Here we go- New Anchor

Mantus has approximately half the hold of a Rocna. Mantus is badly designed. I would not touch it with a barge pole.

Of the 2 you mention you only leave Rocna as a sensible choice.

But there are plenty of other anchors to throw into the mix.

Mantus is an unballasted fluke anchor like a Bugel, Fortress, Knox etc - except the crown, junction of shank and fluke is in the wrong place. All unballasted fluke anchors have the crown at the heel - compare the crown of a Mantus with a Bugel/Fortress/Bruce/Knox/Jambo/SARCA/Danforth etc. and wonder why the Mantus crown is the only one of all the unballasted fluke anchors with the crown forward of the heel. Ballasted anchors include Rocna, Delta, Supreme, Excel, Spade, CQR etc. The crown is about 1/3rd forward of fluke length from the heel - the exact location depends on the amount of ballast and where the ballast is located.

So if you want to ignore the importance of 'hold' then go ahead and buy a Mantus - its has the hold of a similarly weighted Delta. You can of course double the size/weight - as Noelex has done (but omits to mention) - then the hold will be good enough. Because its crown is in the wrong place it sets very shallow as illustrated by Noelex' pictures - and a shallow set anchor will trip more easily than a deep set one. There is no end of research on shallow set anchors as there is a host of research on the location of the crown.

A commercial mooring near us, in Sydney, that was laid for super yachts has specially made shallow set Danforth anchors - to allow easy retrieval.

I've tested all of this - if you drill some new holes and move the crown back - wonderful improvement.

If you read this article it explains the background.

An Inquiry into Anchor Angles - Practical Sailor

For an advance on Mantus look at a Viking which has some advantages - use of high tensile steel in the fluke allowing weight savings. They read the article linked and altered their design (so yes I have an interest because someone actually read the article, made changes because of it, tested the effect off the changes and then set the changes into 'concrete'). Its a good anchor and because it saves weight you don't need to go 'up' a size.

Rocna is a ballasted anchor and is as close as possible to a Spade design without breaching, the then, patents. If you measure the ballast in a Rocna it is similar in weight to a similarly sized Spade's ballast but lacks the concentrated focus in the toe. As a result of the latter Rocna needs a roll bar. The plan of the Spade and Rocna fluke are identical as are the shanks. In fact the shank of the Spade is also the same as Delta, they appear to have taken a French curve and smoothed out the corners of the Delta shank. The Spade is thus a better anchor than Rocna (as it does not need a roll bar) - depends on how much the 2 cost and how you value the use, or not, of a roll bar.

As GHA says in use you will not tell the difference between most of the good anchors of the same weight, Spade, Knox, Supreme, Excel, Rocna, Kobra, Viking etc etc - it commonly comes down to what is available, does it fiand how much does it cost. I would also suggest you carry a Fortress, not too large.

Both ballasted and unballasted anchors are good as they have other characteristics determining choice - do they fit, are they available, how much do they cost.

We use an Excel and Spade but I have tested and used the others, Mantus, Knox, Rocna etc etc. I have been testing a Viking, as I say: a good anchor (but check that it fits - it does not fit on our bow roller) - you might still be able to buy one cheaply (stocked in Belgium). I have not tested the Vulcan nor Mantus M2, though the latter has been withdrawn from sale until mid October.

Good luck

Jonathan

The Kippari tests, linked in Rappey's post above were conducted in a quarry 'using' quarry sand - if you often anchor in a quarry the test is highly relevant. If however you anchor in a normal seabed, much softer than a quarry floor - ignore the conclusions.
 
Neeves said:
The Kippari tests, linked in Rappey's post above were conducted in a quarry 'using' quarry sand - if you often anchor in a quarry the test is highly relevant. If however you anchor in a normal seabed, much softer than a quarry floor - ignore the conclusions.
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I want to ask this in a polite way, what credentials do you have to say what's good and bad as I've no idea who you are ?
 
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But then I don't know who you are either.

I have the same ability to say what is right or wrong as anyone else. My comments on anchors, chain, shackles, swivels etc are based on testing them. I test using standard protocols.

Read the article I linked in my previous post. Scroll through the Practical Sailor search engine with keywords 'Jonathan Neeves' and then Google 'Jonathan Neeves SAIL Magazine'. All my comments are based on testing - and I'm the first to admit some testing can be contrived and some even wrong. I've tried to remove any comments or prejudices I might have.


On the Kippari tests - their conclusion is that Mantus is the best anchor they tested. Quarry floors tend to be fairly well compacted and are composed of angular sand. The US and UK Navy recommend that for hard seabeds you use an anchor with a sharp toe and a low seabed angle (the opposite for a soft seabed where for example Fortress use a high angle). Mantus has the lowest seabed/fluke angle of any anchor, around 16 degrees, and is really suited for a very hard seabed. Most anchors have a seabed/fluke angle of 30 degrees. Unfortunately very hard seabeds are not common so Mantus is optimised for, basically, an extreme and illusory seabed, and sacrifices hold in other, common, seabeds such as sand and heavy mud. If you measure hold of a Mantus in sand as it is supplied and then move the crown aft (easy, just drill 4 new holes), you can double hold as the seabed/fluke angle increases to 30 degrees (from the (as standard) 16 degrees.

Now if you want to check this out - go to Noelex thread (I'm sure he will provide a link) and calculate the seabed/fluke angle for his Mantus and then calculate, similarly, the angle of every other anchor for which he has images. This is done for you in the article linked for Practical Sailor.

We were on the Mekong a couple of years back and I checked the river traffic. Virtually all the vessels carried a Danforth, (I assume copy) and they were all set for 40 degrees. They used fishermans type if they secured to shore.

There is nothing wrong with a Mantus. It has the same hold as a similarly weighted Delta - except it does set more reliably. I think the hold of a correctly sized Delta is adequate - many people have used it with success. But for the same or similar amounts of money as you spend on a Mantus you can buy a different anchor (Rocna, Spade etc), have the same reliability of setting etc etc and twice the hold. Now - maybe the demountable characteristic of the Mantus is important to you. You need to weigh that up against twice the hold.

There is no perfect anchor, they are all a compromise - the individual needs to decide what is important to them. There is no right and wrong. There is no 'my anchor is better than yours' as they all have different strengths and weaknesses - and what is good for me - might not be good for you etc.


Now - for a bit (more) of controversy - Many have bought Mantus of the recommended size and that size would be the same as a Delta recommended for their yacht. There have been no reports (none) of Mantus dragging - which implies to me that Mantus has enough hold (though I'd suggest having more hold cannot be a bad thing). So if Mantus with half the hold of a Rocna is adequate - why oversize the Rocna??

Jonathan
 
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richardbayle said:
Change of boat, need an anchor! So, Mantus or Rocna?
Bound to be asked so boat is 1976 Ron Holland design prototype for the One Ton Cup. She's beautiful and stupidly I fell in love and now she's mine.
She was completely restored in 2017/2018. Needs a refitted interior, currently stripped out as a race boat but I'm going to be cruising on her so new interior needed .
Current sailing area Caribbean
So having lit the blue touch paper I'll retire and wait for the flash bangs
?
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I am surprised that nobody has asked you yet about your One Tonner, so I will - I vaguely remember seeing a boat like this advertised in a Caribbean broker not so long ago. Is she one of the varnished timber hull prototypes?
Can you post a photo or two of her please?
(You could include the anchor on the bow to keep it on topic :) )
 
Check the fit of a Rocna on your bow roller before you commit to buy. A few friends on ours who have Rocna anchors can fit the Rocna but find it isnt secure even when the chain is tight pulling the Rocna hard against the bow roller. They have to fit straps to hold it tight otherwise it bounces up and down in the roller. If you are bashing in to big seas and the anchor is lose in the roller it can be a problem and not easily resolved. By comparison, our Spade in the same roller as our friends with a Rocna needs no securing at all. A tight chain and it doesn't move at all.
 
dune16 said:
We added a Spade to our Dufour due to the other options with the hoop not clearing the bowsprit. Happy with the Spade so far. More consistent than the Delta we had on the previous boat
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Spade will be my next one even though i have never had problems with the Rocna.
 
richardbayle said:
Spade it is. Can get that here in Guadeloupe.
Thanks to everyone who contributed to my question .
Really good exercise .
regards
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Good choice even if i have no experience of it. I will find the test site that convinced me. here it is and is about the best research even though anchors are very subjective.
 
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richardbayle said:
Spade it is. Can get that here in Guadeloupe.
Thanks to everyone who contributed to my question .
Really good exercise .
regards
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Great choice. You wont be disappointed with its performance in the Caribbean. The holding in lots of the Caribbean anchorages can be challenging. Having used a Spade there for the last six years we are very happy with its performance and in particular its ability to set quickly. Have fun
 
geem said:
Check the fit of a Rocna on your bow roller before you commit to buy. A few friends on ours who have Rocna anchors can fit the Rocna but find it isnt secure even when the chain is tight pulling the Rocna hard against the bow roller. They have to fit straps to hold it tight otherwise it bounces up and down in the roller. If you are bashing in to big seas and the anchor is lose in the roller it can be a problem and not easily resolved. By comparison, our Spade in the same roller as our friends with a Rocna needs no securing at all. A tight chain and it doesn't move at all.
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Absolutely right my anchor Rocna sits on the roller nicely and with a tight chain it is ok on the horizontal plane but the vertical plane it moves. The pin hole in the Rocna does not line up with my bow roller . No biggy I just strap it down .
 
I looked at the spade. Two problems with the Spade or maybe three.

The galvanizing is traditionally poor, I have spotted a lot of rusty ones

There is lead in the thing which makes it a pain to get mended.

It bolts together - which a lot of folk are not keen on.

Or maybe four, it's expensive.


.
 
I've got a Manson Supreme which I have found is excellent - always digs in quickly - MUCH better than the 'look alike plough' - which came with my boat, which was B***** useless...!
 
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Viking and knox seem to lack comparison testing other than their own tests.
That's a shame as they are both significantly cheaper than the other modern ones.
From watching many anchor videos over the years I will say every anchor has been shown to fail at some point where the others have suceeded.
 
doug748 said:
I looked at the spade. Two problems with the Spade or maybe three.

The galvanizing is traditionally poor, I have spotted a lot of rusty ones

There is lead in the thing which makes it a pain to get mended.

It bolts together - which a lot of folk are not keen on.

Or maybe four, it's expensive.


.
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Probs with galv seem to be way in the past.
Mended? They don't break. Maybe a bit of hassle getting the lead out if you want to regalv.
It doesn't bolt together, there's a retaining bolt, it's not structural.
Not cheap though, but you can get one VAT free in Jersey and another 10% off if you are registered to cruisersforum.com.
 
doug748 said:
I looked at the spade. Two problems with the Spade or maybe three.

The galvanizing is traditionally poor, I have spotted a lot of rusty ones

There is lead in the thing which makes it a pain to get mended.

It bolts together - which a lot of folk are not keen on.

Or maybe four, it's expensive.


.
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That is interesting. Will keep an eye out nest time at the marina.
 
doug748 said:
I looked at the spade. Two problems with the Spade or maybe three.
The galvanizing is traditionally poor, I have spotted a lot of rusty ones
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The steel Spade is an excellent performing anchor. Avoid the aluminium version unless anchor weight is an overwhelming consideration, as the performance suffers.

The steel Spade is a harder to re-galvanise because of the lead ballast. Also try and keep the fluke /shank attachment clear of substrate accumulation. This part of the anchor can be subject to corrosion from abrasion and trapped mud. Located under the fluke this area is often neglected or missed.

For example this Spade anchor was in good condition overall, with little general corrosion, but the fluke/shank attachment needs watching

9A6D0B2C-47E3-4389-8598-60639664EFBD.jpeg

It is still an excellent anchor and worthy of serious consideration especially in situations where other anchors do not fit well.
 
Rappey said:
Viking and knox seem to lack comparison testing other than their own tests.
That's a shame as they are both significantly cheaper than the other modern ones.
From watching many anchor videos over the years I will say every anchor has been shown to fail at some point where the others have suceeded.
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There is an independent video on a Viking 7, Steve Godwin's Panope videos

.

I have conducted hold tests on a 13kg Knox and a 10kg Viking, 1,950kg and 1,650kg respectively and have conducted a 'mud retention' test on the Viking - where other concave anchors carry mud the Viking came up, surprisingly, clean. This latter may be due to the perforated fluke. I have tested a 15kg Mantus in the exact same area - to its original design and it has a hold of 1,200kg and a 15kg Delta 1,000kg.. Our steel (15kg) and aluminium (8kg) Spade and Excel in the same seabed returns hold of around 2,000kg. In fact our aluminium Excel has a hold slightly less than the steel version (1850/1,900kg) - but in use you cannot tell the difference (the aluminium Excel has a 'thicker' shank (50% thicker than the steel anchor and this may be the cause). I suspect the stength of the aluminium Spade shank is lower than that of the steel version - one of those compromises an anchor maker has to conjure with and this may be the reason Spade are not so 'gung ho' of the aluminium version.

Hold is but one indicator of anchor performance - but hold may be indicative of other perameters, resistance to yawing etc. Priortising hold still seems a good idea.

Sadly new anchors are being released without any hold data - and why anyone would want to buy one in the absence of data is a mystery.

All analysis of anchors concludes that anchors do not 'work' by weight but by design and surface area. We tend to use weight as a measure - but its the surface area (and design) that determines the hold. This is illustrated, in part, when you compare an aluminium anchor with its steel equivalent and the aluminium anchor, in terms of hold per kg, is higher than the steel version but if you compare a similar sized aluminium or steel anchor, say, Spade or Excel the two anchors (aluminium and steel) then have a similar hold for the same physical size. Its less convincing if you compare a steel Danforth and an aluminium Fortress as the Fortress tend to be better - but then it has a thinner fluke and a machined shank. So comparing aluminium Spade with a steel Spade they have the same hold - because they are effectively the same design. I have tested this as I have a Spade and an Excel in steel and aluminium, both of the steel anchors weight in at 15kg and the aluminium ones at 8kg.

We use the aluminium versions of both Spade and Excel - and have used them for 10 years (without issue). We do have a weight fetish - but cannot tell the difference between them. If you ever need to manhandle your anchor, deploying from a dinghy, you might understand why we like them.

Viking recommends a lighter anchor for a given yacht size than do other manufacturers of steel anchors. The assumption, by some will be, that the Viking anchor, being lighter, is smaller than the 'competitor's' product. It is smaller - by weight - but is a similar size by area. The difference is that the Viking uses less steel in the fluke (saving weight) but not sacrificing strength (because they are using high tensile steel). There is another advantage to using HT steels - the fluke plate is thinner and a thinner fluke plate will penetrate more easily.

Based on the test we have made we would happily use a Viking 10 instead of our Excel No4 (15kg steel) or our 15kg Spade the S80(?) - except that the Viking does not fit on our bow roller (because of the roll bar). I believe the owner of Viking Anchors is using the Viking 10 on a Jeaneau 43 as his 'anchor to keep'. Our 38' cat has the windage of a 45 Bav.

Personally I think we have more than enough hold with our 2,000kg for our Spade and Excel and the 1,650kg hold of the Viking 10 is more than enough (based on our current tests). It thus comes down to cost and the Viking currently - as the new kid on the block - looks a bargain.

Returning to Knox - a great anchor, sets easily and reliably. If we were to use one, as a our primary, we would want the toe closed up (as a Fortress might catch detritus between its 2 flukes - so might a Knox) and we would like the pockets under the fluke provided with bigger drain holes to allow any mud to be flushed out more easily. Other wise the anchor is built to battleship standards! (in contrast the Viking - that looks emaciated - but HT steels can afford to be on a diet :)

Viking are the only anchor maker I know with a galvanising specification, of 100 microns (engineering standards are usually 70 microns min) and I checked our Viking 10 (and it met their specification) and I suspect that Knox is well coated also - being part owned (?) by a galvaniser. Viking are the only anchor I know that saves weight by using HT steels in the fluke - it was done with lots of noise with Rocna and its shank - hopefully we will see some new designs follow Viking's lead.

It merits note - thin HT steels are not made by everyone - Bisalloy (made famous by Rocna) don't make anything as thin and as strong as that used by Viking. Though the steels Viking use are possibly used in your car (if its a high end vehicle -same reasons, saves weight without sacrificing strength).

I note the comments on Spade galvanising quality - it merits note - Spade have been around since the early 1990s and I have seen rusty and painted Rocna which were only introduced in 2006. Removing lead from the toe of a Spade is easy - a blow torch will do the job (just weigh before and after and replace like with like. I think you will find new steel Spade anchors have the lead isolated (in both the aluminium and steel versions) with a resin coating to seal the ballast chamber.

And for those who do not know me - I have no fiduciary interest in Viking, Spade nor Knox (nor another anchor maker). But I will write up a more fulsome article on Viking and Knox in the near future.

Jonathan
 
Interesting stuff. ?
How does one know what force ones boat pulls at anchor though ? Weight of boat, windage,waves ?
It seems easy to find ratings for anchors but much harder to find what sort of pull a boat can exert?
 
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