My First Soft Shackle

[Seaworthy Lass]

Originally Posted by Dockhead

Yes, well, I still don't understand how you "encircled" the dyneema around the ring.

Here is an explanation.
I will make it up and photograph it in a sec, as it is hard to explain:

Originally Posted by Dockhead

Concerning the "crossover" noose which I made -- I have been playing with the strop, unwhipped. The "noose" naturally grips the ring, which stays in place. You have to make an effort to pull it out. This is good. It means a bit of stitching would carry very little load and be stable. But now I have another problem -- if I do a 72x bury x2 for a long splice, the damned strop will be too long. Bleh. I might have to go back to brummel eyes on each end.

Because it is a loop, you only need one lot of 72 x the bury, not two. You need exactly the same when splicing a loop in Dyneema (the Brummel is just a lock substituting stitching, it does not add to strength and in fact will decrease it), so there is no extra amount.
The Grog sling appeals, as 30 x is "adequate" and Evans has said that 42 x is plenty.

SWL

[Dockhead]

Originally Posted by Seaworthy Lass

Here is an explanation.
I will make it up and photograph it in a sec, as it is hard to explain:






Because it is a loop, you only need one lot of 72 x the bury, not two. You need exactly the same when splicing a loop in Dyneema (the Brummel is just a lock substituting stitching, it does not add to strength and in fact will decrease it), so there is no extra amount.
The Grog sling appeals, as 30 x is "adequate" and Evans has said that 42 x is plenty.

SWL

Ah, you mean you bury it and let it come out again and continue down as one of the legs? I think I see now. Clever.

[Seaworthy Lass]

Originally Posted by Dockhead

Ah, you mean you bury it and let it come out again and continue down as one of the legs? I think I see now. Clever.

Yes, exactly .

The length is not critical, as long as it is not greater than half the circumference, as if it is greater it pulls on the line awfully to try and emerge straight.

To get the length right, I just laid the dyneema around the ring and marked it with a texta, then buried one end over this length.
Took seconds and holds super snuggly and there is no weird pull on the dyneema as it "emerges" from around the ring completely free.

SWL

[Dockhead]

Originally Posted by Seaworthy Lass

Yes, exactly .

The length is not critical, as long as it is not greater than half the circumference, as if it is greater it pulls on the line awfully to try and emerge straight.

To get the length right, I just laid the dyneema around the ring and marked it with a texta, then buried one end over this length.
Took seconds and holds super snuggly and there is no weird pull on the dyneema as it "emerges" from around the ring completely free.

SWL

OK, got it now! Very clever indeed.

Now let's move to the loop. Why would I not have to bury both ends 72x, with or without a brummel lock in the middle? I thought the strength is a function of bury length, and anything less than 72x is less than the strength of the rope.

Not???

[Dockhead]

Originally Posted by Seaworthy Lass

Yes, exactly .

The length is not critical, as long as it is not greater than half the circumference, as if it is greater it pulls on the line awfully to try and emerge straight.

To get the length right, I just laid the dyneema around the ring and marked it with a texta, then buried one end over this length.
Took seconds and holds super snuggly and there is no weird pull on the dyneema as it "emerges" from around the ring completely free.

SWL

OK, got it now! Very clever indeed.

Now let's move to the spliced loop. Why would I not have to bury both ends 72x, with or without a brummel lock in the middle? I thought the strength is a function of bury length, and anything less than 72x is less than the strength of the rope.

Not???

[Seaworthy Lass]

Originally Posted by Dockhead

OK, got it now! Very clever indeed.

Now let's move to the spliced loop. Why would I not have to bury both ends 72x, with or without a brummel lock in the middle? I thought the strength is a function of bury length, and anything less than 72x is less than the strength of the rope.

Not???

Yes, the bury needs to be 72 x, but there are two legs to a loop stretched out, so that means the length of the strop is 72 x line diameter (not twice this) plus the diameter of the ring.

Once you cow hitch it shortens it even further.

It is minimally different if you create 2 spliced loops, as you did initially.

How long do you need your arrangement to be? Using a Grog sling may reduce the strength a bit, but it will shorten it considerably (length will be 30-42 x line diameter plus low tension ring diameter). If you need something shorter than that, then winding a soft shackle around looks like it would work very well.

SWL

[Dockhead]

Originally Posted by Seaworthy Lass

Yes, the bury needs to be 72 x, but there are two legs to a loop stretched out, so that means the length of the strop is 72 x line diameter (not twice this) plus the diameter of the ring.

Once you cow hitch it shortens it even further.

It is minimally different if you create 2 spliced loops, as you did initially.

Well, that doesn't make any sense to me -- if the interface between two pieces of dyneema needs to be 72x diameter long, to grip with strength equal to the strength of the raw rope, why could you halve that just because you have two interfaces? Chain is only as strong as its weakest link, right? So both of these interfaces need to be as strong as the rope, I would think, nicht wahr?

[Seaworthy Lass]

Originally Posted by Dockhead

Well, that doesn't make any sense to me -- if the interface between two pieces of dyneema needs to be 72x diameter long, to grip with strength equal to the strength of the raw rope, why could you halve that just because you have two interfaces? Chain is only as strong as its weakest link, right? So both of these interfaces need to be as strong as the rope, I would think, nicht wahr?

Hang on, I will photgraph it.

[Seaworthy Lass]

Does this help?

The length of the loop only needs to be approx 72 x line diam, not twice this, as the loop has two "legs":

[Dockhead]

Originally Posted by Seaworthy Lass

Does this help?

The length of the loop only needs to be approx 72 x line diam, not twice this, as the loop has two "legs":

OK, and that confirms what I thought -- that both buries need to be 72x, which means the whole spliced loop can't be less than 1300mm long (for 9mm dyneema). The cow hitch will take it down a bit, but it will still rise more than two feet off the deck.

I might have to try the trick the riggers of that Swan did.

[Seaworthy Lass]

Originally Posted by Dockhead

OK, and that confirms what I thought -- that both buries need to be 72x, which means the whole spliced loop can't be less than 1300mm long (for 9mm dyneema). The cow hitch will take it down a bit, but it will still rise more than two feet off the deck.

I might have to try the trick the riggers of that Swan did.

Yes, sorry if I confused you.
But this is no greater than if you create two eyes using splices with Brummel locks. "Going back" to this does not help.

If 9 mm dyneema is needed, why not bump it up to say 10 mm and create a Grog sling.
The min 30 x bury would bring it well less than 300 mm off the deck if you attached it with a cow hitch.
The stronger 42 x bury would be less than 400 mm with a cow hitch.

If you need even less than this, then perhaps just wrap a soft shackle around the ring?

[estarzinger]

I might note that simple lashings often get forgotten as we all get excited by elegant splices. You can just lash these rings, with 3 to 6 turns of smaller dyneema. You can either lash them in place, or 'free' (eg with the ring at one end and nothing at the other) and cow hitch.

If I remember correctly that is how the very elegant Italian constructions I posted above were made - and then he used a black cover over the multi strand lashing to make it look better and be less snag able.

You can make a lashing just as short as you want with no strength loss.

Edit: either a true lashing or a "loops" like construction with the ends joined.

[estarzinger]

LOl after absolutely insisting that they had tested my shackle designs, Yachting Monthly has now admitted they were Allen's taken from his L36 website,

And for some reason they did not pick the 'stronger' (button with burried legs) design which is also on his website, but rather choose to pick two of his weaker designs.

[Seaworthy Lass]

Originally Posted by estarzinger

LOl after absolutely insisting that they had tested my shackle designs, Yachting Monthly has now admitted they were Allen's taken from his L36 website,

I imagine they will print a retraction. It must be extremely frustrating though, as this article is likely to be read or cited without reference to that.

Originally Posted by estarzinger

And for some reason they did not pick the 'stronger' (button with burried legs) design which is also on his website, but rather choose to pick two of his weaker designs.

Just shaking my head here. Testing methods seem way less than adequate too, so what value are the conclusions drawn?

[Jim Cate]

SWL, things like this are why I have not purchased a yachting magazine in twenty plus years. Full of drivel and thinly disguised ads...

Jim

PS Evans, I'd be pretty angry in your place. You must have damn good anger management skills!