Knox anchor

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J Neeves

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It has been a decent length of time since the Knox Anchor was introduced. Of those that bought one and use it what are the thoughts on its performance? Going against trends for other anchor makers Knox seem to suggest that their anchor is sufficiently effective that one can confidently downsize by 20% - is this proven to be accurate and reasonable.

Has the construction been found to be robust and what is the quality of the galvanising.

I imagine, like other roll bar anchors then the Knox will simply not fit on some bows. Are there other issues, like the compatibility of slot size with shackle size etc?

Jonathan
 
Mine has worked every time so far. Never dragged. The manufacturer recommends a 10kg anchor for my boat and I have the 9kg Knox, so a 10% downsize.The downside is it often seems to come up with a huge clod of the bottom stuck in the groove which makes a mess of the deck to get off if anchored in mud. No galvanising problems apparent.
 
Thanks Angus,

I'm maybe being pedantic - but concave anchors are oft reported to come up full of mud - and you suggesting that the slot makes this worse or that its simply behaving like any other concave anchor?

Its comforting to hear that even being undersized it does appear to be dependable - possibly supporting John Knox' contentions that it holds better than the other new gens. Hopefully there will be some more reports. I'd like to think the Scots can return to the forefront of anchor development :)

The Knox anchor uses a 'very' high tensile stew, from memory 900 MPa,l and high tensile steels are notoriously difficult to galvanise (and the gal looks 'thin') - I just wondered how the gal wore, or performed.

Jonathan
 
High tensile steels are not particularly difficult to galvanize, its just that dependent on the pretreatment route, hydrogen embrittlement can be an issue. And if an issue then it wasn't worth having high tensile steel.
I wonder where they are manufactured and where galvanized?
 
http://www.knoxanchors.com/design-development/about-us/

From this you might deduce the anchors are made in Scotland and a quick phone call will serve to obtain prices.

If they're making in small batches, it would be sensible to manufacture locally, especially, as Peter Smith will testify, one has limited comprehension and thus control over Mandarin speakers
 
I hesitate to clarify Charles' post.

But my understanding was that the Knox Anchor was proudly made in Scotland.

The real unknown is how it has been found to perform by those that have bought one.

Jonathan
 
I own the 18kg (40lb) knox for my Rival 41C which replaced the 27 kg (60lb) CQR. The CQR fitted snuggly over my stem head fitting with the plough under the roller which was my preferred storage place when just day sailing. The 60 lbs was a hassle to manipulate under the pulpit and store in the anchor locker. The Knox does not fit my stemhead fitting and I will have to extent the cheeks and move the roller forward by approximately 2".

I have never sat out a gale with it but I have used my Perkins 4236 at full chat to set it and it sets hard and fast in all bottoms I have tried. My version has the two flukes separated but I understand that they have joined them at some point to prevent fouling although I have never had an issue with this (or with a Danforth / Fortress either). The anchor has not lifted up any mud beyond what I would expect, usually a small amount at the base of the flukes, the split helps the mud wash away, as it does on my Fortress as well. In clay areas the CQR could also lift a chunk of mud.

So far I am impressed with it, never had it roll to my knowledge and skip over the bottom, the chain stretches, goes taught (at low speed) and then her head is brought it, increasing the revs so far has not resulted in the anchor breaking out. Dr Knox has some testimonies from Sailors who have rode out strong winds on the West Coast of Scotland.
 
I'm quite encouraged by that report. Almost all the testing, videos and reports for NGAs seem to be in sand. (some with Bass rock in background!).
But it isn't always sand that the hook encounters, kelp, other weed, rocks, gravel, mud.
If an 18kg holds a Rival 41 OK, then surely will hold a Rival 32. But I guess I'd also need to do some modifications to the bow, as I also often leave the plough of the CQR hanging, with a small rope to stop it slopping side to side.
But its a tossup. The times the CQR has dragged are attributable to some other issue that anchor design.
 
J Neeves said:
I hesitate to clarify Charles' post.

But my understanding was that the Knox Anchor was proudly made in Scotland.

The real unknown is how it has been found to perform by those that have bought one.

Jonathan
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Precisely what I inferred - but none of us know until someone gets in touch (by phone) to find prices and provenance.

I'm afraid, after 25 years of using a Scots-produced anchor I'm now reduced to one made in Texas.
 
Charles,

Sadly I do not think any leisure anchors are made in Texas. I think yours was made half a world away from Texas. The nearest anchor to Texas and still made made in America would be the Fortress.

But a very reassuring testimony from B.O.B.

Jonathan
 
J Neeves said:
Charles,

Sadly I do not think any leisure anchors are made in Texas. I think yours was made half a world away from Texas. The nearest anchor to Texas and still made made in America would be the Fortress.

But a very reassuring testimony from B.O.B.

Jonathan
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To be utterly correct I should have writ "sourced from Texas" - how far down the supply chain does one go - the ore probably came from Australia - so most anchors come from Australia?
 
Chust an aside....

A year or more past, I sought to find out more about Knox Anchors, with a view to buying one. Neither phone calls nor emails elicited a response.

No sale.

I bought a French Kobra and a Murricain Fortress, to add to my eclectic collection. And some rock anchors/pitons in case I ever raise the rocky shores of West Sweden..... or Loch Scavaig. ;)
 
Last year the Prof. lent me 2 anchors to try on my and a friend's boat. He even modified the roll bar on one to allow it to fit on my bow roller without fouling the pushpit. He and his son could not have been more helpful. I didn't buy the Knox or any other NG anchor in the end.
 
Knox anchors are made in Fife, about two years back I decided to "upgrade" my ground tackle and spoke directly to I believe Mr Knox Jnr. Who came across well and clearly new his stuff he offered me the size I needed for £250 which was at least £200 cheaper than the stockists in Newcastle. I later viewed one in the flesh the owner rated it highly but I was not keen on the slot, this has since been adjoined with weld at the tip. I bought a Manson supreme which does the job well. Everyone I have spoken too using the Knox seems pleased. From memory webby of this parish has personel experience and rates them !
 
J Neeves said:
Why not? :)
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'Cos I occasionally race so the anchor can't stay on the roller and I couldn't find any way of laying the Knox on the foredeck without it being a downright nuisance and it wouldn't fit into the anchor locker. My Chinese copy CQR lies comfortably on the deck thanks to its articulation and despite the perceived wisdom of this forum, or because it can't read, it has behaved itself though occasionally it harvests impressive amounts of kelp. So the question became a choice between what I had or the faff of connecting and disconnecting the chain which I didn't fancy - there was also the matter of a limited number of drinking vouchers and a plethora of demands.
As to the performance - all reports are excellent and just pulling it across my lawn had it digging in almost instantly.
 
JVL said:
................ he offered me the size I needed for £250 which was at least £200 cheaper than the stockists.........................!
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This looks like the first spring sighting of any price for one of these anchors.

What size was the 250 quid anchor? Thanks
 
I paid £320 for my 18kg in 2012, which carried as discount as I think I was an early buyer of the the larger size. This was his advice during the query stages with Knox Anchors: -

Yes, the 18 kg Knox Anchor would be what we recommend for a 41ft Rival 41 of 10 tonnes displacement. It should be more than adequate. This anchor should hold around 700 kg when fully buried in sand without moving. If a larger force is applied it will plough slowly through the seabed provided it does not meet an obstacle. 700 kg is about the peak force you might expect for a Rival 41 in a 50 kt wind provided there are not significant waves. The mean force would be around half this. You would almost certainly need a good spring under these conditions such as a 10 metre length of 14 mm nylon multiplait as well as a large scope. Such a spring effectively deals with snubbing and banging of the chain on the bow roller which indicates a bar-taut chain and an enormous force on the whole system. We always use such a spring.
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