My first ever anchor thread .... I've bought a new anchor, am I going to die as a result?

underdog

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I drilled a hole in my 12Kg Kobra anchor in order to fit an retaining pin when mounted on the bow roller some 12 years ago. The anchor has behaved as expected over the ensuing time..Has secured my 32 foot boat in a wide variety of conditions.
 

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Bouba

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I drilled a hole in my 12Kg Kobra anchor in order to fit an retaining pin when mounted on the bow roller some 12 years ago. The anchor has behaved as expected over the ensuing time..Has secured my 32 foot boat in a wide variety of conditions.
I think that Baggywrinkle’s point is that it would have held so much better if it wasn’t for that hole
 

noelex

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I think that Baggywrinkle’s point is that it would have held so much better if it wasn’t for that hole
Drilling an extra hole in the shank is not a good idea, but it will not reduce the holding ability (assuming the anchor is not subsequently distorted). In fact, lightening the shank will improve anchor performance.

Manufacturers go to considerable trouble and expense (for example using HT steels) to reduce the shank weight as much as possible, as this improves the anchor’s centre of gravity and therefore significantly improves performance.

So drilling holes in the anchor shank will improve, rather than hurt, anchor performance providing the anchor is not bent.

Unfortunately, if the anchor shank is too weak (possibly created by drilling holes in the shank) the anchor shank can become distorted, but if you retrieve an anchor that is not bent, any holes in the shank are not to blame for any performance deficiencies.
 

Bouba

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Drilling an extra hole in the shank is not a good idea, but it will not reduce the holding ability (assuming the anchor is not subsequently distorted). In fact, lightening the shank will improve anchor performance.

Manufacturers go to considerable trouble and expense (for example using HT steels) to reduce the shank weight as much as possible, as this improves the anchor’s centre of gravity and therefore significantly improves performance.

So drilling holes in the anchor shank will improve, rather than hurt, anchor performance providing the anchor is not bent.

Unfortunately, if the anchor shank is too weak (possibly created by drilling holes in the shank) the anchor shank can become distorted, but if you retrieve an anchor that is not bent, any holes in the shank are not to blame for any performance deficiencies.
Unfortunately it’s Baggywinkle’s first anchor thread....otherwise he would have known that.....but when he was confronted with that 4mm drilled hole...he felt he had no choice but to buy a €3000 stainless steel work of art
 

noelex

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Unfortunately it’s Baggywinkle’s first anchor thread....otherwise he would have known that.....but when he was confronted with that 4mm drilled hole...he felt he had no choice but to buy a €3000 stainless steel work of art
His thinking is correct. An anchor with an extra hole, particularly a large hole (it looks bigger than 4mm in post #15) , drilled in the shank cannot be relied upon long term, especially a Kobra anchor with it’s narrow shank.

The switch to an Ultra anchor will also result in a significant performance improvement over the Kobra. There are much less expensive anchors that would have been a successful alternative, but anchor performance is an important safety feature that is often underestimated.
 
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john_morris_uk

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I don’t think you’ll die but I fear for your wallet……

View attachment 184055
On the boat I’ve just been sailing and teaching on, the owner had recently replaced whatever anchor the boat came with with an Ultra 30 kg in polished stainless +100 m of stainless chain plus a self righting/stowing gizmo. The chain is 10 mm and wasn’t marked and we spent a happy hour or so laying it all out on the deck and inserting the new style screw in anchor markers in at 10 meter intervals. I must admit the anchor & chain is very shiny and it does self stow very easily and nicely.
 

Bouba

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On the boat I’ve just been sailing and teaching on, the owner had recently replaced whatever anchor the boat came with with an Ultra 30 kg in polished stainless +100 m of stainless chain plus a self righting/stowing gizmo. The chain is 10 mm and wasn’t marked and we spent a happy hour or so laying it all out on the deck and inserting the new style screw in anchor markers in at 10 meter intervals. I must admit the anchor & chain is very shiny and it does self stow very easily and nicely.
I’m sure that Baggytinkle’s anchor will become a local landmark.....when people ask a local for directions, they will be told...go past the boat will the shiny anchor....
 

Baggywrinkle

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His thinking is correct. An anchor with an extra hole, particularly a large hole (it looks bigger than 4mm in post #15) , drilled in the shank cannot be relied upon long term, especially a Kobra anchor with it’s narrow shank.

The switch to an Ultra anchor will also result in a significant performance improvement over the Kobra. There are much less expensive anchors that would have been a successful alternative, but anchor performance is an important safety feature that is often underestimated.
Here's the anchor I removed from my last boat when I bought it in 2011 - It's been a garden ornament for 13 years - guess where the hole is ...

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