Anchors - Bigger is Better ?

[congo]

There is much silence,

I would at least think about it, surely you are not that gullible to not understand that if you weld something to something you are no longer testing the standard properties of what you are supposed to be testing, at least do some research, ask the question, proof, you have belted me enough.

We lay it all out on the table, no gimmicks, no lies; you get what you pay for.

Regards Rex.

[DumnMad]

If Bisalloy 80 is not so good regarding cyclic fatigue failure and crevice corrosion in seawater it would be OK for day sailers but not for cruisers.

[Andrew Troup]

Man oh man, congo, didn't anybody ever mention to you that too much of a good thing is NOT exactly the right amount?

(Liberace was wrong about that, I reckon....)

I reckon if you baited a mousetrap, there wouldn't be room for the mouse....

[Kettlewell]

Apparently, in the April issue of Practical Sailor there will be an article on anchor shank strength. Has anyone seen it yet?

[Kettlewell]

And, here's an old BoatUS test on anchor strength. Those old Bruce anchors were pretty strong, with the CQR not far behind.

[conachair]

Originally Posted by Kettlewell

And, here's an old BoatUS test on anchor strength. Those old Bruce anchors were pretty strong, with the CQR not far behind.

The downside of these sort or articles is that you wander in hoping to find some answers about the real world and come out empty handed, there are none. Just how important is shank strength? When does it start to really count? There isn't the masses of data available and far too many variables to come to any real conclusions.
So I think long distance cruisers do these days just what they always have done, get a big one that seems to work OK and hope for the best

[Kettlewell]

Just how important is shank strength? When does it start to really count? There isn't the masses of data available and far too many variables to come to any real conclusions.

I basically agree, though I have also seen a fair number of bent anchor shanks and other physical damage to anchors, though mostly non-name brands. I think it takes an extraordinary situation before you develop the types of loads needed to damaged things. Most of us try to avoid those situations, so the real-world experiences are few and far between, and often it is impossible to draw conclusions based on widely varied experiences.

[boatman61]

Or to put it another way... if it aint broke.. don't fix it.
Some have better things to spend money on than expensive new fancy anchors when what we've got works just fine.. so a secondhand Bruce/CQR is just fine.. they fit bow rollers..

[Kettlewell]

So, since the subject of strength came up, who knows what Spade anchors are made of? For that matter, does anyone know where they are manufactured these days?

From the Spade website:

SPADE is designed for strength. The shank is designed to be strong yet light, with the classic trapezoidal profile (like a box girder) being used in our welded models. With the new, fabrication technique now used for most of our models, the shank has an "I" profile for the same reasons. The shank sockets into the body of the anchor, with a socket supported by double triangulation, giving a rigid and indestructible joint.

The shank profile and the coupling to the blade, together with the use of high resistance steel alloys give the SPADE anchor very high mechanical resistance.

[Andrew Troup]

Originally Posted by conachair

The downside of these sort of articles is that you wander in hoping to find some answers about the real world and come out empty handed, there are none. Just how important is shank strength? When does it start to really count? .....

From the BoatUS article:

The test procedure was designed to simulate the type of load that results from an anchor's fluke(s) being lodged in rock, coral, a stump, or other unyielding surface in a strong wind or stressful retrieval situation.

I think they make a very good point. It's not always desirable or possible to put a diver down when we've hooked into a biggie.

And if we do get lucky and drag into something immovable (like a bottom chain, often found in basins formerly used for ships) in a bad blow, we want an anchor strong enough to hang in there.

Conceivably a smallish genuine CQR could be dug out from the 'naughty corner' of the lazarette in circumstances where someone needed to seek refuge in a location with a foul bottom of this type (common in parts of the Med, for instance), with the intention of grappling for such a chain.

[Andrew Troup]

A trick for anyone intentionally fouling (or who thinks they might unintentionally foul) an anchor: It's a good idea to have a REALLY strong tripping buoy.

"Oh No!" you cry, "Tripping buoys are a Hazard, and a Menace to Shipping !"

Well, actually, Not if they're submerged.

Here's the trick: you have to have prepared a couple of items of gear ahead of time for this contingency.

A) for the buoy: one thing which works quite well is a small, squat LPG high pressure bottle, like the Primus ones which used to be common in Europe. Find or make a bolt which is a good fit to plug the opening, and weld a strong ring to it. Use a short chain or strong wire from this buoy to shackle strongly to the trip-eye of the anchor.

(Other ideas would work fine provided they're strong enough. Fouled anchors can be highly resistant to tripping)

When your anchor needs to be retrieved, the buoy can be found and secured by dragging a shortish steel bar, bent in a V or C shape which will fit around the bottom of the buoy, between two ropes, one to an eye at each end.

Either use two dinghies, or a single dinghy with the other end paid in and out from the bow of the anchored boat. (Start short, row in an arc sweeping the grapple across the line of the chain, lengthen and row back, etc.)

[conachair]

Originally Posted by Andrew Troup

From the BoatUS article:

The test procedure was designed to simulate the type of load that results from an anchor's fluke(s) being lodged in rock, coral, a stump, or other unyielding surface in a strong wind or stressful retrieval situation.

I think they make a very good point. It's not always desirable or possible to put a diver down when we've hooked into a biggie.

And if we do get lucky and drag into something immovable (like a bottom chain, often found in basins formerly used for ships) in a bad blow, we want an anchor strong enough to hang in there.

Conceivably a smallish genuine CQR could be dug out from the 'naughty corner' of the lazarette in circumstances where someone needed to seek refuge in a location with a foul bottom of this type (common in parts of the Med, for instance), with the intention of grappling for such a chain.

Still tells you nothing about the real world, I've just been watching a documentary about Richard Feynman

[Kettlewell]

Another anchor tripping rig I have heard of is simply to use a short piece of yellow, floating poly line with an eye on the end, making sure it won't reach to within say 6 feet of the surface. When you need it, someone has to dive to hook another line to it, eye to eye. The problem with that is here on the East Coast of the USA we frequently anchor in 10 feet or less of water. However, bottom line for me is that I have never lost an anchor and therefore I don't worry about the possibility. Maybe the day will come, but I haven't been hassling with tripping lines in decades. Then there's the Super Sarca...

[congo]

Re: Anchors, Bigger is Better?
And, here's an old BoatUS test on anchor strength. Those old Bruce anchors were pretty strong, with the CQR not far behind.
__________________
Kettlewell Cruising

The old boat test, Well I rest my case, with video test above on Rocna, why would anybody test incorrectally and quote specific, unreal, load with standing strengths they know full well if proof tested correctly, the shank would more like produce a third of its strength as to their figures? What about the fluke strength, welds.

Kettlewell link confirms our procedure, vertical load two thirds down the fluke puts all componentry aspects of construction and welds under enormous loads, this method is designed to determine the whole anchor designs strength, and the leverage pays out far greater stress loads on shanks.

Why buy a rated tow ball if the tow bar has not been tested, proof load testing, we don’t just make anchors for cruisers but large commercial boats, whilst you may doubt some of these proof loads the commercial industry rely on, anchors that have been stretched to the limit for workable safety reasons, why wouldn’t cruisers want the same guarantee.

But if you were to purchase an anchor proof tested deploying the method as in the video above, you certainly would not be getting anywhere near the loads you have been lead to believe.
We have standards for all things to make them safe and perform when unexpected loads are applied from whatever, why are your shackels tested, chian, why bother if your anchors build strength is unknown.
Regards Rex.

[Kettlewell]

Rex, I'll be a bit of a Devil's advocate here. Is there an argument to be made that real-world conditions would be very different from these test-bed conditions, whatever the protocol? Is the strength being tested here relevant or just a number that doesn't really mean much? I know that car manufacturers often tweak many things in order to maximize fuel mileage on the standardized EPA test, but when someone drives the same car in the real world mileage will generally be much less.