Brummel on a closed Shackle/Ring

[GlennB]

I am trying to spice 5/16" endura on to a closed ring (from a toggle) to replace a running backstay. I have the book, read and spliced a mcdonald brummel with success, but there does not seem to be a way to spice it on to a closed ring.

I have seen references to being able to do this with a Mobius Brummel, but can't figure out how that would work either. I do have access to the other end (about 50' long).

Ideas?

Glenn

[Brian Duff]

look up the 'Cow Hitch'

[Matthew Sebring]

If you do have access to the other end it's an easy thing to do. Make up a brummel on a spare piece of line to see how the order that the line passes through the core and vice versa and duplicate that running the entire length of the line through the tail.

[GlennB]

I figured out how to do it when I had access to the other end and have spliced it on that way. Just wondering if there might be some way to tie it without access to the other end (for future use).

Re: Cow Hitch

It seems like the point of splicing it is to keep the load capacitly at the splice as close to the line load capacity as possible - wouldn't a cow hitch signifigantly weaken the system? This is on a running back stay, so there are signifigant loads and I am replacing 5/16 wire with 5/16 endura.

[Brion Toss]

Originally Posted by GlennB

I figured out how to do it when I had access to the other end and have spliced it on that way. Just wondering if there might be some way to tie it without access to the other end (for future use).

Re: Cow Hitch

It seems like the point of splicing it is to keep the load capacitly at the splice as close to the line load capacity as possible - wouldn't a cow hitch signifigantly weaken the system? This is on a running back stay, so there are signifigant loads and I am replacing 5/16 wire with 5/16 endura.

Hi there,
This actually relates to the discussion on joining mooring line eyes as well. I do not have the data in front of me, but as I recall, ring-hitching an HM eye does not weaken it very significantly. If this is so, I would speculate it is partly because the load doesn't move the parts of the line asymmetrically, as most knots do, partly because the compression from the bight of the hitch is indirect, and spread over two parts equally (minimal deformation of, and compression on, the standing part as it goes to the shackle), and partly because the effective radius is doubled, with two parts going around the shackle. I can't think of another structure that has all of these features. If, for example, you tie a round turn and two half hitches -- which has been shown to weaken HM dramatically -- you get the distribution on the shackle, but the standing part will want to move past the hitches, and the hitches deform the path of the single standing part.
I'll see if I can come up with the test numbers; meanwhile field experience indicates that a ring-hitch is a good thing, assuming it goes to a splice. If it doesn't, then we're back to asymmetrical loading, and weakening.
Fair leads,
BrionToss

[Brion Toss]

One more thing,
Other than ring-hitching, which requires an extra-wide shackle bail, it is possible to make the McDonald Brummel if you have sufficiently loose-woven rope that you can put the shackle through it. There is a sporting limit here, but some ropes are loose enough that, with a small enough shackle, a long enough eye, and a gentle touch, it can be done.
Fair leads,
Brion Toss

[Brian Duff]

to claify cow hitch and ring hitch are uses to describe the same attachment technique.

Runners are generally attached to those t-term ring fittings with a cow hitch(ring hitch)

so are halyard shackles when the cover is stripped

[GlennB]

So, for future reference, if you splice a standard McDonnald Brummel, can you then put the loop through and pass the rest through the loop to attach it without signifigantly weakening the line? (endura)

In the meantime I spliced the brummel passing the 60' of line passing through the middle brummel, with 3 brummels (if that is how one referers to each loop), directly to the T toggle - Navtec-N743-07 T-RING,FITS N740-07 BACK PLT, so I assume this should be fine.

[Brian Duff]

haven't done any load testing here, but in practice I find lines directly spliced to shackles to be more worn or chaffed than lines that are ring hitched (when cover is stripped) so i prefer the latter

I am not sure what you mean about three brummels and the middle one... ?

[mrgnstrn]

Originally Posted by GlennB

I am trying to spice 5/16" endura on to a closed ring (from a toggle) to replace a running backstay. I have the book, read and spliced a mcdonald brummel with success, but there does not seem to be a way to spice it on to a closed ring.

I have seen references to being able to do this with a Mobius Brummel, but can't figure out how that would work either. I do have access to the other end (about 50' long).

Ideas?

Glenn

You can do the Brummel splice directly to the tang without the ring hitch.
However, it requires you to pull 50' of line through one of the holes in the brummel. Not impossible, but perhaps annoying.

-M