Bluewave fittings for dyneema

Y

yoyo

Anarchist
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Zonker said:
Just tie a crown knot inside the collar?
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Looks like an eye splice around a bone..

blue-wave-rope-end-fitting-marine-5.png
blue-wave-rope-end-fitting-marine-6.png


 
S

Scuff

New member
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USA
It seems tyetec just has the one fitting you provided. I did some searching on here and there was a thread mentioned several times that tested the bend radius but my search Kung Fu sucks can anyone link that here? That was a concern with these was how much smaller that radius is vs colligo. I've got stem ball fittings at the masthead and their approach is very compact. The cap shrouds exit a teardrop shaped hole in the sidewall of the mast and the other stuff may chafe on the inside.

Thanks

 
slug zitski

slug zitski

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Scuff said:
It seems tyetec just has the one fitting you provided. I did some searching on here and there was a thread mentioned several times that tested the bend radius but my search Kung Fu sucks can anyone link that here? That was a concern with these was how much smaller that radius is vs colligo. I've got stem ball fittings at the masthead and their approach is very compact. The cap shrouds exit a teardrop shaped hole in the sidewall of the mast and the other stuff may chafe on the inside.

Thanks
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I don’t know 

the safe working load of the fitting is stated 

the limitations of the dyneema interface could be different 

you should ask the supplier for tec advice concerning your application 

my experience with anything high tech is that this  equipment alway needs more vigilance 

 
E

estarzinger

Super Anarchist
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Scuff said:
It seems tyetec just has the one fitting you provided. I did some searching on here and there was a thread mentioned several times that tested the bend radius but my search Kung Fu sucks can anyone link that here? That was a concern with these was how much smaller that radius is vs colligo. I've got stem ball fittings at the masthead and their approach is very compact. The cap shrouds exit a teardrop shaped hole in the sidewall of the mast and the other stuff may chafe on the inside.

Thanks
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The bend ratio on the BlueWave is perfectly fine (I look at this in the past, but just took a refresh look at their cad drawing to confirm). Inside a static spliced loop you only need about 1:1.5 to be full line strength. With a DIY splice, it would be conservative to downrate it perhaps to 80% (which covers up massively f&^king up the bury taper) of line strength. Colligo's bend radius is way oversized for static spliced loops - there is some potential argument that the bigger radius is better for dynamic wear but that is really not going to an issue for the bluewave - the loop is not going to be moving/sawing on the bone.

I have never looked at the tyetec fitting.  But bend radius is usually pretty easy to double check if they have links to their cad drawings.

 
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A

allweather

Member
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baltic
These look pretty nice if one wants to be able to adjust eye size/line length relatively quickly since no stitching needs to be removed? Asking because I tend to get splice length wrong on first attempt for things like stays and this sounds like a neat solution to make handling a bit easier for hands lacking practice.

Though looking at their website, the bottom terminations don't have the toggles I associate with wire ones. Are they not necessary since it is rope instead of relatively stiff wire in regards to bending?

 
E

estarzinger

Super Anarchist
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allweather said:
since no stitching needs to be removed? 

 don't have the toggles ... Are they not necessary since it is rope instead of relatively stiff wire in regards to bending?
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In best practice, these splices will still be stitched.  Good commercial riggers will always stitch just as routine 'properly done' practice.  With a proper bury, and proper pre-tension, the stitching is not needed in 99.99% of cases, but there is always that one case of jerking low loading that without stitching can slip even a long bury. That is even less likely with the bluewave because of the compression, so lets say 99.99%, so in practice yea you can probably safely get away with an excellent splice without stitching (but again a proper commercial rigger would still stitch).

The toggle quest is an interesting one.  I have not seen any testing on it. Assuming the 'mis-alignment' is less than 5 degrees, there will be small 'bend stress' on the dyneema.  I would want a toggle with any more mis-alignment that that as a real stress riser would be created. And I assume the fitting edges are rounded enough not to pose any significant cutting/abrasion threat.  So, the dyneema is probably ok (with small misalignment), perhaps a little strength loss but not much.  That leaves the question about the mis-alignment on the fitting itself - on its tang and/or on the dogbone - idk about this - some other folks with knowledge of metal would have a better idea.

 
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A

allweather

Member
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baltic
Good to know, just keep stitching then. Though I may get away with skipping the stitching for testing purposes until everything fits and then do it after the fact...
Well, shrouds are all wire for now anyway.

Hm, better to just stay on the safe side and put in a toggle then. While I don't have plates and actually round attachment points the terminations can rotate around in two axes, within reason sideways, it is hardly much of a bother, if a few gram more. Only the forestay is an actual flat plate that would torque.

Bigger annoyance is the Selden T-eye that doesn't have a proper data sheet on ropes to use/break loads, but that is a different headache.

 
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