Simi 60,
Thanks, Here is a sample of some of the conversation in this forum. This from page 7 addresses the long setting distances in the Knox text.
“ 1. Storyline Writes
Registered User Location : Liverpool - boat Ardfern
There is a comment on the Knox site in the Anchoring Technique page.
The professor says the following :
A good modern anchor should start embedment immediately and develop its maximum hold or UHC after it has ploughed a 5 to 10 metres. By that time it should have rotated to a vertical position, and should be completely buried.
On face value this seems to say that a NG anchor will continue to move after the initial set. This is not something I have experienced with either of the two techniques we use now with our Rocna. If the bottom is sand then we find no finesse is needed; drop anchor, drop back, dig in (fast or slow makes no difference, the anchor buries immediately). Things are different in a couple of soft muddy anchorages we use and I now use quite a few bursts of reverse to slowly dig the anchor in. You get a feel for what the anchor is doing and typically it will set in just a few metres but with each ever increasing amount of reverse it will move backwards but never more than a very few metres.
Am I reading the professor correctly, is he saying that to achieve a full set the anchor will move back 5 - 10m ? My feeling is that the only way our Rocna could move that far (once set) is for it to break out.
He also says the anchor ends up in a vertical position - can that be right ?
John Writes
Well story line, it depends on who you believe, John Knox is clearly speaking of a anchor pull test, pulled way beyond any load you will experience from your boat when simply setting your anchor, he is quoting max load before break out or drag distance, this test is also governed by the type of substrate the anchors are being tested in, these anchor sizes are normally around 12 to 15 kilo range, anything larger when testing is too difficult to handle and would require serious winching equipment as they will not travel any further than a couple of feet.
So Yes in this instant bigger is better, if you take an enormous anchor like Noelexs on such a small boat it is any no wonder in sand and light weed his anchor travels very little distance before holding, minimum backing up distance, shuffling around, listing as he calls it and staying anchored in a change of tide or wind shift is always going to be the norm with such a large anchor on such a small boat
I do have a problem when some say they are skeptical of a anchor designers test, especially well identified we all know who John Knox is, so when publically throwing down lose comments one should check themselves, in this instant “tell us who you are” what credentials you have other than a Moderator of another forum, photographing anchors , commenting and displaying a mermaid.
Obviously we have all been treated to some eye opening problems when setting anchors,” for this I am great full “ commenting on anchor designs and how they work, you are well of the mark.
I think John Knox is a very intelligent man with anchor design experience few have, I would never insult his intelligence by saying his testing is to be treated with skepticism.
When it comes to skepticism Noelex just has to cop it on the chin for his comments Re John Knox, the anchor on Noelexs boat is huge, given to him, five months of trialing, defending, one has to become a bit partial to this anchor, certainly buds will start to flower in the relationship with the supplier, Just saying.
If you go through any anchor forum, you will find there are now many, many concave anchor roll bar designs dragging,” mainly related to mud” one design as mentioned in this thread is becoming common place and stands out in particular, it has made headlines in the past for all the wrong reasons, looks like it will do it again, if we are talking real world tests over time then this is as real as it gets, even though the bigger is better slogan was mysteriously born shortly after concave roll bar designs hit the market, it has not solved this problem.
Who am I, I am a supplier and advisor for varying sections of the Marine industry, I am involved with ports, fisheries, heavy work barges and delivery of goods to oil Riggs in Bass Strait.
Yours truly John.
Read more at
KnoxAnchor - has anyone any experience of using one? - Page 7
