New Anchor

[BandB]

HaHa BandB,
I have no intention of buying any anchor much less a Knox. Got too much stuff anyway including anchors. I modded my Supreme again too.
Thanks for the nice compliment. I’ll do anything for you for awhile.

Well, we're campaigning they should send you one to test. Knowing you though, you'd be modifying it within a week.

 

[Nomad Willy]

Peter B,
Re your 53 I noticed some time ago that the top (not the bottom) of the Rocna RB is further aft than other anchors. Sarca and Supreme seem about the same but the Knox RB tops out further fwd (toward the rode) than all the others.
On this forum website there is lots of talk about the Mantus also. It’s small and long fluke and big RB. Oddly to me the only thing big about the Mantus RB is it’s width. As a righting device I think the Rocna is best w the top of the RB aft.
That brings up another interesting aspect of the design of anchors is their aspect ratio. That is their length to width ratio. Two very successful newish anchors (the Excell and the Mantus are high aspect ratio anchors. Aspect ratio has tons to do w hull design performance and I have a feeling it signifficantly affects anchor design. I was very supprised when Rex launched a high aspect ratio anchor after marketing a low aspect ratio anchor for years. XYZ did the same. Their first anchor was so unstable it was not a consistant setter. Sometimes I’d give up and throw out my old Dan or whatever unless it was going to blow and then I’d keep at it until it set. Because once set the XYZ anchor holds .. my experience. But that wasn’t the problem w the Sarca. Probably some other element of performance. Anyway I’ve never heard a reason or case for high aspect ratio anchors. I would say off the top that pitch stability is one clear benefit. But that’s all I can make of it.
As to tipping the Sarca anchor over when it’s upside down I think it’s the V shaped pad usually on the top of the anchor.
And I still don’t like the very wide throat angle on the Knox.

But the high performance (if it’s real) and if it’s due to some aspect of the slot I can think of only one thing. Interference drag.
If you try to drag a board through the water sideways it has X drag. If you have 12 boards the same depth but 1/12 as wide as the original board each fence picket-like board say for example 3” wide w a 3” gap between them .... the picket fence will have much more drag than the large single board.
Another example;
If you had a river fairly wide and had 12 posts 12” in dia across the river you’s slow the water flow more w the 12 posts than w one 12’ in dia. Interference drag.
One more;
Two airplanes. One having one wing as usual. The other having the same size wing but as two wings ... a biplane. The biplane will not be as fast because the air needs to be jamed inbetween the two wings being compressed to some degree.

An anchor w multiple flukes side by side will have more drag and hold better. In the slot of the Knox anchor there’s interference drag that wouldn’t be there if it was one fluke.

But I don’t think interference drag is the secret to the Knox anchor .. if there is one. It is interesting though.

 

[markpierce]

Anchor looks top-heavy to me. Not confident it will dig in quickly.

 

[Nomad Willy]

Well, we're campaigning they should send you one to test. Knowing you though, you'd be modifying it within a week.

HaHa not even a week. I’d reduce that throat angle. I’d try it first as a base point though. Made that mistake before.
I don’t feel like I’m campaigning most all the time on anchors. It’t just interesting. However I definitely have my favs and not likes.

 

[Nomad Willy]

Anchor looks top-heavy to me. Not confident it will dig in quickly.

I agree Mark.
It has what appears to be a big heavy shank.
But our Claws do too. And they dig in promptly.
On my modded Claw I added weight to the fluke and that in essence lightens the shank.

 

[markpierce]

My Bruce-copy digs in immediately in the thick SF estuarian mud.

 

[Peter B]

My Bruce-copy digs in immediately in the thick SF estuarian mud.

Ah well, Mark. AS Marin used to say. All anchors work - until they don't.
I guess my 'don't' came along a bit earlier in my ownership of Lotus than for most, but the old CQR knock-off she came with was a bit of a crock of s**t, I must admit. Way too much wear and movement at the hinge, for a start.
Funny thing is, when the boat finally sells, the thing I will miss the most is the Super Sarca anchor. Dunno why, but I just know I will. Maybe it's nothing more than its somewhat agricultural, designed for a purpose, and does the business, look..?

 

[Simi 60]

I hate the divided fluke.
Went to anchor the tender today and couldn't.
Reason, chain had jammed into the slot of the danforth from bouncing around in the anchor well and took 15 minutes or so to manhandle it back out.

 

[markpierce]

I hate the divided fluke.
Went to anchor the tender today and couldn't.
Reason, chain had jammed into the slot of the danforth from bouncing around in the anchor well and took 15 minutes or so to manhandle it back out.

Those Danforth flopping flukes bit my fingers once to often. I'm now a believer of anchors without moving parts.

 

[markpierce]

Ah well, Mark. AS Marin used to say. All anchors work - until they don't. ...

I'm far away from using my Bruce knock-off as a door stop. Perhaps when I retire from boating.

 

[BruceK]

That divided fluke looks like it would cause more problems than create perfection and save mankind. I wouldn`t buy one either Eric, even to test, maybe B&B will buy you one to play with.
There are overtones of "winged keel" mystery to the divided fluke, just how does it work its magic?

 

[Peter B]

Eric mentions somewhere that there is a welded bar connecting the flukes at some point to prevent chain or other fouling debris jamming in the slot between, but I see no such thing in the more clear picture of one Simi post #10 here...
http://www.trawlerforum.com/forums/s42/new-anchor-36543.html#10

...so not sure where Eric got that from. Eric..?

 

[Nomad Willy]

Eric mentions somewhere that there is a welded bar connecting the flukes at some point to prevent chain or other fouling debris jamming in the slot between, but I see no such thing in the more clear picture of one Simi post #10 here...
http://www.trawlerforum.com/forums/s42/new-anchor-36543.html#10

...so not sure where Eric got that from. Eric..?

Here it is Peter,


“How about this for service ?

A reply just in from JK hisself.


"However, we are now making a modification to the anchor which you suggest, fitting a bridge between the tips of the half flukes. We has confirmed that this has no effect on the anchor performance."

Seems to make pragmatic sense, if you want to prevent the flukes jamming into a chain or cable.”

Read more at KnoxAnchor - has anyone any experience of using one? - Page 2

 

[stubones99]

I would vote this anchor as the one most likely hooked on a root or log, and lost forever.

 

[Peter B]

One thing that leads me to feel that this anchor has proven a disappointment is the thread stops in 2014, now 3 years ago. That would be decidedly unusual if it had sparked a lot of real interest, don't you think?