Anchors - Bigger is Better ?

[downunder]

Originally Posted by Fortress

Jonathan,

Thanks for your input. We stipulate:

Boat size recommendations are for boats of average windage and proportions in 30 knots of wind, average bottom conditions, and moderate protection from open seas. For storm conditions we recommend using an anchor one or two sizes larger.

So let's use an example. According to the Horizontal Loads Table that is published by the American Boat & Yacht Council (ABYC), a 40 foot boat of average beam and windage will have a force, or load, against it of 1,200 lbs in 30 knots of wind.

Now if we go to our Selection Guide, for a 40 ft boat we recommend the FX-23 which will provide up to 8,000 lbs of holding power in optimal bottom conditions (hard sand), but only 1,200 lbs in soft mud (poor holding). if the shank / fluke angle is changed from 32 to 45°, then the holding power in soft mud will double to approximately 2,400 lbs.

So in 30 knots of wind, the FX-23 should hold that boat, of average beam and windage, in those bottom conditions.

However, if the wind pipes up to 42 knots, then the load will increase to 2,400 lbs, or double. That's ok if the bottom is hard sand, but in soft mud it might break free, so a larger model would advisable.

Brian

Thanks Brian.

I think you make a good point. Dashew's views on BIB anchors have shaped many cruisers views and your viewpoint confirms this.

A long distance cruiser needs to be prepared for storms in excess of 42 knots so that's why I will go for the BIB viewpoint. Cruising where Evans does definitely. Its a matter of by how much.

cheers

[congo]

Estarzinger Wrote:

Rex, if your anchor is twice as good as a Supreme, rocna or delta, why do you not recommend a much smaller (half?) one than a supreme, rocna or delta does? Same question for Mantus here?

Rex Wrote:

This is the thing, it’s not us that say we have twice the holding power, these figures were produced by Robertson whilst testing our anchors for certification, why on earth would I not take advantage of those independent tests.

Why not recommend a smaller anchor, three basics there are more, boats under survey, their anchors are specked on weight, I for one will not question the Authorities, two, anchor build strength, not much point on having a smaller anchor with the holding power lacking the strength needed, three, if you were to use a anchor half the size than normally recommended the surface area will not take down the chain, bury, so then you have less holding power from an anchor design that has demonstrated twice.

Regards Rex.

[downunder]

[QUOTE=noelex 77;1406654]-----------------------------------------------------------------------

These are exciting times for anchors with the current best anchors Rocna/MS and Spade,----------------------------------------------------------------------------/QUOTE]

Very bold and sweeping statement in light of some of the issues coming to light with roll bar anchors, Evans experience in very testing conditions and that there are other t least equal and new designs available.

All good anchors but best ??????

[JonJo]

Originally Posted by Fortress

Jonathan,

Thanks for your input. We stipulate:

Boat size recommendations are for boats of average windage and proportions in 30 knots of wind, average bottom conditions, and moderate protection from open seas. For storm conditions we recommend using an anchor one or two sizes larger.

So let's use an example. According to the Horizontal Loads Table that is published by the American Boat & Yacht Council (ABYC), a 40 foot boat of average beam and windage will have a force, or load, against it of 1,200 lbs in 30 knots of wind.

Now if we go to our Selection Guide, for a 40 ft boat we recommend the FX-23 which will provide up to 8,000 lbs of holding power in optimal bottom conditions (hard sand), but only 1,200 lbs in soft mud (poor holding). if the shank / fluke angle is changed from 32 to 45°, then the holding power in soft mud will double to approximately 2,400 lbs.

So in 30 knots of wind, the FX-23 should hold that boat, of average beam and windage, in those bottom conditions.

However, if the wind pipes up to 42 knots, then the load will increase to 2,400 lbs, or double. That's ok if the bottom is hard sand, but in soft mud it might break free, so a larger model would advisable.

Brian

It appears Fortress have quantitative justification for their recommended anchor sizings based on the holding capacity of the anchor and the potential load on the yacht (or anchor) at a given windspeed (in flattish water).

One wonders how the other anchor makers produced their recommended sizings.

I have not checked but - average windage? If this refers to all/any vessel then it presumably leans towards caution and covers 40' motor yachts (which might have a windage higher than the average 40' yacht, even with a yacht 'cruisers' high rise development on the transom)? If my assumptions are correct then the Fortress recommendations are very cautious for cruising yachts but might be 'about right' for a multihull.

Jonathan

[congo]

Jon Jo Wrote:
One wonders how the other anchor makers produced their recommended sizings

Rex Wrote:
We have always run with the anchors sizes—specks supplied by the authorities that make the shipping laws N.M.S.C. Lloyds, DNV, so on, in twenty years this has served us well, our insurance companies are touchy on this subject so for alls sake we run with certified regs, we will not make these decisions.
Regards Rex.

[Delfin]

Originally Posted by Fortress

Jonathan,

Thanks for your input. We stipulate:

Boat size recommendations are for boats of average windage and proportions in 30 knots of wind, average bottom conditions, and moderate protection from open seas. For storm conditions we recommend using an anchor one or two sizes larger.

So let's use an example. According to the Horizontal Loads Table that is published by the American Boat & Yacht Council (ABYC), a 40 foot boat of average beam and windage will have a force, or load, against it of 1,200 lbs in 30 knots of wind.

Now if we go to our Selection Guide, for a 40 ft boat we recommend the FX-23 which will provide up to 8,000 lbs of holding power in optimal bottom conditions (hard sand), but only 1,200 lbs in soft mud (poor holding). if the shank / fluke angle is changed from 32 to 45°, then the holding power in soft mud will double to approximately 2,400 lbs.

So in 30 knots of wind, the FX-23 should hold that boat, of average beam and windage, in those bottom conditions.

However, if the wind pipes up to 42 knots, then the load will increase to 2,400 lbs, or double. That's ok if the bottom is hard sand, but in soft mud it might break free, so a larger model would advisable.

Brian

Brian, your comments illustrate why the concept of BIB is pretty squishy. It all depends on where you anchor, how you anchor, how long you anchor, what risks for weather deterioration would be and no doubt other factors. As JonJo notes, many recommendations look like the product of wishful thinking. For example, based on the Ultra selection guide, I need a 176#, which I have. Manson says I need a 60# anchor. Rocna says 73#. Delta doesn't bother posting a selection guide I can find. Sarca Excel recommends a 194#. The anchor brand that must only be praised suggests a 105 - 125# will do. Fortress would recommend the biggest you got - an FX 125.

So while I think that some of the insinuations that anchor manufacturers undersize their recommendations to sell product may be true for some manufacturers, it certainly isn't true for Ultra, Fortress or Sarca.

[Shas Cho]

Originally Posted by JonJo

One facet to come out of this thread is that if anyone knows how the different designs work - they are keeping very quiet.

Maybe it really *is* the certification!
What I have learned on this thread
is that ALL of the new gen anchors
appear to be greatly superior to their ancestors,
even though they have evolved
in widely divergent directions!
That's a real head scratcher, to me.

- Shas

[Delfin]

Originally Posted by congo

Jon Jo Wrote:
One wonders how the other anchor makers produced their recommended sizings

Rex Wrote:
We have always run with the anchors sizes—specks supplied by the authorities that make the shipping laws N.M.S.C. Lloyds, DNV, so on, in twenty years this has served us well, our insurance companies are touchy on this subject so for alls sake we run with certified regs, we will not make these decisions.
Regards Rex.

Which is probably why your recommendation for sizing for my boat is nearly 3 times what Rocna's would be. If you follow Rocna's chart, then BIB up 3 sizes is highly recommended. If you follow your chart and buy your product, it probably is going to be like increasing your dock lines from 1" to 3". It might make you feel better, but is unlikely to add to your safety margin by a measurable amount.

[Shas Cho]

Originally Posted by estarzinger

If the 'next gen' anchors are in fact so much better why are recommended sizes not significantly smaller for them and why are people usually upsizing when they get one?

I think these are somewhat unrelated topics.
Two of the sad realities of modern life
are that,
1- the manufacturers have to satisfy the lawyers,
and
2- consumers have learned to distrust advertising claims.
These two facts combine to promote
the recommendation and purchase of larger anchors.

On a more positive note,
it may be that today's manufacturers
are providing "real world" recommendations
rather than the "ideal world" claims
we have come to expect.
If so, they are to be commended.

I do realise that these suggestions are incongruent,
but then we live in a world of incongruities.
That's part of the attraction of cruising, isn't it?
To embrace a life in which actions and consequences
are solidly related?

- Shas

[congo]

Originally Posted by congo
Jon Jo Wrote:
One wonders how the other anchor makers produced their recommended sizings

Rex Wrote:
We have always run with the anchors sizes—specks supplied by the authorities that make the shipping laws N.M.S.C. Lloyds, DNV, so on, in twenty years this has served us well, our insurance companies are touchy on this subject so for alls sake we run with certified regs, we will not make these decisions.
Regards Rex.


Delfin Wrote:

Which is probably why your recommendation for sizing for my boat is nearly 3 times what Rocna's would be. If you follow Rocna's chart, then BIB up 3 sizes is highly recommended. If you follow your chart and buy your product, it probably is going to be like increasing your dock lines from 1" to 3". It might make you feel better, but is unlikely to add to your safety margin by a measurable amount.
__________________

Delfin,
Not sure where you are getting your figures from?, Rocna 33K.G. 20 TON BOAT –45 FT
Excel, 30 K.G. 21 TON BOAT, 55 FT PLUS
Regards Rex.

[JonJo]

Originally Posted by Hydra

I think that in the past, mariners accepted to drag anchor from time to time: when the bottom wasn't holding well, in severe conditions, etc. The windlasses on yachts weren't really powerful, so owners chose anchors on the light side. They compensated for this by having more than one anchor and they had the manpower to deploy this. Old books are full of explanations on how to set a second anchor.

IMO, the sizing in anchor makers charts is based on this "old" concept.

But the present situation is different: cruisers don't accept to drag any more, even on mediocre bottoms, they don't have any crew to stand watches at anchor but they have a big powerful windlass. Since the quality of chain has improved, it's logical to reduce its scantling and put that weight in a bigger anchor.

Alain

Whereas I agree with this it is a bit broad brush, few of the long term cruisers had big crews, unless they omitted to mention they were married to sumo wrestlers, most of them cruised 'blind' with limited charts and local knowledge, most had non-existent forecasting, depth was by lead line, location by eye:

Electric Windlass have been available for decades. Accurate GPS, or sufficiently accurate for anchor watch, have also been available now for a couple of decades. The take up of G70 chain is minimal (people might now use G43 but probably to the same size as the recommended G30/BBB). But excepting the SARCA (then unknown outside Oz and NZ), Spade (so expensive) and Fortress (hung around with misconceptions) the idea of BIB is recent - in fact the idea of BIB seems to have occurred with the mushrooming of new designs, Rocna, Supreme, Excel, Knox, Mantus et al.

Its as if with the advent of double the holding capacity (of the anchors of around 2005) and the availability of cheap 5m GPS accuracy, a windlass capable of lifting almost anything we have suddenly been made aware that we also need much bigger anchors. This is despite the fact we have an instant availability of wealth of weather forecasts (unknown to our predecessors) and accuracy of depth sounding only a dream of our fathers and capable of determining bottom types. We have amazing chartplotters and radar so accurate you could berth your yacht blindfold (so, if you have the power, it backs up as an anchor alarm). Moreover because more are travelling there is more information on 'good' anchorages world wide.

The logic defeats me

Maybe we have realised our own vulnerability

Interestingly the quotes of modern anchors dragging, of the size recommended by the anchor maker, is very limited and often attributable to ignorance, the catching of a foreign object in the toe or fluke or the wrong anchor for that bottom. The numbers of yachts travelling with recommended sized anchors far outweighs the numbers of yachts with anchors 2 sizes too big and there is little evidence of the yachts with smaller anchors rushing to upgrade - which is what would happen if they dragged frequently.

One thing I would note: our yachts are bigger (so the electric windlass is essential - and as someone mentioned earlier you now need 2, critical with that bigger anchor); more of us are going further afield and we have more money to spend (this latter is not meant to invoke an argument - but I was brought up under effects of war time rationing).

Maybe despite our ability to have space age technology we are more conservative than our forefathers - and less cavalier.

Jonathan

[Cotemar]

Congo,

You sell anchors.

Is there any time that you would tell a customer, well you know you can get by with this smaller anchor.

If I were to sell anchors, I would want to protect my business and my pride and recommend only the BIB anchor. At that point it’s only a recommendation and nothing out of my pocket.

It’s a win win for the seller and the buyer. It’s a bit more money for the buyer, but they are sleeping well at night.

[sabray]

Real life tells me that my now replaced cqr could hold and set so hard I near could not get it loose. Ran it over jack the bow down on the waves. I bent the friggin shank. But it would not hold like that in every bottom. My Bruce held well within the same grounds. New England to chesapeake bay, block island, the vineyard Long Island etc....
I decided that as back up I would move the proven Bruce to second position and added a similar size supreme. The supreme sets faster. Like it locks up and I needed to be careful as I wasn't use to the chain going hard and running as the anchor bites much faster then the Bruce. As a stern kedge I use the fortress. Really haven't put this to a real test except I have rowed it out when I ran aground and it bit well and prevented perhaps movement that would have put me harder aground.
All to say I don't want something so big I can't manage it. It's easy to overkill and go all plant and no talent. Some of you guys can obviously manage these up sized anchors. My talent isn't up fir it. I want an appropriate size plus a tad and really good proven holding. I like some of the newer designs too. I think weight is not the key but well built good bight large surface high holding proven by someone other then me. Think I am repeating myself but that's the fun of getting old. I can't remember so much and old ideas come back up and I think wow now that's a new thought.

[JonJo]

Originally Posted by Cotemar

Congo,

You sell anchors.

Is there any time that you would tell a customer, well you know you can get by with this smaller anchor.

If I were to sell anchors, I would want to protect my business and my pride and recommend only the BIB anchor. At that point it’s only a recommendation and nothing out of my pocket.

It’s a win win for the seller and the buyer. It’s a bit more money for the buyer, but they are sleeping well at night.

The reality is that yes you might suggest the bigger anchor and the punter goes next door and speaks to the competition who do not quote the bigger one - but have lots of spin (or omitting to mention the weak shank etc, maybe you have forgotten the Rocna debacle) - so guess which anchor the punter buys, guess which anchor maker goes out of business first.

Commercially reality.

Jonathan

[Cotemar]

Originally Posted by JonJo

The reality is that yes you might suggest the bigger anchor and the punter goes next door and speaks to the competition who do not quote the bigger one - but have lots of spin (or omitting to mention the weak shank etc, maybe you have forgotten the Rocna debacle) - so guess which anchor the punter buys, guess which anchor maker goes out of business first.

Commercially reality.

Jonathan

Agree, but it seems that all the anchor makers are in the BIB park.
They all seem to be pretty close on sizing there anchors.