Anchor Swivel

[craigsmith]

Originally Posted by Nicholson58

I think that part of the problem with SS swivels is that they get used on galvanized steel chain. I would not be surprised if a local galvanic reaction might shorten the life of the swivel.

Why would it, when there's an abundant quantity of zinc around to protect it? In theory putting stainless next to galvanized components in sea water will shorten the life of the galvanizing on those components c/o galvanic corrosion. In practice the effect is so trivial it's not an issue. Not only are you spreading a myth, you have it the wrong way round...

Originally Posted by Nicholson58

Stainless is prone to cracking and intergranular corrosion expecially when under stress and where there is a crevice.

No it isn't, not per se. What stainless grade are you talking about? Formed and treated how? Be specific. Such a general statement is nonsense.

Originally Posted by Nicholson58

Many of the off-name brand parts are 304 SS instead of the more resistant 316L. 304 is slightly magnetic.

Magnetism is meaningless when it comes to identifying stainless grades or some kind of magic flag of quality: 316 can easily be magnetic depending on how it was formed and finished, and conversely grades far superior to 316 in the marine context (duplexes) are fully magnetic.

[Wand]

Sheesh Craig, you do have an unusual style for a commercial vendor. Most try to influence rather than pummel. You must have such confidence in your product that you think it will sell by itself. That aside, here's a genuine query from me to an obvious expert: what are your views on stainless as anchoring chain?

[craigsmith]

Originally Posted by At sea

what are your views on stainless as anchoring chain?

There's nothing wrong with quality stainless chain if money is no object. Key word quality.

[Wand]

Originally Posted by craigsmith

There's nothing wrong with quality stainless chain if money is no object. Key word quality.

Thanks Craig. I bought 50 metres of galvanised 13mm chain last year and the blokes put stainless in my trailer in error.

Question 1: should I have gone back?

Question 2: this stuff is stamped '316' and 'PMB' or 'PM8' and it looks the goods. Is it?

[craigsmith]

I think you mean PWB, the Australian chain manufacturer. I don't have any reason to impugn the quality of their gear, absent any specific problems or poor reputations I'm sure it's fine. If it really is an M instead of a W, sold in Australia as fake PWB, then that would sound alarm bells.

Assuming it's genuine, 316 can be in various grades. In its weakest it's a G30, or grade L. Depending on what you were originally ordering in galvanized - e.g. if you wanted G40 (M) - then this may be an issue just in terms of mechanical strength. I'd phone up PWB and have a chat to them.

(I wouldn't be using a G30 chain of any material at a size of 13 mm, just because it's so much heavier than necessary on a strength-for-strength basis, but that's a separate issue.)

You should also be able to easily get hold a proof certificate for the chain if you don't have one already. You're relying on the honesty of the issuer/manufacturer but as above that shouldn't be an issue if genuine.

[Wand]

Yes it is PWB; so I'll follow yr advice and call them. Many thanks, cheers.

[colemj]

Originally Posted by Fortress

SailFastTri,

I discussed anchor resetting with Don Hallerberg, the owner of Fortress awhile back, and he reminded me that "You have to remember: Once an anchor breaks loose, it might no longer be an anchor, it might just be a gob of mud or clay, with no sharp edges left and no hope of re-setting."

Robert Taylor of the US Navy concurred, stating: "A typical problem that can occur with any anchor embedded in mud or clay has to do with balling up the fluke with a consolidated “ball” of soil that stays with the anchor after it is pulled out. That “ball” can prevent the anchor from re-embedding."

Based on the above, I would not trust ANY anchor to reliably reset if it broke loose from a sea bottom.

The attached picture shows the problem with a Danforth pattern during a reversal/resetting. This boat dragged past us in a 20kt 180* wind shift in a protected anchorage. The bottom was sandy mud with a small bit of grass - pretty much perfect holding. I have also experienced the same problem several times with a Danforth. I have never experienced the problem with a CQR, Delta, Rocna or Spade. I have experienced the problem with a Bruce.

It is my opinion and experience that relying on a Danforth pattern to reset after a shift is too risky for me.

I do carry a Fortress on board for what I consider proper applications for it. I believe it excels in these applications better than any other anchor.

Mark

[Fortress]

Originally Posted by colemj

It is my opinion and experience that relying on a Danforth pattern to reset after a shift is too risky for me.

I do carry a Fortress on board for what I consider proper applications for it. I believe it excels in these applications better than any other anchor. Mark

Mark,

As Don & Bob concurred from a technical standpoint, a well-buried fluke anchor is not more likely to pull out during a wind shift, and it is hard to understand why it would.

We often talk with Fortress owners down here in our hurricane region where their boats are spun around during a severe storm and their anchor holds fast. In fact, the most common problem we hear about is getting the anchor back out!

BUT

Your experience is what you know and what you have to go by, and as along as you are safe & sound on the water, then that is most important, no matter what anchor you are using.

Take care,
Brian

Fortress Marine Anchors

[colemj]

It is easy to understand - the mechanism is the same as retrieving the anchor. When the shank of the anchor is pulled toward vertical, the flukes are no longer in an attack angle - in fact, they are in a release angle. If it didn't work this way, no one would be able to retrieve their anchors.

It is desirable for an anchor to pivot and stay buried during a 180* shift. When the wind veers around, like during the passage of a storm, most anchors will stay buried and pivot around. This may account for your stories of no release during storms. Or perhaps they did release and rebury without incident (either way, I am very happy for those people).

When a sudden 180* shift occurs, the boat rides over the anchor and the anchor can be pulled up and out (similar to the mechanism of retrieval) and hopefully flip over and reset.

These are the times Danforth anchors are vulnerable to a small rock or piece of coral or grass or mud ball, etc. As the picture above shows. Other anchors, with the exception of the Bruce are far less vulnerable to this problem.

And I just happened to have the presence of mind to snap a picture this time. We have seen this issue with Danforth patterns many times in anchorages.

Again, I'm not arguing against the Fortress anchor. I consider our FX37 a vital piece of our gear. If our boat is in the path of a large storm or hurricane, we will have the Fortress out. But not solely - it will be aligned to take the full force of ONE direction of a storm (the predicted strongest winds direction).

Mark

[Fortress]

Originally Posted by colemj

It is easy to understand - the mechanism is the same as retrieving the anchor. When the shank of the anchor is pulled toward vertical, the flukes are no longer in an attack angle - in fact, they are in a release angle. If it didn't work this way, no one would be able to retrieve their anchors.

Good points Mark. When the shank of ANY anchor is pulled toward vertical, as you described, the (2) flukes of the Danforth/Fortress or the (1) fluke of the Plow/Claw/Roll Bar types are no longer in the attack position, and they are ALL likely to break free in that scenario.

And as Don & Bob stated, when an anchor suddenly breaks loose from a sea bottom, it is likely to be just a glob of clay or mud, with no sharp edges nor ability to reset itself.

It is obvious that the Danforth/Fortress types with their (2) big flat flukes and larger surface area are more likely to come up with a clump of clay or mud embedded on them.....but for that same reason, they are also less likely to break free in the first place when compared to the (1) fluke Plow/Claw/Roll Bar types.

Originally Posted by colemj

These are the times Danforth anchors are vulnerable to a small rock or piece of coral or grass or mud ball, etc. As the picture above shows. Other anchors, with the exception of the Bruce are far less vulnerable to this problem.

True, but I am not trusting any anchor in rocks, coral, or grass. Power setting becomes even more critical in those tricky bottoms. If you back down hard on the anchor and it breaks free, then good, better then than during the middle of the night.

Thanks,
Brian

Fortress Marine Anchors

[Wand]

Originally Posted by Fortress

when an anchor suddenly breaks loose from a sea bottom, it is likely to be just a glob of clay or mud, with no sharp edges nor ability to reset itself. It is obvious that the Danforth/Fortress types with their (2) big flat flukes and larger surface area are more likely to come up with a clump of clay or mud embedded on them.....

And that's why IMHO the fisherman's or admirality anchor is best. In grass it digs in where others slide, and it comes up clean because there's so little surface area for clumps to cling to. It's always my primary but I also carry a fortress and often a third - safety in numbers...

[boatman61]

Originally Posted by colemj

These are the times Danforth anchors are vulnerable to a small rock or piece of coral or grass or mud ball, etc. As the picture above shows. Other anchors, with the exception of the Bruce are far less vulnerable to this problem.
Mark

What the hell are you talking about mate... a Bruce affected by a pebble or a bit of grass or coral... what a load of crap...
Either you don't know what a Bruce looks like or you don't know how to anchor....
Jeez.... this thread is just to funny.

[SailFastTri]

Originally Posted by boatman61

What the hell are you talking about mate... a Bruce affected by a pebble or a bit of grass or coral... what a load of crap...
Either you don't know what a Bruce looks like or you don't know how to anchor....
Jeez.... this thread is just to funny.

I think Mark was referring to a mud ball, with regard to the Bruce. My boat came with a stainless Bruce knock-off and the prior owner told me it was new because he dragged with his last one and lost it because he had to cut it free after dragging across other boat's rodes. He also told me about the time the anchor came up with a big round boulder. One of my first changes was to sell it on eBay and put a Rocna in its place. (I would have bought a Manson Supreme but due to differences in shape I could fit a bigger Rocna. I added this just to annoy Craig. )

BTW no need to throw insults, unless your name is Bruce.

[boatman61]

Originally Posted by SailFastTri

BTW no need to throw insults, unless your name is Bruce.

Nope.... I'm Phil..... Bruce is the 'Roo' on my head...
Also... if you use all chain to the correct length + depth its extremely unlikely an anchors going to do a vertical 180* flip... physics wont allow it... think about it...
Short length (50ft) of chain with nylon rode..?? thats another matter...

[boatman61]

In 1996 I was anchored in Andratx, Mallorca... anyone whose ever anchored there knows thats its a hard bottom and folks have no end of trouble bedding their anchors reversing all over the place... anyway... there were about 20 or so of us anchored on the 12th Sept when a tornado hit the Island.... every single boat dragged and ended up running for the inner harbour and tying up at the breakwater and fishing quay.... the only boat left on the anchorage was a green Westerly Longbow called 'Deep Water' riding out the wind and 2metre swell coming up the ria.... she had a Bruce anchor and 50 metres of chain out in 4metres of water... I added chain as the anchorage cleared.... so yup... I trust my Bruces and I know how to lay em.
That same storm wrecked boats in Palma and various other small places where boats were on moorings... 1 person killed on the front in Palma...
Who knows... maybe someone on here remembers it... I do.. it was the most exciting fun birthday I've ever had


Looking the wind in the seven automatic stations of Mallorca, were possible to follow the trajectory of the vortex through the island (see figure 17). Unfortunately the Radar of Valencia doesn't cover the island of Mallorca because is sited too far. At 1500 UTC the vortex was already at east of Mallorca, passed at south of Menorca at 1700 UTC, in Menorca (Mao airport observatory) were accumulated almost 14 mm of precipitation from 1600 to 1700 UTC. Then the activity of the cyclone began to decrease. When the vortex was over Mallorca there was observed an important increase of the wind, mainly of gusts. Gusts of 30 to 40 knots were normal during this period, and locally were registrated gusts of 40 to 60 knots. At 1800 UTC still remained the cyclone between Menorca and Sardinia, but less intense. It arrived to Sardinia at 2100 UTC.