Rocna reversal phenomenon

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biscuit

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My Rocna anchor (15kg, 8mm chain, electric windlass) always come up the wrong way round, that is with the point facing forwards. Provided that I am very careful, as the shank comes up to the bow roller, it will reverse itself to the correct position, but it can jump off the roller if I am not very careful.
It is joined to the chain with a big Kong swivel, and an oversized bow shackle (as I am on a swinging mooring I prefer to remove the anchor if the boat is left for a prolonged period)
I am baffled as to why the anchor always does this & would be grateful for any solution to this apparently simple problem.
 
biscuit said:
My Rocna anchor (15kg, 8mm chain, electric windlass) always come up the wrong way round, that is with the point facing forwards. Provided that I am very careful, as the shank comes up to the bow roller, it will reverse itself to the correct position, but it can jump off the roller if I am not very careful.
It is joined to the chain with a big Kong swivel, and an oversized bow shackle (as I am on a swinging mooring I prefer to remove the anchor if the boat is left for a prolonged period)
I am baffled as to why the anchor always does this & would be grateful for any solution to this apparently simple problem.
Click to expand...

If it gives you some consolation; my SQR anchor does the same and I didn't find any solution so far :-).
 
biscuit said:
My Rocna anchor (15kg, 8mm chain, electric windlass) always come up the wrong way round, that is with the point facing forwards. Provided that I am very careful, as the shank comes up to the bow roller, it will reverse itself to the correct position, but it can jump off the roller if I am not very careful.
It is joined to the chain with a big Kong swivel, and an oversized bow shackle (as I am on a swinging mooring I prefer to remove the anchor if the boat is left for a prolonged period)
I am baffled as to why the anchor always does this & would be grateful for any solution to this apparently simple problem.
Click to expand...

Fit a banana.

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35277578673_8be39a2254_b.jpg
 
Last edited by a moderator:
http://www.mysailing.com.au/cruising/how-to-boomerang-your-anchor-right-back-at-you


But before getting too engrossed.

Get rid of the swivel - its a waste of time (and money). it will not remove any twists in the chain caused by tide nor wind - unless your yacht makes at least 6 x 360 degree rotations - there is too much friction in swivels. All twists will fall out from torque imposed by the chain being twisted and gravity.

If you insist on keeping the swivel - it might have some propensity itself to deliver the anchor back to front, some imperfection in manufacture - take it off try it attached 180 degrees to what it is now.

Mark what you now think is the correct way - so you can replace. Now take it off and shackle the anchor to the chain - without the swivel.

Check your chain from the gypsy, in the windlass, to bow roller - is the chain straight and untwisted (if not correct - by hand.) The chain should be straight (and untwisted) when the anchor is hanging, say, 300mm below the bow roller. If the anchor is back to front, then undo the shackle and turn the anchor round. If the anchor is hanging sideways chop one link off and reattach the anchor the right way round.

If your anchor still arrives back to front - get your local blacksmith (or equivalent) to make you a Boomerang. You can buy them in Australia and I think the US - but they are pretty simple.

Some anchors are hydro-dynamic they align themselves with water flow - caused by the yacht moving or simply the flow as you retrieve the anchor. But once the anchor clears the water it should self align - go back and check for chain twist, or the anchor being incorrectly attached.

If you have a big anchor then a swivel does allow you to correct the alignment of the anchor using a broom handle - but with a 15kg anchor - it should arrive at the bow roller the right way round - every time (though you might need to be patient to allow twists to fall out).


As an aside - a big (what do you mean by 'big') swivel and a big shackle will reduce the effectiveness of your anchor - they both will act as resistance to setting (they add volume, or area - that needs to be buried). Small shackles (of the correct strength) makes it easier for the anchor to bury itself.

Jonathan
 
My 15kg Rocna also arrives at the bow roller upside down more often than not. I solve it by stopping the electric winch with the remote control when the anchor is just below the bow, grasp the chain between bow and winch, twist and hold half a turn while restarting winch, whereupon the anchor flips just prior to the roller.

Don't forget to let go before hand reaches winch though ... :rolleyes:
 
It may be because of the boat movement: whenever I have forward movement, for example while circling the anchorage area with the anchor barely underwater, the anchor is in the "correct"position as it has just been lowered from the davit but it immediately flips and takes the position with the blade point forward.
 
When I bought my Rocna in Jan 2007 I corresponded with the NZ gentleman from Rocna , who I think was Craig Smith, and he advised me
not to use a swivel. I just use a tested shackle. Mine seems to come up mostly the right way round , but I just wait for it to swing round on the chain and then haul up the last bit. I am usually standing at the bow using a hand control on my electric windlass so it makes judging it quite easy
 
The Rocna's hydro-dynamic properties make it turn and align itself with the sharp end pointing in the direction of travel. So if your boat is going forwards even slightly, it'll come up the wrong way around. You might be motoring forward, or have residual forward motion from pulling yourself up to the anchor before breaking it out.

We either turn it with a short wooden stick we keep in the anchor locker for knocking over the chain pile and shoving mud off it, or preferably reverse slowly out of the anchorage with the anchor dragging just below the waterline. That makes the anchor wash off any dirt nicely and also align itself the right way around every single time.
 
Neeves said:
Some anchors are hydro-dynamic they align themselves with water flow - caused by the yacht moving or simply the flow as you retrieve the anchor. But once the anchor clears the water it should self align - go back and check for chain twist, or the anchor being incorrectly attached.
Click to expand...

My CQR comes up backwards too, and I think this is the reason. Once it clears the water it has no particular reason to flip, but does so reliably as it comes over the roller: the stock pivots back and the anchor rotates so it can dangle down.
 
The reason we've fitted a Kong swivel to the Rocna is because it turns itself forward when being lifted. So, fitting the swivel meant that turning it round to face the right way was simple and effortless. Before the swivel, there was a fifty fifty chance the thing would flip back the wrong way before you could get it up onto the roller....
 
JumbleDuck said:
My CQR comes up backwards too, and I think this is the reason. Once it clears the water it has no particular reason to flip, but does so reliably as it comes over the roller: the stock pivots back and the anchor rotates so it can dangle down.
Click to expand...

Our Delta swings so it's correct under forward motion so we leave the anchorage with it in the water to wash the mud off and orientate it before the final lift - if a Rocna does the opposite then I'd be tempted to reverse out as suggested.
 
Plenty of food for thought, thanks for all the responses! so...
1. It's not just me.
2.It's not just Rocnas.(but the wide flat shank section makes the capsize more dramatic , c.f. a narrower shanked CQR for example).
3. Swivel may only be useful for rotating it.
4. Motoring ahead or reverse when raising might be worth a try.
5 A "banana" looks like a solution - are they available commercially?
I re-attach the anchor several times a season, so there is a degree of randomness as to how it is attached.
I have also tried raising the anchor when moored in still water (and insignificant wind movement) and it still comes up the wrong way around so I don't think aero-/hydrodynamics can be significant.
It must be something to do with the weight distribution, perhaps?
 
I always back away from my anchor if at all possible and keep going in astern with the anchor under water until all the grunge has been washed off and kelp cleared - I don’t want to be sucking any of that into my engine intake..
 
To solve the problem of the anchor coming up the wrong way round, I made up a simple device shackled between the anchor and the chain. It is a piece of round bar (steel) with an eye in each end, and a bend in the middle. Works perfectly every time. It's what Jonathan (Neeves) calls a boomerang 'cos some of his mates in Oz saw the design, liked it, and made a modified version of it.
 
NormanS said:
To solve the problem of the anchor coming up the wrong way round, I made up a simple device shackled between the anchor and the chain. It is a piece of round bar (steel) with an eye in each end, and a bend in the middle. Works perfectly every time. It's what Jonathan (Neeves) calls a boomerang 'cos some of his mates in Oz saw the design, liked it, and made a modified version of it.
Click to expand...

You mean like the one in post #3,
 
Our last boat had a banana swivel, almost exactly the size and shape of a real banana with a swivel in the middle. Galvanized rather than stainless but factory made, not sure where.
 
Rogershaw said:
You mean like the one in post #3,
Click to expand...

Well, I'm sure it works the same way, but for obvious reasons, I don't like his fork end direct on to the anchor, and I see no reason to fit a swivel. The basic idea is similar. When the bend in the link reaches the bow roller, it automatically rotates the anchor into the correct orientation.

It helps if the bow roller is extended forward, so that the rotating anchor doesn't ding the bow. It also requires sufficient length between the windlass gypsy and the end of the anchor, to accommodate the link.
 
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