What size anchor chain?

ProDave

ProDave

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Simple question.

Anchor chain seems to be sized by the thickness of the "wire" that is bent round to form each link of the chain.

But an important criteria is the chain must fit down the haws pipe into the anchor locker. The haws pipe has an internal diameter of about 32mm

So what's the largest size chain I can use? i.e how does overall size of a chain link relate to the diameter of the wire it's formed from?
 
No I probably don't need 10mm. So what size should I have for an 18ft boat weighing less than a ton?

The (albeit short) length of chain on my old anchor is something stupid like 12.5mm (half inch?) with an overall "diameter" of 40mm so won't go down the haws pipe. I'm determined to get it right with my new anchor.
 
ProDave said:
No I probably don't need 10mm. So what size should I have for an 18ft boat weighing less than a ton?

The (albeit short) length of chain on my old anchor is something stupid like 12.5mm (half inch?) with an overall "diameter" of 40mm so won't go down the haws pipe. I'm determined to get it right with my new anchor.
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Interestingly, the weight of your boat is a minor part of the equation of what load will appear on your anchor cable. The biggest contribution is the windage of the vessel. Of course the snubbing effect as you veer about under the worst conditions produces the peak loads that break an anchor out, but for all intents and purposes maximum breaking strain is usually not an issue.

Why don't you check Jimmy Green's website out as I believe that there's a fair amount of guidance on anchor chains there. I will guess that you only 'need' chain that's a few mm - but in terms of handing and peace of mind at anchor then the largest that's reasonably practical might be a better bet. On a boat your size, you might be best having a length of chain spliced onto a nylon warp. All chain is nice as you don't skate around so much at anchor, but I am mindful of the weight you will accrue on your 18 footer. I remember having all chain on a 22 footer so it is possible.
 
What draft are you? whats the local tidal range? What depth do you normally anchor in?

I would guess 1m, 4m and 1m underneath you at LW?

So max anchouring depth HW Springs plus draft UKC = 6m

3x depth for chain... 20m chain plus rope for other places???

Chain size? Will leave that to better people but 6mm or 1/4" which would be about 20kg???

All from memory and only advice but would be along my thinking...
 
On my 26ft I personally decided I could fit 50m of 7mm in my locker rather than 30m of 8mm. The 7mm grade 40 is almost the same strength as the 8mm grade 30 that is kicking around and much easier to handle especially when you send the wife up to haul anchor :) but personally I sleep better with 30m of 7mm out compared to 20m of 8mm even if the weight is the same.
 
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