Anchor Swivel

[estarzinger]

for those interested . . .here are the detailed dimensions of the Osculati twist (10mm size).

View attachment 40672

Feeling the action of the swivel part, I suspect (I will test this when I install it) it will in fact swivel every time it turns the anchor around. Not sure how important that is, but it will keep twists out of the chain.

 

[Andrew G]

Norman - IIRC your bent link is made out of 1/2" rod with eyes on the ends? How have you formed the eyes and any chance of a pic?

Re the bent tube idea above (post #98), I'm still researching your suggestion of a 135 bend - looks like only 31 or 38mm OD off the shelf so either too small (just) or possibly too big (it might only need a short, say 150mm, straight section at one end).
I'm also thinking about the risks of gal chain wedged tightly within a ss tube (over time) - could this lead to abrasion of the gal and corrision at the Fe/ss interface?

Whilst the bent tube has advantages are there fatal disadvantages? Andrew

 

[NormanS]

Norman - IIRC your bent link is made out of 1/2" rod with eyes on the ends? How have you formed the eyes and any chance of a pic?

Re the bent tube idea above (post #98), I'm still researching your suggestion of a 135 bend - looks like only 31 or 38mm OD off the shelf so either too small (just) or possibly too big (it might only need a short, say 150mm, straight section at one end).
I'm also thinking about the risks of gal chain wedged tightly within a ss tube (over time) - could this lead to abrasion of the gal and corrision at the Fe/ss interface?

Whilst the bent tube has advantages are there fatal disadvantages? Andrew

Andrew, Yes mine is just made out of 1/2" rod, with eyes welded on. The eyes are made from links of 1/2" chain, with the ends of the links cut out, so that the rod sits into the end of the link. This gives a good long and strong weld. The eye at the anchor end must of course lie vertical with the bend. I don't have a clue about posting pics on here, but I'll try to PM a pic to you tomorrow.

Re the bent tube, which would have the possible advantage of not requiring an extra shackle, I wouldn't use stainless tube on galvanised chain. Others will disagree, but I've had galvanising destroyed by interaction between stainless and galvanising. You wouldn't want anything nasty happening inside the tube, out of sight. I would use galvanised pipe with galvanised chain, but understand the predicament with available sizes.

 

[Andrew G]

Thanks Noman - You've strengthened my fears. I'll pm you additional contact information. Cheers, Andrew

 

[estarzinger]

Regarding the tube . . . How much force will bend it? Would say a 1000kg load on the chain bend it streight?

 

[Andrew G]

Regarding the tube . . . How much force will bend it? Would say a 1000kg load on the chain bend it streight?

As you'll see above I have gone a little cold on the idea of the tube because of the concern over abrasion/corrosion and the lack of potential tube sizes. I have not looked at its ability to resist straightening - that should be tested (eg in Vyv's machine).
However, a 316 tube of say 38mm OD and 1.6mm wall is going to put up a serious fight against straightening, since the deflection of the chain is relatively small. If it were to straighten it would not be a big deal as the chain is always taking the load and should not be being compromised in any way. What do people think? Andrew

 

[estarzinger]

Quickly . . . in my first tests, the Twist does perform brilliantly. It turns the anchor right way around very smoothly with no need to slow or stop the windless. The swivel does in fact swivel every time the anchor is turned, keeping the chain straight. It appears to have freedom to articulate more than 90 degrees in any direction. And it just fits between my anchor and windless.

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[NormanS]

Quickly . . . in my first tests, the Twist does perform brilliantly. It turns the anchor right way around very smoothly with no need to slow or stop the windless. The swivel does in fact swivel every time the anchor is turned, keeping the chain straight. It appears to have freedom to articulate more than 90 degrees in any direction. And it just fits between my anchor and windless.

I can see that in your case, with little space between the "Twist" and your windlass, the swivel is a big help. I have more space here, so a bit of twist in the chain doesn't matter to me, so I don't need the swivel. Glad you are finding the bent link so successful. Like you, I have found mine to be a great help.