Which anchor shackle?

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Deleted User YDKXO

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I've just bought one of THESE and I need to attach it to my anchor with an appropriate shackle. Anchor is 25kg Delta with 10mm chain.
What type and size of shackle would be most appropriate? Screw type closing or spring closing?
And just out of interest, how much force can a 46ft flybridge boat apply to an anchor shackle assuming anchor stuck fast and boat shearing around in high winds ie shock loading?
 
Just get a s/s shackle that "looks right" (you know what I mean) and it will have a strength multiples of what you need. The shackle wont fail, and if it does it will be from fatigue cracking not the load imposed by your boat pulling. For that reason a non stainless steel shackle is theoretically better (less prone to fatigue cracking) but that's all academic and a chunky s/s shackle wil be fine
 
And seize the pin with stainless wire - sorry, much pushing and poking involved, and nasty protruding ends if you're not careful!
 
Each to their own, but I'd just tighten the shackle pin with spanner to nip the U of the shackle a bit closed, and not bother with seizing wire
 
I changed mine for a D type shackle with a allen key pin head.

Thus flush and no chance of the pin catching on anything, rock, stem roller whatever.

Seems to work OK

At the time looked at loads of in service boats and new ones to see if the pin should go through the anchor or the chain.

Believe it or not it was 50/50.
 
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I changed mine for a D type shackle with a allen key pin head

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Thanks, mjf, that was also a concern of mine but what does this shackle look like?
 
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And just out of interest, how much force can a 46ft flybridge boat apply to an anchor shackle assuming anchor stuck fast and boat shearing around in high winds ie shock loading?

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Theoretically not enough force to snap the stainless goose neck you are about to fit.

However there are numerous incidents of stainless failing and wrecking boats.
So many that many if not all Harbour by laws prevent the use of stainless steel in ground tackle.

I do not understand why stainless

anchors
chains
swivels
goose necks

are supplied /forums/images/graemlins/confused.gif

I must be missing something ?

Stainless is too ridged and may fracture under snatch load.
 
The Twist wotsit works better if you have the shackle quite tight on the anchor shaft. Imagine the anchor being lifted the wrong way up, it'll get to a certain stage where the dog leg in the Twist is facing upwards, and the winch will be trying to lift the anchor up higher than the bow roller. At some point gravity makes the anchor fall one way or the other, so the dog leg is facing down (that's how the twist works). Ideally the Twist would be welded to the anchor shaft, then the above would all happen very smoothly, but that's not practical so you need a shackle, but the tighter the shackle is on the shaft, the earlier the dog leg will turn, and the less general clatter you'll hear.

Hard to explain, but easy to visualise, if you think it through. The best I think is an elongated U shackle just wider than the anchor shaft, with the round end through the Twist, and the screw pin through the slot in the Delta, then the legs of the shackle tightened up to pinch the anchor shaft.
 
I recently had to recover a small cruiser where the shackle had worked undone on a mooring strop and opened up. So, I would go for the seizing option for peace of mind.
 
Thanks. Good website. I've just ordered it online
 
Thanks Nick H. I was a bit surprised when I looked at the Twist because it's dog legged in one direction, which I expected, and bent in the other, which I didn't. In fact I rang them up to complain but the guy explained that it was supposed to be like that /forums/images/graemlins/smile.gif I take your point about the shackle being tight. When the Twist corrects itself in the bow roller, is there any risk of damaging any grp as the anchor turns?
 
Yes, the most important point: aesthetics.

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I must be missing something ?

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