Anchor Shackle or Connector

[ctva]

Thank you one and all, especially the technical info and links.

I will digest and see where I go. Shame that to buy one shackle is expensive when you add in P&P but such is life and sleeping sound at anchor is a big plus!

 

[Neeves]

And on 'D' shackles in particular, or any shackle

If you read the small print for use of lifting shackles they advise that side loading at 90 degrees will reduce the WLL by 50% and side loading by 45 degrees will reduce strength by 25%.

I have tested shackles loaded as such and can confirm the data is right. A shackle that articulates is less likely for this to occur but a 'D' shackle does not articulate and it is much more likely you will side load it. Shackles are designed, tested and specified in a straight line pull.

A 3/8th or 10mm shackle, especially a 'D' shackle, and that would include all the stainless shackles has a WLL of 1t, plenty high enough for 8mm chain (but getting marginal for 10mm chain) and a waste of time for 8mm G70. Loaded at 90 degrees, quite possible - it will be below the WLL of the chain.

This is why we use Grade B bow shackles (sometimes called 'anchor' shackles), 3/8th" WLL of 2t. whatever attitude the shackle has the WLL is above that of the chain. The cost of mail order of a Crosby G209A shackle might be high from Tecni (I'd buy 2 off) - but if something is going to fail - as long as it is correctly moused or secured with Loctite - it will not be the shackle that fails.

I still have seen no stainless shackles that can offer the strength, and thus security, of a decent rated galvanised shackle - and if rated gal shackles are expensive then a decent stainless shackle will make your eyes water.

Jonathan.