Two Anchors In-Line vs In a 'V' Pattern for Storm Anchoring

[Loquat]

Is anchoring with two anchors in-line as opposed to the normal 'v' shape a good idea? I have 180' of 3/8" chain on a 45# cqr. Connected to the cqr would be up 150' of rode with a 45# danforth.

If Irene comes to close to Charleston I will have to leave the dock, anchor out.

Any thoughts?

[AnchorageGuy]

Any time an anchoring question comes up you are going to get lots and lots of opinions. There is little evidence that tandem anchoring is of any benefit and some suggestions that it actually creates more problems than it solves. I can tell you from out past experience with 15 named storms that even the V technique does not always work since you might mis-judge where the wind will come from as the storm approaches and passes. In every anchoring situation in storm force winds and seas that we have been in we have use the Bahamian moor with lots and lots of scope. In several occasions in hurricane force winds we had three anchors out in a Y pattern for want of a better explanation. That worked best for us and we felt the most secure. Good luck. Chuck

[smurphny]

The V method minimizes the swing. The largest loads are encountered when the boat builds up speed and is jerked back the other way from one side of the wind to the other. This can be extreme in 100 knots of wind. Boats can actually get knocked down at this point. I can't see how 2 in-line anchors reduces swing at all. I have never anchored in a hurricane but have anchored safely with a V in a few sustained wind 50+ knot storms.

[svHyLyte]

With "Tandum" anchoring, there is no point to having an extended length between the two anchors. The idea is that they work together. In our case I connect our FX-23 to the crown of our 45# CQR with 20 feet of 3/8" BBB with a wrap of the chain around the curve in the shank of the CQR forward of the pin (Not the cast-in eye!). We pay out enough rhode to give us a 10:1 scope taking into account the likely surge. We then lay out out FX-37 storm anchor at roughly 60º from the primary with 50 feet of 3/8 BBB and 3/4" brait payed out to give us similar scope.

FWIW...

[Loquat]

Ok, yes this is tandem anchoring. So- does the rode of the foreward anchor attach to the 'hole at the back of the cqr plow' or to the end of the cqr shank? I am assuming the end of the shank. I will work on a drawing to just to get some feedback...

[svHyLyte]

Originally Posted by Loquat

Ok, yes this is tandem anchoring. So- does the rode of the foreward anchor attach to the 'hole at the back of the cqr plow' or to the end of the cqr shank? I am assuming the end of the shank. I will work on a drawing to just to get some feedback...

As I noted earlier, above, I pass the chain around the curve in the shank above the flukes and forward of the pin of the CQR. The forward "eye" isn't strong enough to take the strain and, if one passes the rhode to the forward anchor over the flukes of the aft anchor, to the back of the aft anchor shank, there is too much opportunity for the forward rhode to foul the aft anchor's flukes and prevent embedment.

Think about how the yacht will swing as the storm passes and lay out your second anchor accordingly. It may be wise to use a kellet to ensure that the rope rhode to the second anchor (in my case) hangs below the keel and rudder to ensure, to the extent possible, that these do not foul the rhode as the yacht swings.

FWIW...

[capngeo]

Originally Posted by Waterwayguy

In several occasions in hurricane force winds we had three anchors out in a Y pattern for want of a better explanation. That worked best for us and we felt the most secure. Good luck. Chuck

What he said! The ONLY method I would ever use would be anchors set at 120°, with a kellet set at the junction.

[Benebobby]

What a Kelley ? And while your at it what does popcorn mean ?

[Benebobby]

I mean' t Kellet ?

[capngeo]

Originally Posted by Benebobby

What a Kelley ? And while your at it what does popcorn mean ?

Ha! the popcorn smiley is just someone saying they are going to sit back and enjoy the show.....

A Kellet is a weight connected to an anchor rode to add catenary or curve to keep the angle of force on an anchor closer to that of the seabed. There has been a lot of discussion as to the actual merit of a kellet, but in a hurricane mooring with 3 anchors it is the key factor in success.

[svcambria]

Discussion and photo from S/V Third Day and others on the SSCA net about tandem anchors:

SSCA Discussion Board • View topic - Estuary Anchoring
SSCA Discussion Board • View topic - Tandem Anchoring

Fundamentally: use two crowned (in line), make a mess...

Michael

[unbusted67]

I don't really understand the Bahamian mooring technique in a hurricane. Doesn't the direction of the wind shift 180 degrees as the eye passes over? doesn't that not allow your boat to swing with that wind shift? Am I missing something?

[david samuelson]

I am a firm believer in 2 inline anchors. I have seen too many problems with V setup. Also, because my boat sails at anchor, I hang a tyre off the bow. Our boat sails one way then Tacks as it cannot get any further up wind and we get laid down on the other tack with gunwales in the water. I speak from experience. But all boats behave differently at anchor. Beware of chafe where rode goes through fairlead or over roller.

Good luck.

[capngeo]

Originally Posted by unbusted67

I don't really understand the Bahamian mooring technique in a hurricane. Doesn't the direction of the wind shift 180 degrees as the eye passes over? doesn't that not allow your boat to swing with that wind shift? Am I missing something?

Nope, you are not! The ONLY advantage is that you reduce your swing circle HOWEVER (IMHO) that advantage is negated as soon as you are 90° to the “line” and tear both anchors free! A Bahamian mooring is only effective if the loading is parallel to the set of the anchors as in a tidal situation.

[svcattales]

Originally Posted by Loquat

Is anchoring with two anchors in-line as opposed to the normal 'v' shape a good idea? I have 180' of 3/8" chain on a 45# cqr. Connected to the cqr would be up 150' of rode with a 45# danforth.

If Irene comes to close to Charleston I will have to leave the dock, anchor out.

Any thoughts?

We have weathered several hurricanes/tropical storms in Florida and we rode out hurricane Isabel in the Chesapeake. Here are the basic principles we use in our preps:

- Since you must start your preps long before the storm arrives you don't know which direction the wind will come from and it may come from all different directions. (Don't bet on the track or intensity of the storm... things change fast.)

- Look for a hurricane hole that gives you wind & sea protection from as many directions as possible, but leaves enough swinging room to swing 360 degrees. Hills all around is the best situation. Think about how much protection you will have if the storm surge puts you 15ft higher. (Another alternative is a very narrow creek without swinging room. In this case I would use a bow anchor, a stern anchor, and I would spider web lines to trees or mangroves to keep the boat in the middle of the creek. In this situation the boat will not swing at all so you need very good protection on both beams.)

- Decide which direction is the most exposed to wind and seas. Set your best anchor and your bow in that direction.

- Set two or three more anchors at 120 degrees or 90 degrees. (We used 4 anchors for Isabel set 90 degrees apart.)

- Secure all your anchor lines at the bow with enough slack so your boat can rotate 360 degrees without fouling on the keel. Put kellets on each rode so as the strain transfers from one anchor to the next, the kellet will hold the "lazy rodes" below the keel and not foul.

During Isabel, our boat made a 360 rotation without any fouling and we had no damage during that 100yr storm.