Rocna's new anchor/ Hey, Anchor thread!!!

[thinwater]

Originally Posted by transmitterdan

In general, I am unimpressed by anchor demonstrations that have any of these characteristics:

1) Small anchor (few kilos) as "proof" that the design works at larger sizes.

2) Dragging any size anchor through soft gunk like a plow just to prove it can "dig deep".

3) Test conditions that tend to favor one anchor design over all others. Especially so if those conditions are uncommon.

4) Tests that appear to intentionally cast a competitive anchor in a bad light. Even if that test seems legitimate I am so skeptical that it has little value to me.

5) Tests that attempt to "prove" stainless steel does anything to improve an anchor's intended purpose.

Well....

1. In consistent bottoms (sand/mud) I have seen many tests, including the US Navy, that show anchor holding is proportional to mass at the 1 - 1.1 exponent. This is proven fact and you will have to dismiss a lot of testing to refute it. In grassy, hard, or rocky bottoms, a whole different thing, obviously.

2. Of course, that is exactly what happens in very soft mud. They drag long distances to get deep enough to hold. The "set in a shank length" stuff is pure fiction; 10-20 shank lengths is more likely. They may need to be 5 feet down to get out of the pudding.

3. Please explain. What bottom used in a test is "uncommon?" If you are referring to the Solomons Island test, it is valid many coastal areas. If you do not have pudding mud in your area, then it dones't matter to you. But those tests were very worthwhile for Chesapeake sailors. We could care less about sand.

4. Kind of hard to define that as unfair. So long as the bottom was real, it is up to the reader to understand the limitations of one test location.

[redsky49]

Originally Posted by thinwater

Well....

1. In consistent bottoms (sand/mud) I have seen many tests, including the US Navy, that show anchor holding is proportional to mass at the 1 - 1.1 exponent. This is proven fact and you will have to dismiss a lot of testing to refute it. In grassy, hard, or rocky bottoms, a whole different thing, obviously.

2. Of course, that is exactly what happens in very soft mud. They drag long distances to get deep enough to hold. The "set in a shank length" stuff is pure fiction; 10-20 shank lengths is more likely. They may need to be 5 feet down to get out of the pudding.

3. Please explain. What bottom used in a test is "uncommon?" If you are referring to the Solomons Island test, it is valid many coastal areas. If you do not have pudding mud in your area, then it dones't matter to you. But those tests were very worthwhile for Chesapeake sailors. We could care less about sand.

4. Kind of hard to define that as unfair. So long as the bottom was real, it is up to the reader to understand the limitations of one test location.

Solomons was my homeport for many years. Those areas of both Back Creek and Mill Creek near the harbor entrance are quite accurately described as "poor holding". Miserable holding is more like it. And that type bottom occurs often enough that it can be a major concern for Bay boaters.

I have to agree, anchoring in sand is a pleasure to be cherished.

[Dockhead]

Originally Posted by thinwater

Well....

1. In consistent bottoms (sand/mud) I have seen many tests, including the US Navy, that show anchor holding is proportional to mass at the 1 - 1.1 exponent. This is proven fact and you will have to dismiss a lot of testing to refute it. In grassy, hard, or rocky bottoms, a whole different thing, obviously.

2. Of course, that is exactly what happens in very soft mud. They drag long distances to get deep enough to hold. The "set in a shank length" stuff is pure fiction; 10-20 shank lengths is more likely. They may need to be 5 feet down to get out of the pudding.

3. Please explain. What bottom used in a test is "uncommon?" If you are referring to the Solomons Island test, it is valid many coastal areas. If you do not have pudding mud in your area, then it dones't matter to you. But those tests were very worthwhile for Chesapeake sailors. We could care less about sand.

4. Kind of hard to define that as unfair. So long as the bottom was real, it is up to the reader to understand the limitations of one test location.

If you will look at the large selection of photos in Noelex's anchoring thread, you'll see that setting "in a shank length" is not at all a fiction. If good technique is used, and the seabed is suitable for the particular anchor, the anchor goes right in. Particularly in good bottoms like sand.

I also don't agree that the right way to set an anchor in soft mud is to drag it through the mud until it sets. Soft mud is in fact the case where if you want any hope of setting the anchor, you have to let it settle and sink in before you start to pull on it. If it starts moving a significant distance, then it won't set, and will likely get fouled. That's the whole challenge of anchoring in soft mud in my experience.

I do, however, believe your statement about ultimate holding force mostly being proportionate to mass of the anchor. With some exceptions like Fortress and Aluminum Spades which hold above their weight class.

In my opinion ultimate holding force is not the most important quality of an anchor, and maybe it's even trivial. What we care about rather is how reliably and easily it achieves a set in a variety of bottom types.

[EllesBelles]

Originally Posted by skipgundlach

I love our rocna - except that it hauls up a monster load of bottom, most of the time, leading to running along to rinse.

That leads to stern-to orientation of the roll bar, leading to fouling trying to get it up in the chocks, as the top of the shank presents rather than the bottom.

This design looks much like a spade, and I think that it would eliminate the fouling on raising I have nearly every time (when the bottom is non-stick sand, it comes up fine, but any rinsing makes it point-forward, and I have to use a boat hook to twirl it to the right orientation).

One concern is that it's already 'sharp' in terms of a roller; the new design seems to have an even sharper presentation to the roller. Perhaps without an over-center upside-down issue, that won't be of concern, but I go through any type of material I've tried, eventually. I admit I've not paid to have a custom SS roller made, but it may come to that.

Getting the anchor up has been a bit of a challenge, sometimes, as I suspect that there have been times where there was at least 100# of bottom (usually with grass to help hold it together, but sometimes looking very much like concrete or tabby) attached, and frequently taking a great deal of motoring with the anchor at various depths to clear that off before loading.


From that I impute that if it has a bottom other than rock, I'm unlikely to drag, and if it manages to upset (I watched it do that once, as we were anchoring in clear water but difficult current/wind conditions), it will reset immediately. Because it's usually so deeply set (we back hard), my norm is to pull up using the catenary to advance the boat, which develops way on our 44k# boat. When it gets to vertical, I just quit raising and let the weight of the boat and the zero scope pull it loose. See above for raising, at that point ☺

HTH; I don't want to spend the big bux for a vulcan, but if I were doing what I did 4 years ago when I got the standard 33KG model, I'd go with vulcan. It would have made my anchor roller system much simpler...

We can relate to what you said....here in the eastern Cyclades we're lucky to find anchorages that aren't sheer volcanic rock dropping off at a great rate of mountainous tilt. When we find a shallow bay, it's heavy mud-sand and grasses and pulling up our rocna, we hoist a lot of the bottom. As you said, it's then a slow cruise out of the harbor while we clear the anchor. At least the water is crystal clear and we can see well.
We do love the rocna's excellent holding in these 30+ knot harbor breezes (we had 37 knots in a protected anchorage on the south side of Mykonons recently and our rocna held us firmly while other boats dragged)

[Fortress]

Some excellent and insightful comments, and a few further thoughts:

- During the Chesapeake Bay testing, each anchor was given the relatively same amount of time to "soak," so to speak, into the soft mud bottom (the depth was approximately 27-ft) while the research vessel moved into a pre-determined position before the pulling began.

Undoubtedly, more time to soak would have benefited all anchors, and maybe the heavier ones more so, but then again, maybe not. If one of these anchors landed upside down, then sinking deeper might have made it more difficult for the anchor to orient into the fluke downward position when the slow pulling (10-feet per minute) started.

- While those aboard were surprised at some of the results, our consultant Bob Taylor, who again has been in anchor design and soil mechanics for over 45 years with the US Navy, was not. He stated that anchors which are designed and optimized for harder soils will oftentimes only have a holding ratio (holding capacity divided by anchor weight) of 10-15x in a soft mud soil, which is almost exactly what we found.

- The stainless Ultra performed better than the galvanized Spade, which was inexplicable. Was the more slippery stainless Ultra able to slice deeper than the galvanized Spade, which the soft mud clung to more? I haven't a clue.

- While the images of Noelex have value as to an anchor's orientation and engagement into sea bottoms, they tell us little about the anchoring technique used to set the anchors. Did the boater toss the anchor overboard and then try to set it at a long or a short scope, and very shortly afterwards, he started his cocktail hour.....or did he take the additional time to let the anchor soak and then power set it by backing down hard to insure that it was well buried and properly set?

I am not sure that any questions concerning the boater's setting technique are answered by the images.

- Regarding re-setting, after one pull we broke the wire rope at 3,500 lbs while trying to retrieve the Fortress FX-37, and directly above it at a 1:1 scope. The wire rope had slipped between the vertical and horizontal rollers on the custom-made fairlead after waves hit the boat, which left metal grinding on metal.

At that time, the winch operator estimated that the anchor was buried 13-ft into the mud. The idea that this anchor might have come out easier at a longer scope and with a change of direction seems more than a bit impossible, leading to the conclusion that a well-buried Fortress, with its two massive flukes, is not more likely to break free from a sea bottom due to a tidal or wind shift.

- That said, the Danforth / Fortress anchor-type is likely to be greatly challenged in bottom conditions such as grass, weeds, or rocks where those two large flukes might have a greater difficulty in penetrating compared to a single, narrow fluke anchor-type that has considerable weight behind it.

- There is no question that increasing the shank / fluke angle, as confirmed by the Chesapeake Bay testing, will in turn dramatically increase an anchor's holding capacity in soft mud, and among pleasure boat anchors, only the Fortress and Super Max have that capability, to the best of my awareness.

This is no secret among large anchor manufacturers such as Bruce, Baldt, the US Navy, and Vyrhoff, all of whom make anchors that have a wider shank / fluke anchor to improve holding in soft mud.

[impi]

Originally Posted by Goosebumps

A good contribution here would be to find out who has been living on the hook for years, in which circumstances, not next to a marina in its protected mooring area. Then find out what their anchor experience is considering the type of boat, cruising area, climate, tides, prevalent winds..... i have a 34 foot cat, ditched the CQR, the electrical windlass, installed manual windlass and 20kg, 5kg more than minimum for my boat, Rocna. I am only sorry I didnt do that earlier. i have tried to get the Rocna to drag where my CQR, my Bruce, my Danforth dragged! Result failed. Sure the Rocna ships loads of soil when in mud but are we cruisers not always prepared for that, with deckwash pressure or simple oar?

Must say we really sleep well on ours.

[colemj]

Originally Posted by Fortress

Some excellent comments, and a few further thoughts:
……..
- While the images of Noelex have value as to an anchor's orientation and engagement into sea bottoms, they tell us little about the anchoring technique used to set the anchors. Did the boater toss the anchor overboard and then try to set it at a long or a short scope, and very shortly afterwards, he started his cocktail hour.....or did he take the additional time to let the anchor soak and then power set it by backing down hard to insure that it was well buried and properly set?

I am not sure that any questions about the boater's setting technique are answered by the images.

……..
At that time, the winch operator estimated that the anchor was buried 13-ft into the mud. The idea that this anchor might have come out easier at a longer scope and with a change of direction seems more than a bit impossible, leading to the conclusion that a well-buried Fortress, with its two massive flukes, is not more likely to break free from a sea bottom due to a tidal or wind shift.

The Noelex thread does show much of the techniques in use. His, for sure, is always described, and he describes what he sees others do - including taking pictures of originally unset or poorly set anchors after winds shift and blow harder. Scope, setting technique, "soak" time, etc are described as best as possible.

I agree that a Fortress set in 13' of mud is not pulling out during a wind shift. That is, if the boat has enough power to set the anchor that deep (not all of us have research vessels to set our anchors). However, you gloss over the fact that this set depth is unique to a specific bottom type and condition. Much of the world does not contain soup mud, and a Fortress design will not be 13' under - even in good sand - and will pull out during a strong shift reset. I don't even need theory or Bob Taylor for this - I witness it in practice often. This is why we have a Fortress as a special-use anchor (IMO the best choice possible for this), but would never recommend one as a primary unless someone is staying in a very specific bottom type area.

Fortress is unique in their market position as they are highly regarded as secondary anchors, so a large number of boats buy them for such. Other manufacturers clamoring for primary anchor position don't have anywhere near Fortress's marketshare - most boats have one of the other's primary AND a Fortress. It is a good moat to have around one's business. I fail to see why Fortress attempts to tarnish this reputation by pushing their design into the primary anchor category. Particularly since there doesn't seem to be much further market share to gain (it is unlikely one is going to buy a Fortress primary to go along with their Fortress secondary).

Mark

[darylat8750]

" While the images of Noelex have value as to an anchor's orientation and engagement into sea bottoms, they tell us little about the anchoring technique used to set the anchors. Did the boater toss the anchor overboard and then try to set it at a long or a short scope, and very shortly afterwards, he started his cocktail hour.....or did he take the additional time to let the anchor soak and then power set it by backing down hard to insure that it was well buried and properly set? "

Nolex and his Mermaid add comments about the drop and setting technique when they manage to observe the action. There are also several sequences where they have managed to get multiple images over a span of time that included changes to the wind speed and/or direction.

It is interesting that the SS Ultra out performed the Spade. It is possible that with a 100 sets instead of 5 that may look different.

My friend uses a Fortress on a big Hatteras and has bent a couple of shanks when caught in rocks in positions that I think any anchor would have either bent or would still be there. The quick and no hassle replacement of the bent part sold me on making one my mud anchor next time I need to purchase one.

[Fortress]

Originally Posted by colemj

Fortress is unique in their market position as they are highly regarded as secondary anchors, so a large number of boats buy them for such. Other manufacturers clamoring for primary anchor position don't have anywhere near Fortress's marketshare - most boats have one of the other's primary AND a Fortress. It is a good moat to have around one's business. I fail to see why Fortress attempts to tarnish this reputation by pushing their design into the primary anchor category. Particularly since there doesn't seem to be much further market share to gain (it is unlikely one is going to buy a Fortress primary to go along with their Fortress secondary).

Mark

Mark,

I appreciate your input. Fortress anchors are commonly used as primary anchors aboard smaller boats in the under 40-ft length range, and a significant amount of our unit sales volume falls into this market.

Boats above 40-ft will typically have some type of plow anchor as their primary, and in those cases, possibly a Fortress as a stern or storm anchor.

The bottom line, if you will pardon the pun, is that every boat should have at least ONE Fortress aboard!

Stay safe,
Brian

[darylat8750]

I'm a slower typer than Mark. In post 112 he said it better than I.

[impi]

At anchor almost every day of our lives and in differing bottoms since we travel a lot. Our Rocna has been great, and yes, we do struggle in sea grass - we have to look for the open patches and in poor visibility let it settle for some time before backing down 'slowly'. We have found different sea beds require different approaches and for me, outside of sandy bottoms where I am backing up even before the tip hits the floor, it pays to let natural gravity and motion work things out for a while before backing it in. I guess the heavier chain on Lagoons helps somewhat - I dive on every set and it is not out of the ordinary to see us set within a shank length. I have to sheepishly admit one of my worst sets was about 30m though Probably goes back to my farming days where I like to plough everything up. In that scenario we had sand overlying shale and the tip could not dig deeper. Just for interest, I have come across an anchor that sets better than ours - would love to have one but not in stainless steel and it was only available in that - called an Ultra anchor ... Still, Rocna has my approval and we just replaced the second anchor chain in 5 years - same anchor!

[downunder]

Originally Posted by impi

At anchor almost every day of our lives and in differing bottoms since we travel a lot. Our Rocna has been great, and yes, we do struggle in sea grass - we have to look for the open patches and in poor visibility let it settle for some time before backing down 'slowly'. We have found different sea beds require different approaches and for me, outside of sandy bottoms where I am backing up even before the tip hits the floor, it pays to let natural gravity and motion work things out for a while before backing it in. I guess the heavier chain on Lagoons helps somewhat - I dive on every set and it is not out of the ordinary to see us set within a shank length. I have to sheepishly admit one of my worst sets was about 30m though Probably goes back to my farming days where I like to plough everything up. In that scenario we had sand overlying shale and the tip could not dig deeper. Just for interest, I have come across an anchor that sets better than ours - would love to have one but not in stainless steel and it was only available in that - called an Ultra anchor ... Still, Rocna has my approval and we just replaced the second anchor chain in 5 years - same anchor!

Now Impi. You should know ROCNA's don't plough.

[impi]

Originally Posted by downunder

Now Impi. You should know ROCNA's don't plough.

Hey Downunder ... being brave on a Rocna post huh

Was really hoping to catch up with you in Oz mate - we have delayed the visit a bit as circumstances have moved us in the direction of NZ for now ... will catch up when we next pass there though ..

[ranger58sb]

Originally Posted by motion30

The problem with the fortress, danford design is related to resetting when the current shifts 180 degrees. That design has proven unreliable on resetting. In my experience

We only experienced a reset issue once. We were in a quiet creek with almost zero scope and a casual toss of the Fortress -- no particular effort to set it well, since we were essentially using it as a temporary lunch hook. A surprise cyclonic squall came through, and we spun a 360° on the anchor within the course of about 1-2 minutes. We simply hauled the anchor and puttered back to our home slip, about a mile away.

I would not call that a Fortress failure to reset. That was all about our technique, and our short-term intentions in the first place.

In all other cases, we've never had a problem with our Fortress not resetting. I suspect when it's properly set in the first place, i.e., completely buried, there's no turning it around anyway in normal wind or tidal shifts.

Originally Posted by thinwater

Please explain. What bottom used in a test is "uncommon?" If you are referring to the Solomons Island test, it is valid many coastal areas. If you do not have pudding mud in your area, then it dones't matter to you. But those tests were very worthwhile for Chesapeake sailors. We could care less about sand.

Originally Posted by redsky49

Solomons was my homeport for many years. Those areas of both Back Creek and Mill Creek near the harbor entrance are quite accurately described as "poor holding". Miserable holding is more like it. And that type bottom occurs often enough that it can be a major concern for Bay boaters.

I have to agree, anchoring in sand is a pleasure to be cherished.

Sand? Whassat? I've heard of it before...

Originally Posted by Dockhead

If you will look at the large selection of photos in Noelex's anchoring thread, you'll see that setting "in a shank length" is not at all a fiction. If good technique is used, and the seabed is suitable for the particular anchor, the anchor goes right in. Particularly in good bottoms like sand.

Many of the pics show the anchors still visible; not sure I consider a still-visible anchor to be actually "set."

Originally Posted by colemj

Fortress is unique in their market position as they are highly regarded as secondary anchors, so a large number of boats buy them for such. Other manufacturers clamoring for primary anchor position don't have anywhere near Fortress's marketshare - most boats have one of the other's primary AND a Fortress. It is a good moat to have around one's business. I fail to see why Fortress attempts to tarnish this reputation by pushing their design into the primary anchor category. Particularly since there doesn't seem to be much further market share to gain (it is unlikely one is going to buy a Fortress primary to go along with their Fortress secondary).

I would be comfortable with a Fortress as our primary anchor, here in the Chesapeake. And in fact one was, in our early days with this boat.

It's not our primary now, but that's partly because our bow roller isn't optimized for a Danforth-style anchor... and partly because we like having more than one anchor design (weight, etc.) available. Once we were able to install an electric windlass (to handle more weight), and since the Fortress is easily dismantled, stowed, and "re-mantled," it seemed the better choice for which one we would use as back-up.

Edit: I had forgotten another reason we decided to make our Fortress the back-up: the SuperMax we use as primary is adjustable from on deck without having to dismantle/remantle the whole anchor. We keep our Max in the middle setting, but if necessary we can change it to the no-kidding-soup setting relatively easily -- and we know many of the wheres/whens to do that. In the unlikely event we discover some of that "sand" stuff people keep going on about, we can also bring the Max back aboard and reconfigure for especially hard bottoms without making quite as much of a mess on the bow.

But it wouldn't have taken much to decide the Fortress was our best option. No electric windlass? Danforth-friendly bow roller? Mud bottom? Lighter weight for size is good, and respectable performance in this kind of holding ground would make it a top contender. For us.

-Chris

[colemj]

Originally Posted by ranger42c

…….

In all other cases, we've never had a problem with our Fortress not resetting. I suspect when it's properly set in the first place, i.e., completely buried, there's no turning it around anyway in normal wind or tidal shifts.

………..

Many of the pics show the anchors still visible; not sure I consider a still-visible anchor to be actually "set."


I would be comfortable with a Fortress as our primary anchor, here in the Chesapeake. And in fact one was, in our early days with this boat.

Like I said in my post, a Fortress is a good primary anchor only in a specific and invariable bottom type. The Chesapeake mud fits this perfectly. However, outside of the Chesapeake and some other near-by East Coast places, soupy mud is not the bottom one encounters.

In other bottoms, there is no way an anchor is setting 13' under the surface. That is why anchors are still visible in those pictures. By definition, anchors set only until they fully resist the forces applied to them. In your case, that resistance might need 13' of burying to accomplish, but in most other bottom types, it only needs to have the flukes buried to withstand great force.

Here is an example of why a Danforth-type anchor should not be used as a primary outside of specific bottom conditions. This was a boat set well until the wind shifted strongly 180*, the anchor unset and obviously could not reset itself. The anchor is a Fortress, although that is neither here nor there in this case.

Alain Pourad (sp?) did a great analysis on roll stability of anchors in resetting and showed why danforth-type anchors will naturally unset during directional changes, unless very deeply buried so that roll stability cannot come into play at all. Soupy mud is about the only bottom that can provide this environment.

Mark