Two anchors, one rode - best practice?

[meirriba]

I have never done that, and I wonder what is the best way to connect two anchors on one rode (chain) to enhance anchoring in strong wind.

Two of my friends, both with extensive cruising experience, have differing opinions.
One proposed to connect the secondary anchor about 2 meters (~7 feet) distance behind the main one. The other guy firmly proposes to connect them together, with the stock of the forward one connected by two shackles to the crown of the aft one (he adds a buoy to the crown of the forward anchor for ease of recovery).

Any wisdom will be appreciated.
Please do not write advice on using two rodes...different matter that deserves its own thread

[GordMay]

➥ Two to Tandem: Maximizing Holding Power by Tandem Anchoring

➥ Setting Two Anchors

➥ Setting Tandem Anchors - Sail Magazine

[gjordan]

It is one of those things that may or may not work, but would be hell to have to deal with. The clutter on the foredeck when trying to get underway would seem to make it a much less than useful method. When most of us spend a lot of money to get an anchor system that will bring it up into a bow roller without having to touch anything but an up button or a handle on a manual winch, why would you want to add having to go forward with wire cutters( It is all safety wired?), a wrench, gloves and drag more chain over the bow and an anchor, unshackel the second anchor, get it tied down and then get going. All of this without damaging the gelcoat or your fingers and maybe in a hurry because some boat in front of you started dragging. Why make life more difficult? Buy a bigger main hook and sleep well. Just my 2 cents worth. ______Grant.

[belizesailor]

Oh Boy, an anchoring thread! :sly:


Seriously though, most multiple anchor configurations are intended to reduce swing scope to accommodate various limited swing room scenarios or to deal with dramatic current/wind shifts (see Bahamian Moor for example). Most are not intended to increase holding power.

One debatabe exception is anchors in tandem (like the link Gordy posted). This method does not significantly affect swinging scope, but in theory at least, is intended to increase holding power. Some believe it does. Some argue it does not.

I've used tandem anchoring "successfully" in foul weather. Meaning I didn't drag. I believe it increases holding power, but Ive never done any structured testing.

Ive also held just fine on a single anchor in really shitty conditions. Unforecast weather, big wind, breaking waves in the anchorage...wild ride with little sleep, but didn't budge an inch (Fortress anchor in deep sand)

That illustrates that a single anchor, properly sized, and appropriate for the bottom type, can also be extremely effective.

Ok, thats my 2c....LET THE GAMES BEGIN!

[btrayfors]

Originally Posted by gjordan

....... Why make life more difficult? Buy a bigger main hook and sleep well. Just my 2 cents worth. ______Grant.

+1

If you need 2 anchors on a single rode, your anchor(s) are too small.

Bill

[meirriba]

Originally Posted by btrayfors

+1

If you need 2 anchors on a single rode, your anchor(s) are too small.

Bill

The question why do I need to carry a humongous anchor at all times when the need for extra weight may be necessary only once in long while.
I have asked about tandem anchoring as it seems a useful technique to add to the arsenal of anchoring tools.

[thinwater]

I challenge ANYONE to demonstrate that 2 anchors on a single rode (one attached to the crown or heel of the fluke on the other) is functional in sand or mud if the wind shifts more than 20 degrees, and yes, most boats yaw that much. It works for oil platforms, since they are multi-point moorings.

This is pure myth. I've done a lot of testing, trying to find a way to make it work, and it doesn't. The forward anchor always trips at high load. No insult to Gordo, those links do not represent real testing. For example, Rocna did NOT show a veer, and the anchors in the images are NOT well set. In fact, they are clearly coming out. Even Wemar's only photos and video show an anchor tripped.

Two anchors on separate rodes, perhaps with those rodes connected at some point (this was shown in 2 of the links), is a different case. More complex to be sure, but it can work very well.

Yes, a bigger anchor is better. Obviously.

---

There are several related cases where in-line tandems really work, perhaps better than a larger anchor (depended on the test run--I had it go both ways). Can you guess?

[Stumble]

Originally Posted by meirriba

The question why do I need to carry a humongous anchor at all times when the need for extra weight may be necessary only once in long while.
I have asked about tandem anchoring as it seems a useful technique to add to the arsenal of anchoring tools.

If you have two anchors then you are already carrying around the weight. Tandem anchoring is justnot really a good idea. In a very limited case it might add something, but in the real world it has never been shown to be effective. And it comes with a massive problem. A 180 degree wind shift is guaranteed to tangle the chain.

[Boatguy30]

In soft bottoms it can work well to shackle two inline as the first anchor generally loads up with muck and weed and clears a firmer patch behind it. Best to set the second anchor in front by hand in the clear patch.

Sat thru several days of 30-40 knots if wind in southern Cuba drug twice in 48 hours after never dragging our Manson ever in winds over 50 knots. Reset the Manson and put a mere 13lb danforth 15' in front. No more dragging!

[StuM]

Originally Posted by meirriba

The question why do I need to carry a humongous anchor at all times when the need for extra weight may be necessary only once in long while.

What's the weight difference between one humungous anchor and two "ordinary" anchors?

[meirriba]

Originally Posted by GordMay

➥ Two to Tandem: Maximizing Holding Power by Tandem Anchoring

➥ Setting Two Anchors

➥ Setting Tandem Anchors - Sail Magazine

Thanks! this is what I was looking for!

[meirriba]

Originally Posted by Stumble

If you have two anchors then you are already carrying around the weight. Tandem anchoring is justnot really a good idea. In a very limited case it might add something, but in the real world it has never been shown to be effective. And it comes with a massive problem. A 180 degree wind shift is guaranteed to tangle the chain.

Tandem anchoring may not be the solution, but carrying one extra-large anchor is not the solution either.
All I asked for was an analysis of the technique involved.

With one very heavy anchor, I would have the extra weight to deploy every time when I really need it once in a blue moon.
On the other hand, I would anyway need a second anchor for the versatility it provides - Bahamian mooring, second anchor from the stern, replacement to the main if lost etc.

[conachair]

Originally Posted by meirriba

Tandem anchoring may not be the solution, but carrying one extra-large anchor is not the solution either.
All I asked for was an analysis of the technique involved.

With one very heavy anchor, I would have the extra weight to deploy every time when I really need it once in a blue moon.
On the other hand, I would anyway need a second anchor for the versatility it provides - Bahamian mooring, second anchor from the stern, replacement to the main if lost etc.

Practical sailor did some testing, but you need to pay to see the whole thing...
Doubling Up: Full-size Tandem Anchoring - Practical Sailor Print Edition Article

Their findings seem to echo the general consensus.....
"In our view, tandem anchor rigs are only useful for exceptional situations in which a conventional anchoring setup (one anchor on one rode) or a twin anchor arrangement (two anchors set on separate rodes) won’t work. If you are consistently having problems setting your primary anchor, rather than immediately experimenting with tandem anchors, or other unconventional approaches, we recommend that you review basic practices and consider getting a larger or different style anchor that suits your cruising grounds. "

I was interested in the system for a while, but after research decided it isn't a good idea, too many unknowns. Better off with a size up well known new gen and vee if the conditions warrant it.

[UNCIVILIZED]

FWIW there are a few different shackles that can be used without requiring a full tool box to undo them. But odds are they will be covered with mud, etc. after a trip to the seabed.

[packeteer]

Use the second anchor (or a weight) as a kellet