By bbalme - 15 May 2012
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?
|
By DariaBlackwell - 12 Dec 2012
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?
|
By bbalme - 12 Dec 2012
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!
|
By DariaBlackwell - 13 Dec 2012
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?
|
By dcaukill - 21 Dec 2012
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?
|
By DariaBlackwell - 23 Dec 2012
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!
|
By dcaukill - 23 Dec 2012
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.
|
By DariaBlackwell - 23 Dec 2012
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.
|
By wmccandless - 11 Jan 2013
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
|
By BillonAdvent2 - 9 Feb 2013
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
|
By DariaBlackwell - 9 Feb 2013
Hi Bill,
I am not surprised by the situation you describe. The Bruce has the highest percentage set on first try of any anchor (all the new ones included). It also has the lowest drag value (meaning lowest holding power),particularly if it catches a rock or gets blocked with hard substrate as you describe. Many people recommend overspec-ing the size of a Bruce for that reason. Steve Dashew was one such proponent, until he switched all his boats to Rocnas. The new generation scoop-type anchors (Rocna, Manson Supreme, Spade, Ultra) dig very deep and are far less prone to pulling out. They are engineered to allow the substrate to pass over them rather than catch and pull.
|
By sveasygo - 12 Feb 2013
On Easy Go we have set Bahamian Moorings, two chain anchorage moorings, two chain v moorings and my favourite a Moitessier Mooring. The Moitessier mooring is simple to set and retrieve, does not allow the chains to get tangled on each other and has incredible holding power. We have successfully sat out a couple of Cat 1 hurricanes with this mooring. We were once blown ashore after setting a v two chain mooring.
We set the Moitessier mooring by putting down our main bower which is either a Bruce or Fisherman 's Anchor. We set this well giving it the entire scope required for the depth. If we have anchored in less than 25 feet we will then retrieve the chain until we have about 60 feet remaining in the water. We attach a second anchor, out little bruce usally, to 30 feet of chain and attach this chain to the main chain rode with a shackle and swivel. We set this anchor down carefully and again let out all the chain we need for the anchorage we are in. This places the anchors about 30 feet apart. We have only one chain over the bow roller, no tangles and if the wind gets up we can let out more rode and even put a float on the rode to act as a hydraulic damper/snubber. We have swung around on this system without dislodging the anchors and have never had a foul up even in kelp.
We have yet to drag anchor with this method and Easy Go has been known to sit to this anchor system for four months.
To retrieve we bring in the chain until we get to the connection of the two chains then bring in the 30 feet and small bruce, while staying connected to the bottom, put this all away then finish getting our bower up and stowed.
|
By dcaukill - 13 Feb 2013
To be clear, the smaller Bruce is set in line with the main bower?
|
By DariaBlackwell - 13 Feb 2013
Easy go, great idea. Much like a tandem anchor setup but better because it doesn 't attach to the crown. Still achieves 100:1 scope between the two anchors, doesn 't it? I 'll have to re-read Moitessier 's books. I have to say though that I 'd rather use two scoop anchors rather than a Bruce or a fisherman or a plough.
|
By sveasygo - 13 Feb 2013
I 'm a better sailor than an artist. I hope the sketch I have drawn explains the anchoring method. Unfortunately the image is not loading to this message. If you would like the image email me and I 'll send it along.
Use whatever anchors your comfortable with and are appropriate for the circumstances.
Easy Go has a junk rigged schooner sail plan and tends to wander around quite a bit in strong winds in an anchorage. I have found that the Moistessier set dampens that somewhat. I 'll often put a second small anchor over the bow roller on its own chain to the depth of the water plus another fifteen feet. This drags around the bottom and stops the boat from wandering as much. If the wind shifts it is easy to raise and allow the boat to swing.
|
By simoncurrin - 13 Feb 2013
If send me the diagram by email I will work out how to save it on the Forum.
Simon
Simon@medex.org.uk
|
By simoncurrin - 15 Feb 2013
Great the pictures are back on! Below is the Moistessier method
[attachment=63]image.jpg[/attachment]
|
By Dick - 9 Aug 2015
Hi Daria,
Has anyone else documented your observation that a Spade needs more scope than a Rocna to set? I pay a good deal of attention to ground tackle and anchoring techniques and this is a new observation to me.
I am uncomfortable with casual asides of a critical nature from those whose advice will likely be heard and followed without an attempt at balance. Many casual readers will read your statement:
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.)
As an endorsement of Spade over Rocna. You may mean that to be the message, but there are some concerns over Rocna’s design (and occasional problems in action) that leads many thoughtful sailors/experts to endorse a Spade over a Rocna.
That said, I believe both to be superb anchors, far more effective than older generation anchors.
My best, Dick Stevenson, s/v Alchemy
|
By Dick - 9 Aug 2015
Hey all,
Some thoughts on deploying 2 anchors:
One consideration that leads me to suggest that one should lean towards seldom deploying 2 anchors is the occasional need to up anchor and move in the middle of the night under adverse conditions. I attempt to anchor any time we overnight ready for gale conditions with only one anchor and I always know a bearing for departure from the anchorage. In 3 -10 minutes (depending on scope) I can be free and gone (faster if I do it by hand which I had to do a back wrenching time on the Thames River 2 years ago). With 2 anchors, quick departures becomes far more difficult.
Handling 2 anchors in adverse conditions can also be dangerous.
Deploying anchors in a “Y” formation is an invitation for dragging boats to “funnel” into your bow and get pinned there making considerable damage likely and extraction dangerous to people.
Far better to devise your primary anchoring system to be robust enough to rarely call for a second anchor.
My best, Dick Stevenson, s/v Alchemy
|
By DariaBlackwell - 9 Aug 2015
Hi Dick,
In one of the better comparative tests of anchors published in SAIL magazine in October 2006, the effect of scope on holding power was evaluated. That test showed that the holding power of the Spade was excellent at 5:1 but significantly reduced at 3:1 scope. That was not the case for the Rocna, Manson Supreme, Fortress or Wasi(Bugel). Anchor tests always have their own issues but we have found that more scope is better for the Spade in our own experience.
We all know that more scope is better in general and we normally would never use less than 5:1, but sometimes (crowded anchorage, deep water) there is no other choice. I agree that the Spade is an excellent anchor. This finding is just something to be aware of.
[attachment=257]Picture1.jpg[/attachment]
|
By Dick - 9 Aug 2015
Daria, Interesting. I am largely much more of a fan of field reports such as yours than any of the various tests that publications periodically indulge in.
Looking for your reply lead me to see that there are multiple pages for some threads that I was unaware of (computers are not my area of expertise by a long shot) which meant that some of the items I addressed had already been commented on.
My apologies. Dick
|
By bbalme - 10 Aug 2015
It 's interesting re-reading this thread - lots of interesting discussions every time anyone mentions anchors!
I 've ended up in the camp of one big modern anchor for all duties - 80lb Manson Supreme on a 44ft boat.
Dick: When I first purchased Toodle-oo!, she had a Spade of similar size. I can say that my own experience echos Daria 's and the theoretical test above - in that it was much more susceptible to dragging if less scope was used when compared to the Manson.
I ended up selling the Spade in favor of the Manson (which I 'd experienced on my previous boat) though I wish I 'd kept it as a back-up... I 'm now thinking of getting an Aluminum Spade as a back-up that could be deployed if needs be from a dinghy...
|
By Dick - 10 Aug 2015
Dear Bill,
Thanks for the info and you do mirror what Daria was reporting. It is always nice to get actual field reports.
I absolutely support you choosing to put your weight allocation in a big modern anchor. My world has led to more experience with Spade and Rocna. The Manson is presently getting a real world test by an American sailing guru, Ralph Naranjo that is being written up in Practical Sailor, an American magazine that is usually worth spending time with.
You might consider a Fortress over an aluminium Spade as a kedge. It is my take that some anchors are more dependent on weight for effectiveness and some more dependent on design. When going for light weight, such as a kedge, especially where the pull will be in one direction and you need worry less about re-setting characteristics, I see the design of the Fortress as hard to beat for that duty. I am less sure how the Spade, where lead in the tip seems to me very important in the galvanized version, would fair, but I do not have any experience with the aluminium Spade and I have used the Fortress as a kedge a good deal.
My best, Dick Stevenson, s/v Alchemy
|
By DariaBlackwell - 10 Aug 2015
[quote="bbalme" post=2296] I 'm now thinking of getting an Aluminum Spade as a back-up that could be deployed if needs be from a dinghy...[/quote]
Hi Bill, I must concur with Dick on the Fortress aluminium anchor as a best bet as back up. We have one to deploy from the dinghy. It is so light weight for the holding it delivers. It works extremely well in soft bottoms and stows flat which is great. Both the Spade and the Fortress disassemble for stowing, but the Fortress takes up slightly less space and is lighter weight.
Some time ago, the aluminium Spade was having some problems (see this blog) which I understand they have addressed. But it means being cautious with second hand purchases.
Both Sea Tec & Fun and Fortress have excellent reputations for service.
|
By bbalme - 10 Aug 2015
Fortunately, I can concur too! I already have a Fortress back-up! My primary aim for a third anchor is as a replacement should the Manson be lost for some reason - and I think the Spade will more ably fill in for the Manson - especially where kelp might be involved.
The advantage of the Spade is it can be taken apart and Aluminium means it 's not too heavy. The disadvantage is that it 's aluminium and not too heavy!!! I am thinking that the lighter weight of the Aluminium will likely make it more difficult to set - but I also can imagine that once set, it 'll probably hold as well as a conventional Spade.
|
By Dick - 10 Aug 2015
Hi Bill,
I would lean away from any lightweight anchor as a replacement for a bower, especially if you are thinking kelp or weeds, as you state is your intention. Weight and a penetrating tip such as the new generation anchors have is what allows the anchor to wiggle down into the sea bottom. Danforth (Fortress) style anch ors tend to get hung up (in weeds/kelp) and never reach the sea bottom, especially those that are light in weight. A galvanized Spade is ideal for a back-up bower in some ways as it can be taken apart for ease of stowage and can be transported in pieces (assembled on deck) which is a lot kinder to the furniture (and your back) as you get it out of its storage place. In some ways back up anchors are cruising ground dependent. Those of us who have occasion to anchor out in a hurricane may choose to have more robust back-up ground tackle.
My best, Dick Stevenson, s/v Alchemy
|
By pmorley - 22 Aug 2015
I have frequently deployed two anchors as a bahamian moor when anchoring on a strongly tidal river such as the Guadiana or the Tamar - i.e. when strong currents are expected in different directions.
The method I 've used only really applies in shallow water (not the Tamar on springs then!), but has the benefit of being feasible under sail and single-handed.
1. deploy first anchor - the primary if it 's ebbing, or the secondary on the flood - boat lies to tide
2. let out full length of rode (i.e. more than necessary for adequate scope, possibly extending with warp if needed)
3. lower second anchor
4. pull first anchor rode in while paying second anchor rode out to get to desired scope on both
I see this as an advantage over one anchor with a huge amount of chain as
both anchors are at least partially set from the off, and definitely from the first change of tide. Thereafter they never need to re-set, but boat swings between them and the load is taken by the primary anchor on the ebb and the secondary on the flood.
Personally this gives me more peace of mind than the aforementioned big anchor/long chain as in my experience setting the anchor is when any problems are likely to manifest.
It also significantly reduces wandering around at anchor - admittedly this does mean it 's only really practical near other boats using a similar technique!
The chains do tangle but I find this is just a twist at the top which can be cleared easily by freeing the boat end of the rode (having first secured the chain lower down!) and unwinding the top, usually from the dinghy.
For what it 's worth the primary is a 45lb CQR (24ft boat, but pretty heavy) - concievably my approach might change with a Rocna or similar, but I suspect not as I assume they are still vulnerable to a patch of gravel or fouling something that stops them bedding in properly.
Obviously cruising grounds, anchorages, boats and people all differ - hence we end up with interesting conversations!
|
By Dick - 22 Aug 2015
PMorley,
Sounds like a well thought through and effect strategy for what can be a challenging anchoring situation. I know for sure that the River Guadiana has good holding until one finds the spot(s?) where (it seems) a gravel barge dumped its load. I like your 2 anchors for a few reasons, not least as the River Guadiana (maybe most rivers) has a great deal of debris coming down stream and it takes little build up to add tremendously to anchor loads. Two anchors would bring piece of mind in that regard.
There are certainly anchoring challenges which call strongly for 2 anchors. Generally, though, I lean towards one anchor and about 5-1 or so of scope and a good stretchy snubber. If you think you are good to near gale conditions with the above, then you are likely in good shape ground tackle-wise. If you think you would not be good, I would be looking to get either a bigger anchor or a better designed anchor. In your case, you got the weight nailed. but at some point I suspect you will try a Spade or a Rockna (maybe a Manson, but I have no experience there) and be quite surprised by how superior they are to the CQR.
My best, Dick Stevenson, s/v Alchemy
|
By Wild Bird - 23 Dec 2016
We seem to be able to set our 33kg spade on our 44ft, 19t ketch with suprisingly little scope. In 40kts of wind we have had just 4:1 scope and it holds perfectly. We would have let out more chain but the anchorage was crowded.
|
By Dick - 23 Dec 2016
Hi WB,
Always nice to hear field reports.
May 2017 may also bring safe anchoring.
My best, Dick Stevenson, s/v Alchemy
|
By Dick - 23 Dec 2016
Too early in the morning to be typing clearly. D
|
By simoncurrin - 2 Jan 2017
I am trying to post this on the OCC forum chain discussion but it doesn 't work. Would you please post it for me? Thanks
Best wishes,
Charles
s/v Dawnpiper
Hi:
I want to add several comments and suggestions. I also had problems getting my Rocna 88 lb anchor to set unless backing extremely slowly. S/v Dawnpiper is a Trintella 47, 40,000 lbs.
The Rocna also failed to reset when the tide turned, and I dragged. I was so disappointed in the Rocna that I switched to a galvanized Spade 99 lbs. I do not use a swivel as I have seen failures in stainless swivels The chain is stabiled by a roller with a notch in it for the chain so it never seems to come up twisted, or need a swivel. My spare is the Spade aluminum 66 lb, and kedge is the Fortress Fox-37.
I concur with Dick that the Morgan 's Cloud AAC site is excellent: everyone could benefit from the careful discussion there.
The end of my chain is attached by a heavy line to a bulkhead below with the length adjusted to keep and ensure the chain stays on the gypsy. A 50 foot length of yellow polypropylene 1/4 inch line is affixed to the end of the chain. I can cut the heavy securing line at deck level if I ever have to loose my bower in an emergency, and the polypropylene floating line allows later easy retrieval.
Best wishes
Charles Starke, s/v Dawnpiper
|
|