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Old 29-11-2007, 07:16   #1
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in-line dual anchors

anyone use two anchors in-line on the same rode? The lead anchor being attached to the head of the rear anchor that's attached to the chain/rode.....

I like the idea of being able to carry multi lighter anchors with the ability to beef up the holding power by attaching them together on one chain/rode when/if conditions require extra holding power...

I lean toward a Fortress as the lead and my 22lb Bruce as the following anchor. Mainly because the Bruce is my primary anchor on the bow.

thanks
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Old 29-11-2007, 09:35   #2
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I've done this a couple times, when I didn't know what the bottom was like. It worked well when the winds picked up but was a hassel to get them back on deck.
and I always use a "tag" line off the back of the anchor to retreve it. The line runs to a bouy, so if I cant pull it out forward, I'll grab the tag and pull it out backwards.
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Old 29-11-2007, 10:03   #3
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I've not yet but intend to try it. I've got lots of different anchors that I can use for the experiment. The only thing that concerns me is the possibility of the chain from the lead anchor fouling the aft anchor on a reset. I would think your heavier anchor should go down first and then attach the lighter anchor at a distance equal to the depth of water plus 10 feet so you are not pulling both anchors from the bottom at once. Anyway, when I get the boat back in the water I'm going to try it.
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Old 29-11-2007, 12:46   #4
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I did it one time when I was leaving my boat in the Chesapeake Bay for 4 months (Galesville, MD.) July-Oct. We had just sailed straight from Capetown SA, non-stop for our daughter's wedding.

I thoroughly baried my biggest high tensil Danforth as far as I could, on 50' of chain. I took the bitter end of that chain and fixed it to my 55# Delta anchor with 100' of chain and 150' of nylon (in 20' of water at HT) and dug it in good. I had the stearn tied to a dock that was kindly loaned to me by USN Admiral Welander.

There was a hurricane that passed over the area while I was gone and the boat didn't budge in 60+ kts of wind. Although, Admiral Welander told me that the stearn of the boat was about 1' off of the dock in the gusts (from the stretching of the nylon road).

Both anchors were dug in so far that I had a heck of a time getting them up. The chain between the two anchors was bar tight. I tried diving down to separate them. I couldn't even turn the shackle bolt.

As a side note. The Admiral's wife died in her sleep that night. Boy.... did I feel small when I called, worried about my lousy boat. It still hurts to think about it.
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Old 30-11-2007, 00:16   #5
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Two to Tandem: Maximizing Holding Power by Tandem Anchoring
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Old 30-11-2007, 08:14   #6
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Lightbulb Just a thought

Beth Leonard and Evens Starzinger ( Welcome to Beth Leonard & Evans Starzinger's home page ) recently had a very good article in one of the sailing magazines on this very subject. I suspect if you contact Evens through his web-site (above) he can offer some good information.

Aboard our yacht we carry 4 anchors of various weights and types and will use a tandem arrangement for very dirty weather. Our primary anchor is a 45# CQR attached to 3/8" chain. To add a tandem anchor to this we use our secondary which is a Fortress FX-27 attached to 25' of 3/8" chain by passing a double wrap of the end of that chain around the shank of the CQR just above the plow and shackling it to itself. (The double wrap keeps the chain from slipping and interfearing with joint in the shank above the plow-blades). This allows the tandem anchor to set 23+ feet ahead of the primary. For retrieval, we add a length of 3/8" braided nylon line led from a point on the inboard side of the chain to the primary anchor to a link in the chain to the tandem anchor that is far enough ahead of the CQR to permit that chain to loop under the bow and reach the anchor windlass through our secondary bow roller. To keep the 3/8" braid from fouling the primary we pass it through the end loops of a number of small rubber bands that are stretched around the chains at intervals and hold the line in place but easily break if a load is applied to the line. With this arrangement, once we've retrieved the primary anchor, we can free the line, pass it through our secondary bow roller and retrieve the tandem anchor in the normal fashion.

Our storm anchor is an FX-37 kept ready for assembly in a nylon bag below deck which can be attached to a 50' length of 3/8" chain and, as necessary, several hundred foot lengths of 3/4" nylon rode. With this and the tandem anchor set-up above, if necessary we can set both in a V pattern to the likely prevailing winds in a storm. (We have never done so, however, and I hope never to need to do so!)

Cheers,

s/v HyLyte
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Old 18-01-2008, 06:30   #7
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I have done that when called by my marina on lake Champlain to move my boat out since the marina would be exposed to the full force of the wind and seas of the remnants of hurricane Isabelle(I believe). I put a 75# FOB(French fluke anchor) in front of my 66# CQR. The mooring was all chain 12 mm with a strong bridle of nylon. I was well protected from seas, but I exposed to the full wind forces and blasts(50 knts average, and 66kts blasts) most of the night: not funny!. I was alone on my 47 ft sailboat, and everything held very well. The only problem: retrieving my 75# FOB the next morning. The thing was buried so deep it took me 1/2 hour to pull it off. The chain was soiled with mud for 6 ft. So I can attest, it works.
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Old 18-01-2008, 10:44   #8
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Bruce made for tandem!

Hi "rabates"
Sure your idea works. I've tested it. Had a yacht your size with a 22lb Bruce as my main anchor. I spent 5 years in the West Indies in the nineties, and used tandem anchors whenever I put my boat in a hurricane-hole.
I had 100 feet of 3/8" chain on the Bruce. Then chained to the Bruce with 20feet of 5/16" chain was a Danforth-type anchor.
Contrary to what the sales-pitch for Rocna says, the Bruce anchor is very suitable for tandem anchoring. This was actually a design consideration. The trick is to chain the anchor in front of the Bruce to the vertical part at the head with a loop (using a shackle), not to the tiny hole provided.
This works!. My yacht sat out hurricane Luis (1995) in English Harbour Antigua with sustained wind to 120 kts. All mud bottom.No dragging, not even when other boats dragged down and hit mine. Personally, I avoided the hurricane by doing a delivery to Gibraltar .
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Old 18-01-2008, 11:04   #9
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Quote:
Originally Posted by cagney View Post
the Bruce anchor is very suitable for tandem anchoring. This was actually a design consideration. The trick is to chain the anchor in front of the Bruce to the vertical part at the head with a loop (using a shackle), not to the tiny hole provided.
I'd be interested in your source for this information. To the best of my knowledge the Bruce was designed for the offshore oil industry to anchor semi-submersible drill rigs in multiple anchor (eight I think) configurations (distributed angularly, not in-line).

The hole is for a trip line.
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Old 18-01-2008, 11:41   #10
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Originally Posted by cagney View Post
Hi "rabates"
Sure your idea works. I've tested it. Had a yacht your size with a 22lb Bruce as my main anchor. I spent 5 years in the West Indies in the nineties, and used tandem anchors whenever I put my boat in a hurricane-hole.
I had 100 feet of 3/8" chain on the Bruce. Then chained to the Bruce with 20feet of 5/16" chain was a Danforth-type anchor.
Contrary to what the sales-pitch for Rocna says, the Bruce anchor is very suitable for tandem anchoring. This was actually a design consideration. The trick is to chain the anchor in front of the Bruce to the vertical part at the head with a loop (using a shackle), not to the tiny hole provided.
This works!. My yacht sat out hurricane Luis (1995) in English Harbour Antigua with sustained wind to 120 kts. All mud bottom.No dragging, not even when other boats dragged down and hit mine. Personally, I avoided the hurricane by doing a delivery to Gibraltar .
Hi Cagney:

I appreciate your personal experience. especially since you were using a Bruce as I do... Thanks for posting....
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Old 18-01-2008, 13:00   #11
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Attaching to the Bruce??
Cagney,
Trying to envision how you attached the chain from the danforth to the head of the bruce. If you loop the chain around the "vertical" part of the bruce above the flukes won't you be setting yourself up to foul the bruce when setting it? How would you be sure that you don't wrap the chain around the flukes?
I like the idea of tandem anchoring but want to be sure that I'm not setting myself up for failure.
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Old 19-01-2008, 00:12   #12
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Quote:
Originally Posted by cagney View Post
Hi "rabates"
Sure your idea works. I've tested it. Had a yacht your size with a 22lb Bruce as my main anchor. I spent 5 years in the West Indies in the nineties, and used tandem anchors whenever I put my boat in a hurricane-hole.
I had 100 feet of 3/8" chain on the Bruce. Then chained to the Bruce with 20feet of 5/16" chain was a Danforth-type anchor.
Contrary to what the sales-pitch for Rocna says, the Bruce anchor is very suitable for tandem anchoring. This was actually a design consideration. The trick is to chain the anchor in front of the Bruce to the vertical part at the head with a loop (using a shackle), not to the tiny hole provided.
This works!. My yacht sat out hurricane Luis (1995) in English Harbour Antigua with sustained wind to 120 kts. All mud bottom.No dragging, not even when other boats dragged down and hit mine. Personally, I avoided the hurricane by doing a delivery to Gibraltar .
A 10Kg Bruce in 120 knots wind, unless in about the best holding imaginable - that's likely to very quickly become a 10Kg kellet on 120' of chain to a Danforth.

That the Bruce was designed for tandem rigging is nonsense. The placement of such a loop of chain would be impossible to control, with it slipping unpredictably either to the top of the vertical section of shank or to the bottom. It would also need to be tied somehow to the flukes in order to prevent the loop riding up the shank and getting hung up on the main rode's shackle or the end of the shank during launch / setting. The angles of force transfer are critical, and had Bruce intended for this technique, a dedicated attachment point would certainly have been provided as with the Rocna.

It is little consequence to us whether boaters engage in tandem anchoring or how they do it (so long as they're not upwind of our nearest and dearest...). But it is of personal interest to us, and we've done a large amount of testing with the intent of having the Rocna designed to work well in tandem rigs. The "sales pitch" is an in-depth article which talks about some of the conclusions of this, with a number of allegories and contributions from other well respected authorities who have experience on the topic.

It's difficult and rare to accumulate experience of anchoring in extreme conditions. A story that "this worked for me" is a single report which says only that the teller didn't have his luck go against him that once.

As the skipper of the boat unwittingly featured in the UK MAIB report referenced in the article would no doubt agree, the correct theory and practice and knowledge of it is of great importance. If you choose to automatically reject a piece of advice because it comes from a commerical source, that is your choice - but contradicting recognized experience and theory to the extent of setting up others for costly or dangerous failures of their own should be condemned in the harshest manner.

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Old 19-01-2008, 01:15   #13
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It is difficult to know what to belive in these forums sometimes. We all have our persoal experiences. Craig, I don't doubt you have tons of experience due to the cruising you have done. It's just a little harder to shallow that everytime you post, your product is somehow mentioned. I think you could make a better point if you gaves us your knowledge as a generalization rather than a subtle promotion of your product with pictures.
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Old 19-01-2008, 01:18   #14
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To the best of my knowledge the Bruce was designed for the offshore oil industry to anchor semi-submersible drill rigs
No that is actually a falicy. Bruce as in the company, make anchors for Oil rigs and so on. In fact, they no longer make any anchors for the recreational market. So a genuine Bruce as the liesure market knows it, is no longer available. The anchors that Bruce make for the rigs and platforms are quite different. They range in sizes upto 60tonnes in weight and are the size of a Truck. The shank alone is somewhere around 10m(33ft) on the 60tonne anchor. Believe it or not, they actually have a shape alot more along the lines of the varies ones we are talking about, like Rocna, XYZ and so on.
This is just one of the designs. Looks kinda familiar doesn't it.
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Old 19-01-2008, 01:23   #15
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Gee Wheels...If ya put a loop around the top of that schematic it would look just like a ....
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