Anchor problems - a warning!

[MartinANick]

Pulled the anchor up after a pleasant day in Sark. Just as it came up onto the roller the holding bracket snapped and it headed off into the depths. Gone a 15 kg stainless steel Bruce anchor.
Extremely annoyed.
The anchor was held on by a stainless steel swivel bracket which is in 2 parts. It allows the anchor to swing and seat more easily. All I was left with was the 'female' part of the bracket hanging on the end of the chain.
My boat is only 5 years old and this is the first time I've ever heard of this happening.
Moral - check your anchor to chain linkage on a regular basis!
The most frightening thing about this is that if we had not been on board and the anchor had parted company...................!!

Martin

 

[duncan]

I believe, anecdotally, that it's not unusual with certain designs/manufacturers

However, just to be absolutely sure what failed and how, it would be really good if you could post a few pictures of 'what's left' - otherwise you will just end up with a generic thread along the lines of the opening sentence above.

FWIW mine has been fine for 9 years

Finally, I assume you noted the GPS position and can arrange recovery easily enough?

 

[Deleted User YDKXO]

Was this a Kong type swivel like thishttp://www.chandlerycompare.com/products.php?categoryId=1235&productId=7526? If so, I have found that the female end tends to splay outwards after a few years use. Also the screws need checking for tightness occasionally. To be fair, you should check any connector between the chain and the anchor regularly as the safety of your boat may depend on it

 

[andy59]

Hmmm , which would i rather happen , my anchor coming up nice and neatly so i dont have to touch it , or possibly watch my boat float away on the tide , choices , choices .

 

[MartinANick]

Yes its a kind of Kong swivel although a slightly different design but on the same principle. And yes I am arranging to retrive said anchor with a friendly diver. I know exactly where it is and its on a sandy bottom. New price quotes from £350 to £550 so hopefully no one else gets there before me!

I must admit I have been lax at checking the linkage - its just something that hadn't crossed my mind. I religously always make detailed checks on all the boat equipment but missed this!

I do have a pic of whats left and have tried to upload it but it doesn't seem to have attached

 

[benjenbav]

Hang on a sec. Doesn't the chain do quite a bit of the actual holding?

 

[Deleted User YDKXO]

Yes its a kind of Kong swivel although a slightly different design but on the same principle

IMHO never use shackles for any purpose without knowing their provenance and test load. The Kong is well known and widely used and I would be surprised if one actually failed

 

[Deleted User YDKXO]

Hang on a sec. Doesn't the chain do quite a bit of the actual holding?

Yes thats my experience too. One of the advantages of being in the Med is that I can doggy paddle out to my anchor and see what it's doing which is invariably f*** all. If I put out about 3x depth, normally I see at least 50% of the chain sitting on the sea bed apparently not moving at all which indicates to me that there's little or no load actually on the anchor. Even when I think I've set the anchor, it's often still on it's side rather than dug in. The only time I've seen my anchor well and truly dug into the sea bed was after a night at anchor off Ibiza when the wind really blew up

 

[MartinANick]

I have checked 4 other boats that moor near me and they all have the same connectors to the anchor so they do seem to be popular. Maybe my anchor gets a lot more strain here in the Channel Islands and it is not unknown for us to anchor in a 6 or 7 knot tide so it does have quite a tough time but even so it shouldn't have failed in such a short life. I have contacted Windy (I have a 37 Grand Mistral) for their comments but have not heard anything as yet.
Its interesting though Mike that anchoring with my Bruce can be a bit of a hit and miss affair and I have seen in low water that the anchor quite often turns over on its back and it requires several attempts before getting a good grip

 

[Nick_H]

The anchor was held on by a stainless steel swivel bracket

A lot of people don't like stainless steel anchor swivels because they are more prone to stress fracture than galvanised, although we don't know the failure mode of yours without more info.

As Deleted User says, if you do want to use stainless, it's probably a good idea to go for a reputable make and check it regularly.

 

[Deleted User YDKXO]

Its interesting though Mike that anchoring with my Bruce can be a bit of a hit and miss affair and I have seen in low water that the anchor quite often turns over on its back and it requires several attempts before getting a good grip

Yes thats my experience too. I'm no expert but Bruce anchors seem to work well in mud but have a problem getting a bite on hard sand or stones or weed. My personal preference is a Delta which, for me, has worked better in a wider variety of conditions. I also like the look of the Rocna although I've never used one in anger but I see increasing numbers of these about

 

[AdeOlly]

Yes thats my experience too. I'm no expert but Bruce anchors seem to work well in mud but have a problem getting a bite on hard sand or stones or weed. My personal preference is a Delta which, for me, has worked better in a wider variety of conditions. I also like the look of the Rocna although I've never used one in anger but I see increasing numbers of these about

I agree that the Bruce works very well in mud; anytime we anchor in Newtown Creek our Bruce invariably comes up with several kilos of stinky sticky black mud semi-welded to it.

 

[DAKA]

I thought there was a test done in MBM MBY ? August time ?
I read up on it somewhere around that time where different makes were tested to destruction.

Several models were tested and the Inox came out top due to the way it was manufactured and in particular the way the pin was held fast both sides of the fastener, which should stop this from happening

It is important to over spec the swivel as stainless 316 is fragile compared to steel and it is theoretically possible to break it with the snatch action.

Anchoring off Sark (and the CI) can be in deep water with fast tidal flows, I can understand your apprehension.

 

[Deleted User YDKXO]

I thought there was a test done in MBM MBY ? August time ?
I read up on it somewhere around that time where different makes were tested to destruction.

Several models were tested and the Inox came out top due to the way it was manufactured and in particular the way the pin was held fast both sides of the fastener, which should stop this from happening


It is important to over spec the swivel as stainless 316 is fragile compared to steel and it is theoretically possible to break it with the snatch action.

Anchoring off Sark (and the CI) can be in deep water with fast tidal flows, I can understand your apprehension.

I can't find any reference to the INOX swivel anywhere on the net other than your link which is odd. What is also odd is that the word Inox is the French/Italian word for what we call stainless steel. Maybe the Canadian website has misdescribed what looks very much like the Kong swivel which is made of Inox? I stand to be corrected though.
Yup, your pic of the Kong swivel illustrates what I was saying about the female end splaying out which I believe is caused by the allen screw which is supposed to hold the anchor in it becoming loose which is why it's always worth checking the tightness regularly

 

[DAKA]

I can't find any reference to the INOX swivel anywhere on the net other than your link which is odd. What is also odd is that the word Inox is the French/Italian word for what we call stainless steel. Maybe the Canadian website has misdescribed what looks very much like the Kong swivel which is made of Inox? I stand to be corrected though.
Yup, your pic of the Kong swivel illustrates what I was saying about the female end splaying out which I believe is caused by the allen screw which is supposed to hold the anchor in it becoming loose which is why it's always worth checking the tightness regularly

That has me confused now(not saying you are wrong).

The swivel that came out top had Inox on it, the difference was the end pin, it wasnt screwed in , it had a key that fixed in with a 90' twist, effectively it couldnt open up like the others.
I will do a search and see what I can find.

 

[NormanS]

The moral to all this is: DON'T USE A SWIVEL. Unless you are sailing in water with the viscosity of treacle, any swivel is entirely unnecessary.

 

[DAKA]

I Think

The link you posted of a Kong swivel is not actually a photo of a swivel.
It shows the 'swivel' as being split in two which is a real concern, my guess is the photo isnt a kong or a swivel.

The one here http://www.proboat.co.uk/item.asp?cat_id=24&prod_id=443 is very different , as the best in the test I saw there are two differences to look out for,

1 the Allan bolt does not hold the chain, it only keeps the shackle closed together.
2 the pin holding the chain is a key fitting which twists 90' to lock in place.

We are talking about the same type of principle design which is stronger than other types . (although the broken photo I posted looks like the Kong/Inox it is not the same as it lacks the Allen bolt that locks it together, the broken one relies on the same bolt that holds the chain which will fail first.



I will have a search over the weekend for the test as it was a very good test and made good reading.
I have my doubts that the link I posted in my previous post is actually the wrong photo for the product too.

 

[Deleted User YDKXO]

We are talking about the same type of principle design which is stronger than other types . (although the broken photo I posted looks like the Kong/Inox it is not the same as it lacks the Allen bolt that locks it together, the broken one relies on the same bolt that holds the chain which will fail first.



I will have a search over the weekend for the test as it was a very good test and made good reading.

The Kong definitely has 2 allen bolts at each end. I would be very concerned about a swivel which had a 90deg bolt at one end. I dont remember the comparison in either MBY or MBM but I would be interested if you find anything

 

[Deleted User YDKXO]

The moral to all this is: DON'T USE A SWIVEL. Unless you are sailing in water with the viscosity of treacle, any swivel is entirely unnecessary.

How do you stop the anchor coming into the bow roller inverted?

 

[NormanS]

How do you stop the anchor coming into the bow roller inverted?

It's never been a big problem, but using either a roller with a decent diameter, or two rollers (one behind, and higher than the outer one) are the normal solutions.