Anchor swivels

[Abigail]

Hi - I'm reviewing all our anchoring gear on our liveaboard 40' ketch and would appreciate thoughts on identifying strong and effective swivels. Roaring Girl weighs about 14 tons, and one chart I saw suggested I should allow for maximum loadings (in storms) of some 6000lb on my anchor gear.

I am most concerned at the moment with the way the (lovely, strong, big) chain is attached to my (lovely, tough 65lb) CQR. It has been on a swivel shackle, like two D's attached in the middle, probable breaking strength 3000lbs. Really annoying to use as it catches badly on the bow roller going up and down.

Replaced it with a smooth piece of stainless steel with two allen key screws in it. The one I have has no manufacturers name on it and I cannot find any info on breaking strengths of such a thing. But it in principle makes the anchor much easier and safer to manage.

What info does anyone have on the relative breaking strengths of swivel links of various kinds, who the best manufacturers are etc.

Thanks for all comments


<hr width=100% size=1>Sarah&Pip

 

[Rick]

For the life of me, I can't remeber where I read the article, but it was about anchoring in general, and swivels in particular. The gist was, don't use one. I've debated the issue frequently at the local club, and have not been convinced one way or the other.

Proponents argue the swivel is necessary to stop the anchor being pulled out with direction change. Non-users argue the anchor pulls out and resets anyway, and the swivel is creating a fuse to break at some stage..

I'm inclined to the non-user view, and apart from having had to content with one or two twists in the chain, (and only after anchoring for days in one tidal spot,) have had no trouble. What thoughts have others on the issue?

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[Robin]

There was a discussion here some while back on anchors & anchoring and Alain Hylas who is a regular on the forums (and designer of the Spade anchor as well as the author of a french book on anchoring) warned that some S/S swivels had broken in use. From memory there were a couple of instances in the Canaries where side loads on the swivel jaws had caused the failures, Hylas warned to check the breaking strains were adequate where swivels were used.

We have used a S/S swivel to attach chain to anchor for some years, firstly connecting a 45lb CQR to 10mm chain on our last boat, now attaching a Delta to 10mm on our current boat. Initially my concern was with the possibilty of the allen screws securing the swivel pins loosening, despite the locking screws, and I applied Loctite as well to everything. After the warning from Hylas, I looked at the swivel from the point of view of a large side load on the jaws and could see his point, there was plenty of meat in the straight pull direction but the side jaws were a little thin on the model I had fitted. I therefore hunted around for a better one and fitted a much beefier version though once again I believe the breaking strain was quoted only in the straight pulll direction, however I was (and still am) satisfied that the one we now use is strongly enough made.

Why use a swivel at all? Well we used to use a simple shackle to attach the chain to the anchor shackle but this made recovery awkward with our electric windlass and occasionally the 2 shackles would twist up and lock giving a non-straight pull on the anchor (difficult to describe!). It was not possible to use just one shackle as the size required for the anchor was too big to fit the chain directly. The S/S swivel replaced the 2 shackles, gave a straight pull at all times and allowed the anchor to turn right way up in the bow roller when recoved with the windlass. We fitted a similar swivel in the anchor system on our latest boat when we bought her.

My preference is for a swivel therefore, both to aid windlass recovery and to prevent the shackle twist scenario that could perhaps cause the anchor to break out or not reset properly. Moorings always have a swivel in the system, so for anchoring other than for short term I believe a swivel will help. However, take heed of Hylas's warning and make sure it is strong enough for the job.



<hr width=100% size=1><font size=1>Sermons from my pulpit are with tongue firmly in cheek and come with no warranty!</font size=1>

 

[Guest]

To swivel or not to swivel ...

As with many boats - I do not use a swivel on my anchor, but will gladly use one on the mooring.

There is good reason for the mooring swivel - this is usually during high / part tide situations raised of the seabed and then can do its job of reducing twists in the tackle.

I cannot see the point of a swivle in an anchor system - except for when recovering the anchor and allowing it to turn to stow .... same reason as on commercial ships ! But when the anchor is deployed and doing its job ..... the swivel will be laying on the beed and literally useless and failing to do its job then. In fact I side with the no swivel group as I believe especially with a CQR that it should break and set without a swivel affecting its 'in-built' design factors ......

Anchoring - sail designs - motor-sailers - solent - clyde ........ they are all subjects that are biased and info generally is supplied based on personal preference rather than any scientific or physical proof .... if it works then thats what I continue to use sort of scenario for most I believe !!!!!


<hr width=100% size=1>Nigel ... and of course Yahoo groups :
http://groups.yahoo.com/group/gps-navigator/

 

[Robin]

Re: To swivel or not to swivel ...

The need for 2 shackles on our CQR (one on the anchor big enough for the shank and to clear the end of the shank, the other to attach this to the chain) gave rise to a twisted and locked connection occasionally such that the shank/shackles/chain pull resulted in a 'Z' formation and therefore an incorrect pull direction on the anchor which didn't set.

<hr width=100% size=1><font size=1>Sermons from my pulpit are with tongue firmly in cheek and come with no warranty!</font size=1>

 

[mirabriani]

Vaguely remember item in PBO on swivels. I think in the "New Gear" section , a search should bring it up,(or not)
Briani

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[Abigail]

Thanks everyone for comments. I'm interested in having a swivel both for the stowage and management reasons but also because I will/do frequently anchor for periods over tidal change and I want to have the same ability to swing as the mooring bouys! But I know there will always be differences!

Robin - you talked about hunting for better swivels and finding one you were happy with in terms of breaking rating. Could you pass on the details?

Thanks

<hr width=100% size=1>Sarah&Pip

 

[Robin]

I bought our original one in France (about half the UK price of the same model) which I believe was made in Italy and although the SWL quoted on the pack for 10mm chain was apparently OK I later thought the side cheeks were relatively thin and could be bent/distorted open with a side load as Alain Hylas suggested. The one I subsequently bought as a replacement was from Quay West Chandlers in Poole but they are currently closed after a massive fire a couple of weeks back, however Cobb's Quay Chandlers in Poole I think had the same ones. There was no fancy packaging and no makers name but they were very substantially made, all parts were much beefier than the original and they were not frighteningly expensive either, about £30 if memory serves 3 years ago. I rather suspect that they might be made up by one of Poole's S/S specialists. Cobb's Quay are on Tel 01202 682095.



<hr width=100% size=1><font size=1>Sermons from my pulpit are with tongue firmly in cheek and come with no warranty!</font size=1>

 

[MainlySteam]

Re: To swivel or not to swivel ...

The real CQR's unfortunately have a shackle on the end or a hole for the pin to go through and I appreciate your difficulty there.

Ideally, in my opinion, the anchor stock should have a slot for the shackle so that a bow shackle can be threaded through the slot and the pin placed through the chain so that only one shackle is needed and the bow takes up minor directional changes in the line of pull. Some of the classification society certified ploughs eg Manson, are made this way.

Normally a shackle of pin one size larger than the chain dia will go through short link chain and this produces a cable of full integrity eg the inner width of commonly used 10 mm chain is 12 mm. I use a ss bow shackle for extra strength again but never use a swivel for the reasons already given.

Regarding Nigel's point of the anchor coming up the wrong way to stow on the roller, I just grab and lift the horizontal run of the chain from gypsy to bow roller (easy due to the mechanical advantage) and twist it a quarter or half turn and let it down again - the twist transfers over the roller to the anchor so that it rotates.

John

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[Robin]

Re: To swivel or not to swivel ...

Hi John

We have a secondary design requirement too since the geometry is such that with the anchor pulled up tight into the roller the shank/chain join is right dead centre in the small hood in the anchor well lid. The swivel fits in the hood nicely but a big shackle doesn't, nor do shackles like coming over our roller, they invariably catch on the forestay fitting! The ideal might be to remove the anchor but manhandling this through the gap between pulpit and reefing gear is an awkward 2 handed job, if we had to do that we would be more reluctant to anchor frequently I suspect which would defeat the objective.

Robin

<hr width=100% size=1><font size=1>Sermons from my pulpit are with tongue firmly in cheek and come with no warranty!</font size=1>

 

[MainlySteam]

Re: To swivel or not to swivel ...

Hi Robin

Yes, one is stuck with how the boat turns out - our anchor stock hits the bottom of our furler drum if pulled over the bow roller too vigorously.

On the positive side these problems usually come about from using an adequately sized anchor rather than a toy one /forums/images/icons/smile.gif.

John

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[Guest]

What about replace shackle ?

There are various ways to join chain /anchors etc. that re not as bulky and awkward to stow / pull through rollers etc. as shackles ....... AND there is no need for swivels......


<hr width=100% size=1>Nigel ... and of course Yahoo groups :
http://groups.yahoo.com/group/gps-navigator/

 

[Guest]

Size of anchor ...

A wander around the marina shows the typical of the stock boat with its pitiful anchor ..... WHY do dealers etc. supply boats with anchors that I would only use on a dinghy ? Tables of size vs anchor weight are great if nature read the same book .... Small boats can snatch hard in a gusts enough to lift a reasonable anchor .... so biggest you can stow / handle is my opinion.



<hr width=100% size=1>Nigel ... and of course Yahoo groups :
http://groups.yahoo.com/group/gps-navigator/

 

[Robin]

Re: What about replace shackle ?

Such as? There is a connector that is a swivel-less swivel in appearance, but it has the same narrow cheeks of it's swiveled partner.

Personally I am quite happy with a beefy swivel that is regularly examined, it does the job, clears the forestay/roller gear and allows the anchor to self align as it comes up. my feeling about anchor loads though is that it is always the snatch load that does the damage, therefore we always have a nylon snubber line in the system, hooked onto the chain with a proper chain hook and with a stretchy rubber mooring compensator wound into it. It is fascinating to watch it working in the gusts as the bow swings, gradually absorbing the extra load and releasing it again as the gust passes, no snatch and quiet too if you are sleeping up front. Mechanically it must be very difficult to bend/break something by pulling on it with an elastic line!

<hr width=100% size=1><font size=1>Sermons from my pulpit are with tongue firmly in cheek and come with no warranty!</font size=1>

 

[MainlySteam]

Re: Size of anchor ...

Hi Nigel

My interest was raised and I have since had a wander just on our pier of the marina to look at this on a couple of Beneteaus (the only AWB's on our pier). Both have plough anchors which I had previously noticed and regarded as small (either in weight if one believes in weight or in plough area if one believes in area) but on both boats the stock extends well into the anchor locker through a slot in the front of the locker lid.

On one vessel the slot was badly damaged from the shackle (probably avoidable) and the other boat is only a couple of months old and the anchor looks as if never used yet. Would seem that if one wanted to fit a bigger anchor on them it might be a bit of a trial doing so.

John

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[Guest]

Re: Size of anchor ...

Agreed ...... but I would rather a bigger better anchor than a cosmetic pretender !

Mine - I have the familiar chocks screwed to the deck and it sits in those with light lashing ...... that can be easily cut to free in emergency's....... I can't hang mine in the stemhead fitting 'nicely' and really don't intend to.

When anchoring - I use a light lashing to hold the chain into the roller fitting - as I am dead against steel pins etc. With the lashing a normal knife can slash it and you are free to work anchor / chain as reqd.

Like most things ....... and it seems that boats are bad for it - often some items are cosmetic and not really meaty enough for the extremes we sometimes we put them to.


<hr width=100% size=1>Nigel ... and of course Yahoo groups :
http://groups.yahoo.com/group/gps-navigator/

 

[smb]

Re: What about replace shackle ?

Some months back I believe there were some pictures in PBO of modifications Hylas has made to his yacht. Unless I am mistaken, his anchor/chain connection was made up of a rigging toggle or two.

That would be capable of pulling cleanly over the bow without clattering the forestay, but as to it's strength in various directions I have no idea.

For the record I have a stainless swivel purchased from Compass 3 years ago. Whilst the two side cheeks might be a weak point they are braced at the open ends by a large screw from one side and a small locking screw from the other. This seems a sturdy enough arrangement-suggest at least as much metal in each pair of cheeks as there is in each chain link.

If I survive the kind of conditions that force it to part I will probably want to buy a caravan with the insurance money.

What concerns me more is the 'hidden' swivel which I cannot inspect so have no idea of its true diameter and condition.

Steve

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[Robin]

Re: What about replace shackle ?

I think you are right I saw something like that too. The swivel strengths though are tested in the SWL figs since that is the straight pull, of more concern was the side jaw force figure where the bending/twisting force caused a problem. I changed ours which was similar to yours but never had a problem with it but as I said elsewhere we always have a snubber (nylon & rubber) in the system to take out snatch loads. We have with original and newer swivels sat out F6 blowing directly onshore in a 'Vent Solaire', although the waves were plentiful over 4hrs or so they hadn't really built up fully. Our snubber was working well though!

<hr width=100% size=1><font size=1>Sermons from my pulpit are with tongue firmly in cheek and come with no warranty!</font size=1>