How heavy is too heavy?

[onavegador]

It is not only the size of the anchor who is important but also the chain. With heavy anchor an a light chain the shaft of the anchor my be lifted under circumstances.
As mentioned by other CF members look which anchor fits your bow and then buy enough chain with 5/16 dia. I guess 200 ft of 3/8 chain is too heavy for a 32 ft boat.

But I do not know where you plan to sail.

[Qayaq]

I had an oversized Manson on a 40 foot Amel and always slept well. An unexpected issue turned up when anchoring in 20 meters in the Pacific. I had a newish Lofrans Tigress and ran 10mm chain, but when pulling up the anchor and chain when it was a straight up vertical pull the windlass would trip, ended up over sizing the circuit breaker.

[Mike OReilly]

My approach for my bower is to get the largest ‘new-gen’ anchor me, my boat, and my anchoring system can reasonably manage under most condition. By this I mean having an anchor (& rode) that stores securely, does not put undue weight on the bow, can be easily deployed and retrieved by the crew, and is sized adequately with rope/chain and windlass (if applicable).

I think it is possible to go too big for a bower anchor (not a storm anchor). It’s not so much the setting issue — I think bigger is almost always better in this case. It’s the ability to manage the anchor so that the size doesn’t interfere with good anchoring technique. If the anchor is so big as to significantly tax you or your windlass you may be less inclined to haul it up for the fourth time and try for a better set.

So I say go big … but not too big .

[donradcliffe]

Originally Posted by onavegador

It is not only the size of the anchor who is important but also the chain. With heavy anchor an a light chain the shaft of the anchor my be lifted under circumstances.
As mentioned by other CF members look which anchor fits your bow and then buy enough chain with 5/16 dia. I guess 200 ft of 3/8 chain is too heavy for a 32 ft boat.

But I do not know where you plan to sail.

One of the problems you can have is setting your anchor in weed. A bigger anchor is more likely to penetrate the root system and set--weight and a sharp tip matter if your sailing grounds include weed.

Heavier chain does not prevent the shaft of the anchor from being lifted when the wind pipes up, but it can cut down on the amount you sail at anchor in moderate winds.

[noelex 77]

Even heavy chain can lift off the seabed in strong conditions.

However, the shank of the anchor will not lift unless you have a very short scope.

This is an example of an Ultra that is not very well dug in (it was a poor substrate). Despite this handicap, and the high angle of the chain, the shank is not lifting off the seabed.

Many people imagine the angle of the anchor shank is the same as the angle of the rode at the anchor end. This is not what occurs.

[denverd0n]

Originally Posted by a64pilot

I have heard the too big to set thing myself... I can't imagine how big too big to set would be.

I think "too big to set" would have to be very big indeed. Not like going from 25 to 40, but more like going from 25 to 110, for example. So big that some of the other factors (boat balance, ability to handle it) would come into play before you got there.

[barnakiel]

It is too heavy when you cannot lift it.

Our boat 3 tonnes light, the anchor is 15kg (33lbs).

So I would use a 20kg or better a 25kg anchor on a 34 footer.

Cheers,
b.

[sailorchic34]

20kg is all you need. I had a 44# bruce clone and now a 45# mantus on my Islander 34 (actually 33' and 7 tons) Never worried with either, though the mantus really holds 2 to 3 times better based on how hard it is to pull up.

[Moontide]

Have not read,all the replies, but the ones I did only talked about weight.i think the design is alao a major consideration.

I would take a somewhat lighter modern design (Mantus, Rocns, any spade type over a heavier less effective design (plow, danforth, Delta, Bruce, etc.)
Bill

[Spade Anchor]

Originally Posted by Moontide

Have not read,all the replies, but the ones I did only talked about weight.i think the design is alao a major consideration.

I would take a somewhat lighter modern design (Mantus, Rocns, any spade type over a heavier less effective design (plow, danforth, Delta, Bruce, etc.)
Bill

Great Point! Once an anchor is set the weight of the anchor then becomes a minimal factor. After the set, the design of the anchor is what is primarily holding the vessel.

The quickest way to find a properly designed anchor is look at the manufacturer recommendations for rodes. For example the Spade anchor only requires 20 feet of chain (for chaffing along the bottom) as the Spade anchor does not depend on the weight of the chain to hold it in place. Other anchors will recommend much more chain as their anchors need the help of the weight from the chain.

Also pay attention to scope recommendations. The Spade anchor will perform at 100% holding power at a 3:1 scope. Other anchors need at least a 5:1 scope, this is due to the fact that it is using the weight of the chain as crutch to help it.

A Spade Anchor s100 ( now 30% off) is the correct size storm/primary anchor for your boat.

[skipper53]

I'm using a 35# CQR as,the overnight hook on my Islander 32mk2 which is similar and weight to some of the boats listed above. Have to extend the bow,roller and channel to get it to nest right, but I think that's a worthwhile investment. We use a much lighter Danforth for a lunch hook.....

[thinwater]

Originally Posted by noelex 77

Even heavy chain can lift off the seabed in strong conditions.

However, the shank of the anchor will not lift unless you have a very short scope.

This is an example of an Ultra that is not very well dug in (it was a poor substrate). Despite this handicap, and the high angle of the chain, the shank is not lifting off the seabed.

Many people imagine the angle of the anchor shank is the same as the angle of the rode at the anchor end. This is not what occurs.

This is only true in good sand and very firm mud. In soft mud, that sort of upwards tugging will liquefy the mud around the anchor, and it will pull at only 20% of what it would at long scope.

In fact, the anchor in the picture is at less than 50% of full holding capacity, based on a considerable volume of pull test data of anchors at variable scope. It is good enough, because the sand is good, but it is NOT as good as it would be at long scope. Ask Ultra.

[thinwater]

Originally Posted by Spade Anchor

The Spade anchor will perform at 100% holding power at a 3:1 scope.

Show us the data, because I very seriously doubt that is true. In fact, Spade has been reported by many sailors to be somewhat weak at short scope.

Show us the data. A graph of holding capacity vs. scope from an independent source. What you are saying is not true of any data set on any anchor I have reviewed. Otherwise, I read this as hype. If I am wrong, I apologize, but it defies soil mechanics.

[noelex 77]

Originally Posted by thinwater

This is only true in good sand and very firm mud. In soft mud, that sort of upwards tugging will liquefy the mud around the anchor, and it will pull at only 20% of what it would at long scope.

In fact, the anchor in the picture is at less than 50% of full holding capacity, based on a considerable volume of pull test data of anchors at variable scope. It is good enough, because the sand is good, but it is NOT as good as it would be at long scope. Ask Ultra.

The point I was making is that the shank does not adopt the same angle as the chain. As you can see in this example.

This does not mean the holding power at short scopes is the same as longer scopes. From memory the scope in this case was about 3:1. As you point out the holding power of most anchor designs is typically around 40% at this sort of scope, in average anchoring depths and substrates.

[noelex 77]

Originally Posted by thinwater

Show us the data, because I very seriously doubt that is true. In fact, Spade has been reported by many sailors to be somewhat weak at short scope.

+1.