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Factor 25-03-2013 15:52

Anchor design and misnomers
 
I have observed that there is a lot of labelling followed by didactic reasoning on anchor threads. Indeed some of the logic could be described as Orwellian (two legs bad four legs good). A classic example is the continual reference to convex anchors as ploughs, a derogatory term designed to suggest that convex anchors "plough" the ground, leaving aside that most anchors I have seen are symmetrical and most ploughs - well not so much, the fact is - a convex anchor does not plough - it buries.

Indeed, if you look at an old fashioned plough it is much more like a concave anchor than a convex anchor. As I type this I am look at a CQR thinking how one side of it looks like a concave anchor.

Concave anchors work okay if the scoop can continue to move the bottom aside, this is where the Spade seems to work so well. Newer roll bar scoop anchors work very well, but their limitation is the roll bar, particularly if the bottom is such that it clogs the space between the bar and the scoop. Scoops are designedc to scoop, ploughs to shift soil to one side, what we really need is an anchor that is designed to bury. To dig into and keep digging into the bottom, this is where convex anchors like the SARCA EXCEL work really well and indeed the FORTRESS also achieves excellent holding power - because it continues to dig in. These anchors penetrate without ploughing and penetrate without scooping.

When these ROLL Bar concave anchors hit the market there was a wow factor as they were sharper and pointier than anything previous, instant hold, Bruce anchors were being hung up in garages everywhere, now what do you see, new threads on how good the Bruce anchors are.

The Bruce anchors are still of concave design but have no roll bar, slow to dig in most times but will perform over a wider area than concave roll bar designs and dig deeper as they have no roll bar restriction, this is now being recognized and the old Bruce is having some renewed recognition, as it is concave it is still limited as the depth it will dig, that is why you hear all the time a bigger Bruce works better, low and behold you are now hearing the same thing with the concave roll bar, two times bigger seems to be the general consensus, even though they are supposed to be rated as S/H/H/Power anchors, and the Bruce anchor were only H/H/Power, just amazing.

Dont get me wrong, I think Supreme Rocna et al are great anchors, but I really think a discussion on the physics and a reduction in the use of of didactic, black/white reasoning would be good.

The chances of that happening are of course , minuscule

DISCLAIMER - I have no commercial involvement with Sarca or Fortress

motion30 25-03-2013 16:04

Re: Anchor design and misnomers
 
respectfully , you pose many premeses that are not accepted or not proven to be fact.

estarzinger 25-03-2013 16:07

Re: Anchor design and misnomers
 
I have never seen a SARCA EXCEL in person.

In photos it looks like a delta copy.

I am curious how you think it fundamentally differs from or improves on a delta?

Specifically how does the geometry differ?

Factor 25-03-2013 16:25

Re: Anchor design and misnomers
 
Quote:

Originally Posted by motion30 (Post 1194550)
respectfully , you pose many premeses that are not accepted or not proven to be fact.

Respectfully - name them

Quote:

Originally Posted by estarzinger (Post 1194552)
I have never seen a SARCA EXCEL in person. In photos it looks like a delta copy. I am curious how you think it fundamentally differs from or improves on a delta? Specifically how does the geometry differ?

Been down this path before Evans - its not a Delta copy, if it were then it would have a HHP rating like the Delta, rather than the SHHP rating that it actually has. I have seen both side by side, hell I have owned both on the same boat, the difference is quite marked when you see them up close and side by side. Certainly they are quite different in their anchoring behaviour and reliability. If appearance was the benchmark then every danforth style anchor would perform as well as a Fortress or as badly as a crap copy. If appearance was the key, then every Bruce copy would perform as well as the original or as well as the Manson Ray.

downunder 25-03-2013 16:31

Re: Anchor design and misnomers
 
Haven't used one personally as yet but we are seeing them fitted to quite a lot of vessels in Australia thesedays.

They are quite a different anchor to the Delta in live view.

Unfortunately the SARCA Excel thread was closed down. It was drawing quite a few actual users to comment when I think a moderator overstepped the mark with comments without having seen one. Don't think anybody has been game to restart a SARCA Excel thread since.

Cheers

estarzinger 25-03-2013 17:01

Re: Anchor design and misnomers
 
Quote:

Originally Posted by Factor (Post 1194570)

Been down this path before Evans - its not a Delta copy.

I read the whole other thread and NO-ONE gave a specific answer on how it differs from a delta. We were just assured it was somehow different "trust us". Are the angles different? Does if somehow have more surface area? What are the specific differences?

The "HHP/SHHP rating" is not an explanation on how or if it physically differs, as I am quite sure you know.

If it performs so much better there MUST be specific, quantitative and explainable differences.

Your answer actually sounds like you think it is in fact a delta copy, but an improved copy. Is that correct? If so how specifically do you think it has been improved (in basic design and geometry).

Jimbo485 25-03-2013 17:11

Anyone got a side-by-side photo of the Excel and Delta? I would be interested to see the difference visually as well.

We had a 20 kg Delta that we tossed due to unsatisfactory performance. The 20 kg Supreme has been 99% excellent, but I am considering getting a Sarca Excel or a Manson Boss, probably 30 kg.

Any first hand comments on the Boss, apart from its shear physical size?

Stu Jackson 25-03-2013 17:13

Re: Anchor design and misnomers
 
Oh, No! Not another one.

When your new anchor pulls you off the bow, you KNOW you have the right one.

Until the next generation comes along.

Cotemar 25-03-2013 17:18

Re: Anchor design and misnomers
 
5 Attachment(s)
Their is just one problem I see with the CONVEX anchors.
The spine is bent the wrong way.
They are designed to cut the seabed and push it to the sides.

A FLAT or CONCAVE anchor will hold or compress the seabed on the face of the fluke. It’s an evolution in anchor design.

Kettlewell 25-03-2013 17:21

Re: Anchor design and misnomers
 
I will say that many of us have seen ample evidence that anchors vary greatly in how they perform based on very subtle differences that may not be evident upon a cursory examination, such as is made using low-resolution online photos. I once bought a Danforth copy that looked good, but certainly did not perform anywhere near as well as a genuine Danforth, which I soon replaced it with. Minor differences in dimensions and angles made a large difference in performance. The same situation has been noted when comparing genuine Bruce anchors with some of the Bruce clones--they look similar, at first glance, but perform very differently. I have also observed this with "plow" anchors, that often get called "CQRs" by folks, even though they are not genuine CQRs.

Factor 25-03-2013 17:22

Re: Anchor design and misnomers
 
Quote:

Originally Posted by estarzinger (Post 1194596)
I read the whole other thread and NO-ONE gave a specific answer on how it differs from a delta. We were just assured it was somehow different "trust us". Are the angles different? Does if somehow have more surface area? What are the specific differences?

Email the manufacturer - ask him.

Quote:

The "HHP/SHHP rating" is not an explanation on how or if it physically differs, as I am quite sure you know.
No - but it is an indication about how if physically performs

Quote:

Your answer actually sounds like you think it is in fact a delta copy, but an improved copy. Is that correct? If so how specifically do you think it has been improved (in basic design and geometry).
[I am not sure how you arrived at that - I think I said - its not a Delta copy, and I have seen both side by side, hell I have owned both on the same boat, the difference is quite marked when you see them up close and side by side.

But this isnt a thread about Excels and Fortress, its about understanding the difference between a scoop, burying and ploughing anchor, between concave, convex and flat, between roll bar and not, but most importantly its about trying to take away some of the misnomers in the conversation.

Jimbo485 25-03-2013 17:24

Quote:

Originally Posted by Stu Jackson
Oh, No! Not another one.

When your new anchor pulls you off the bow, you KNOW you have the right one.

Until the next generation comes along.

Hoho! No, Stu, I just want a third anchor to complement the MS and Fortress, in case I lose one or have to leave somewhere in a hurry. Very happy at the moment, but figure if I get a third it has to be different from the other two.

Kettlewell 25-03-2013 17:28

Re: Anchor design and misnomers
 
Quote:

When your new anchor pulls you off the bow, you KNOW you have the right one.
I had to laugh at that. It has happened to me with a well set Danforth, CQR, and Fortress--no need for the "new" or "next" generation, just proper technique.

estarzinger 25-03-2013 18:17

Re: Anchor design and misnomers
 
4 Attachment(s)
Lewmar has made the delta CAD files publicly available. If someone wanted to get me CAD files for the Excel I would be happy to do a completely objective and independent comparison of them and describe/explain the differences (I would certainly be happy to keep the actual excel CAD's confidential if it was requested).

It seems to me that, given the way the Excel looks (just like a Delta in photos), this is just simply such an obvious question that has to be well answered or will be a significant barrier to acceptance. I know it is for me. I certainly don't trust the mfg's anchor 'tests', not the website 'testimony'. We all know how those can so easily be manipulated. We even know from the public Rocna e-mails how 3rd party tests can be manipulated (providing non-production anchors that are specially 'tuned' for testing, and influencing testers to only test in situations where the anchor will do particularly well, and analytically manipulating test results).

Right now we don't even have any side by side photos. All we have are these:

Delta:
Attachment 57870
Excel:
Attachment 57871
Delta:
Attachment 57872
Excel:
Attachment 57873

But based on these photos we do have, honestly, if this is not a Delta copy, I don't know what would be. Perhaps it's an "improved" copy. I would certainly like to believe that, but find it hard to take simply on "trust" given the anchor industry (with the notable exception of fortress) past actions and experience.

As to "plow", and "next gen", and "concave", etc . . . I personally figure this is mostly important to those with marketing and spin agendas. I personally find the discussion of them all much too simple to explain behavior in a complex range of bottoms and dynamic loads. I don't have any agenda except to carry the best anchor on my own boat and don't regularly use any of that terminology. I (try to) talk about specific anchors and specific features and specific geometry.

Cotemar 25-03-2013 18:35

Re: Anchor design and misnomers
 
3 Attachment(s)
Anchor evolution

Convex plow, problem bend is up, which cuts the seabed and pushes it to the sides.

Flat Fluke, holds the seabed on the face of the fluke.

Concave fluke concentrates and holds the seabed on the face of the fluke.

estarzinger 25-03-2013 19:19

Re: Anchor design and misnomers
 
^^

Cotemar, I honestly think most of us get that. But I at least don't think it is all that useful in understanding anchor performance.

The more important questions:

- which ones dig in deeper/faster in penetrable bottoms
- which ones can be constructed to have greatest surface area, while still having the other desirable traits
- which ones set better in hard but still penetrable bottoms
- which ones set best and hold most reliabily in non- penetrable bottoms

The "pushing dirt to the sides" vs "pushing dirt to the middle" aspect really does not answer any of these more important questions. And there may well be complex non-obvious trade-offs, just for example the convex shape may have a lower coefficient of friction, which on a simple examination would seem to reduce holding power, but may in fact increase its ability to penetrate deeply and thus actually increase holding power.

transmitterdan 25-03-2013 20:00

Re: Anchor design and misnomers
 
Quote:

Originally Posted by Factor (Post 1194570)
Been down this path before Evans - its not a Delta copy, if it were then it would have a HHP rating like the Delta, rather than the SHHP rating that it actually has. I have seen both side by side, hell I have owned both on the same boat, the difference is quite marked when you see them up close and side by side.

The rating differences is not an answer to the question. Since you have seen the physical differences side by side then please describe them to those of us not in a position to see the Sarca. A plus would be an explanation or theory as to why those physical differences should be expected to result in better performance.

downunder 25-03-2013 20:15

Re: Anchor design and misnomers
 
Quote:

Originally Posted by Cotemar (Post 1194666)
Anchor evolution

Convex plow, problem bend is up which cuts the seabed and pushes it to the sides.

Flat Fluke, holds the seabed on the face of the fluke.

Concave fluke concentrates and holds the seabed on the face of the fluke.

Evans,

This is a good example of the plough discussion you comment on.
I expect we need a new SARCA Excel thread started with a heap of photos showing the differences between the Delta/Excel.

All we know is that actual users believe they act quite differently and do not act as a plough as suggested by some. I have not used one but as a prospective purchaser of an anchor value any useful contribution.

As a farmer I certainly would not want an anchor that ploughs the seabed. I want one that buries and holds to its maximum in various seabeds.

Cheers

Marqus 25-03-2013 21:50

Re: Anchor design and misnomers
 
Quote:

Originally Posted by estarzinger (Post 1194702)
And there may well be complex non-obvious trade-offs, just for example the convex shape may have a lower coefficient of friction, which on a simple examination would seem to reduce holding power, but may in fact increase its ability to penetrate deeply and thus actually increase holding power.

This single sentence raises the level of the discussion by orders of magnitude.

Cotemar's diagrams may be taken to imply that the "weight" of the soil/clay/stuff scooped up by the anchor surface is what delivers the anchor's performance, whereas it may be more strongly related to factors mentioned in the above post (in addition to scooping). The latter factors are obviously going to vary based on the type of seabed involved, which would make mathematical modeling in anchor design such an incredibly challenging task.

So I think "gut feel" and intuition when comparing anchors visually cannot really be relied on. Could be like saying "that shape of aircraft wing will fly faster than this one, based on looks".

You would imagine well-capitalized anchor manufacturers to analyze and model geometries (time consuming and expensive), before adding a great deal of experimentation and empirical data to the mix before releasing a new model to compete in the market.

Don't think they'll want to make all their data public.

Can part-timers like most of us on the forum obtain/produce even a fraction of the data the manufacturers deal with? I'm pessimistic.

I'm not offering a solution, and enjoy reading these forum contributions as much as anyone, but some of the posts tend to underestimate the complexity of the physics, as the quoted post so strongly suggests. And too much underestimation will not lead us to a useful place.

Factor 26-03-2013 01:12

Re: Anchor design and misnomers
 
As I understand it Cotemar, that is the whole idea of the spine as you call it, it is designed to separate, penetrate, if you look at the excel it has a single plane fluke, when you watch the video presenting the Excel you will see how it forces the substrate over the rear rather than plow it to the sides

In the concave anchor environmental destruction video it is clear as well. Whereas the Delta has a plow shear, the Excels toe is turned down and is accompanied with cutting edges all round to further aid setting in hard clays, weed, and other various substrates. I think the underside is also interesting , it has a bulbous shape which I am told aids in pivoting/turning in tide changes or wind.

But honestly these are questions for the manufacturer, what I know is that the excel sets better and holds longer than the Delta, by far. I dont have to justify it to Evan or you, I had to justify to me before I spent the money and after.

It was worth every cent.

Again though I will say that I have no commercial involvement with SARCA. Just a happy owner and user. I dont give a toss if you like/don't like the Excel, couldn't care any less. I do object to justifications by people using misnomers and I do simply want a place where I can talk with other users of Excels to learn from them the good and bad experiences.

Dockhead 26-03-2013 02:40

Re: Anchor design and misnomers
 
Quote:

Originally Posted by Marqus (Post 1194786)
This single sentence raises the level of the discussion by orders of magnitude.

Cotemar's diagrams may be taken to imply that the "weight" of the soil/clay/stuff scooped up by the anchor surface is what delivers the anchor's performance, whereas it may be more strongly related to factors mentioned in the above post (in addition to scooping). The latter factors are obviously going to vary based on the type of seabed involved, which would make mathematical modeling in anchor design such an incredibly challenging task.

So I think "gut feel" and intuition when comparing anchors visually cannot really be relied on. Could be like saying "that shape of aircraft wing will fly faster than this one, based on looks".

You would imagine well-capitalized anchor manufacturers to analyze and model geometries (time consuming and expensive), before adding a great deal of experimentation and empirical data to the mix before releasing a new model to compete in the market.

Don't think they'll want to make all their data public.

Can part-timers like most of us on the forum obtain/produce even a fraction of the data the manufacturers deal with? I'm pessimistic.

I'm not offering a solution, and enjoy reading these forum contributions as much as anyone, but some of the posts tend to underestimate the complexity of the physics, as the quoted post so strongly suggests. And too much underestimation will not lead us to a useful place.

:thumb:

Marcus and Estarzinger have both raised the level of the discussion unrecognizably (especially for an anchor thread!:)). It's great to see that it is actually possible, after all, to say something intelligent about anchors. Who would have thought!

noelex 77 26-03-2013 04:24

Re: Anchor design and misnomers
 
Quote:

Originally Posted by Marqus (Post 1194786)
Could be like saying "that shape of aircraft wing will fly faster than this one, based on looks".
.

Someone with a reasonable knowledge of aerodynamics could do just that.

I think in a similar way we can intelligent comments about the performance of anchors based on their geometry. This is easier to do when the design is extension of an existing design rather than a radical new concept (like say the Hyrobubble).

There are a number of anchors that have a fixed convex design blade. The Delta and Kobra are very popular designs in Europe. These two anchors share many common characteristics.

In a similar way the concave roll bar anchors Rocna, Manson supreme, and Mantus also show similar performance.

We can evaluate the anchors further looking at weight distribution tip sharpness, blade area etc.

A good aircraft (or yacht) designer can predict the performance of their creation very accurately before its ever left the drawing board. We are not at at that level of sophistication when evaluating anchors, but I believe we can come to some useful predictions.
Once an aircraft is constructed its speed, climb rate, fuel consumption etc can be accurately measured. Evaluating anchor performance is far less precise, so concentration on those designs contain favourable characteristics for further evaluation is especially helpful.

This does not mean that all convex anchor will perform the same. Sharper and more complex tip profiles, better weight distribution, tweaks in the geometry can all achieve worthwhile improvements and produce class leading performance.

But I am skeptical that they can elevate themselves above the limitations of their class that are governed by the fundamental geometry.

Time will tell.

Kettlewell 26-03-2013 04:42

Re: Anchor design and misnomers
 
Quote:

I dont have to justify it to Evan or you, I had to justify to me before I spent the money and after.
So, how did you justify the performance of an Excel before you spent money on it? I'm not trying to be snide, just wondering what evidence and facts you had that prompted you to write that. For myself, I find it hard to determine what is the best anchor for me based on the claims, counterclaims, flawed published anchoring tests, and just the looks of an anchor.

Factor 26-03-2013 05:17

Re: Anchor design and misnomers
 
Fair question Kettlewell. I spoke at length with the designer, watched the videos, spoke to the independent testing agency, spoke to lots of owners and current users, spoke to a few former work colleagues in various Water police establishments - and well you get the idea.

All of which convinced me it was probably worth a shot.

The big key was that the manufacturer said to me if you don't like it - give it back, no problem.

So I tried it - liked it - a lot and I am not giving it back.

And unlike some other people, I don't say its the only good anchor out there, I am sure that Manson Supreme and the rest are quite good. But I want a convex burying anchor for a number of reasons.

I didn't dive my anchor on the weekend, I walked it, when the tide was out it was in knee deep water, it was buried, and there was little evidence of furrowing. I walked a number of other anchors and with out exception the CQR types were all barely in the sand. There were a couple of roll bar types that were in - but I wouldn't call them buried. But that may have been slack technique as much as design etc.

Jimbo485 26-03-2013 05:34

So who has a Boss? Any comments, positive or negative?

denverd0n 26-03-2013 05:40

Re: Anchor design and misnomers
 
I majored in physics at university and, personally, have very little interest in the physics of anchor design. What I am interested in are real world results. What sort of experiences are actual people having using the particular anchors in a variety of different anchorages? That's all that really matters in the end.

Kettlewell 26-03-2013 05:53

Re: Anchor design and misnomers
 
Quote:

Fair question Kettlewell. I spoke at length with the designer, watched the videos, spoke to the independent testing agency, spoke to lots of owners and current users, spoke to a few former work colleagues in various Water police establishments - and well you get the idea.
I think that's more than most of us do, so kudos on your hard work, but you have to admit it is still not a scientific method. For myself, I have tried a few different anchors numerous times in the same harbor that I know intimately, and I have observed others using many other types of anchors in the same harbor, and my conclusion is that given decent holding and a reasonable-sized anchor that it mostly comes down to technique up through gale force. A properly set anchor and a decent amount of scope and you're good to go with any modern anchor. It is very rare that most of us get to test the outer limits of an anchor's holding power, so things like ease of setting and handling are more important 90+% of the time.

The one place modern anchor designers have improved things greatly is realizing that a very sharp and weighted point can make a huge difference in hard bottoms and weeds, extending the versatility of the main anchor. I sometimes wonder if you could take almost any old fluke design and put a sharp enough point on it to start penetration and you're good to go for the most part. Though the new-gen anchors also have designs that orient the anchor more quickly to get that point started into the bottom. That's how the Fortress anchor beats out the Danforth, despite having nearly identical dimensions--sharp blades start deep penetration faster.

So I wouldn't be surprised if the sharp-pointed Excel beats out the similar looking Delta. And look how the Bruce aficionados point out how the originals have much sharper flukes than the knock offs. And, we have read how some CQR users believe in sharpening the point with a file.

Cotemar 26-03-2013 06:02

Re: Anchor design and misnomers
 
2 Attachment(s)
Here is an illustration of how the problem bend on a Convex plow anchor not only
cuts the seabed and pushes it to the sides, but it also loses projected surface area

Flat Fluke, holds the seabed on the face of the fluke and has the most surface area.
This is why Fortress with its sharp tip flukes, once set in a straight one direction pull, cannot be beat.

Concave fluke, concentrates and holds the seabed on the face of the fluke, but also loses projected surface area.
It loses less projected surface area than a Convex plow anchor, because its bend angles are smaller

Liam Wald 26-03-2013 06:56

Re: Anchor design and misnomers
 
Anchors that I have owned since 1980;
Danforth Standard
Danforth HT
Fortress
CQR
Bruce
Delta
Rocna

Anchors that have dragged after set;
Bruce.

Current anchors on board;
Rocna (primary)
Delta
Fortress

Anonymous7500 26-03-2013 07:13

Re: Anchor design and misnomers
 
I spent some time on the Anchor Right website reading about there tests and watching the videos. The problem that I have with the test is that the rode is always at an infinity-to-one scope. If the most widely used scope is 5:1, why aren't the anchors tested using this scope?

The testing apparatus doesn't need to be complicated. The TATS tool is going in the right direction though. However, they seem to use the infinity-to-one scope. Of course, they don't say what scope they used for the test. The TATS connection point looks to be about 3' off of the ground. Unless they are using a 15' rode the test doesn't reflect real world conditions. The test stand only needs a connection point for the anchor 5' above the ground and the pull point with a force scale slightly lower on the opposite side. There doesn't need to be an operator chair. Putting a human in that position is irresponsible at the very least.

The SARCA Excel does appear to be a modified whatever. But, who cares? It seems that they have made significant improvements over the design that they modified. The outermost part of the blades appear to be in the same plane on both sides while the plow portion is at a much leaner angle. There is also a two stage angle from the point back along the center-line which presents the tip in a downward posture. The back edge is flares back down, minimizing the plow affect.

One last thing, SARCA does not do themselves any favors with the pictures that they post of their product. It is too easy to develop a 3D part that can be rotated in the web browser to not have one. The shiny surfaces of the part and angle that the pictures are taken make it difficult to accurately determine the geometry

Delfin 26-03-2013 07:18

Re: Anchor design and misnomers
 
Quote:

Originally Posted by estarzinger (Post 1194596)
I read the whole other thread and NO-ONE gave a specific answer on how it differs from a delta. We were just assured it was somehow different "trust us". Are the angles different? Does if somehow have more surface area? What are the specific differences?

The "HHP/SHHP rating" is not an explanation on how or if it physically differs, as I am quite sure you know.

If it performs so much better there MUST be specific, quantitative and explainable differences.

Your answer actually sounds like you think it is in fact a delta copy, but an improved copy. Is that correct? If so how specifically do you think it has been improved (in basic design and geometry).

From the Sarca website:

"Q. Sarca Excel looks similar to a delta style or plough anchor, why is the holding power so much greater?
A Take a second look, Sarca Excel has a single rear plain fluke that doesn’t plough, this unique design compressors the substrate and forces it over its rear, incredible pressure is applied to the convex surface area of the Excel, when this happens these forces not only multiplies the anchors holding power but drives the anchor down filling in behind it. Excel also incorporates extended and slightly concave cutting edges. You will further notice the toe of the Excel is turned down also with extended cutting edges. The turn down of the toe allows the anchor to set in most cases within the length if its fluke, it has low resistance when penetrating and will readily bed itself in a wide variety of ocean type substrates, sand, mud, reef, gravel and many more.
"

This might all be manufacturers hype but for the simple fact that you don't have to look very far into anchor threads to find people who were unhappy with the performance of their Deltas, while I have yet to read a single complaint about an Excel. Must be some difference, or the real world experiences would be the same, would they not?

Examples: GMAC - "We have been replacing Deltas with Excels on a range of 40 to 44fter imported yachts, they arrive with Deltas on them. All the owners have had issues with the Delta and all say the Excel just doesn't give them that grief. 90% just swapped equal weight for weight."

foggysail - "Gosh, that anchor sure looks a lot like a Delta. OK, maybe it has hidden features but! I used an 88# Delta on my 40" Silverton aftcabin this summer that I purchased new from Defender late last year. I had great expectations for my Delta only to find that it either slipped or plowed. In any case, the boat moved while being subjected to about 20K wind and strong tidal change currents."

Bash: "My boat, which displaces 15 tons, came with a 44 lb. Delta, which we used for a short while on an all-chain rode. The anchor was insufficient in mud. Traded it for a good bottle of wine, and felt I got the better part of that deal."

The specific, quantitative differences include metallurgy, weight distribution, and tip design. Apparently they have resulted in improvements that manifest themselves with an SHHP rating.

noelex 77 26-03-2013 08:06

Re: Anchor design and misnomers
 
1 Attachment(s)
High holding power anchors (HHP) and super high holding power anchors (SHHP) are terms used by anchor manufacturers so its important to realise what they mean.

SHHP in particular sounds very impressive, but anchor corresponding to this standard only has to hold 4x the force of a standard stockless anchor. That's like the one shown in the photo. They store well in a hawse pipe, but don't work very well when scaled down to the sizes used on yachts.

Another definition is that a SHHP power anchor has to hold 6x its mass.
For say a 35lb anchor that's 210 lb. the yachting world tests showed similar sized anchors were holding over 5000lb.

These standards are expensive for manufactures to obtain, but I don't think they mean much

Dennis.G 26-03-2013 08:59

Re: Anchor design and misnomers
 
Quote:

Originally Posted by Delfin (Post 1195002)
This might all be manufacturers hype but for the simple fact that you don't have to look very far into anchor threads to find people who were unhappy with the performance of their Deltas, while I have yet to read a single complaint about an Excel. Must be some difference, or the real world experiences would be the same, would they not?

You will find complaints about any anchor made, assuming enough have been made and are used on boats.

I have seen hundreds of Deltas on boats but have never seen an Excel anchor (except a photo). I have never spoken to an Excel owner, so no suprise that I have heard no complaints of that anchor. That fact does little to boost confidence in the Excel however. :rolleyes:

Cheechako 26-03-2013 09:13

Re: Anchor design and misnomers
 
The Delta is both convex and concave. It is convex at the point of entry and continues back for a ways and to aid it in digging into the bottom. The flukes then become concave shaped where they are bent outward to hold in the bottom. This presents surface area to the sand. This is the only holding power an anchor has really; presenting surface area to the sand. The danforth or spade do this very well as they present that surface area (and a lot of it!) quite perpendicular to the pull. The Bruce has almost no resistant area presented. It's basically a hook.

Cotemar 26-03-2013 09:22

Re: Anchor design and misnomers
 
1 Attachment(s)
Here is an illustration of how the seabed forces act on modern day anchor profiles.

Factor 26-03-2013 13:18

Re: Anchor design and misnomers
 
Im sorry - COMPRESS, whats compressing what?

Cotemar 26-03-2013 13:26

Re: Anchor design and misnomers
 
Quote:

Originally Posted by Factor (Post 1195282)
Im sorry - COMPRESS, whats compressing what?

Compress (squeeze) and hold the seabed at the face of the anchor fluke.

It’s the opposite of cut & separate the seabed on the face of the anchor fluke.

MarkSF 26-03-2013 13:30

Re: Anchor design and misnomers
 
Every time I'm thinking of replacing my CQR, I see a thread like this, and am so thoroughly confused that I decide not to bother.

Kettlewell 26-03-2013 13:35

Re: Anchor design and misnomers
 
Quote:

Compress (squeeze) and hold the seabed at the face of the anchor fluke.

It’s the opposite of cut & separatethe seabed on the face of the anchor fluke.
Interesting theory that this is an important feature, but where is the evidence that it means anything? If compression is so great why do most tests show a Fortress with flat flukes or a Danforth at the top of the holding power heap? Why do at least some offshore oil rig anchors have a convex shape?

https://preview.turbosquid.com/Previe...d2dcLarger.jpg

Cotemar 26-03-2013 13:53

Re: Anchor design and misnomers
 
Quote:

Originally Posted by Kettlewell (Post 1195292)
Interesting theory that this is an important feature, but where is the evidence that it means anything? If compression is so great why do most tests show a Fortress with flat flukes or a Danforth at the top of the holding power heap? Why do at least some offshore oil rig anchors have a convex shape?

Your pictures proves the theory. No compression, but plenty of surface area for dive and hold.

I do not see a sharp upward pointed spine doing any cutting. I just see a large flat area, which would give great holding power. Just as a Fortress anchor would.


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