Swaging 10mm s/s wire rope

[Ray Perry]

18 months ago I re rigged my shrouds with 10 mm galvanized wire. Already bad rust is starting to appear. My last set of standing gal rigging lasted 15 years and was serviceable. The only reason I replaced it was because I will soon be leaving to complete my cruise.

I am going to replace the gal with 10mm 7/19 316 s/s wire. IS IT ADVISABLE TO SWAGE IT WITH THIMBLES AND SWAGES My problem is that the clevis pins are 15mm at the mast cap and 12mm at the turnbuckles.

It is sad that the quality of gal wire has deteriorated so much.

Any advice would be appreciated.

[Snowpetrel]

Curious to know what sort of wire you used? I've had a good run (nearing 14 years) out of korean 7x7 class A galv.

[double u]

if you use thimbles make sure tehy are extra-heavy-duty
https://www.cs-rigging.com/UserFiles...l/ZW119912.jpg
or similar to
http://www.blitzkrueg.com/i//new_thimble.jpg

[Ray Perry]

My main concern is if it is safe to thimble swage 7/19 s/s wire.

[double u]

if your thimble is too weak it will "point" under load, dramatically decreasing the bending-radius of the wire which will break there

[Snowpetrel]

If done properly it is ok. There is a theoretical reduction in ultimate breaking strength somewhere around the 5-15% mark as I recall, but this can be managed with decent rigging sizes and engineering.

An unusual choice of 7x19 for the standing rigging, It has much more stretch than 1x19 or 7x7 (something like twice the stretch from memory). Fine for a gaffer or low stressed rig I guess, was the old stuff 7x19 as well?

You could easily weld up normal stainless thimbles to stengthen them. Another trick is to use inserts a similar OD to the ID of the thimble to better distribute the pin loads.

[OZwingle]

Maybe this thread should be over in Deck Hardware: Rigging and Sails forum??

[Cherod]

Originally Posted by OZwingle

Maybe this thread should be over in Deck Hardware: Rigging and Sails forum??

Why ? I find it quite interesting and may ( prob ) not have seen it .

[OZwingle]

It is an interesting topic. Merely mis-categorized under the forum for OpenCPN navigation software. It's like finding anchor chain in the paints section of the hardware store. Maybe interesting, but a bit out of place. If you are interested in these sorts of topics, browse the Deck hardware: Rigging, Sails & Hoisting forum. Interesting stuff.

[OZwingle]

I have never seen 'swage' and 'thimble' used together. Maybe something like a nicropress fitting is intended with thimbles? This would be more common. Swage fittings are most usually are applied to stainless steel standing rig wire as terminals with eyes, or forks, or threaded studs for turnbuckles.

An alternative would be mechanical terminals such as Hayn Hi-Mod or Sta-Lok with SS standing wire. More expensive up front, but reusable. And most critical for a long cruise: Field Servicable with the correct spares kit.

[Jim Cate]

I have never seen 'swage' and 'thimble' used together.

The act of squashing the Nico Press sleeves is indeed a form of swaging as you seem to suspect, and the use of very sturdy thimbles is needed in this sort of application.

And I too am surprised at the use of 7x19 wire in standing rigging. 7x7 should be flexible enough to use thimbles and swages as terminals, is usually less expensive and way less stretchy. OP, could you explain your choice here, please? Really curious, I am!

Jim

[UNCIVILIZED]

I don't see where it would be a problem, though I'd be inclined to use solid bronze thimbles, & probably 2+ Nicopress fittings per wire end. The catch being that with solid thimbles, there's usually a hole in the center designed to work with a particular size pin. Albeit I'm sure these can safely be "adjusted" a bit in terms of how large the hole is. But you'd need to allow for pivoting/toggling on 2 axis. I'm not sure how well the idea of a standard thimble with a welded cross bar will work. As you'd wind up point loading the thimble & pin where the 2 meet up. Thereby reducing the amount of bearing area, & thus strength, by a good bit. I'll have to dig out The Rigger's Apprentice & look.

[Snowpetrel]

Never seen a galv thimble stretch when used on yacht rigging. Not to say it doesn't happen, but the standard pressed galv thimbles seem ok in general, though they are slightly heavier than the stainless ones. Two nicopress or other swages may reduce the strength of the wire. Anotger approach for 7x7 or 7x19 wire is a flemish eye with a special swage or even just a seized or spliced tail. This worls out pretty strong.

Bernard Motessier was a big fan of bulldog grips. Simple and cheap, and if done with a flemish eye its near 100% breaking strain.

Hand splicing 7x19 is pretty easy and quick.