Minimum anchors size, what’s the point?

[jmh2002]

I'm still waiting for the Vodka Martini, the Gin and Tonic, and whatever Mike is drinking there!

Here where I am at the moment you can have a Vodka and, well, just Vodka...but I''ll share.

[malbert73]

Originally Posted by double u

gentlemen let's not forget one imho quite important little fact:
even for the very experienced here-their anchorage-wisdom is based on anecdotal evidence. hardly anybody here has collected data from a significant number of boats in a statistical way. while after a good 100.000 miles & I-don't-know-how-many-days-at-anchor I am inclined to strong opinions I still try not to forget that this is the experience of 1 person with 2 boats...

This is very true. But I have never sat anchored in any conditions wishing I had a smaller anchor.

(55 lb mantus on 18K lbs T40- and considered bigger)

[thinwater]

Originally Posted by Dockhead

We don't indeed, and there's lots of good information in this post


I remember your actual measurements of rode tension a few years ago -- can you give us a link please? This is also very useful information for this discussion. Observations are gold (theories are bronze etc.).

The rode tension measurements were published in Practical Sailor and can be found there. However, the simplified version is this:

• Wind-only is about 4 times less than ABYC.
• All-rope is about 30% ABYC, depending on exposure to waves.
• Chain with no snubber in shallow water (6') and some wave exposure is about equal to ABYC. There will be some hard snubbing once the wind gets up. This is what ABYC was based on.
• With a short snubber (6') the load in shallow water will be about 70% ABYC.
• With a long snubber (30-40') the load will be about 30-45% ABYC.
• In deeper water it all depends on how much chain and how deep. Over 30 feet it is pretty much just the wind load.

Perhaps the main take-away is that you should always have a long snubber available, in case you get caught in a bad place (shallow and some waves). It protects the chain and may keep your anchor from dragging. You may not always need it (deep harbor), but you should have one.


Multihulls always use bridles, so we always have a snubber. A curious correlary is that if a multihull uses rope, the yawing and load will be less if he uses a non-stretch bridle, because the bridle angle will not distort. The rope provides the shock absorption. With rope rode I have used both polyester and Dyneema. Seems strange, but it works.

[Dockhead]

Originally Posted by thinwater

The rode tension measurements were published in Practical Sailor and can be found there. However, the simplified version is this:

• Wind-only is about 4 times less than ABYC.
• All-rope is about 30% ABYC, depending on exposure to waves.
• Chain with no snubber in shallow water (6') and some wave exposure is about equal to ABYC. There will be some hard snubbing once the wind gets up. This is what ABYC was based on.
• With a short snubber (6') the load in shallow water will be about 70% ABYC.
• With a long snubber (30-40') the load will be about 30-45% ABYC.
• In deeper water it all depends on how much chain and how deep. Over 30 feet it is pretty much just the wind load.

Perhaps the main take-away is that you should always have a long snubber available, in case you get caught in a bad place (shallow and some waves). It protects the chain and may keep your anchor from dragging. You may not always need it (deep harbor), but you should have one.


Multihulls always use bridles, so we always have a snubber. A curious correlary is that if a multihull uses rope, the yawing and load will be less if he uses a non-stretch bridle, because the bridle angle will not distort. The rope provides the shock absorption. With rope rode I have used both polyester and Dyneema. Seems strange, but it works.

Thanks. That's really valuable research


For whatever it's worth, incidentally --


I haven't used a snubber in several years, and in all kinds of weather. 1/2" chain, and I rarely anchor in less than 10 meters (33'). Under provocation of someone on CF some years ago who disagreed with something I posted about snubbers. He challenged me to try it, and I was amazed that as long as the water is deep enough, the snubber isn't needed even in quite strong weather. One of many cases where being proven wrong in some argument on here, has turned out to be valuable.





Interesting observation about Dyneema bridles. I can imagine that this is true. FWIW, I made my Jordan Series Drogue with Timm Acera (a UHMWPE rope equivalent to Dyneema).

[hpeer]

Originally Posted by Mike OReilly

Cheers folks. It's afternoon drinkies time here in NFLD.

Ran outta .Kraken, suffering through with Capt. Morgan.

[Mike OReilly]

Originally Posted by jmh2002

I'm still waiting for the Vodka Martini, the Gin and Tonic, and whatever Mike is drinking there!

Sippin' wine spritzers right now: chilled white wine, chilled tonic, lime. All while swinging from my oversized anchor somewhere on the west coast of Newfoundland. Life is good [emoji1]

[Mike OReilly]

Originally Posted by hpeer

Ran outta .Kraken, suffering through with Capt. Morgan.

Oh the horror. THE HORROR [emoji6]

[jmh2002]

Originally Posted by Mike OReilly

Sippin' wine spritzers right now: chilled white wine, chilled tonic, lime. All while swinging from my oversized anchor somewhere on the west coast of Newfoundland. Life is good [emoji1]

Life sounds very good

[kmacdonald]

OK, I'm going to go out on a limb here. 10' of chain max to save weight. Put the weight in the anchor, not the chain. Use a double braid anchor line with polyester outer braid for abrasion resistance. Polydyne or Double Esterlon or similar work well. A new generation anchor will have a much greater holing power than a Delta or other older plow style anchor so don't overdo it on anchor weight. A 10kg Rocna on a 35' cruiser isn't crazy small. It might drag in really soft mud but no more so than a 44lb Delta.

[sailorboy1]

Great, now you’re that boat in the anchorage swinging and drifting different than everyone

[kmacdonald]

Originally Posted by sailorboy1

Great, now you’re that boat in the anchorage swinging and drifting different than everyone

Yep, and have battle scars to prove it!!!!!

[barnakiel]

I am with the Dashews. Then again the way we sail and anchor has some sort of 'alike' factor.

Cannot see why everybody should follow the same suit.

Chose the anchor that fits how you use the boat.

b.

[rognvald]

Whenever we look at a situation whether it be a passage, striking sails or anchoring, we always consider options for a worst-case scenario. And, for those of you with large boats and over-sized anchors, what is your strategy when your electric anchor windlass fails and you have to a.) retrieve it mechanically by hand cranking or b.) literally, by hand? Especially if it trips in storm conditions or a violent wind shift that precedes frontal passages? Can you physically retrieve your hook on a dragging 20-40,000 pound boat and if not, what are your options? I am always amazed at how some sailors have complete confidence in their electrical/mechanical systems as if failure is never an option. But, those who have accumulated many sea miles know, even a well-maintained/well-found boat will default at some point. So, what is your plan B when you have an electrical failure? What would you do? Rognvald

[thinwater]

Originally Posted by Dockhead

Thanks. That's really valuable research


For whatever it's worth, incidentally --


I haven't used a snubber in several years, and in all kinds of weather. 1/2" chain, and I rarely anchor in less than 10 meters (33'). Under provocation of someone on CF some years ago who disagreed with something I posted about snubbers. He challenged me to try it, and I was amazed that as long as the water is deep enough, the snubber isn't needed even in quite strong weather. One of many cases where being proven wrong in some argument on here, has turned out to be valuable.


Interesting observation about Dyneema bridles. I can imagine that this is true. FWIW, I made my Jordan Series Drogue with Timm Acera (a UHMWPE rope equivalent to Dyneema).

Yes, it seems to be mostly about how much chain is out, which intuitively makes sense. Both theory and practice say that deep water and shallow water are two very different cases. Except a few times at 7-10 meters in testing, I have only anchored in more than 3 meters 5-10 times. 2 meters is my norm, has been for 35 years. It's a US mid-Atlantic, multihull thing. Lots of shallow, protected areas available. I leave the deep water for those who require it. I generally only anchor deep if there is fetch and risk of waves.

[thinwater]

Originally Posted by sailorboy1

Great, now you’re that boat in the anchorage swinging and drifting different than everyone

Or are you....? Rope is common in some areas.