Photos of Anchors Setting

[noelex 77]

This was an Ultra in 8m @ 4:1.

It had not been given much setting force at this stage. It is starting to set well. We would need to see it after more force was applied, although in this nice sand all anchors are performing well, so I am not sure it would tell us much.

Notice the owner has drilled a hole in the shank, presumably to retain the anchor on the bow roller. I don't think this is a good idea, although it is done on all sorts of anchors very commonly.

The Ultra shank is a fabricated structure consisting of two curved sheets of stainless steel with a gap (in later models there is some cross bracing) in the middle. This enables the shank to be strong, but lightweight. Weight in the shank is quite detrimental to anchor performance so this is an important feature of the anchor. Many anchors use high tensile steels in the shank for the same reason.

It has been suggested on internet forums that the Ultra shank is sealed. This would give the shank buoyancy to help offset the shank weight and would further increase performance. The shank sides (my guess is these are about 8mm on this 45kg anchor) would have withstand a considerable pressure so I am not sure if this is accurate. Does anyone know? Of course, if it was originally a sealed chamber, then the hole is a really bad idea.

[Alan Mighty]

Originally Posted by noelex 77

The shank sides (my guess is these are about 8mm on this 45kg anchor) would have withstand a considerable pressure so I am not sure if this is accurate. Does anyone know?

I've drawn a blank. I did my usual trick of looking for the patent document. I 'think' the Ultra anchor is covered by Turkish patent TR200502406U. That lists the inventor as Nejat Ogutmen (I think the correct patent should list Nejat Övütmen and Yılmaz Yücel as inventors. But what would I know?). Anyway, each time I have downloaded TR200502406U, all but the front page are blank!


I did get the patent for the Ultra swivel - if you would like that, just ask.


And a surprise: the Ultra website has a user manual for the Ultra anchor. And it has something I've not seen before: a recommendation that scope should equal Beaufort Force number but never be less that 3:1!

[skipgundlach]

Originally Posted by Alan Mighty

(clip)


And a surprise: the Ultra website has a user manual for the Ultra anchor. And it has something I've not seen before: a recommendation that scope should equal Beaufort Force number but never be less that 3:1!

I know the reasons for using such a scope have been mentioned here, but when even a top current anchor maker (i.e. it should hold) recommends STARTING at 3, and working up in Beaufort scale numbers instead of 3, I stand with Nigel Calder:

Chain does me no good in the locker. And I rarely use less than 7:1 - but I choose my spots, and sleep well at night.

Just for fun (assuming I ever get off this %$^&&*^% dock), I'll throw out my 2x oversized Rocna somewhere safe in a blow and see if it holds at 3:1. I'd love to see it work.

[noelex 77]

Thanks for the research Allan.

As a rough rule of thumb, I like Ultra's scope recommendation of:

"Should equal Beaufort Force number but never be less that 3:1"

Ultra's diagram is slightly wrong though. The depth used for the scope calculation should be taken where the anchor is located rather than the depth of water where the boat has come to rest. t might also be helpful to mention the effects of tide on depth.

It is also important to consider the effects of slope where the anchor is located, but this is perhaps getting a bit complicated for what is obviously a simple anchoring guide.

[skipgundlach]

On the Beaufort scale, my 7:1 is only adequate to about 30 knots per Ultra. On the other hand, my nasty-weather 10:1 is good to about 50 knots. And, of course, that's for the 'right sized' anchor, while mine is 2 levels bigger/heavier. Still...

As I get frequent squalls to and over 30 knots where I usually anchor, I think I'll stick with my 7:1

[noelex 77]

This boat was doing a "Hoppy"

The owner was obviously far less talented than the genuine Hoppy, they only managed to thread the chain under the rock once . Nevertheless, this was enough to hold the boat quite securely with the anchors doing little or no work. Once again people worry about their anchor getting caught when catching the chain is more common, at least in the cases I have seen.

You also need to be careful of this problem in tidal waters. I have seen a boat that managed to get its chain jammed like this in coral waters. The tide rose while the owner was away and the bow was close to being pulled under by the time the problem was discovered.

I will show the anchors they deployed in the next post.

[hoppy]

Originally Posted by noelex 77

This boat was doing a "Hoppy"

LOL


I did a "Hoppy" again today but that was after some other anchor related drama.

My bowsprit has the anchor roller integrated into it and it came standard with a tilting roller. Because of the height of the Rocna's shank, it did not work well and I had to modify it. This year I replaced the tilting roller with a large single roller. It works much better, BUT the mounting design is as dumb as sh!t. The roller wheel has a sheave in the middle that it spins around. Stupidly, the sheave has thread each end and is held onto the bowsprit by 2 bolts.

This roller was made by the same company as my bowsprit and in spite if this, it come with 2 counter sunk screws to mount on thin sheets of SS




Twice in the past month, one of the screws came loose and went swimming. I'd used loctite, but it's not enough to overcome a stupid design

The sheave should be hollow and a bolt should go through it. When I find an engineering shop, I will get them to drill through the sheave.

Anyway, it was blowing 30+ off Ios (party beach next bay to the main port) and I had 70m in the water. Something funny was going on with the roller as I was bringing it up and sure enough when the anchor pressed against the roller, it flicked up because there was only one screw.

I decided to sail to a shallower anchorage at the bottom of Ios where I was the day before and planned to anchor in 5-6 meters of sand. I got there dropped the anchor missing a dark patch and dug into sand, or so I thought.

I removed the roller and refitted the old roller as whilst it has problems, falling apart is not one of them.

Later I decided to get out my 1kg shiny bruce copy I have for my dinghy and threw it in the water. To my shock I could not retrieve it. It was holding the boat side on to 20+ knots. So I tied a fender to it and released it and got ready for a swim.

This is the sight that greeted me



This is what was holding my baby Bruce



Found this big rock face nearby



Luckily there were no real problems with the chain like last time.

It seems I was soooo close to sand


So close to sand, at both ends...


After the swim, I tested the reinstalled roller and relocated in the bay.

This time it's all sand. When I was on the bow dropping the anchor, I was still moving forward so the Vulcan was facing the wrong way and had to spin perhaps 120 degrees before it could try to set.

I dropped in about 6m and let out 45m. I used about 2800rpm backing down. Just had a gust of 48 knots and according to the GPS we are holding nicely.

[noelex 77]

This was their primary anchor of the boat with chain caught under the rock in post #2481. It was a small Delta.

The Delta has hooked itself into the rock so I think there was some force on the anchor before the chain jammed itself. Typically, the chain seems to get caught as the yacht swings around. After setting, the anchor (hopefully) remains stationary but the chain will move around over a wide arc.

[noelex 77]

They also set this second anchor, a Danforth or more correctly called a Danforth copy.

The boat was held by the chain caught under the rock. The rode to this anchor was slack, but at some stage it had managed to ingeniously wedge itself into the rock:

[rgesner]

John of Attainable Adventure Cruising has posted an article on Rocna reset failures upon a 180 degree shift.

http://morganscloud.us5.list-manage....d&e=3afe8091b2

The article will be readable on his site without a subscription until sometime tomorrow.

Basically, he is saying it will reset poorly when even a relatively small amount of mud has stuck to the flukes.

It is based on this testing by Steve of SV Panope

https://www.youtube.com/watch?v=WL9JL9AK6ss

[eheffa]

Originally Posted by Panope

Evan, I too have had intermittent "growling" of the chain in what I believe to be a plain old sandy/mud bottom. My conclusion is that sometimes the chain is being dragged across a portion of itself or the anchor.

Steve

Thank you Steve,

This seems to occur when the current is shifting from one direction to another...almost 180 degrees in this one particular anchorage. I have an anchor alarm on and when it's gone off, attributed this to having too tight a circle. (I've usually stayed awake for a while to ensure that we aren't dragging and although I can't detect any drag at the time post-alarm, it's possible the Rocna has rotated dragged and reset.) The sound though leaves me wondering... your recent Rocna anchor video does not leave me feeling confident as we often anchor in areas subject to strong diametrically opposed tidal currents.

Noelex has described a 'shuffle' style reset in the face of a change in wind or current.

I'm curious about what you think of this. Have you seen this shuffle type of behavior in response to the change in pull in any of your videos?

-evan

[Panope]

Evan,

Yes, I did see the Rocna (and Manson Supreme) sometimes remain engaged with the seabed and stay-put after a rather quick "shuffle", during my re-set tests. I am quite sure that if I executed the re-set at something other than 180 degrees (many other person's anchor tests use a 90 degree "veer" test), the Rocna and Manson Supreme would "shuffle" reliably.

Here are two extreme conclusions that a person could have after watching my re-set tests:

"Steve's tests are ridiculous. They simulate an extremely unlikely scenario and should not be used to make an anchor purchasing choice".

"Steve's tests are fantastic. I want the best gear possible and those video's show me a weakness that I want to avoid - no matter how unlikely".

I cannot argue with either of those (fictitious) personal conclusions. Both are valid.

Steve

[eheffa]

Originally Posted by Panope

Evan,

Yes, I did see the Rocna (and Manson Supreme) sometimes remain engaged with the seabed and stay-put after a rather quick "shuffle", during my re-set tests. I am quite sure that if I executed the re-set at something other than 180 degrees (many other person's anchor tests use a 90 degree "veer" test), the Rocna and Manson Supreme would "shuffle" reliably.

Here are two extreme conclusions that a person could have after watching my re-set tests:

"Steve's tests are ridiculous. They simulate an extremely unlikely scenario and should not be used to make an anchor purchasing choice".

"Steve's tests are fantastic. I want the best gear possible and those video's show me a weakness that I want to avoid - no matter how unlikely".

I cannot argue with either of those (fictitious) personal conclusions. Both are valid.

Steve

Thank you Steve.

These video tests are a fantastic resource.

Lots of food for thought here... We have a huge personal investment in our boat. To skimp on the ground tackle makes no sense. I thought the Rocna was the best option for our primary anchor when we bought it a year ago but we will now have to re-think our choice... Cognitive dissonance would push me towards the first 'fictitious' opinion above but I really would prefer to support the second 'fictitious' opinion.

Thank you for all your hard work in providing us with this information.

- evan

[noelex 77]

Originally Posted by eheffa

I thought the Rocna was the best option for our primary anchor when we bought it a year ago but we will now have to re-think our choice.

The rotation of anchors to a new wind direction is a very important property. All anchors lose some grip while they are rotating and if an anchor is going to drag it is a common time for this to occur.

I believe anchors that rotate well should always, or at least very nearly always, "shuffle" as they rotate around to new wind direction, providing the two criterion of a reasonable set and reasonable substrate have been met. An anchor that "shuffles" rotates, but does otherwise not move. It remains with its flukes buried and retains its grip on the seabed.

The alternative is that the anchor breaks out, drags, and hopefully resets. This is very unreliable. No matter what design of anchor we have, if it then encounters debris or unsuitable substrate, it is not going to set.

So I think the focus should be on anchors that shuffle well. This is quite easy to judge underwater. Anchors that perform well remain with their flukes well buried throughout the rotation with little list. Anchors that rotate poorly develop a high list and lose grip over most of the fluke area. Anchors that rotate poorly still will not break out on most rotations, but they lose so much grip while rotating it is obvious that they are vulnerable to a gust at the wrong time. I think even small differences in an anchor's ability to shuffle in a competent fashion is an important distinction between different anchor models.

Steve's videos are interesting, but my experience with our Rocna and observing others is that "shuffles" very well and I think this is the key to an anchor that is going to rotate reliably.

[kas_1611]

Judging by the way my Vulcan coped with the 90º change of direction between our original, wind orientated, drop to how it ended up after we'd decided to tie up stern to shore recently I have to say that there is probably little to worry about.

Fundamentally the Vulcan did not move during the operation but merely reorientated itself to the new direction of pull (1500rpm reverse for several minutes) and dug itself in even further than the original drop (see post#2375).

I have seen us wander back over the Vulcan and end up with the chain running backwards from the anchor but this has only ever been in quiet conditions. Never had to ride out a strong blow with a 180º switch but I'll report in what we find if we ever find ourselves in said situation.

Cheers

Keiron