Photos of Anchors Setting

[GRIT]

OK, I'll play.

The Nyloc nut is not tightened enough to engage the nylon "locking" part. And, of course, there's no way to "mouse" the nut.

Thanks for all your work, and your wife's work, on this thread. It's very educational.

Cheers.
Paul.

[poiu]

The bolt attaching the anchor shank looks loose.

I know you said the problem wasn't in this area, but to my eyes the stainless shackle attaching the chain to the swivel looks like it is very probably undersized. With G40 chain and a good shackle, not a cheap one, the shackle arm will normally be the same or usually a big bigger in diameter than the chain. This one looks a little smaller. Considering the rough appearance of the shackle it is probably a cheapy, so even more likely to be undersized.

[noelex 77]

Originally Posted by svquintana

OK, I'll play.

The Nyloc nut is not tightened enough to engage the nylon "locking" part. And, of course, there's no way to "mouse" the nut.

Bingo. We have a winner

Congratulations to all the other posters too. You have raised some very valid points that I missed. I hope it encourages everyone to think about their own set up and examine it carefully.

Here is Nyloc nut problem that would concern me:




The Kobra uses a Nyloc nut to hold hold the fluke at the correct angle. If this bolt is missing, the anchor will not work at all, as seen from the example we saw last year:




Nyloc nuts are secure and I have no problem with the Kobra arrangement (swivels are also often dependent on a single bolt), however, it is important to use them correctly. The nyloc part of the nut is only a thin bit of material on the end of the nut. The idea is that it engages the threads of the bolt and stops the bolt gradually working loose.

To work correctly, the generally accepted rule is that 1 to 3 threads of the bolt must be protruding from the end of the bolt.

This bolt had no threads visible. In fact, I think the bolt was not engaging with the nyloc part at all. It looked to have been tightend up as much as was reasonable, so the bolt was just a little too short. This was an older anchor so I assume this bolt was one the owner replaced rather than the one supplied by Plasimo (Kobra makers).

I would encourage owners of Kobra anchors to check their bolt. It lies under the fluke so it is difficult to see when the anchor is on the bow roller. A nyloc nut should be perfectly satisfactory if the bolt is of the correct length, but as the anchor relies on this single bolt I would be tempted, myself, to peen the end of the bolt over in a "belt and braces" approach. An alternative would be to add some Loctite as well, although this may effect how the nyloc part functions.

Don't be put off the Kobra because of this bolt. It just needs a bit of care with installation. This owner was not putting much thought into his set up. Unfortunately, this is very common.

You are far more likely to get into trouble because your anchor does not hold and you drag, but the details like mousing your shackles are not hard to fix. Be particularly careful with any of the problems where the chain could become disconnected from the anchor. Without an anchor attached, the boat will drag rapidly in any sort of wind. If there are hazards in the way, you are unlikely to have enough time to recover control and will hit, or run around with more force than would occur in a normal drag.

[noelex 77]

Originally Posted by poiu

The bolt attaching the anchor shank looks loose.

I know you said the problem wasn't in this area, but to my eyes the stainless shackle attaching the chain to the swivel looks like it is very probably undersized. With G40 chain and a good shackle, not a cheap one, the shackle arm will normally be the same or usually a big bigger in diameter than the chain. This one looks a little smaller. Considering the rough appearance of the shackle it is probably a cheapy, so even more likely to be undersized.

Thanks for the input. Yes, I all agree with all that.

I think this an area where you should use a name brand shackle with a properly specified safe working load. Wichard and Ronstan come to mind for SS, Crosby and Green pin for galvanised, but there are many others.

I also agree the shackle looks a little small. They have used a shackle because the the shackle pin on the swivel was too big to go through the chain link, but I think they might have gone down two sizes.

It is silly to make any of the connections weaker than the actual chain and considering there may be some side loading it is worth going stronger if you can, but without knowing the chain specifications it is difficult to know for sure.

[tchavei]

Originally Posted by noelex 77

Bingo. We have a winner [emoji2]

Congratulations to all the other posters too. You have raised some very valid points that I missed. I hope it encourages everyone to think about their own set up and examine it carefully.

Here is Nyloc nut problem that would concern me:




The Kobra uses a Nyloc nut to hold hold the fluke at the correct angle. If this bolt is missing, the anchor will not work at all, as seen from the example we saw last year:




Nyloc nuts are secure and I have no problem with the Kobra arrangement (swivels are also often dependent on a single bolt), however, it is important to use them correctly. The nyloc part of the nut is only a thin bit of material on the end of the nut. The idea is that it engages the threads of the bolt and stops the bolt gradually working loose.

To work correctly, the generally accepted rule is that 1 to 3 threads of the bolt must be protruding from the end of the bolt.

This bolt had no threads visible. In fact, I think the bolt was not engaging with the nyloc part at all. It looked to have been tightend up as much as was reasonable, so the bolt was just a little too short. This was an older anchor so I assume this bolt was one the owner replaced rather than the one supplied by Plasimo (Kobra makers).

I would encourage owners of Kobra anchors to check their bolt. It lies under the fluke so it is difficult to see when the anchor is on the bow roller. A nyloc nut should be perfectly satisfactory if the bolt is of the correct length, but as the anchor relies on this single bolt I would be tempted, myself, to peen the end of the bolt over in a "belt and braces" approach. An alternative would be to add some Loctite as well, although this may effect how the nyloc part functions.

Don't be put off the Kobra because of this bolt. It just needs a bit of care with installation. This owner was not putting much thought into his set up. Unfortunately, this is very common.

You are far more likely to get into trouble because your anchor does not hold and you drag, but the details like mousing your shackles are not hard to fix. Be particularly careful with any of the problems where the chain could become disconnected from the anchor. Without an anchor attached, the boat will drag rapidly in any sort of wind. If there are hazards in the way, you are unlikely to have enough time to recover control and will hit, or run around with more force than would occur in a normal drag.

Threadlock (loctite 243, 603 and similar) will eat the nylon with time. One should never apply any kind of threadlock to nylon nuts.

Btw, a nylon nut was made to grab ONCE as it should. It wasn't designed to hold multiple insertions/removals. It's advisable to replace the nut after a strip down.

Regards
Tony

Sent from my keyboard through my phone or something like that.

[Spade Anchor]

A quick and inexpensive additional safety measure (in addition to using a nylock nut) is to use stainless steel bolt with a hole for a cotter pin or wire wrap.

[JPA Cate]

Interesting concept, Spade Anchor. You'd only use that somewhere it was unlikely to cut you or snag on something else. Wouldn't double nutting perhaps be a better idea?

Ann

[Spade Anchor]

Originally Posted by Ann T. Cate

Interesting concept, Spade Anchor. You'd only use that somewhere it was unlikely to cut you or snag on something else. Wouldn't double nutting perhaps be a better idea?

Ann

Double nutting is a good idea but most of the time the bolt is not long enough to accomplish that, especially with the nylock nut. You can also wrap wire though the hole in the bolt if the cotter pin does not seem safe enough for you.

[cwyckham]

Originally Posted by four winds

Oh, I totally misjudged the size. Thanks.

LOL. Me too. That second photo sure makes it look like he has massive hands! I wonder if he's a giant?

[cwyckham]

Originally Posted by Kenomac

Noelex,

That ain't nothin'.

Two weeks ago, I pulled up our anchor and noticed that it had some weed on it so I lowered it to maybe two feet below the water surface to allow my slow motoring to clean it off. I motored over to a friend's boat to say goodbye, but they were still asleep, so I unfurled the sails and continued on my way to the next anchorage. After an hour, I noticed that I'd left the anchor chain locker open, so I went froward to close it. Maybe an hour after that, I noticed that the bright yellow float attached to my anchor via a SS cable was not on deck... thinking I must have left it in the water by accident, I went forward to discover the anchor was still dragging along under the surface by two feet. Oops.

I'd sailed for over two hours with the anchor dragging along in the water. Luckily, no harm done.

I bet it was nice and clean, though!

[cwyckham]

Originally Posted by Panope

This time I pulled my trusty 33 pound Bruce (genuine) out from under the V-berth. My father bought this anchor after he lost his CQR in one of those 60 knot, hot and dry winds that frequently blow off of the West coast of Mexico.

We successfully used this anchor for 10 years and felt it was a very fine anchor - vastly superior to the CQR. That said, we never encountered serious wind while using it.

I always had the feeling that the Bruce would be a bit small for really angry conditions. Hence my decision to get the larger Manson Supreme to use as my #1 bower.

Steve

These are great videos, Steve! Thank you for posting them. I was very surprised by how poorly the Danforth did and who well the Bruce did (though I do like that anchor, I had the impression it would not react well to a snatch force. I was wrong).

It sure would be cool to borrow a CQR just for fun...

One question: Is the 2 knot bounce your usual setting procedure, or just for use in the filming? It seems backwards to shock load an unset anchor and then ramp up the rpm to set it. Once an anchor starts dragging quickly, it will continue to drag, so a gentle set at first with gradual load seems to be a far better setting technique.

Of course, the 180 drift at 3.5 knots is a potential realistic (though worst case) scenario and makes for some exciting footage!

[cwyckham]

I was super excited to get in the water and try to contribute to this thread.

We were finally anchored in shallow and clear water at Sucia Island in the San Juans (PNW) in about 3m of water.

I got my underwater camera out and braved the 9.5C water for about 15 minutes trying to find the damn anchor. Unfortunately, there was a thin layer of delicate, flat weed hovering an inch or two off the bottom and I couldn't find it.

I had an ice cream headache the whole time and came back with no picture.

I may need to put on one of those cool floats.

[noelex 77]

Originally Posted by cwyckham

I got my underwater camera out and braved the 9.5C water for about 15 minutes trying to find the damn anchor. Unfortunately, there was a thin layer of delicate, flat weed hovering an inch or two off the bottom and I couldn't find it.

9.5° Ouch! Thanks for trying . It is great to see lots of photos.

The anchor can be a bugger to find at times. A couple of things that can help:

• A temporary anchor float. Put a weak link in the connection. When you have finished, give the float a pull and the weak link will break.
  
  
• if you have an accurate GPS of the anchor position ( and this is is always worth knowing) a laser rangefinder (a great gadget) together with a Hand bearing compass can get you reasonably close. You need a helper on the boat giving hand signals.
  

[Panope]

Originally Posted by cwyckham

These are great videos, Steve! Thank you for posting them.

It was my pleasure as I thoroughly enjoyed making them.

I was very surprised by how poorly the Danforth did and who well the Bruce did (though I do like that anchor, I had the impression it would not react well to a snatch force. I was wrong).

I was surprised as well because Danforth anchors are heavily used and with great success in our area. Closer examination of this particular Danforth COPY, shows some glaring flaws compared to genuine Danforth anchors: Blunt fluke tips, very wiggly shank pivot, general shabby construction.

We used that Bruce anchor for 10 years without a problem so I knew it would do good in the test. Still, it was pretty impressive to see it remain buried during the wind shift test.

It sure would be cool to borrow a CQR just for fun...

I will keep my eye out for all sorts of different anchors to test

One question: Is the 2 knot bounce your usual setting procedure, or just for use in the filming? It seems backwards to shock load an unset anchor and then ramp up the rpm to set it.

As a child, I was a passenger aboard an engineless schooner that was on a lee shore under full sail. The situation worsened rapidly and the thing that saved us from ramming a dock or driving ashore, was the instantaneous deployment of a big fisherman anchor - at hull speed. The anchor set and saved the day.

I have since developed a belief that an anchor is a safety device that should set under demanding conditions.

So yes, I often deploy and set the anchor with lots of boat motion. I helps me develop and maintain procedures that work for the anchor, myself and the boat (I still have all my fingers and the bow roller and chain stopper have not been ripped out of the decks).

Once an anchor starts dragging quickly, it will continue to drag, so a gentle set at first with gradual load seems to be a far better setting technique.

This is true, and I am sure that I could have eventually nursed that Danforth Copy into the seabed with a very gentle pull. However, I am much happier knowing that that particular anchor will not tolerate an abusive setting technique. Consequently I will not tolerate having that anchor on the boat.

Of course, the 180 drift at 3.5 knots is a potential realistic (though worst case) scenario and makes for some exciting footage!

It sure does. I was hoping I could have been accurate enough with my reverse courses that the boat would pass exactly over the anchor and possibly pull the anchor out of the seabed (back-flip). The tendency for the these anchors to remain level and buried while being pulled from the opposite direction seems very strong.

Steve

[kas_1611]

Well we can all screw up sometimes!! Can't believe it actually held reverse like this but there you have it.
Thankfully I was able to dive down, reset the shackle and flip her over. We then reapplied reverse and got her to set properly.


Starting to dig in


Continuing to dig in


Dug in and set with 1500rpm reverse.

Goes to show how important it is to swim over and check your anchor. I'd honestly have thought it was dug in nicely if I hadn't checked visually.

Keiron