Fortress Anchor

[C08]

If a Fortress Anchor is left assembled in the soft mud position how would it be expected to perform in hard sand. At some point of angle the points only may be expected to dig in a hard bottom and the anchor "cartwheel". Just wondering what experiences there are with this?

 

[noelex]

In my opinion it will probably not set at all and therefore have minimal holding capacity.

 

[zoidberg]

Why not ask the makers? They have video of several configurations.

 

[macd]

As Noelex suggests, I suspect it would struggle to set. Fortress certainly don't recommend it. As new, the 45º angle holes should be covered by a sticker stating "soft mud use only".
The Chesapeake mud in which Fortress performed so well at the increased angle is very gloopy, more like mousse than mud.

 

[macd]

Why not ask the makers? They have video of several configurations.

By way of a PS to that, zoidberg, a Fortress representative pops up on here from time to time, so might be along with the full 'official' view. I've no doubt there will also be quantitative comparisons with 32 and 45º fluke angles for various substrates in some of the many tests Fortress link to on their site, should anyone have a spare evening. Or weekend.

 

[C08]

In my opinion it will probably not set at all and therefore have minimal holding capacity.

That is my suspicion also.

 

[NormanS]

I leave mine on the "shallow angle" setting all the time. It gives me an excellent performance even in soft mud.

 

[Neeves]

In mud and soft sand it will perform and produce hold better than any other similarly physically sized anchor when the fluke is set at 45 degrees. It will not perform well in a harder substrate for which the fluke angle should be reset for 32 degrees. If you read the Chesapeake test results you will note that even in very soft mud the Fortress though outstanding compared to the other anchors would not be reliable, if sized correctly for the yacht, in strong winds and the evidence suggested that really a bigger Fortress would be required. Sadly the ideal is have a bigger one set at 45 degrees and the more normal sized set at 32 degrees.

This is the same evidence used to suggest that a shallow setting anchor, like a Mantus (which has a fluke seabed angle of 16 degrees) will not develop ultimate hold anywhere near as high as its peers, Rocna, Excel, Spade with a seabed/fluke angle of around 30 degrees etc. To get the same hold with a Mantus you need a bigger anchor to compensate for the low angle. A shallow angle is used to allow easy retrieval, which tells you something - perhaps, and is also used for very, exceptionally, hard seabeds. I actually know of no anchorages where most common anchors hare defeated. A shallow angled (fluke/seabed) anchor will take a longer distance to set in sand than one at 32 - in the same way a fluke/seabed angle of 32 degrees does not develop (or takes distance to develop) any hold in mud..

Anchors are a compromise - there is no one perfect anchor. If you think your anchor perfect - you live in cloud cuckoo land. If you are anchoring in a cross section of very different seabeds, mud, sand, pebbles, weed - you need different anchors or accept that hold will be compromised.

A considerable amount of work has been conducted on the angle at which the fluke addresses the seabed - which is why most anchors are optimised at around 30 degrees (Bruce, Delta, Rocna, Supreme, Danforth, Spade, Excel, Kobra, Bugel to name a few), some at 45/50 degrees (commonly commercial anchors), some offer an ability to vary around 45 and around 30 (Fortress, Supermax) and an exception few are as low as 22 degrees (I only know of a Danforth type) and one odd one at 16 degrees, (Mantus).

We have been leaving our Fortress set at 32 degrees and do use it at that angle in mud if the anchorage is very sheltered and no particularly strong wind is forecast. If the anchorage is exposed and stronger winds forecast we have altered the angle to 45 degrees (and have found it very effective).

As with any anchor if the anchor is oversized it will be difficult to deep set, our auxiliary engines are simply insufficient, and the anchor may trip with a change of tide (or wind) - so if you have an overly large Fortress, which you carry as a Storm anchor (or any other anchor) do not expect it to be deep set under engine power alone.

Jonathan

 

[JumbleDuck]

In mud and soft sand it will perform and produce hold better than any other similarly physically sized anchor when the fluke is set at 45 degrees. It will not perform well in a harder substrate for which the fluke angle should be reset for 32 degrees.

Mine was second hand and came without the mud palms. Would you, from experience, recommend them?

 

[macd]

Mine was second hand and came without the mud palms. Would you, from experience, recommend them?

If you search past threads, JD (at a rough guess, about a year ago), you may find one begun by someone else who bought a used Fortress lacking its mud palms. The chap from Fortress I mentioned in post #5 above responded by offering free mud palms to him and anyone else on here who was missing them.

Fortress' website certainly recommends keeping mud palms attached, whatever the sea-bed. The same representative of Fortress made this very clear in the earlier thread. Mud-palms, it seems, is something of a misnomer.

 

[Neeves]

IThe chap from Fortress I mentioned in post #5 above responded by offering free mud palms to him and anyone else on here who was missing them.

Fortress' website certainly recommends keeping mud palms attached, whatever the sea-bed. Mud-palms, it seems, is something of a misnomer.

+1

Fortress have an exceptional replacement/refurbishment policy. Primarily - no questions asked, possibility you might need to pay for postage.

 

[NormanS]

How soft is "soft"? Some of our anchorages in sheltered lochs are soft mud, but I imagine that as the anchor penetrates the soft stuff, it meets with somewhat stiffer stuff underneath, which has had more time to consolidate.

 

[zoidberg]

e.g. Puilldoran.... east end of Loch na Droma Bhuidhe.... off the pub at Inverie.....

 

[Neeves]

A problem with many, if not most anchors, is they depend on having a firm substrate on which to self right. When the Delta was developed it has a self righting shank augmented by the weighted toe (lots of anchors copy this). Lay it anyway you like and it will roll onto its side ready to engage the seabed. Anchors with roll bars do exactly the same. If the substrate is soft the anchor can arrive at the seabed upside down and simply 'settle' with the shank and or roll bar submerged and the fluke 'sitting' on the surface - it will not self right. You can pull it as long as you like but until the 'rolling' device, shank or roll bar, hits something sufficiently hard it will never roll over. This is true of Spade, Excel, Delta, Supreme, Rocna etc etc.

An advantage of the Fortress or Danforth is that it does not matter how it lands as there is no top and bottom. A genuine Bruce will also self right as the 'wings' of the fluke will force it into the correct orientation - with time and space.

If the anchor has no opportunity to self right it really does not matter how firm the seabed might be deeper down - it may never get further down but simply swim in the softer substrate upside down - and this characteristic is 'possibly' why many anchors performed appallingly in Fortress' tests. I have seen this effect in very soft sand, quite an eye-opener, where there was clear water - but confess to have never seen it in mud (where visibility is commonly non existent) - so I'm extrapolating.

Interestingly, and as you suggest, when Fortress retrieved their anchors in the Chesapeake tests, i.e. the FX models, they all had what looked like firm mud attached (not dry but certainly not soupy) suggesting they did get down to a firmer substrate. But you can also see there was a soupy substrate - from the mess on the operators hands and on deck.

Of course the anchor might land right way up - but its not something I would want to depend on.

Jonathan

 

[Stork_III]

If you search past threads, JD (at a rough guess, about a year ago), you may find one begun by someone else who bought a used Fortress lacking its mud palms. The chap from Fortress I mentioned in post #5 above responded by offering free mud palms to him and anyone else on here who was missing them.

Fortress' website certainly recommends keeping mud palms attached, whatever the sea-bed. The same representative of Fortress made this very clear in the earlier thread. Mud-palms, it seems, is something of a misnomer.

http://www.ybw.com/forums/member.php?49443-Brian-Fortress ?

 

[thinwater]

If a Fortress Anchor is left assembled in the soft mud position how would it be expected to perform in hard sand. At some point of angle the points only may be expected to dig in a hard bottom and the anchor "cartwheel". Just wondering what experiences there are with this?

It won't set (yes, I have tested this numerous times). Really, it should be more clear on the web site that the mud angle is ONLY for soft mud where holding is inadequate.

Most anchors will land right-side-up if you are backing slowly when you lower, you release rode at a matching rate, and then gently tip them over. Most of the time. This is most iportant in soft mud, for the reasons Neeves stated, and because the farther you have to drag the anchor, the more likely it is to trip on a stick.

 

[JumbleDuck]

A genuine Bruce will also self right as the 'wings' of the fluke will force it into the correct orientation - with time and space.

I anchor regularly in a freshwater loch where the bottom is, in places, very soft mud and the Bruce copy I have works very nicely there. Not a great copy, but not as bad as some.

 

[Neeves]

Peter Bruce, who has only just retired, and designed what we know as the 'Bruce' anchor I understand was an aeronautical engineer. He, apparently, designed the anchor so that the wings of the fluke provided lift and would self right (though this might be more effective in some seabeds and less so in others).

Many bruce clones might not have this facility - as many people who copy - don't understand the reasoning behind some 'minor' characteristics.

(If there is another characteristic of the Fortress Chesapeake tests - it showed how anchor, ostensibly similar, are so different. Spade and Ultra, Fortress and Danforth, Supreme and Rocna).

edit

And why suggesting a Kobra is 'just' a Delta or a Mantus is the 'same' as a Rocna is simply ignorance. Little differences produce performance differences out of proportion to the the apparent change.

close edit

But if JD's clone is a decent copy - that would provide one reason for it working well.

If this seems far fetched - as Thinwater suggests some anchors (I'm not sure how many) are hydrodynamic and will align with water movement (or your yacht moving back or forth). I was sceptical - but I hung one anchor in the wind - and it aligned with, or with the fluke 'across', wind direction - and always aligned correctly if you were move backwards. Of course if your yacht is moving in the 'wrong' direction then you might lose any positive (or negative advantage).

But returning to focus - Fortress (and Danforth and other such articulated fluke anchors) have no up and down, no right or wrong - however they land on the seabed - its correct.

Just make sure you have the right fluke angle for the seabed - if you are using a Fortress.

Jonathan

 

[macd]

http://www.ybw.com/forums/member.php?49443-Brian-Fortress ?

Thanks, Stork. That link brought up nothing useful in itself, but helped me to find the thread I mentioned earlier. Post #15 here gives the skinny on obtaining free mud palms: http://forums.ybw.com/forums/showthread.php?455928-Fortress-anchor-design/page2

The thread was rather more than a year ago (18 months to be precise), so apologies if I sent JD off on a wild goose chase.

The same thread also includes this from the Fortress website, which I was unable to find the other day:
""We have found from our research and from our customers that the Mud Palms help the anchor to set faster in ANY bottom. Our advice is to install the Mud Palms on the anchor and leave them on.""

 

[vyv_cox]

The same thread also includes this from the Fortress website, which I was unable to find the other day:
""We have found from our research and from our customers that the Mud Palms help the anchor to set faster in ANY bottom. Our advice is to install the Mud Palms on the anchor and leave them on.""

Which I did when I bought my Fortress in 1998. Since when it has never failed to set in a huge variety of bottoms, although it has failed to reset on very light windshifts on two occasions.