Anchor Siz/Weight

[apagano]

I know this is a topic well worn but.A I am planning on anchoring 80 % of my time I would like to get it right. I have been researching this to the point of confusion.

I have a 40 foot Marine trader Double cabin. I just found out she weighs in at 30,000 lbs
I have been looking at Spades, Mantus, and Mansons.
what anchor weight do I need.
Thank You
Alfonse

 

[Pete Meisinger]

I think you should use the search mode of this forum. We are really pretty tired of the anchor question

pete

 

[dhays]

I know this is a topic well worn but.A I am planning on anchoring 80 % of my time I would like to get it right. I have been researching this to the point of confusion.

I have a 40 foot Marine trader Double cabin. I just found out she weighs in at 30,000 lbs
I have been looking at Spades, Mantus, and Mansons.
what anchor weight do I need.
Thank You
Alfonse

The place I would start would be the manufacturers information. Most will have tables that will list anchor sizes for different size boats. Mantus for example would indicate likely a 55lbs anchor.


https://www.mantusmarine.com/mantus...AQbTbrC-IgOn6Fwz9CiJ1-DHdbkE017IaAsuTEALw_wcB

 

[rsn48]

I have a Rocna and happy with it but if I were to buy again, I'd get a Vulcan. You will hear this time and time again here, but go one size up from the recommended. I'm too lazy to be totally factual but also pay attention to what wind the "base" anchor is tested to for the recommendation at a particular lenght/weight. So Rocna/Vulcan test out at a base of 50 knot winds, others test out at 20 knot winds. So make sure you do an apples to apples comparison.

So on your boat you could get away with a Rocna/Vulcan 25 kilogram anchor, but instead bump up to 33 kilograms.

https://www.google.com/search?q=roc...ECAoQDg&biw=1920&bih=937#imgrc=jbgTDx6Tf7H-lM

 

[Peter B]

There were a lot of opinions expressed re long term anchoring on this thread, https://www.trawlerforum.com/forums/s62/leaving-boat-anchor-long-term-51764.html
although the op had different reasons from yourself. However, much of it is relevant to your question.

As to which anchor..? Have a look at all the new generation anchors, like Sarca, Manson, Mantus, Rocna, Spade, etc. and then be guided by the weight they recommend. It isn't rocket science, but there is some science behind it all.

 

[O C Diver]

Probably part of the discussion should include chain size as well. While having a big anchor that acts like a mooring, is important, chain, snubbers and cleats are important also.

Ted

 

[Beaverlake]

Don’t forget cruising area and typical bottom conditions in areas you will anchor.

 

[rslifkin]

On my slightly smaller, slightly lower windage 38 footer at 26k lbs, I went with a 73 lb Rocna Vulcan. It's a size above recommended on Rocna's chart. Mantus recommended a 55lb like Rocna for normal use or a 65lb for storm use.

 

[JohnS]

We are a little heavier, at 38,000 and 40 ft. We use an 80 lb Manson Supreme and are comfortable at anchor with it.
As stated above, do start building your rode from the anchor up. Once you have ghe size and holding power of your anchor, select the size and grade of the chain, and swivel, if you will use one. We have 5/16 G4 chain, which may be a little small for the anchor. 300 ft, backed by 150 ft of 5/8" Yale 8 brait, and a Maxwell 10-8 windlass rated for 1400 lbs pull.
Good luck with your research and happy anchoring.

 

[78puget-trawler]

While not fancy or the latest and greatest, its hard to beat a Danforth fluke anchor. You might look at the hi tensile model, great steel, and for their holding power they are lighter than many anchors. Meant primarily for soft bottom. Many naysayers but they have been doing the job for a long time. I use a 20-S Hi Tensile on my 34 CHB, true length is nearly 36' however and not quite as heavy as yours, and this anchor holds fine, with all chain rode. Stand by for retort!

 

[ranger58sb]

I know this is a topic well worn but.A I am planning on anchoring 80 % of my time I would like to get it right. I have been researching this to the point of confusion.

I have a 40 foot Marine trader Double cabin. I just found out she weighs in at 30,000 lbs
I have been looking at Spades, Mantus, and Mansons.
what anchor weight do I need.
Thank You
Alfonse

Lots of threads here about that. Use the advanced search; works better than the standard one.

We usually start with anchor manufacture recommendations, which usually suggests boat length and weight and so forth... then we add for our windage... up to the biggest we can fit OR the largest I'm willing to try to lift manually if the electric windlass craps out.

I think there are about 10-12 anchor brands/models currently in vogue... not just those three.

-Chris

 

[Wayfarer]

I'm a little longer, but about the same weight. I went with a Mantus and have been very happy. They recommended a 55, and I went with a 65. No regerts.

 

[motion30]

If you were going to anchor about 80% of the time I would recommend a 85lb mantus. As long as it will fit your pulpit

 

[psneeld]

I have a 60 pound Manson Supreme for my 40 double cabin. It is upsized one from recommended and seems to be plenty for my boat..

But I opt out of anchoring in hurricanes.

 

[apagano]

Thanks all, I went with a 65 lb mantus with a Maxwell HRC 10 and am now deciding on the length of chain so far I have 75 foot of chain

 

[High Wire]

Thanks all, I went with a 65 lb mantus with a Maxwell HRC 10 and am now deciding on the length of chain so far I have 75 foot of chain

75 alone is not enough. You could add rope to the chain to give you at least 150 overall. Inspect the rope/chain splice monthly.

 

[apagano]

Yes I agree, I have 100 feet 5/8 Nylon line, I was still thinking adding more chain. My goal is to drop the anchor and feel good about it.BTW We are currently in Northern NJ and will be headed south Sept.

 

[Nomad Willy]

The ARA Excel sets extremely well, veers well, works on a wide variety of sea floors and unlike most all other anchors is designed to not bring up copious amounts of MUD. Most of us anchor on mud. Probably 80% of seafloors are mud .. just different kinds of mud.

As to size most go a size larger that the manufactures recommend or bigger. I suspect most of the recommendations on this thread or even forum are too big. Probably says something about how conservative this group is. People do seem to be scared to death of dragging anchor. The concept that you need an anchor big enough for every conceivable situation is bogus. Especially these days with our gps anchor setting feature.

See Anchor Setting Video’s. It’s in the anchoring section but it’s easy to find as it’s the only thread w over 600 replies. Look mostly at how well the anchors set.

 

[rslifkin]

As to size most go a size larger that the manufactures recommend or bigger. I suspect most of the recommendations on this thread or even forum are too big. Probably says something about how conservative this group is. People do seem to be scared to death of dragging anchor. The concept that you need an anchor big enough for every conceivable situation is bogus. Especially these days with our gps anchor setting feature.

Some of it is us being a conservative bunch. But some is also that many of us don't carry an even larger storm anchor like people historically did. I carry a reasonable size Fortress, but it's more for times where I need something different or need a stern anchor. For many of us, the primary *is* the storm anchor. That's likely a product of big windlasses becoming common, most boats having bow rollers, etc. so actually using the big anchor isn't any more work than a smaller one. Which means you might as well just use it rather than having it waiting in the bilge just in case.

 

[freshalaska]

We also anchor 80 percent of the time. On occasion you will have to anchor on shorter scope than you would like and a oversized one or two sizes up will probably allow this. One or two sizes up just allows me to never have to get out of bed when it starts to blow. When setting I do back down on the anchor very throughly and take my time and use a snubber and try and pick my anchorages carefully. Heavy anchors just gives you more room for cushion.
If your windlass and bow sprit will accommodate and no reason not to go heavy.
Here in Alaska I see many commercial fishers anchoring with very very heavy anchors and with very short cope. Couldn’t tell you how often they drag but must work for them.

 

[Nomad Willy]

Fresh Alaska,
Then why not use an anchor that has a good record for short scope.
Manson Supreme, SARCA, Bruce and w a good set even a Danforth (w forged shank).
But some new age anchors fall short. Probably in the quest for max holding power. They know most shop for that. Unfortunately most anchors are probably tuned for best holding at long scope.

Look at Steve’s Anchor Setting Vid’s.

 

[rslifkin]

Fresh Alaska,
Then why not use an anchor that has a good record for short scope.
Manson Supreme, SARCA, Bruce and w a good set even a Danforth (w forged shank).
But some new age anchors fall short. Probably in the quest for max holding power. They know most shop for that. Unfortunately most anchors are probably tuned for best holding at long scope.

Look at Steve’s Anchor Setting Vid’s.

You'd definitely want to pick a design that's good at short scope. But even an anchor that's good at short scope still has less holding power than it would with longer scope (up to a point). So going bigger means you can get away with shorter scope before the holding power isn't enough.

 

[Nomad Willy]

Some of it is us being a conservative bunch. But some is also that many of us don't carry an even larger storm anchor like people historically did. I carry a reasonable size Fortress, but it's more for times where I need something different or need a stern anchor. For many of us, the primary *is* the storm anchor. That's likely a product of big windlasses becoming common, most boats having bow rollers, etc. so actually using the big anchor isn't any more work than a smaller one. Which means you might as well just use it rather than having it waiting in the bilge just in case.

Spot on ...... until it goes over the top and becomes excess weight. Think if you used that philosophy all-round. Big cleats, oversized rudder and shaft, oversized prop shaft, extra thick hull bottom and heavy cabin glass. And many other things. A boat can easily become a dog. My dad had such a boat. He was always on the phone telling the builder (in Maine) “I want my boat to be skookum”, and the builder did. It was 36’ of heavy duty Lobsterboat that made a max of 9 knots w a 6-71. Big wake. Big and heavy everything. Probably would have been 5,000lbs lighter if it had been mine. Fabulous boat in all other respects. Even had a Dickinson oil stove.

Ground tackle need’nt be heavy but on trawlers weight can be tolerated better than other boats so 20% above the norm would be considered appropriate. But if you’ve got a “skookum” mindset keep check on yourself .. and your boat.

 

[rsn48]

You might want to start a seperate thread about rode length as you will continue to get anchor answers here.

I don't know average depths in your area. If you were here in PNW & coastal BC, I'd say add 250 feet of line to your chain especially if you plan on out of season cruising (think winds here). You have a fair size boat so I am foolishly assuming it will hold that amount of line/chain.

I have 100 feet of chain and 200 feet of line so with a total depth of 50 feet, depth plus boat bow height that gives me a 6 to 1 rode. I am thinking of adding a new line in a year or so to 250 feet for a 7 to 1 ratio. During summer during our benign wind period and crowded conditions, 3 to 1 is pretty normal, with or without being stern tied.