Fortress anchor quirk: bent stock

[Mickeyrouse]

Hopefully this thread will not degrade into an infinite “this versus that” back-and-forth over which is the best anchor or technique. I have two Fortress FX-23 anchors that I have used for 23 years. I swear by them. I have no interest in changing.
Rather, I’m curious if any other Fortress user has encountered this peculiarity: About three times now I have replaced the stock on the one that gets all the use. After some time of use, say about 4 or 5 years, I have noticed the crown to be bent. The direction of bend is inward, in the same plane as the flukes, on both sides, sometimes more one side than the other.
When I first noticed this I assumed that at some point the boat had gotten up against a piling at a dock or something. But since my hands alone have been at the wheel while docking for 25 years, I knew I hadn’t had any incidents like that. I think it would a significant impact to bend it. I then ruled out the next possibility of the boat encountering an obstruction on the dock while I was away, because there have never been any such obstruction possibilities where we have home-docked. Yet the bent stocks have appeared just the same.
Since Fortress unfailingly honors the warranty on their anchors, it’s not a money issue. The bent stock doesn’t seem to effect holding power. I usually set an anchor alarm, and have never detected dragging with the bent shank. Where we have cruised in the last twenty years (the Gulf coast) it’s generally mud west of Mississippi Sound and sand from the east.
Except for one time, I have never knowingly fouled anything, and that one time there was no observed bent stock. Yet the stock(s) seem to bend with time, or at least I become more aware of it, at which point the Fortress warranty kicks in and I replace the bent stock.
Here’s what I think happens: As the anchor sets, flukes and stock dig in equally. As wind shifts and tide changes, lateral force is exerted on the anchor assembly, especially the flukes and stock. The extended ends of the stock, which are unsupported, would have the max load. If it is really dug in- I use 70 feet of 3/8” chain with usually about 50 feet of rope, rarely in water over 15 feet- I can imagine a pretty strong force on the stock ends, thus bending over time. While I understand aluminum to have pretty impressive tensile properties, I don’t know about its tendency to deflect -bend- for a given cross-section compared to steel.
I have used Danforth anchors- really the steel critter the Fortress is descended from- off and on since the seventies. I have noticed the only comparable sign of load/strain to be that the ends of the Danforth stock is where the zinc has always failed. Our Danforth- likely an original piece of gear now fifty years old- has an arrow-straight (to my eye) stock
So: is my diagnosis right? Is any other Fortress user experiencing bent stocks?

[Mickeyrouse]

Correction to previous post. In second para. “Crown” is not bent . It is the stock.

[Hartleyg]

I have an FX-37 that I bought back in '96 for our first boat, and I've kept it on our current boat since 2004 as a backup/second anchor. I hit a piling with it back in '97 or so, and it bent the stock. Fortress immediately replaced it (though I kept the old one after straightening it out!). But we don't use it day-to-day, so no bends have appeared in the stock since.


Aluminum isn't as stiff as steel, and has a larger diameter than a steel stock of comparable strength, so I think your supposition of having the stock buried and resisting the force of re-orienting the anchor causing the bend is correct. If you check out the videos on the Board, you can see that the "inside" end of the stock is likely to bury quite deeply into the substrate if the force on the anchor changes direction. With a reasonably stiff substrate, I could see this force adding up to eventually bending the stock, though each occurrence might be only a slight change.


Unless it bends enough to disrupt the action of the flukes and shank, it shouldn't really affect the holding properties (IMHO).


Hartley
S/V Atsa

[Kettlewell]

Old thread revival. I have two FX-23s onboard that have been in use since almost when they first became available back in the early 1990s. They have been on various boats of mine since then, and have been in use in winds up to hurricane force. Nothing has bent on either of them ever. After Hurricane Bob it took the better part of a day to winch them out of the bottom they were so deeply buried. Frankly, I thought I might damage them with the force involved to retrieve, but they seemed fine and have been used many times since. However, they are mainly used in such a way that the direction of pull will remain relatively constant. Occasionally I have rotated around one in light winds, but not in heavy air.

[noelex 77]

Fortress anchors often lose grip during a change of wind direction, but they still bend reasonably easily. Fortress have always been excellent at honouring their warranty.

Fortress changed their marketing and selling model a few years ago, but hopefully their excellent warranty service is unaffected.