Anchors - Bigger is Better ?

[congo]

Sorry Ann.

I realy appologize for the incorrect initals, it was not intentional.

Regards Rex.

[JPA Cate]

Congo,

"J Cate Wrote:
Big ooooops, guys, sorry. The anchor in question is a Rocna, not an Excel.

Please accept my apologies, I blew it.
__________________
Ann Cate, as/v Insatiable II, cruising "

No, Congo, that was Ann who wrote that, Ann who was wrong. It was me! I had a senior moment, and I blew it, not Jim!

Ann

[Graceunderway]

Originally Posted by Kettlewell

At a glance I don't think that's a Hi Tensile Danforth, but probably the regular one. The Hi Tensile ones are a lot stronger. What size anchor and boat and where were you anchored?

This was the regular Danforth. 45 ft LOA and the anchor came with the boat when we bought it. It was rated for that size of the boat (it was not size up). Now we have Delta (main and 2nd) rated for 45-55 ft boats. So far so good.

[Kettlewell]

This was the regular Danforth. 45 ft LOA and the anchor came with the boat when we bought it. It was rated for that size of the boat (it was not size up). Now we have Delta (main and 2nd) rated for 45-55 ft boats. So far so good.

I've seen more than one Danforth that looked like that. The problem is they can get so deeply buried there is no way they will rotate when the wind shifts, and something has to give. That's one reason that R.D. Ogg, co-inventor of the Danforth type anchor, always recommended using two lightweight anchors to limit the change in direction of pull.

It's also why some here on CF make the argument that a lot of the new-gen anchors have shanks that are potentially too weak for their holding power.

From another thread here on CF:

[Delfin]

Originally Posted by Kettlewell

I've seen more than one Danforth that looked like that. The problem is they can get so deeply buried there is no way they will rotate when the wind shifts, and something has to give. That's one reason that R.D. Ogg, co-inventor of the Danforth type anchor, always recommended using two lightweight anchors to limit the change in direction of pull.

It's also why some here on CF make the argument that a lot of the new-gen anchors have shanks that are potentially too weak for their holding power.

From another thread here on CF:

When Peter Smith first built the Rocna, he stated that 800 mpa steel was necessary because the shank was thin, by design. Rocna doesn't use steel of this grade, although Manson does and the Excel has this grade. Side loads can be significant if the anchor is pinned on a rock, so it makes sense to use this grade of pretty springy and very robust steel, which is what you want if you want the holding power of a new gen anchor.

Speaking of anchors, I submit what may be the worst picture associated with a recommendation for a particular anchor I have seen. Correct me if I am wrong, but isn't the point of an anchor to keep the boat off the beach? This one from the testimonial section of the Mantus site.

[Andrew Troup]

Kettlewell

Indeed. I indirectly had some dealings with Robert Danforth Ogg at the height of his powers, possibly designing and manufacturing a new direction (non anchor or compass) product line for which we had IP and in which he expressed an interest ... and he noted my interest in anchors, so he made me a present of his accumulated written wisdom on anchoring.

As a consequence we never laid to a single Danforth in any sort of a breeze, and found a small Danforth as a second anchor a perfect complement to our main anchor, which was a Fisherman (because our sailing grounds tended to be rocky).

The Danforth, laid in a V at say 30-45 deg with the Fisherman, would compensate for the mediocre holding of the latter in mud and sand, as well as preventing the chain on the fisherman fouling the upstanding fluke. Partly this was because, even in a prolonged gust coming from the direction of the fisherman, it was being pulled in the same line as when the wind came from the Danforth, so the fisherman was not being disturbed, and would stay well dug in.
Then of course, the fisherman protected the Danforth's shank from it's Achilles heel weakness. And supplemented the sometimes patchy performance of the Danforth in rocky bottoms.

We were anchored like this in a very windy situation in the notorious Cook Strait region wind-funnel. We had to rig a temporary baby-stay because the mast was pumping so hard from vortex shedding it was shaking the boat. The big Colin Archer next to us had a massive Danforth which made ours look toy-like, but he was lying only to that.

All our anchors held, his as well as ours, except that when we raised, his was bent as per the above photo, while ours was straight. Moreover, he had sheered wildly about for twenty hours at the height of the blow, while we lay quietly head to wind.

Delfin:

Anchors have many uses, it seems to me, other than the one you highlight.

They serve a very useful purpose for boats with retractable keels which intentionally dry out: they need something to hold them from travelling further inshore when the tide comes back, and they need a convenient way of hauling out into water deep enough to get underway.

[Kettlewell]

They serve a very useful purpose for boats with retractable keels which intentionally dry out: they need something to hold them from travelling further inshore when the tide comes back, and they need a convenient way of hauling out into water deep enough to get underway.

Like how they are used from the stern on landing craft to pull them back off the beaches.

[noelex 77]

Originally Posted by Delfin

Speaking of anchors, I submit what may be the worst picture associated with a recommendation for a particular anchor I have seen. Correct me if I am wrong, but isn't the point of an anchor to keep the boat off the beach? This one from the testimonial section of the Mantus site.

The photo shows a retractable keel yacht drying out. A common practice in many parts of the world.

[Snowpetrel]

Originally Posted by Delfin

This one from the testimonial section of the Mantus site.

Cool picture. Looks like one of Matt Laydens awesome little microcruisers. Complete with chine runners.

[Kettlewell]

I met someone who cruised in something like that in the Bahamas once, except this boat was only slightly larger than a coffin and rather looked like one too! Out of ear shot we called it the "coffin boat," but he was way down in the Exumas and seemingly having a great time in a boat that many of us would be afraid to take across the bay.

A key point of looking at various bent anchors is that there is more to consider than sheer holding power. Some have wondered if anchors like the Kobra II have more holding power than their construction can handle. I don't have a definitive answer, but it seems like we are seeing a lot of reports of various bent and mangled anchors in recent years.

[boatman61]

Proof that global warming is affecting life on earth for sure...

[Delfin]

Originally Posted by noelex 77

The photo shows a retractable keel yacht drying out. A common practice in many parts of the world.

Yes, I gathered that.

Just seemed that in promoting an anchor, a shot of a boat not on the beach might be more effective. Kind of like advertising a car by showing it toodling down the freeway rather than torn apart in the repair shop.

[Kiwikat]

I just found this thread so I have not gone through and read all of the 700 and something odd posts but would like to add my 2 cents worth in as I missed out posting on those other threads before they unfortunately closed them.

The initial reaction is of course Bigger is Better.......... unless you are moving to a more superior anchor. Just my opinion, so shoot me down in flames if you so desire.

Six months ago we switched from a 32kg Trefoil (Bruce lookalike) to a 25kg Super Sarca as our primary anchor. Four of those six months have been out cruising and on the pick full time in a wide variety of anchorages and conditions. We chose a #7 which falls well into the manufacturer's recommendations for our boat length and weight and even though we are a catamaran, we felt we did not need to go one size up as a #8 would have seemed a bit of an overkill.

We have had a Sarca on our monohull for the last eight years. We were on the borderline spec for that one so we did take the upsize option but we soon realised that we needn't have bothered.

Incidentally, we went out diving for scallops with our cruising buddy and his boat last month. He was very impressed that our Super Sarca was perfectly set whilst his big heavy CQR was lying on it's side - we had not even tried to set our anchor - he had. We sleep very well at night!!

Cheers
Lisa

[DumnMad]

Originally Posted by Graceunderway

Winds 40kt and it held all night! But ride was rough!

Bent shank - thats how the shank should fail if overloaded. Higher tensile steel is more brittle - over 500MPa not allowed in building - less able to take cyclic loading and second bend can break without warning.

High strength has its place but if the shaft bends don't continue to use it.

[Pelagic]

I understand there are now new regulations for barbless anchors.

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