Neeves
Well-known member
The best way to size your shackle is to do so in the chandlers. Take your anchor (or check they have the identical model) and 3 links of chain and try their shackles. All 3/8th" shackles, etc etc are very similar. You need a shackle whose clevis pin fits the hole in your link and that you can thread through the slot on your anchor. Once you fit the shackle, bow in the slot, check that it rotates freely and does not or cannot bind. If it binds - try a bigger shackle or smaller one.
Some anchors are more easy to fit than others. The better ones have the slot bevelled, on the inside - (bull nosed?) and more difficult ones are laser cut and the slot edge is at right angle and binding is more of an issue.
Our 15kg Excel takes a 3/8th" shackle neatly our similarly sized aluminium Excel (which has a slightly thicker shank) will only accept a 1/2" shackle.
Once you know what size shackle fits you can then ask the chandler for the appropriate Crosby shackle. They will not stock Crosby and you can then walk out, still feeling virtuous, and order one from Knox Anchor - thanks for the heads up.
You will find that the shackle that fits both chain and slot will be of the appropriate strength (as one too big will not fit the chain and one too small will bind in the anchor slot and/or not articulate through lack of space between attached chain and end of shank.
You are aiming to use a shackle whose WLL when loaded at 90 degrees so 50% of the embossed WLL is greater than the WLL of your chain. If you are using chain stronger than a G40 (so Cromox or HT chain) this will be an issue and you will need some form of enlarged link (+ spares) on the end of the chain so as to accept an appropriately sized (strength) shackle
Jonathan
Some anchors are more easy to fit than others. The better ones have the slot bevelled, on the inside - (bull nosed?) and more difficult ones are laser cut and the slot edge is at right angle and binding is more of an issue.
Our 15kg Excel takes a 3/8th" shackle neatly our similarly sized aluminium Excel (which has a slightly thicker shank) will only accept a 1/2" shackle.
Once you know what size shackle fits you can then ask the chandler for the appropriate Crosby shackle. They will not stock Crosby and you can then walk out, still feeling virtuous, and order one from Knox Anchor - thanks for the heads up.
You will find that the shackle that fits both chain and slot will be of the appropriate strength (as one too big will not fit the chain and one too small will bind in the anchor slot and/or not articulate through lack of space between attached chain and end of shank.
You are aiming to use a shackle whose WLL when loaded at 90 degrees so 50% of the embossed WLL is greater than the WLL of your chain. If you are using chain stronger than a G40 (so Cromox or HT chain) this will be an issue and you will need some form of enlarged link (+ spares) on the end of the chain so as to accept an appropriately sized (strength) shackle
Jonathan
