mdonnelly
Well-Known Member
Just got a new anchor. The old one is attached to the chain with a shackle. Is this the best way?
Attaching chain to anchor
- Thread starter mdonnelly
- Start date
noelex
Well-Known Member
There are pros and cons of swivels, but a bow shackle is what I use.
Given the low cost, it is at least worth using a rated lifting shackle. These will have the working load embossed on the shackle. They are generally no stronger than a similar sized no name model, but the quality control is better, which means less chance of a sub standard unit. If the chain separates from the anchor the resulting drag tends to be very rapid and therefore more likely to cause damage, so it pays to be conservative.
Even better, is one of the high strength (typically G8) lifting shackles. (If you use high strength chain these can be essential.) Shackles are less strong when subject to a side load, so having a shackle that is rated stronger than the chain is not as silly as is sounds.
The Crosby 209A is a popular choice (it is what I use), but there are other manufacturers of similar products.
https://www.thecrosbygroup.com/prod.../crosby-209a-alloy-screw-pin-anchor-shackles/
Given the low cost, it is at least worth using a rated lifting shackle. These will have the working load embossed on the shackle. They are generally no stronger than a similar sized no name model, but the quality control is better, which means less chance of a sub standard unit. If the chain separates from the anchor the resulting drag tends to be very rapid and therefore more likely to cause damage, so it pays to be conservative.
Even better, is one of the high strength (typically G8) lifting shackles. (If you use high strength chain these can be essential.) Shackles are less strong when subject to a side load, so having a shackle that is rated stronger than the chain is not as silly as is sounds.
The Crosby 209A is a popular choice (it is what I use), but there are other manufacturers of similar products.
https://www.thecrosbygroup.com/prod.../crosby-209a-alloy-screw-pin-anchor-shackles/
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savageseadog
Well-Known Member
The Kong anchor connector is good
sarabande
Well-Known Member
Apart from a Crosby store in London, does anyone know of other UK based suppliers please ?
MagicalArmchair
Well-Known Member
I used a high breaking strain shackle too:
http://www.albinballad.co.uk/technology/rocna-anchoring-solution/
Quote from above:
http://www.tecni-lift.co.uk/ for the Crosby 209A I used.
http://www.albinballad.co.uk/technology/rocna-anchoring-solution/
Quote from above:
http://www.tecni-lift.co.uk/ for the Crosby 209A I used.
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MikeBz
Well-Known Member
On the off-chance that anyone here hasn't already read this... http://coxeng.co.uk/anchoring/connectors/
sarabande
Well-Known Member
Neeves
Well-Known Member
From memory (I'm still on the Mekong and will be for another week and don't have my notes) the smallest shackle that Crosby make of their G209A range is 3/8th" (which fits an 8mm chain) if you are using 6mm chain you are out of luck. Campbell in the US make the same quality of shackles and they are of equal quality - but I don't know of sources outside America. Columbus Mackinnon (again US), and Van Beest (France/Holland) similar story, no small sizes.
This quality are called a Grade B and most other rated shackles are Grade A. I, for convenience, compare these at the 3/8th" size - Grade B have a WLL of 2t and the Grade A 1t.
The reason for using a Grade B shackle is that when loaded at 90 degrees, if the shackles jams in the slot in the anchor the WLL reduces to 50% and for the cost it seems worth the trouble to buy the 'better' shackle. I've tested Crosby and Campbell shackles and can confirm they meet their specifications and have tested a variety of other shackles, including Crosby and Campbell and can confirm that the WLL is reduced by 50% if side loaded (and it does happen!).
You can buy them from a variety of sources in the UK and I buy mine, note I'm in Oz, from Tecni (who have always been reliable).
CMP in their Titan range sell rated shackles, Black Pin shackles. I found that they did not meet specification and you will now find that (after publication of the results), coincidentally CMP reduced their specification. They do not meet Grade B specifications but are better than Grade A shackles and do come in smaller sizes. I think Jimmy Green stock them. Some websites do not have the new specifications, so be careful, and check the specs for Titan shackles on the Titan website. They have been selling off their old stock, marked WLL 2t - but this will, or has changed). Do not be confused with Titan's Yellow, or Orange Pin shackles - they are Grade A.
I only use Campbell or Crosby Grade B shackles. I have seen too many failed shackles. Do not be tempted to buy West Marine's rated shackles, they meet strength specifications but bend like spaghetti.
Try also Knox Anchor, they sell shackles (possibly only Grade A but might have found a source of Grade B).
Jonathan
This quality are called a Grade B and most other rated shackles are Grade A. I, for convenience, compare these at the 3/8th" size - Grade B have a WLL of 2t and the Grade A 1t.
The reason for using a Grade B shackle is that when loaded at 90 degrees, if the shackles jams in the slot in the anchor the WLL reduces to 50% and for the cost it seems worth the trouble to buy the 'better' shackle. I've tested Crosby and Campbell shackles and can confirm they meet their specifications and have tested a variety of other shackles, including Crosby and Campbell and can confirm that the WLL is reduced by 50% if side loaded (and it does happen!).
You can buy them from a variety of sources in the UK and I buy mine, note I'm in Oz, from Tecni (who have always been reliable).
CMP in their Titan range sell rated shackles, Black Pin shackles. I found that they did not meet specification and you will now find that (after publication of the results), coincidentally CMP reduced their specification. They do not meet Grade B specifications but are better than Grade A shackles and do come in smaller sizes. I think Jimmy Green stock them. Some websites do not have the new specifications, so be careful, and check the specs for Titan shackles on the Titan website. They have been selling off their old stock, marked WLL 2t - but this will, or has changed). Do not be confused with Titan's Yellow, or Orange Pin shackles - they are Grade A.
I only use Campbell or Crosby Grade B shackles. I have seen too many failed shackles. Do not be tempted to buy West Marine's rated shackles, they meet strength specifications but bend like spaghetti.
Try also Knox Anchor, they sell shackles (possibly only Grade A but might have found a source of Grade B).
Jonathan
prr
Well-Known Member
what kind of lifting power has your winch ?? Or your arms ??
Neeves
Well-Known Member
If this refers to me - I test on conventional pneumatic test rigs, NATA approved, capable to tensile loads of 100t with a maximum length of 20m. The rigs are fairly common and used to test lifting slings etc (and in my case for the Oz mining industry) Data obtained provides full detail of deformation.
If you want the full detail check Practical Sailor articles on chain and shackle testing over the past 6-8 years. They have a reasonably good search facility. I'm overseas - other wise I'd provide some links.
Jonathan
Dave100456
Well-Known Member
Have a look here
http://www.gsproducts.co.uk/galvanised-steel-green-screw-collar-pin-bow-shackle/
They cost less than 'marine specific' shackles are they as good? I use the 13mm dia pin varient with working load of 1500kg and min breaking load of 6x that.
http://www.gsproducts.co.uk/galvanised-steel-green-screw-collar-pin-bow-shackle/
They cost less than 'marine specific' shackles are they as good? I use the 13mm dia pin varient with working load of 1500kg and min breaking load of 6x that.
NormanS
Well-Known Member
I just use a galvanised shackle, at least one size up from the chain size.
mdonnelly
Well-Known Member
Took a walk around the marina today looking at anchor set ups on a number of boats. Double Shackles seems the commonest set up.
Neeves
Well-Known Member
I would strongly recommend a reconsideration - rated shackles are cheap and unrated unmarked shackles that I have tested (and even some rated shackles) have an amazing propensity to bend - making them impossible to release - except with bolt croppers, hacksaw or angle grinder. They can be very soft and the pin simply pull out of the thread.
You might be lucky, I don't believe in luck (or I'd spend more time in a casino!)
Jonathan
Neeves
Well-Known Member
Usually with a bit of searching it is possible to attach chain to anchor with only one shackle. There is nothing wrong with 2 shackles (appropriately sized) except it means 2 shackles to be moused or secured with Loctite.
Using a stainless shackle is as bad as a non rated shackle - they again bend like spaghetti. They might meet rated UTS but deform too easily (stainless has a low yield point). You can buy stronger stainless - its cheaper to buy from a supplier in the UK of Crosby shackles.
Ideally you want to use a bow shackle, not 'D' as the bow offers articulation.
Jonathan
