How big is too big?

[1Sunseeker]

As mildly brought up before, you may have to hand haul that baby and it's chain back on your boat. So I hope your winch is both electric and manual. And/or you have a healthy crew.

[a64pilot]

Originally Posted by 1Sunseeker

As mildly brought up before, you may have to hand haul that baby and it's chain back on your boat. So I hope your winch is both electric and manual. And/or you have a healthy crew.

Yes, given enough time it will happen. I plan on using my Genoa winch with my Milwaukee drill, I've done it once before, worked better that I had hoped.
I think I can put a winch handle in the top of the Windlass, and if so then maybe I could use the drill, but would that mean I would be trying to turn the electric motor too?
The Genoa winch worked before, it will again, just a little more work is all.

[twohapence]

Originally Posted by a64pilot

Weight is I believe not such a good way to size anchors, is it weight or surface area that gives an anchor its hold?

Now that's a really interesting point.

What does hold you to the bottom? I have a mooring with a large concrete sinker dropped into the mud. Is it the weight that makes the mooring work? Concrete is, I believe, 40 times less dense than steel and therefore more buoyant. it would be more efficient to use an equivalent mass of steel such as a railway wheel.

However, the mooring's holding power is about the mass of the sinker and the mass of the water column above it because it has sunk into the mud. So having a less dense sinker with a bigger surface area gives more holding than a smaller denser material. You've got to over come the "suction" of the mud.

When a builder or *competent* DIYer anchors something to a wall they choose the appropriate fixings. Banging six inch nails into plasterboard isn't going to hold a loaded shelf for long. Never mind failing to pass the Admiral's inspection. Using lighter weight properly engineered fittings produces more holding power.

The best anchor isn't necessarily the heaviest lump as established in test after test. What's also clear is that no one anchor excels in every condition. Few of us would carry a fisherman or admiralty anchor but there are some situations where it might just be the perfect anchor to deploy.

Having over sized chain doesn't seem to me to be the best solution either. Increased weight in the bows while sailing. Additional load on the winch when raising or the anchor. Would it not be better to have chum or an angel that can be deployed in more testing conditions? Depending on the size of boat you could have 2 old fashioned 10KG (or bigger) training weights on a bridle. Cheap to source second hand on eBay. Crucially the extra weight could be stored nearer the centreline of the boat and therefore there would be less weight in the ends.

Running an angel down the cable so that it is not quite on the bottom will reduce yaw and sailing at anchor, improve the catenary effect of the chain so there is a straighter pull on the anchor and reduce snatch loads.

My set up of a fortress and a spade covers many of the conditions I face. On my next boat I'll have the same combination but bigger. Probably an FX37 and a 25 KG Spade. I'm confident I can row the FX37 out as a kedge when required. I may buy a bigger Fortress if the budget permits.

[River Cruiser]

I cruise on the rivers and occasionally the Great Lakes and anchor out most of the time I'am away from my home marina. I use a fortress fx-37, I believe it's 2 sizes bigger than what fortress recommends for my 38' sedan bridge power boat. I can set it and get a good nights sleep is the main reason I use it. On the way back from Lake Michigan 3 weeks ago we rode out a storm on the Illinois River. I had set a anchor alarm on my iPad, about midnight a tstorm blew through with heavy rain and at least 60 mph wind. My daughter woke me up and said it was storming very bad and a tow boat was up River a ways and swinging his spotlight around. I got up and checked, the tow was stopped, the wind was out of the north on our port bow. In the light of the tow I saw 3' rollers coming down the river, our boat was hobbyhorseing , our 17' cc tied up on the transom was whipping back and forth like a happy dog's tail. At this point I could not believe we weren't dragging so I checked the iPad again, it still indicated no dragging. I went to the flybridge and started the engines in case I need them, then I contacted the tow to see if my position was a problem, I was sure he could maintain his position with the wind. He told me he wasn't moving for at least another hour as there was a 2nd front possible coming through. I stayed on the bridge with the engines running and using my spotlight on the shore, the rain was blowing through horizontally and felt like sandblasting. After 30 minutes it started to subside and I shut the engines down and went back to bed. I never expected a storm this severe on the rivers, sometimes the fortress gets a really good set if I stay put for a few days and strains the windlass. When choosing a anchor pick one for conditions that you can imagine happening to you and your boat. I'am wondering if a fx-55 is to big?


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[reed1v]

Originally Posted by barnakiel

I have run some numbers thru a catenary formula. It seems, given total weight of the chain constant, a shorter and higher size chain is better than a longer lower size piece.

By better I mean shank angle is lower.

So the mathematics / physics cahoots run contrary to my earlier thin air assumptions.

This could imply when going for stronger chain (G7 vs. G4) one is better off sticking to the original size.

"If you have 10mm chain, if you upgrade to G7, stick with 10mm, do not go 8mm" in plain words.

The function is clearly not linear as the chain size/weight is not linear either. Chain is volume (3d), not area (2d), as simple as that.

Cheers,
b.

Something is screwed up. You want your chain to be as horizontal to the anchor as possible so the load is causing the anchor to dig deeper. A shorter chain will not do that.

[reed1v]

Originally Posted by a64pilot

I know the apply an irresistible force to in immovable object and something is going to give.
Had Frankly caution me too, told me about a powerboat that rode out a Storm in St Andrews bay, anchor and rode held, bow attachment didn't, it stayed connected to the anchor while the boat was beached.
Snatch loads can easily be four or more times what the constant pull is, I've seen more than a few times a bumper pulled off a truck stuck in the mud using chain where a snatch strap would pull it out without damage.
Wonder if a snatch strap would be a good snubber?

The reason for using chain to pull out trucks is to avoid whipping of ropes or cables through the air that can literally remove the truck's body, decapitated nearby folks, and cause all sorts of damages. Chain simply breaks and falls.

[NV US]

..here on the canal du midi its never ever about being too big... its mostly about how much wine you can safely store aboard without sinking....and drink before it might go off.. in the years I've been on the canal I've never heard of anybody throwing wine away because "its gone off " ...mind you I'm only on the canal less than 10 years so you never know.. early days.....on the how big is too big issue... you'll be told...and you'll have a big smile on your face for a month....
😃😃😃

[a64pilot]

Watch this you may want to go about three min into it as that is where the recovery is, but a snatch strap is many time more effective than a chain, unless you have a tow truck or something with a massive winch that has enough power to slowly pull you out

https://www.youtube.com/watch?v=-Ire31FrEAI

[NV US]

..thats it.. not even going there... over here "snatch straps" are only covered by forums on the deep web.. goodnight all... now, where did I leave that bottle of merlot ?...

[twohapence]

Originally Posted by NV US

..thats it.. not even going there... over here "snatch straps" are only covered by forums on the deep web.. goodnight all... now, where did I leave that bottle of merlot ?...

You really shouldn't drink Merlot. Allegedly it gives you the most awful headache if you have more than three bottles.......

[a64pilot]

Originally Posted by twohapence

You really shouldn't drink Merlot. Allegedly it gives you the most awful headache if you have more than three bottles.......

Which is unfortunately the problem I have with wine, perhaps I just haven't found the correct wine?


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[Tayana42]

If it comes in six packs in cans it is not good wine.


S/V B'Shert

[Jim Cate]

Originally Posted by Snowpetrel

Jim, it's a 38 footer. That's like you guys fitting a 125lb anchor. By the same metrics your 65lb anchor is a tiddler in comparison to your windage.

Sent from my SM-G930F using Cruisers Sailing Forum mobile app

Well, his boat's listed displacement is just about the same as our light ship displacement, and with its high freeboard, etc, I doubt if his windage is all that much less... so I dispute your conclusion, Ben!

And when we were replacing the anchor we lost in the Gordon a few months ago, I seriously considered going from 60 to 80 lbs... but it wasn't readily available (actually, neither was the 60, but that was yet to be learned!). I think if I were in A64's place I'd go with the 66 lb if buying a Rocna, but what I would do is not relevant!

Cheers,

Jim

On edit, I see that others have already addressed this issue... sorry for the repetition!

[twohapence]

Originally Posted by a64pilot

Which is unfortunately the problem I have with wine, perhaps I just haven't found the correct wine?


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Keep looking. Send me some and I'll help with the research.

[Dockhead]

Originally Posted by a64pilot

Weight wise I think is irrelevant, I have G40 chain with the idea of saving weight, I bet the heavier anchor would be a wash for the lighter chain.
Difference in weight is 33 lbs, and to be truthful I can't tell any difference with a 200 lb person on the bow. IP seems to tolerate weight on the ends better than some others I guess. I was worried about hobby horsing as I have a 200 lb genset in the Lazarette and a couple of hundred lbs of chain and anchor in the bow. Boat does sit enough lower in the water now, enough that the anti foul needs raising next bottom job.

I am wondering other than being 33 lbs heavier on the bow, what are the downsides?
I have searched the forum and all I can find is maybe it's a bear to break out, use the boats inertia and you may bring up a large chunk of real estate with the anchor, but haven't heard a reason not to oversize, or when does it just get stupid.
Rocna says you don't need to oversize, they already did that, but what does oversizing hurt, other than the wallet?

A64, the only disadvantage of a bigger anchor is that at some point it becomes hard to handle. The 33 lbs difference is irrelevant to sailing ability (and it's an IP after all anyway, not a racing boat).

If it fits your bow roller and your windlass can deal with it, then you will be glad you did it. Bigger anchors work better disproportionate to their size. I don't really know why but it's really true.

I went with a 55kg (121 pound) Rocna when I first bought my boat, and found it was too much. The Rocna is inherently unbalanced so one issue was getting it right side up into the anchor roller (I had to use a swivel). But the sheer size of it made the process uncomfortable.

So I replaced it with a 47kg Spade and that's turned out to be just right.

You might go through something similar, but I would say -- go for it, and just see how you like it. Shouldn't be hard to resell it if you don't end up liking it.