Fortress anchor no chain? Just rope rode?

[Don C L]

Originally Posted by Cheechako

I think the chain is necessary when first anchoring. As said, once it's deep in the bottom doesn't matter much.
A Fortress saved my 47 ft boat in 70 mph winds by simply throwing it overboard with 20ft of chain and rope rode.

The main anchor didn't fail, the bottom failed.

See what I mean?

[Cheechako]

Originally Posted by Don C L

See what I mean?

Further explanation:
As I said "The main anchor didn't fail, the bottom failed."
What I mean is precisely that.

A couple hours after the storm cell passed, after the Fortress stopped us just yards from the beach with the depth sounder reading the same as our boat draft, things got calm. The engine probably helped prior to deploying the Fortress as it was at max rpm but the boat was still moving, stern first, toward the beach.

When we pulled the main anchor, which was still out with 150-200 feet of chain rode in 15 ft of water, It came up with the bottom still attached to it!
You could not see the anchor other than maybe 16" of shank. It was completely encompassed in bottom clay like material, like an 18-24" ball of goo.

[Don C L]

Danforth HT or Fortress, don't leave home without 'em!

[Kettlewell]

It's a bit curious to me how these threads often talk of turning to a Fortress or Danforth when a "secondary" anchor is needed, and then that anchor holds in a raging gale when the primary is in doubt

Well for example, we were anchored in the San Blas Islands in a small hole with coral reefs all around. We dropped our primary in the middle in about 35 feet, but there was only enough room for about 3.5:1 scope without our rudder hitting coral. Knowing that this area was prone to sudden "Chocosana" winds from the mountains, we also put a Fortress out as far as possible in that direction with maybe 5:1 scope. Yep, just at dusk the wind switched 180 degrees in an instant--so fast our boat sailed downwind then snapped around facing into the new wind with coral close by and now the Fortress being our main anchor out to windward. Everyone else was dragging fast as the wind built to a measured 56 knots, and the holding was not the best but we hung in there through the next few hours with one boat just motoring in circles around our anchor light to stay off the coral. One boat was on the reef and suffered pretty heavy damage. Another outside the reefs dragged probably half a mile until they held with their engine. Secondary anchor.

[Patrick of M]

Great bunch of information, thank you, everybody.

[Fore and Aft]

We use our Fortress stern anchor all the time with just 12mm yacht braid rope. It's a fantastic anchor in the sand. I often dive on it to retrieve it and usually require two feet on the seabed to pull it out. Light and easy for my kids to handle in their kayak when setting.
Cheers

[Kettlewell]

Secondary anchors? Here's an article I wrote on the subject: https://www.jjkettlewell.com/2015/03...wo-anchor.html

[conchaway]

As long as you never anchor off where there are coral rocks and such, you might be ok.

[Jubilee39]

I have both a Fortress FX37 and danforth 55H. I've experinced many Caribbean hurricanes and typhoons worldwide over the last 30 years. The only time I deployed a Fortress successfully was to kedge off a grounding in soft mud with a long scope and no chain. The danforth has held and taken many hours to retrieve after a blow. The Fortress would come up easily if it hald at all. Granted I always had a significant length of chain on the Fortress so reading the comments that may have been the cause.

[Teremoana]

I think a bit of chain is a good idea on this type of anchor for two reasons. First, the weight of the chain makes the pull on the anchor closer to parallel to the bottom. It's similar to having a long enough scope. Second, the part of your rode that's at the anchor is most exposed to chafe on the bottom. Chain doesn't chafe much.

[letoile]

Originally Posted by Don C L

Hmmm, I'd like to see that in action. I would think that even if the chain did sink into the mud and pull the shank down, as soon as the chain is pulled, the crown should still be the element that is working to cause the flukes to begin to bury. Eventually the flukes will dive below the shank if they get a bite on something.

As far as all rope, I'd say as long as you don't start pulling till you have a decent scope out, it should set fine. It's just that you have lost one major benefit of chain which is chafe protection.

Don CL , I have seen it many times until I figured out how to set the Fortress in weedy or soft mud bottoms. I dive my anchor regularly and was shocked the first time I saw the flukes virtually on top of the mud and the shank buried to its full range of motion. It seems to happen more when anchoring in deeper water. If you watch a fortress play out when dropping anchor it will literally fly/glide backwards in the water. If the water is shallow or you only have a short section of chain or all rope rode it will pay out/fly backwards until the anchor hits the bottom first and will set beautifully. In deeper water with more chain, 5m plus, the fortress will initially start to fly backwards until the weight of the chain stops the backwards anchor glide and drags it straight to the bottom( even as you are backing up slowly)with the shank chain connection hitting the bottom first. Combine this with a 5:1 to 7:1 scope, the shank speared into the mud and the small angle fails to lift the shank before it digs in and the flukes plain across the top of the mud.

Our procedure in soft mud is to lower the fortress slowly and as vertical as possible by the anchor chain with only slight backwards boat motion, this allows the crown to hit bottom first then the flukes with the shank slightly elevated off the bottom or only a very short section of the anchor chain contacting the bottom( 2:1 scope). Its all by feel in deeper water ,but you can feel the flukes bite/grab and start to dig in as you start to back down. Once the fluke angle is set downward you can pay out your desired full scope and back down to secure. Initially not being confident that the flukes had grabbed I would dive the anchor and was pleased to confirm the anchor was set properly. Sounds complicated but not that bad once you get the feel for it . Love our Fortress anchor for its light weight and holding ability even though it takes a bit of finesse with longer anchor chain in mud.

[Don C L]

Originally Posted by letoile

Don CL , I have seen it many times until I figured out how to set the Fortress in weedy or soft mud bottoms. I dive my anchor regularly and was shocked the first time I saw the flukes virtually on top of the mud and the shank buried to its full range of motion.

Interesting, I'd like to se that. I actually have never tried a Fortress, but since it is a Danforth style, I would think it would be good. I have often wondered if the lightness of the flukes was really a good thing, since they have less inclination to dive than a Danforth's heavier flukes. The Danforth will also fly to the bottom, and it is kinda nice to watch it fly out ahead of the bow so I know the chain will not be landing on top of it. When it comes to holding a boat still, I am a fan of Danforth HTs. And I know you can't take them apart but really, are they THAT much heavier than Fortress? I mean a Danforth 35H could probably hold a battleship.

[noelex 77]

The Fortress anchor does work with an all rope rode and this can be useful. Without any chain the total ground tackle weight is very low. The anchor can even be swum out, especially if a small fender is used.

Like most anchors, all rope rode reduces the anchor’s ability to initially penetrate less than ideal substrates. This reduces the anchor’s versatility and while the Fortress anchor has outstanding holding in soft substrates it does struggle in harder bottom types even when using all chain.

The other factor to consider when using rope rode is the reduction in chafe protection.

[rslifkin]

Originally Posted by Don C L

Interesting, I'd like to se that. I actually have never tried a Fortress, but since it is a Danforth style, I would think it would be good. I have often wondered if the lightness of the flukes was really a good thing, since they have less inclination to dive than a Danforth's heavier flukes. The Danforth will also fly to the bottom, and it is kinda nice to watch it fly out ahead of the bow so I know the chain will not be landing on top of it. When it comes to holding a boat still, I am a fan of Danforth HTs. And I know you can't take them apart but really, are they THAT much heavier than Fortress? I mean a Danforth 35H could probably hold a battleship.

Aside from the lighter weight for a given size, one of the big things about the Fortress is that you can disassemble it. So if it's a rarely used but large anchor, you can stow it in pieces so save space.

[Don C L]

Originally Posted by rslifkin

Aside from the lighter weight for a given size, one of the big things about the Fortress is that you can disassemble it. So if it's a rarely used but large anchor, you can stow it in pieces so save space.

True, though the smart-aleck in me says, as the hurricane approaches, "Anyone seen where I put the nuts for this? Oh man, they fell down the cockpit drain!"