Anchoring: What am I doing wrong?

[Surrymark]

You have perfectly good chain and rode (though you don't need stainless). More chain wouldn't hurt, but you have a boat length, which should be fine. You allow more than enough scope (the "momentum argument may have some merit, but I've never heard that you can have too much scope, if you have room to swing.) You really blast the backing down, but so what? So what's left? Your Danforth-type doesn't reset? That's news? Your new Rocna works swell under the same conditions?

[Dkdoyle]

Originally Posted by callmecrazy

Actually you do have a second option, you can use another danforth (or any style) anchor in a bahamian moor.

Keep in mind that 10-1 scope, you're boat has to travel twice that distance in a 180 degree wind/current shift. So if you have 100' rode out, the wind/tide shifts, you're rode goes slack, the boat travels over top of it, 200 feet later all 8500lbs of momentum suddenly pulls backwards (or sideways) on the anchor.

The further the boat has to travel, even in a .5knt current, the more momentum it builds and the higher the shock load on the anchor when it reaches the other end. So 10-1 scope is not always ideal unless you're experiencing strong winds and in a mostly predictable direction. With a bahamian moor, you're boat never travels much more than a single boat length. You're always being held properly by one or the other anchor, or sometimes by both anchors at an angle. but there is far less shock load on the anchors, and they are always pulling from the correct direction, negating the shortcomings, and making full use of the superior holding power of the danforth style anchor.

BTW: I didn't just make this up, you can read more about it here.

or you can just buy a bigger/better anchor and a bunch of chain

I read this with interest. I had thought of using the technique of using two anchors for changing tides but that I could tie one to the stern and one to the bow. Any issues with this? It would seems to eliminate wrapping around the rode with my fin keel.

[SailFastTri]

Originally Posted by MarkJ

Its nothing to do with your anchor.

Its your woefully inadequite amount of chain.

I have 330 feet (100 meters) and you have 30 feet (10 meters)

.

With 330 feet of chain who needs an anchor???

[Pete R]

Originally Posted by Dkdoyle

I read this with interest. I had thought of using the technique of using two anchors for changing tides but that I could tie one to the stern and one to the bow. Any issues with this? It would seems to eliminate wrapping around the rode with my fin keel.

I use a kellet to keep the rodes under my keel. I tie them both to the bow, or the boat won't point into the wind. I don't use a swivel, just unwind the lines occasionally, but lots of people do use one.

I've also found that a cheap, heavy Danforth digs better than a fancy, light one.

[skipmac]

Originally Posted by Dkdoyle

I read this with interest. I had thought of using the technique of using two anchors for changing tides but that I could tie one to the stern and one to the bow. Any issues with this? It would seems to eliminate wrapping around the rode with my fin keel.

Better to keep both anchors to the bow. The way to avoid fouling on the keel is to keep enough slack in the second anchor so the rode hangs under the keel. When the tide or wind reverses the keel swings over the slack rode then falls back on the second rode now putting the slack in the first.

You will probably have to untangle the rodes on the bow if you stay several days in the same spot.

[Ziggy]

Originally Posted by Shrew

Boat: 28 ft. Power (Express Cruiser)

Weight: 8,500 lbs

Current Ground Tackle: Fortress Fx-11 (Danforth Style), with 30 ft. of ss 5/16th chain, 200ft. of 5/8 inch braided line.

Bottom Conditions: Mix of sand, crushed shells and some clay.

Anchoring Method: ease down anchor until it reaches the bottom. Back up and simultaneously pay out line. Once I reach between 10:1/12:1 I cleat off the line, then reverse and hold it for 30 seconds. Then increase rpm's to 1,000 -1,100 and hold for another 30 seconds.

1) Fortress FX-11 is way too small for a 8,500lbs 28 foot power cruiser. I would think Fortress FX-23 would be minimum, and FX-37 a lot better.

2) In addition, a lightweight aluminum anchor like Fortress will have trouble penetrating a relatively hard clay bottom, so it mayl not reset well.

3) The length of chain and rode you have is adequate.

4) Unless the stainless chain is high tensile (G4 or better), 5/16" may not be strong enough

5) Unless you anchor in an open roadstead, I would think you might have trouble finding enough swinging room for 12:1 scope. Furthermore, most other boats probably release ~6:1 scope, so you might get uncomfortably close to your neighbours.

[MarkJ]

Originally Posted by SailFastTri

With 330 feet of chain who needs an anchor???

Thats exactly the point.

And I am, to put it mildly, surprised many of you have said his 30 feet of chain, 10 meters is adequate.

I beggars belief that anyone could think that short amount of chain is adequate.



I need my early moring coffee


Mark

[MarkJ]

And.... length of chain can have nothing to do with the length of the friggin boat.

Where's the science in that?


Back to the coffee.


Nescafe Classic. Instant. With gritty bits in the bottom. What gives?



Mark

[Ziggy]

Originally Posted by MarkJ

Thats exactly the point.

And I am, to put it mildly, surprised many of you have said his 30 feet of chain, 10 meters is adequate.

I beggars belief that anyone could think that short amount of chain is adequate.



I need my early moring coffee


Mark

There are a few reasons for chain:
1) Protect the rode from chafing on the bottom. To accomplish this you need a relatively short length, which depends on the depth of the water more than anything else.
2) Put enough weight close to the shank of the anchor to maintain a small angle with the bottom. However this weight become completely ineffective in strong wind or surge as the rode is tensioned to bar tight and the chain is lifted off the bottom. In general, if you or the windlass can handle, say, 100 lbs of ground tackle, the optimum weight allocation would be to put it all into the anchor. So this is not really a good reason.
3) Compatibility with a windlass or capstan. This is why many like an all chain rode

[captainKJ]

1) Fortress FX-11 is way too small for a 8,500lbs 28 foot power cruiser. I would think Fortress FX-23 would be minimum, and FX-37 a lot better.

I agree,,,I had a 27 foot light sailing catamaran with a FX-37 on it,,,never dragged once,,,,,,,was in 50plus knots of wind and did a couple of 360,,,,that and a 100 feet of chain helped out,,,,,oversize your anchor for a good nights sleep,,,,get some more chain,,,,,,,nothing wrong with more weight down below,,,,people thought I was nuts to have such a big anchor but after dragging a couple of times with a smaller anchor the extra time it took to raise and set was worth it, never dragged after that and slept good,,,those anchor charts are usually worthless IMO,,,go oversized and more chain 3-5 scope for a lunch hook, 5-7 scope for overnight and 7-10 plus for storms

http://www.fortressanchors.com/fortr...hor_guide.html

NOTE: Hard sand holding power figures above represent loads actually achieved on production FORTRESS and Guardian anchors under controlled horizontal pull conditions without dragging or resulting in disabling structural deformation.

[Pete7]

Originally Posted by MarkJ

Back to the coffee. Nescafe Classic. Instant. With gritty bits in the bottom. What gives? Mark

Mark, length is important as you say, I suggest you leave the coffee to disolve longer or buy a more modern coffee rather than one of those old classic types.

Back to the anchors.

Originally Posted by callmecrazy

Actually you do have a second option, you can use another danforth (or any style) anchor in a bahamian moor.

Idea has merit but we have twin keels so maybe not for us, it could fowl up very quickly on a change of tide.

Pete

[motion30]

Originally Posted by Pete7

Mark, length is important as you say, I suggest you leave the coffee to disolve longer or buy a more modern coffee rather than one of those old classic types.

Back to the anchors.


Pete

Now that you mention it my girlfriend said something along those lines the other day

[zeehag]

ok the anchor is too light and the chain is tooo short .....please find a used danforth or something and get a bunch more chain and keep th ss chain for decoration in your home. you will do fine. make sure you have 100 ft chain--5/16 is good, and make sure your anchor is 30 pounds or thereabouts..35 pounds wouldnt hurt. i bet then you wont have any trouble at night sleeping--- promise, actually......i would go with 3/4 inch 3 strand rode, and 400 ft of it-- but that is another thread......lol....with firehose for antichafe.
and,mark-- do let the coffee dissolve longer or grind beans for drip in a cone filter--is not as instant tasting.....but just about as fast to make...UNLESS ye like the bits in bottom for a caffeine rush......

[downunder]

Originally Posted by MarkJ

And.... length of chain can have nothing to do with the length of the friggin boat.

Where's the science in that?


Back to the coffee.


Nescafe Classic. Instant. With gritty bits in the bottom. What gives?



Mark

Mark,

You need to head further south and find some real coffee. Suprised you are still drinking instant after time in the med.

Totally agree with you on the chain.

[S/V Alchemy]

I have a 33 foot sailboat weighing 9,000 lbs. and a new FX-23 Fortress. I think your anchor is undersized for your application.

I have 1/2 inch three-strand and am going to 5/8". I have about 10 metres of chain.

While I haven't experimented enough with my 15 lb. Fortress, I could not veer it out in reverse power without threating to part the rode or damage the deck gear. This was at 7:1 scope in about 16 feet of water with a sandy bottom. On the other hand, when right over the anchor, I was able to break it out by arm strength only, and not much of that.

Interestly, I set the anchor at much shorter scope: 4 or 5 to 1, and back down away from the prevailing wind and set slowly. Only then did I pay out the full scope.

So you definitely need a bigger anchor on general principles, and a different approach in wind reversal scenarios. The Fortresses work on the principle of fluke area and being almost sharp. Think "door jamb wedge"...they don't weigh much, either, but can keep a door wedged shut to the point of destruction.

It makes sense that the Fortress is going to tend to bust out if the chain acts as a lever on the shank, so the Bahamian moor (a second Fortress as a stern anchor) or the hammerlock technique of two anchors "Veed" out from the bow would tend to make sense. You still ride to one anchor, but you have two buried and the boat will veer to take up Anchor Number 2 if the wind or current goes 180 degrees around.

Because even an oversized Fortress is very easy to handle and retrieve (making it safer in my view to use on deck in the sense that I know what type I would prefer to fall on my toes, and it ain't a Bruce), they are a good choice, but you have to think about how to best use them. I think a couple of FX-23s used together will do the trick, and while expensive, is likely a easier fix than a 33 lb. Bruce/CQR/Manson style, as stowage and bow area to work with the anchor can be an issue on power boats.

Fortress has a "Safe Anchoring Guide" you may find helpful here:

Fortress Anchors - Safe Anchoring Guide

It shows exactly what I'm talking about. In addition, this graphic here



suggests how to use a couple of them.

For me, the FX-11 is simply too small for a boat with windage. Under 15 knots, I'd keep it as a lunch hook, meaning chuck it over the side and walk the rode to a forward cleat, cleat off, back down to 5:1 or 6:1 and eat a sandwich/repeat as necessary. But generally, even when weight is NOT the foundational design factor, I prefer to go one size up, particularly when that bigger size is STILL only 40% of my old primary's weight (a 33 lb. CQR/33 lb. Bruce).

If you are in dodgy conditions or you know you are going to get them, experiment with a CQR as the primary and the upsized Fortress as the secondary, particularly if you are expected that secondary to take a straight-line pull with a strong wind shift, as can happen on the backside of squall lines.