Daria Blackwell
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Scary thought and photo John. And it would happen just when things are hairiest out there. Thanks for sharing that.
Vice Commodore, OCC
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Daria Blackwell
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By the way, another great post on the subject here by John http://www.morganscloud.com/2010/09/12/anchor-swivels/.
Vice Commodore, OCC
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Daria Blackwell
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Alex and I are not proponents of swivels. One of our main reasons is that you cannot see inside the housing of most swivels to be certain there is no corrosion; this is especially important for stainless steel swivels which are particularly susceptible. The Quickline cast SS swivel was recalled a couple of years ago and there was a good discussion in Practical Sailor. http://insidepracticalsailor.com/quickline-recalls-cast-stainless-steel-flip-swivels/
Friends of ours lost two SS anchors off their bow while underway. First one sheared so they replaced it with am "improved version". Then the second failed. In both cases the swivels sheared at the pin. See photos. The swivel pin was not visible inside the housing and corroded in a very short period of time. The corrosion is particularly aggressive in wet areas - like on the bow which is always subject to spray.
Ultra has created a new swivel which allows inspection of all the parts and also eliminates the need for a shackle. http://www.ultraanchors.com/ultraswivel.html They have sent us a sample for inspection and testing so we 'll let you know what we think later this season. [attachment=22]DSC08867.JPG[/attachment]
Happy Hooking!
Vice Commodore, OCC
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Simon Currin
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Bill yes it may be time for a re-think! What disturbs me most about John 's photo is that I think it was the the same model as ours. Looks like most people carry a lot more chain than us too so plenty of food for thought. Simon
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Bill Balme
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[quote="simoncurrin" post=252]I can 't imagine not using a swivel but obviously Daria is the expert so we will await her wise words. Simon[/quote] Simon, looks like you 're in the minority regarding that use of the swivel... maybe a re-think is in order having looked at John 's picture! As it happens we 're doing an inventory on Toodle-oo!, including all the stuff that came with the boat. In amongst the junk I found myself an anchor swivel of a type I 've not seen currently available. Good job too - it 's a ball and socket arrangement which I have to believe must be a real weak link! Hopefully it 's a discontinued item. Anyone want to buy it? :unsure:
Bill Balme s/v Toodle-oo!
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John Franklin
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[attachment=16]Anchorconnector.jpg[/attachment] Here 's the photo of the failed swivel. The opened yoke had been attched to a "D" shackle on the end of the CQR stock. The pin of the shackle was through the hole in the anchor stock and the pin of the swivel yoke was through the "D" of the shackle. I think that on one of our violent perambulations the chain must have come up tight leading almost parallel to the anchor stock causing a twist across the jaws of the yoke, which just spread them open (13 tonnes of boat travelling at 2-3 knots) and popped the pin out. This is how the swivel was when we hauled up the chain, with the other (smaller) end still attached to the chain.
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chrisdevans (Past OCC Member)
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Johns horrible experience with a conjoined double shackle type swivel (I am assuming from description of failure) is very much the same as where we were heading with our problem twisted swivel.
Our new one is the Kong swivel which is very clever in that there is basically a two part manufactured piece - hard to describe - so both chain and anchor connections cannot twist out like shackles can. Recommend check out Kong website/catalogue.
The Kong is more expensive than most, but seems to me to be money well spent.
The extra chain between swivel and anchor is obviously only possible if windlass is sufficiently far from roller. It also does avoid extra pressure on swivel over roller when not directly connected to anchor.
Chris SV Tulu of Fowey
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rptrsn
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Chris,
Good idea on the 6" chain between the shackle on the anchor and the swivel. I think I 'll dig up a short length and give it a try! It might also make it easier for the anchor to come up over the bow roller.
Cheers, Pete s/y "Brilliant"
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John Franklin
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Chris makes an important point here - inserting the swivel in the chain rather than having one end attached to the anchor stock or even to a shackle on the stock. For the integrity of the swivel it is vitally important that it must have full articulation. We have not used a swivel aboard Al Shaheen since ours parted in Chatham Bay, Union Island one dark night and we nearly went on the rocks. During a short period of intense katabatic downdrafts the boat had sailed to the end of her scope (30 metres of 10 mm chain), several times and come up hard when the chain became taught. The gusts dropped as quickly as the came and all was quiet so we didn 't know that the swivel had parted company with the chain. When the pull of the chain on the anchor (20 kg CQR)came at an angle to the anchor stock it severly strained the fork of the swivel, resulting in the forks opening and pulling the pin out.....No connection! I 'll post a photo of the failed swivel when I can find it.
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chrisdevans (Past OCC Member)
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We have a 32kg Delta and a high grade galvanised 4-part commercial shackle connected to around 6" of chain, THEN the Kong swivel, then the main chain. This ensures absolutely no potential problem with sideways pull (even though swivel is rated to 2T WL sideways). The issue to me is one of matching the MWL and breaking strain with all the components. No point is a 2T max working load on chain if swivel is 1T - you really do have a weak link. This assumes reputable manufacturers of components telling the truth on MWL and breaking load!!
Before this set-up we did have a mismatch with a lower grade swivel connected directly to the anchor, and over a season with many anchorages, the swivel did warp due sideways load. Luckily did not break, but easily could have in a blow.
Lesson to me is buy best possible quality components and make sure they are matched in specification, or at least the joining parts (shackles/swivels) are rates higher than the chain.
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