Index

Life Lines- Vinyl Coated SS Wire Versus Dyneema.
INDEX - Catalina, Panache

CORROSION - The problem with vinyl coated SS wire is that the vinyl will develop cracks that lead to water intrusion and then UV corrosion.  There is no way to gauge the quality or strength of SS wire long after the old vinyl coating cracked.  Consider that it took 30-40 years for industry and race committees to come to this conclusion.  Their realization and guidance happened after several crew members separately broke through a life line and died during recent ocean races.  As a result many ocean race committees now consider vinyl coated SS wire unsafe and no longer allow it. 
At a glance a person might judge aging wire to be strong enough to keep them on deck, but a closer inspection will likely reveal many flaws.  Granted a crew on a fresh water SJ23 is more likely to trip over a low lifeline than to break it but you should heed the advice of these committees.  Just like the service life of standing rigging in the southern US is ~10 years, so should a life line there have a shorter life.  Panache's 40 year old life lines in Canada have many cracks and are due for replacement.  Corrosion just takes longer in the north.  Ah the impressions of guestimating (SWAG).
- Dyneema does not corrode but has a definitive life when exposed to UV light.

WEAR - Then there is the wear with vinyl coated SS wire passing through the 3/8" hole in each stanchion.  The vinyl and wire will wear at each post, especially if the line is left drooping so it can swing sideways with the hull.  A lifeline should be tensioned to just snug, no more and no less.  Hopefully the tube through the stanchion is smooth with slightly rounded corners.
- Dyneema must be protected against chafe where it goes through a stanchion. This can take the form of lacing twine, vinyl tube, or any other tough material.

AVAILABILITY - Not many companies manufacture vinyl coated SS wire anymore due to the liability issues and risks of corrosion.  
- Today there is a solution in the form of soft Dyneema line.  It comes in 6MM (1/4") which is slightly thicker than the factory SS wire and far exceeding the strength.  It is quite OK to install thicker Dyneema as it is easier to rest against.  Dyneema is available at most any chandler. 

SAFETY - One safety advantage for a Dyneema lifeline is the ability to cut it with a sharp knife to more easily pull a person onboard since the line almost always blocks your way of reaching the casualty.  It is next to impossible to pull a casualty through the 16" tall gap below the line.  Go ahead, try cutting the SS wire!
- The factory SJ23 life line configuration must be released with the single pelican hook at the transom.  This is handy only if there is a crew in the cockpit.  Both lines would go slack or certainly droop lower.  So this is an instant justification to install a Dyneema life line that can be cut.
- On Panache the forward 2/3s of the SS life lines are locked permanently with the bow section having a net of criss-cross lines to keep a jib on deck.  Lots of SJ23s are configured with netting like this.  There is no way I can lower the forward line nor could I pull a person onboard below it.  That leaves a cockpit gate as the only place to pull a casualty onboard.  So an instant justification to install Dyneema life lines that can be cut.
- 1/4" SS lifeline is painful to lean against for any length of time, less so with thicker Dyneema that flattens with body pressure.  However, even with Dyneema I still wouldn't go without my cushions padding the cockpit gate lines.
- Dyneema is easier against the foot of the jib when sailing close hauled. 
- Dyneema can fold easily when the tension is released.  This makes it easier to tuck out of the way during winter layup where it must go straight down a stanchion so the winter cover can pack tight against the stanchion and against the toe rail.  It also makes it easier to clear the deck when a cockpit gate is open.  While I usually keep Panache's transom gate open, with Dyneema the pelican hook can be clipped to the pushpit, leaving the soft line hanging below it.  This takes less room and saves the gel coat.
- The Dyneema line will never break if you are flung against it with full body weight.  It is far more likely that the stanchions will give.  Just don't make it a practice to rely on a lifeline to keep yourself on board.  So far this author has managed to stay dry, but I've come close! 
- In thinking about lifelines on a short pocket cruiser, the real strength comes from being attached at the ends; pulpit and pushpit/cockpit post.  The stanchions between simply keep the line from drooping.  The short angle bracing at the bottom of a stanchion serves to offset the strain of being pulled inboard due to hull curvature.  There is no way the stanchions can stop you from going overboard.  That's my theory and I'm sticking to it.

FABRICATION - It is surprising how much line an eye splice and locking Brummel knot takes.  You discover this after you splice the second eye and realize how much shorter it is than when you measured.  Some of the length can be recovered by stretching the line; construction stretch.  This stretch basically removes the slack in a spliced eye, brummel knot plus tucked in portion.  After that the line length stays at the stretched length.  Remember to account for this "shrinkage" when determining the location of the splice at the other end of the line.  Failing that you may end up having to redo the splice a tad further down the line.  It can be done but you need a good pusher fid.  Fortunately I had enough extra tapered line tucked inside. 
- Do include a SS thimble inside the eye as it adds considerable strength to the splice.  Add a whipping over the thimble to keep it in place.
- Remember to leave a long length of tapered line tucked inside.  It maintains considerable strength.
- Use this splice https://www.youtube.com/watch?v=d0B6tYTVHVM for the easy end of the line.
- Use this splice https://www.youtube.com/watch?v=4WW7Qvg3VjI for the difficult end of the line.

I'm fabricating new lifelines for Panache this winter and don't have any photos of a completed installation yet.  Only the individual splices shown below.  In addition, shown below are my ideas installed on a friend's Catalina 27.  He was concerned enough to start his replacement this summer.
 

CONVERSION TO DYNEEMA on a CATALINA 27.

Fig 1, Cockpit Gate - The lifeline gate stanchion at the front of the cockpit.  This stanchion is equipped with the all important SS tube through which the life line passes.  It protects the lifeline from chafe.  To add further protection we opted to add whipping line over the Dyneema.  Note the SS thimble to prevent the line from slipping through the stanchion and to attach the gate line to.  The gate will be converted to Dyneema before the sailing season ends.

Fig 2, Mid Stanchion - This middle stanchion is also equipped with the all important SS tubing to minimize chafe.  The Dyneema is double protected with none waxed whipping line that slides easier, leading to less chafe.

Fig 3, Pulpit - At the bow the owner opted to terminate the line with a spliced eye and SS thimble terminated with a frapping knot in place of the previous turnbuckle.  For comparison you can see the previous SS line on the port side.  The knot makes for convenient fabrication since the length is no longer critical. The lifeline of this Catalina doesn't come down for winter storage.  But if it had to, it would only require releasing the frapping knot.  On Panache I will retain the turnbuckle since the lifeline must come down for the winter storage cover.

If Dyneema isn't good enough you could install solid stainless steel railing.  Now that is something to experience.
 

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