Lifeline fittings for my sailboat

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mickri

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I am replacing the lifelines on my sailboat. Current lifelines are plastic covered wire and are very expensive to replace. You have to have a hydraulic sewaging tool (very expensive) to sewage the fittings onto the wire lifelines. So I am converting over to dynema lifelines and need to convert four of the wire fittings to be usable with dynema. Dynema is a synthetic rope that is stronger than steel yet can be spliced like any other rope. No special tools required. Here is one of the fittings.

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The hole is threaded for 14-28 LH thread that the wire lifelines screwed into. This is how it fits on the boat.

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In order to convert to dynema I have to have an eye on both sides of the stanchion. I can think of several ways to do this. I am looking for feedback on the pros and cons of my ideas.
First idea is to get an eye bolt and rethread the shank of the bolt to 1/4-28 LH thread. Because of the way eye bolts are made I would have to buy 5/16 eye bolts and turn the shank down to .25 then thread it for 1/4-28 LH.
Second idea is to buy .25 stainless steel rod, thread one end for 1/4-28 LH and the other end for 1/4-20 RH and put an eye nut on this end.
The third idea that I can think of is to bore out the fitting that I have and thread it to 5/16-18 RH for a 5/16 eye bolt. This would require tapping a blind hole. This seems to be the easiest solution. I worry about breaking off either the drill or the tap in the blind hole.
All of the parts will be 316 SS.

Suggestions please.
 
An eye splice in each end than a cascading loop of smaller line to adjust the tension where it terminates on the hard fittings, you may also include snap shackles at gates
This is common practice with fiber rope lifelines.
As explained by the USSailing guidelines seen here. https://www.ussailing.org/wp-content/uploads/2018/01/Dyneema-Spectra-Lifeline-Revision-Jan-2014.pdf

Above all protect these materials from sunlight.

In the distant past I worked in the racing sailboat industry, I still race weekly during the season, have made machined parts for manufacturers recently but have not worked directly in that business for 35 years.
 
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My main hobby since college has been crewing on ocean racing sailboats off Southern California and Mexico. Have tens of thousands of miles out on the ocean in all kinds of weather. Then I went cruising for seven years and never got past Mexico. Life was too good and the living too easy in Mexico. My sailboat is tired and I am just starting to bring it back. Lots to do. Replacing the lifelines is the first of many projects.
 
Check the major and minor diameters for the threads you are considering. There may not be enough fat there to do what you want safely.

If you have only 4 fittings might it not be easier and possibly less expensive (considering buying a new HSS tap or die ) to just buy threaded eyes to match the eye bolts you are purchasing anyway? Sure it's less fun but...

BTW when I replaced mine about 10 years ago I went with uncoated 1x19 wire and paid the rigging shop to do the swaging, IIRC the swaging costs accounted for about 1/3 of the total. I'm still very happy with them, they still look like new.

For my standing rigging I used Sta-Lok fittings that I did myself.
 
These pieces are at the lifeline gates. The one I showed is just the eye but the other side of the gate is a joined gate eye with a short piece of wire that connects to the pelican hook. Those parts are over $200 for both sides. I am looking at the Sailrite catalog for prices. I don't want to replace all of those parts. Prices have gone up on lifelines. I can remember back in the day when West Marine had the sewaging tools in the store and you could make your lifelines. Not any more. I checked into wire lifelines and the cost with all the new fittings and pieces was in the $750 range give or take for my boat. The dynema lifelines will be a fraction of that cost.

Still looking for feedback on how to connect the eye bolts to the eyes that I have.
 
My buddy striped off the plastic jacket on his life lines . Looks pretty good , there was a little rust on the wire but that was easy to get off . What kind of boat do you have ?
 
I have a Gulfstar 37 that I have extended the transom 30".

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I stripped off about a foot of the plastic covering and the wire strands were starting to break. Lots of meat hooks just waiting to tear your hands apart.
 
And there's the oddly named Morro Rock in the background. Never got any traction explaining to people that to name a rock "Morro" is nonsensical. Of course it's a rock! (Morro is the Spanish word for rock)
 
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Very nice boat!!!!

I'm assuming you have thoroughly inspected the fittings you have for crevice corrosion. It might be worthwhile to take some of the money you're saving on cable and replace the fittings with new. I've had friends take a swim when lifeline fittings failed. Not too big a deal on a warm summer day, but in rough conditions you'll want to know everything is right with these critical parts. JMHO.

John Matthews
ABYC Electrical & Marine Systems

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