads and snatch loads are higher than the loads that the wind develops by imposing on the yacht's surface area. Snatch loads and developing kinetic energy are not to be encouraged and 2 anchors in a 'V' reduce that specific issue#. Additionally as each anchor is set at an angle each anchor when it is loaded is loded in the 'set' direction and the set direction is when it is more efficient.

The big issue with the single big anchor answer is:

What do you do in those anchor environments where your anchor is not ideal (for example when your roll bar sinks into the soft seabed and the anchor will not self right) and what do you do if, for whatever reason, you need abandon your anchor.

These are issues that the single large anchor camp have not really addressed.

To my mind discussing anchor designs that people have often never seen let alone used seems to be not so useful - no matter how confident they are of their opinions

Jonathan

[noelex 77]

Originally Posted by Delfin

Just one opinion, but the perfect anchor is one that will dive and bury itself, which lets out hoop style anchors simply because the hoop will reduce the anchor's ability to dive.

The thick balasted toe of the Spade and Ultra (necessary because they have no roll bar) inhibits diving and unfortunatly this impediment is present as soon as the anchor starts to set.

Originally Posted by Delfin

Another opinion is that the largest anchor you can handle is going to be superior to a lighter anchor because of simple physics and the effect of gravity.

+1

Originally Posted by Delfin

The idea that there is some inherent problem with convex anchors is simply rubbish since all anchor tests belie the notion

You must be reading different anchor tests.
I think the anchor test have shown overwhelmingly the superiority of the concave anchors and the (flat) aluminium Fortress.
I cannot think of single anchor test where the convex anchors have done anywhere near as well as the concave.
It dangerous to read too much into just one test. The test you quote is the only one I can remember where a convex anchor anchor featured in the top three. Nevertheless even in this test the only two concave anchors included in the group were rated number one and three. (Rocna was not included in the test anchors.)

[congo]

Noelex

Concave anchor design Ultra and spade, these two anchor designs as time pass more and more anchor test's will be done and mark my words, the other brands of concave simply do not rate against ultra and spade.

Convex anchor design in the near future via independent testing will show they are superior over concave, I will be sure to bring it to attention, spade and Ultra’s ability to set is certainly not impeded by their toe design, you may be talking a distance of maybe the fluke length if you are lucky, certainly no down side there.

I hear the real world mentioned often, well it’s about time that some tuned in.

Regards Rex.

[conachair]

Originally Posted by sailorboy1

I don't know if I can take it much longer:

So what is the perfect anchor and size? Surely after all this there is a real answer that doesn't use the word depends.

One that keeps your boat where you left it all day every day in any kind weather and in any kind of bottom.
Sadly such a thing doesn't exist, not does any serious scientific research on small boat anchors, as far as I'm aware.

So you are left with magazine articles and anecdotal evidence from the Internet.

Which leads to one unanswered question, what is it about talking about anchoring that makes some people so grumpy?

So, it depends...

[congo]

If anyone is interested in fully independent anchor test's then check out the National Marine Safety Committee tests on our anchors, these test were carried out by Robertson lifting and rigging N ATA accredited company, much of the testing attracted media, boat builders, survey officers and the like, the actual test graphs can be found on our web site and clearly the convex anchors were superior over concave in those tests.

These test graphs show anchors performance over a wide range of ocean floor types, this is a real world test as it was carried out independently to obtain Super High Holding Power Certification, no cheating here, and I am sure Noelex you would be aware of these tests.

Regards Rex.

[noelex 77]

Originally Posted by JonJo

The idea of setting 2 anchors in a 'V' is not specifically to gain extra holding capacity, there is extra hold - but it is obviously not 2 times. The idea of the 'V' is to stop the yacht veering from side to side as a result of wind gusts that develop either side of the average wind direction. Veering can result in snatch loads and snatch loads are higher than the loads that the wind develops by imposing on the yacht's surface area. Snatch loads and developing kinetic energy are not to be encouraged and 2 anchors in a 'V' reduce that specific issue#. Additionally as each anchor is set at an angle each anchor when it is loaded

I think this gets to heart of the matter.
Two anchors are needed in some anchoring situations to reduce swing, or to align the boat with the swell to reduce roll, but the real crux in relation to the "bigger is better" question is how much do two anchors increase your holding power.(and here I include the increased holding from the factors that Jonathan mentions such as reduced sheering).

Many (wrongly in my view) believe two identical anchors give them 2x the holding power of a single anchor. I think the gains are much more modest.
Is it worth mucking about setting two anchors (for increased holding) when a 5 kg, or 10kg (10 -20lb) increase in your main anchor from say a 20 kg to 25-30 kg would achieve the same effect? Especially when this only represents a 4-8% increase in weight of your main anchoring gear (assuming 50m (150feet) of chain).
How often are you going to caught with just a single small anchor down when the weather forecast is wrong? How often will you be unable to set two anchors because you will swing differently to your neighbours?

Originally Posted by JonJo

The big issue with the single big anchor answer is:

What do you do in those anchor environments where your anchor is not ideal (for example when your roll bar sinks into the soft seabed and the anchor will not self right) and what do you do if, for whatever reason, you need abandon your anchor.

These are issues that the single large anchor camp have not really addressed.

The days of swapping anchors for different substrates are thankfully over (with the possible exception of very thick weed where a specialist weed anchor may be needed), but it is a good argument for over sizing your anchor. Even a non optimum substrate the larger size will compensate and ensure adequate performance.

I agree all boats need to consider that they may need to cut away and lose their anchor, or anchors.
If you regularly use two anchors in bad conditions that means you need to carry 4 anchors and appropriate rode. This means carrying a great deal of heavy chain, if you are venturing into areas where rope is unsuitable, such as coral waters.

I think even when the issue of backup anchors are considered "bigger is better" wins in simplicity, ease and the overall weight of gear that needs to carried.

[noelex 77]

Originally Posted by congo

I will be sure to bring it to attention, spade and Ultra’s ability to set is certainly not impeded by their toe design, you may be talking a distance of maybe the fluke length if you are lucky, certainly no down side there

I agree Rex the Spade is very good design and sets very quickly. I think the Ultra will also prove to be a top anchor. Time will tell.
Both these anchors have a much thicker toe than the roll bar anchors, necessary because of the ballast needed self right the anchor without the roll bar.

Non roll bar anchors without a thick toe have been developed (such as Oceane, Sword, Raya and Boss) but so far none seem to work consistently (it is too early to tell definitively about the Boss) so we are left with the choice of thick toe, or a roll bar. It is remarkable that two very different design approaches have led to such similar results, both producing excellent anchors.

My point is to single out drawbacks of the roll bar without mentioning the drawbacks of the alternative (a thick toe) is misleading. Especially when the roll bar has no effect untill the the anchor is already well buried.

See photos showing the thicker toe of the Spade this is particularly discernible from the rear showing the ballast chamber

[JonJo]

Originally Posted by noelex 77

Especially when the roll bar has no effect untill the the anchor is already well buried.

In thin mud the roll bar will not right the anchor (the roll bar needs a firm seabed on which to operate) - you are quite correct the roll bar will have no effect, it will leave the anchor sitting upside down.

I have yet to see any, positive, test results on a roll bar anchor's holding ability upside down.

So, to say again,

What do the 'one bigger anchor is better' faction do when their anchor is well buried but upside down.

This is not to denigrate 'roll bar' anchors or concave with roll bars (you can pick that out - but its not the point) but to illustrate there are other benefits to carrying more than one anchor and more than one design.

Again - all anchors are a compromise. I'm fascinated by the lack of an answer to how that roll bar is going to work in a soft seabed - suddenly a deathly hush?

Jonathan

[JonJo]

Noelex,

In nearly every test conducted internationally since 2006 the Spade has consistently performed as one of the top anchors having an ability to set quickly and develop exceptional holding capacity. These tests have been conducted in a variety of seabeds

But you say it does not dive

Possibly you can account for its consistent positive performance in tests (if it does not dive) in such a cross section of seabeds.

Accepting that people have an unhealthy need to protect their choice of anchor, particularly perhaps when it costs more than most other anchors, maybe you can also account for the very high support level for Spade across Europe and N America (maybe read Morgan's Cloud?)


You are very disparaging of the Voile et Voileurs testing despite their acceptance across most of Europe, their consistent test programmes and their acceptance (given their tests have been published essentially verbatim but translated by 'perfidious Albion') by the British. Possibly you can account for your insider knowledge as to why their tests should be discarded.

Finally - the Spade has a blunt toe, might it be possible that the simple weight of the anchor, in the right place, overcomes this issue? Equally Mantus have tested their own anchor and with roll bar removed they say that the anchor dives more deeply (with which I agree - having tested it without roll bar) - might it be possible that (in the absence of a roll bar in the first place) the Spade has a greater ability to dive than some, or all, roll bar anchors. Might it also be possible that the heavy weight of the Spade allows it to self right, even in soft seabeds - where roll bar anchors will swim upside down - never to right.

It might be possible (according to you) a roll bar anchor engages more quickly than the Spade in a very hard seabed. Equally might it also be possible that the Spade will set in a soft seabed - where the roll bar design might never set?

Anchors are a compromise

Jonathan

[conachair]

Originally Posted by JonJo

In thin mud the roll bar will not right the anchor (the roll bar needs a firm seabed on which to operate) - you are quite correct the roll bar will have no effect, it will leave the anchor sitting upside down.

How do you know? How does it end up upside down?

I know my rocna works fine in soft mud but have never watched it to see how.

[congo]

Jonathan makes a valid point.

When you look at the original Sarca where the roll bar is attached at the top, we found exactly what Jonathan is talking about, when you look at the Super Sarca you will find a patented secondary fluke, this fluke prevents the shank from burying and lifts and rights the anchor in soft mud should it end up upside down.

Further our roll bar is thinner but solid round creating less drag , resistance to the anchors ability to bury, the new generation hoops they are thicker but hollow, so when the anchor is upside down they are filled with water further impeding the problem Jonathan is talking about.

Before we attached the hoop to the shank in our proto types we also found that when wedged between rocks where as the fluke was doing nothing and only the roll bar was creating the hold, the roll bar was easily bent, there are many bent roll bar anchors now in Australia and the Sarca is not one.

I would like to post some photo’s but I am hesitant to do so for reasons I cannot go into, but Noelex if you want to view a real anchor test then go to our web site and further check out the equipment that was used for accuracy.

Regards Rex.

[noelex 77]

Originally Posted by JonJo

In thin mud the roll bar will not right the anchor (the roll bar needs a firm seabed on which to operate) - you are quite correct the roll bar will have no effect, it will leave the anchor sitting upside down.

I have yet to see any, positive, test results on a roll bar anchor's holding ability upside down.

So, to say again,

What do the 'one bigger anchor is better' faction do when their anchor is well buried but upside down.

This is not to denigrate 'roll bar' anchors or concave with roll bars (you can pick that out - but its not the point) but to illustrate there are other benefits to carrying more than one anchor and more than one design.

Again - all anchors are a compromise. I'm fascinated by the lack of an answer to how that roll bar is going to work in a soft seabed - suddenly a deathly hush?

Jonathan

I think the premise that the roll bar don't work in a soft seabed is wrong. The large fluke area and the greater resistance of the concave blade of the roll bar anchors make them a very good in this sort of substrate.
The Spade is also good, but the slightly smaller blade area puts it a a small disadvantage. Some of the convex anchors such as the Delta do very poorly, it is the sort of bottom they struggle most in.

The best anchor for these sort of conditions is a Fortress on the 45 degree setting,

Once again the advantage of a good design significantly oversized anchor is that there is adequate reserves to cope with less than ideal substates.

In very soft soupy mud there can be some problems setting all anchors. The Fortress that is by far the best holding anchor in this type of bottom, but can be one of the worst to get an initial set in these conditions. If the mud is soft enough for the chain to sink below the levels of the flukes it can especially be a problem. Setting initially on short scope and giving the anchor some time to settle are both techniques that usually work, but it requires some finesse and skill.
The roll bar only has an effect on a small number of sets, the anchor will generally land the right way up anyway. Vey soupy mud is one substrate where all anchors, including the new generation anchors can need a few goes to set and reach the (hopefully) firmer mud underneath.

In these sort of substrates ( indeed in all) the anchors set should be tested with a healthy dose of reverse.