Deploying Two Anchors


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Bill Balme
Bill Balme
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Forgive the inexperience, but to date in my short sailing career, I 've never set two anchors at once. I 've been fortunate that I have not needed to - but recently heard of an approach that seems considerably easier than any other two anchor deployment methods that I have previously heard of...

1. Deploy main anchor and set.
2. Motor ahead of the first anchor and deploy the second anchor and set it.
3. Release tension on the second anchor rode and fall back to lie on the first anchor again. Leave "some" slack in the second anchor rode.

As I understand it, the first anchor holds the boat, but if she should begin to break out, the boat will fall back to lie on the second anchor, with greater scope.
If the second anchor fails, in doing so, there is a good chance that the first anchor would be able to re-set - since it would have ceased dragging while the second anchor took up the load.

Wind change through 90 degrees would tend to convert this anchoring system into a more normal; one to starboard one to port type arrangement I guess - and when it goes through 180 degrees, I imagine the first anchor would be allowed to drag a long way before the second anchor took up the load...

So question to you all - have I got this all wrong? I plan to try it out sometime this season - so maybe you can tell me where I 've got it wrong in advance of making an idiot of myself! Thinking I 'd do it with short scope to try to encourage movement - thoughts?

Bill Balme
s/v Toodle-oo!

Daria Blackwell
Daria Blackwell
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Hi Bill,
I am so sorry to have missed your posting. As I read your post, it appeared that you were thinking about deploying the two anchors on two rodes rather than in tandem on a single rode. The problem with the technique you describe is that you run the risk of the two rodes becoming entangled and then you could have a real mess on your hands just when you least want it. Typically in setting two anchor with two rodes you would use the same method but set in a V-configuration by driving to one side to separate the two rodes. Of course if the wind shifts, that could be negated and you could end up with the two anchors in line.

Perhaps a better way to deploy two anchors is in tandem connected by a chain from the shank of one to the crown of the other. You need a retrieval line between the two as well. You drop the first anchor, then fall back to drop the second anchor, then set both together in a line. What that does is effectively gives you a 100:1 scope between the two anchors. US Navy tests have shown that it increases the holding power of your system by 30% over deploying two anchors separately. The limitation is that both are connected to a single point of deck hardware. We cover this in detail in our book (Happy Hooking: The Art of Anchoring -- reviewed in Flying Fish 2011/2)and webinars for SSCA by the same title. We are in process of writing a short article on the subject for our website (www.coastalboating.net) which I will post here when it 's ready.

Did you try your method in the past few months? Mind sharing the results?

Vice Commodore, OCC 
Bill Balme
Bill Balme
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Hi Daria,

I did not try the two anchor method last year - actually completely forgot the project... However in re-reading my post, I remain intrigued by the prospect (can 't remember where I read about it). It seems to me to have a great advantage over the tandem anchoring you describe, since you can actively set each anchor on their respective scopes - whereas the tandem approach could leave you with one anchor upside down or at least not set. I think we 'd all agree that when things start dragging is not the time to hope an anchor is going to set...

I take your point regarding possible tangles - but I suppose it 's no worse than people that deploy two anchors at 45 degrees... ?

Hoping to be in your neck of the woods next year - heading to the Azores for a while and then planning to cruise the west coast of Ireland in August/September... (I 'm thinking it 'll likely be wet!)

Cheers!

Bill Balme
s/v Toodle-oo!

Daria Blackwell
Daria Blackwell
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Hi Bill,

We have used the V configuration successfully many times. Still the tandem technique has great merit in a difficult bottom substrate. Of course, you have to have an anchor that has a suitable attachment point in its crown, like a Rocna.

We have now posted an excerpt from our book on the subject here http://goo.gl/s497I.

If you do come our way, please let us know and come to visit us in Clew Bay. We are planning to head up to Scotland in the Spring but should be home in Aug./Sept. Yes, those months tend to be quite wet. Although this year,we had considerably less rain in the West than in the East and South. Perhaps a trend?

Vice Commodore, OCC 
dcaukill
dcaukill
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Daria. Four random observations.

1. You say don 't use a plough as your primary because if it slips your secondary will find poor holding. Ploughs for this purpose must include Rocna, Spade etc? What anchor combination do you use?

2. Isn 't the poor holding psoint true whatever type you use? A Danforth as a primary makes much the same mess of the bottom ( unless it pulls out entirely)

3. Whenever I have set a Bahamanian Moor, I have ended up with a right tangle. It would be useful to be able to work out how many times one has spun through 360 degrees BEFORE you try to recover it. Any tips?

4. In the rolly anchorage situation, with swell and wind in different directions, I usually prefer to set a bridle to bring the head down into the swell. Attach a warp to the anchor rode, (rolling hitch) and lead it to a stern cleat. It takes a few minutes to set up but it is easier to retrieve than a second anchor. Any thoughts?
Daria Blackwell
Daria Blackwell
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Hi David,
First, it is important to note that the Rocna, Spade, Manson Supreme, and Ultra are all scoop anchors not plough anchors. The scoop type anchors are concave. They are meant to dig as one would with a spade or shovel and they do. They just go deeper and deeper as the load increases. The ploughs include CQR, Delta, Kobra 2 and Brake. They are convex like plough shares. Ploughs are meant to plow. B)

We have aboard and use the Ultra as our primary and the Rocna as our storm anchor. We also have the Spade but find that it needs more scope than the other two. (After all, we write about anchors and anchoring so we have lots of them.) We have left our CQR and Luke behind as lawn ornaments. We have a lightweight aluminium Fortress for deploying from our dinghy especially in soft bottoms (it won 't sink the dinghy). We use a smaller Delta for kedging, stern deployment or as the second anchor when we want to point into the waves and it 's a hard bottom.

2. The more recent "scientific" tests of anchor performance shows that the scoops have far superior performance in most substrates, including those often considered to offer poor holding. Our personal experience bears this out. On the other hand ploughs typically work better than flukes in hard bottoms and Danforth-type anchors (flukes) work better in soft bottoms, so unless you know what the bottom composition is and deploy the right anchor, you are likely to experience poor holding.

3. One way to avoid the tangle is to connect the two rodes and drop the connection point with a kellet or weight down to the bottom on a single riser. Of course, then you only have one rode to depend on. As to tips once you have the tangle, we 've used the dinghy to spin the boat around until the rodes separate. It can be a bit dizzying! :silly:

4. We used to deploy a bridle that way on our sloop and it worked great. For some reason, our ketch doesn 't like that set up, so whatever works for you and your boat is what you should use.

I hope that helps. Happy Hooking!

Vice Commodore, OCC 
dcaukill
dcaukill
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Plough or scoop (or Danforth), whatever you set as your primary, if it is dug in and then drags (as opposed to pulls out) isn 't it going to make much the same mess of the bottom and ruin the holding for the secondary? I can 't imagine that furrow will be any less disturbed by a scoop than a plough so I still don 't see the advantage of deploying in tandem. You are relying on the holding of the primary - once that slips.....

As regards Bahamanian mooring, yes, i am used to putting a weight down to keep clear of the keel - but I have always used a separate rode for each anchor. I imagine it might be hard to recover such a rig on a single rode ..... but frankly no harder than untangling the cat 's cradle that follows a lively night in a narrow anchorage in variable conditions. I will try it.
Daria Blackwell
Daria Blackwell
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The issue is that scoops rarely drag (if ever when properly set) whereas ploughs (esp. CQR) drag fairly often.

That 's why we set two scoops if we need to, but with our oversized Rocna we rarely need to.

Vice Commodore, OCC 
wmccandless
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Two anchors are a waste of energy and can be a big problem if trying to up anchor in a crowded anchorage in a blow. Take the weight of two anchors and convert to one big anchor and a heavy chain rode. Sleep well at anchor and stop fiddling around. On our Najad 490 we had a 50 kilo bruce and 10 mm chain and never dragged once in 10 years. Cheers
BillonAdvent2
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I totally agree with wmccandless. Combine the weight of the two anchors and use it all the time. It served us well for 10 years. We use a 50kg Bruce on a 36ft boat. Then last summer we were hit with (ofically reported) 60 kts and dragged. 6:1 scope. About a mile later the storm subsided. At first I thought the anchor was hooked into something, but when I got it up it carried a huge ball of bottom. All I had was a 100kg dead weight of anchor and bottom mud. I couldn 't even see the anchor. It took many minutes of poking at it with an oar to break the ball of bottom from the anchor. Instead of digging into the bottom, the anchor "grabbed" a chunk of the bottom and pulled it out.
I still use the big Bruce, but I think a tandem burying anchor would have prevented my dragging. I think I would want the burying anchor the farthest from the boat, with a infinite scope.
Bill Doar
s/v Advent II
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