Soft Rigging Solutions

[village idiot]

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[catsketcher]

Nice tri. What is she?

 

[village idiot]

Newick tremalino

 

[HydroNick]

Discussion on Dux diamond stays:

http://www.boatdesign.net/forums/multihulls/dux-diamonds-53862.html

 

[HydroNick]

Eyesplice Maffioli Powergrip

Does anybody have any advice about splicing Maffioli Powergrip.

http://www.gottifredimaffioli.com/prodotto.php?idF=4&idSF=7&idPr=26&idV=46


I followed this video

https://www.youtube.com/watch?v=pGbCr7hnGX8

which seems pretty good, but the Maffioli cover seems very tightly woven.

Tried once and failed. Second attempt I have a big ugly ball of core that won't go into the cover. Should soon have a halyard that will be...too short.

Thanks

 

[brian eiland]

There's a lot of good ideas from the past, ships were rigged with natural fiber for centuries, I've worked on refits to Endeavour replica & just last week made some "needle" shroud tensioners for a Viking ship, both a wedge & lever & pretty clever stuff from old times.
Jeff.

Brian,
Have a look through here https://vikinglongship.wordpress.com/page/3/ & click & zoom some of the pics, nature of operation will be apparent.The shroud or stay/ whatever leads through the eye of the needle & a couple of turns taken around- these turns resist splitting of the timber needle also as they grip around it, the length adjusted until point of needle is roughly level with the simple "loop" chainplate- here the taper/wedge of the needle is important as pushed in it takes up some slack, then the needle is pushed up & tensions through lever action and simply held by one hand around needle & shroud then some light line simply ties the needle to shroud. These were just made of 90 x90mm post stock, if wider material used I think it may be possible to overcenter a little more or even shape with a slight twist/helix to hook around the back of shroud.
I've seen some variations that look kind of "male" in design also but we chose these kind for simplicity.
Jeff

Hi Jeff,
I was not able to find those photos and enlarge them as you suggested.

 

[brian eiland]

proper name for these 'mast connection'?

These are a few photos I had stored on my computer

Those staggered cheeks are quite unusual.

What name might be proper for these 'blocks' that would attach to the mast tube to keep a 'loop' of rigging rope/wire from sliding down the mast ??

cheek blocks?.....

The actual jumper stay ‘cable’ itself will be constructed from one of the new-age synthetic rigging materials such as Dyneema, Spectra, PBO, LCP, Aramid, C-6 carbon tow, etc. Ideally this stay material will have NO pre-stretch requirements thus no pre-loading. It should be very strong upon immediate application of force, and in a minimal diameter that it can be looped around the mast section in a continuous manner, at least on one end, maybe both. As a continuous loop, ‘both sides’ will always be carrying ½ the total load, rather than one side under load, while the other might be slack. There will also be a minimum of ‘fittings’ required to attach them to the mast (less weight, less failure pts). I imagine a simple ‘block’ of material attached to the mast around which the loop of this jumper stay can not slide any further along the mast….and one end needs to be adjustable

 

[brian eiland]

..a couple of other photos I ran across of something similar to what I am speaking of...

 

[brian eiland]

Another type of soft fiber rigging connection to the mast.
( I like these but they are not quite what I am looking for in this instance)

http://www.colligomarine.com/mastconnections-gallery/

 

[DGreenwood]

Brian
They have more than one name that I've heard but we always referred to them as a "thumb". A cheek, a bolster and of course the general term for the landing of a "soft eye" is "the hounds".

 

[HydroNick]

www.sail-world.com/147237

 

[BobBill]

Decent stuff. I am using Samson Amsteel with 7x19 wire and Clamcleats, so basically, Amsteel is the link in the chain, watching how it does...will provide pics when the rain stops...hope the thread goes on forever...love experimenting.

 

[Stumble]

Generally amsteel is considered far too stretchy for standing rigging. It will work but the size required to control stretch is rediculious. The prefered option is a heat set variety of dyneema like D12 MAX 99.

 

[BobBill]

Now that is interesting, as I thought Amsteel was Dyneema...D12? Have to check that one. It is new to me!

I also have some really small diameter Technora...strong but very stiff. I bought some 7/32 Amsteel to support a tramp, but have not installed. I get my fat *** on it, will know how stretchy it is...

 

[Stumble]

Dyneema comes in different grades. The sk-75 (amsteel) is the lowest end stuff currently on the market, and at the top of the market is SK-99. The major difference is the higher the number the stronger the line.

But there is also a heat setting process (HSR) that is applied to the base dyneema. So SK-75 becomes SK-78 HSR. The heat set process increases the strength of the fibers, reduces creep, and greatly reduces stretch, but makes the line much stiffer.

For running rigging SK-75 is pretty much ubiquitous with the higher end stuff just being used in specialty applications and where price is absolutely no issue (it's insainly expensive), while SK-78 was the first one that really was used for standing rigging (Colligio et al). I don't have the numbers in front of me, but I think the HSR typically reduces stretch by about 75%, basically it puts it right in line with SS wire.