Replacing the Lifelines with Dyneema

Replacing the Lifelines with Dyneema

By C42 Association Technical Editor Gene Fuller


In this issue we highlight a safety maintenance item that many of us could consider. If you see the telltale dark stains at the ends of your lifelines, read on. Terry and Carol Hogan are world travelers on their C42, Common Sense, which is a 2002 model. They are Australian, but they purchased their boat on the East Coast of the USA. They proceeded down the ICW to Florida, over to the Bahamas, then Bermuda, Azores and the Mediterranean. They have spent winters in Tunisia, Turkey, Sicily and Spain. They are now about to head back to the USA via Cuba. Their travels are in a blog called "Welcome Aboard Common Sense".
 They recently replaced the lifelines on Common Sense. –Gene Fuller, gefuller42@comcast.net
 
Our original lifelines were looking decidedly shabby, and the tell-tale rusty patches suggested that the wire inside its plastic coating was not in great condition. They are called "lifelines" for a reason. It was time to replace them. We read an article by David and Marcie Lynn in Good Old Boat magazine, where the authors describe refitting their lifelines with Dyneema. This had immediate appeal, as Dyneema offers great strength for its weight, and it has very little stretch. It looked good, and we could do the splicing work ourselves.

 We used CS Johnson fittings. We considered others but even though our boatyard in Turkey had a skilled stainless steel operator, who could machine stuff up quite well, the rod size was simply not available – his was all metric. We could have had a complete set made up but the cost of that plus pelican hooks was no saving at all. Also, as you may see from other articles on this project, it is possible to make eye-splices and then insert a shackle with a pin, which makes the splicing job quite easy. It is much more difficult to splice in a Johnson fitting, as you cannot simply pull the pin out, make an eye, then put the pin and shackle back in. Added to this is the problem that the Johnson fitting is quite long and the whole length of the unit needs to go back through the splice. Nevertheless, the final look of the CS Johnson lines is far more sleek and professional, and we thought it was worth both the cost and the added complexity in fitting.

The turnbuckles on Common Sense have 1/4-28 threads but, beware, the pelican hooks are 5/16-24 thread. The same may not be true on your boat, but it caught us. We had to exchange, which was difficult from Southwestern Turkey. In addition to that, even after the exchange we found the thread was different. We ended up by cutting the bolt ends from the old swage fittings and having them welded onto the CS Johnson fittings anyway. You need to take care here. Not only is the size in question, some available fittings have left-hand threads. Measure and inspect carefully.
 
Parts needed: 
• 8 x 1/4-28 Johnson part 20-62 for the fore and aft turnbuckles.
• 4 x 1/4-28 Johnson part LS 3300 for bow to gate – this fitting has an eye that the Pelican Hook slips into.
• 4 x 1/4-28 Johnson part LS 3200 for stern to gate - this is a double-ended fitting that holds the rear (fixed) part of the gate.
• 4 x 5/16-24 Johnson part 20-64 that connects to the pelican hooks. (double check the size here.)
 
Line length: 
The 12 lines should be measured individually, not just the total. The safety margin for errors is per length that we would need to cut. Three runs in each lifeline:- bow-to-gate, gate-to-inside-gate, gate-to-stern.
 
• Times 2 for top and bottom, which are not the same
• Times 2 again for each side.
• We used 5 mm steel grey Dyneema (STS 12-75) from New England Rope.
 
The total measured length needed was about 120 feet. An additional margin of 40 feet was added to account for splices (24 of them) and a fabrication safety factor.
 
Fabrication: 
A set of four nested fids made the job of splicing the lines much easier. A YouTube video provided instructions, and we found it very easy to follow. Dyneema is quite workable, with a slightly "slimy" metallic feel to it. The fibers work apart quite readily to allow you to get the fid through a line, or the line through itself, and the fact that it has no core means that you can finish a splice neatly by pulling the bitter end inside of the line itself. Working a fitting through the line is reminiscent of a python stretching to engulf its prey. This was actually a useful mental image as it encouraged patience and perseverance with a challenging task! Remember that Dyneema is very tough – you will need a very sharp knife and a means of re-sharpening it as you go.
 
1. Tape the bitter end to prevent fraying as you work. Thread the Dyneema through the fitting and double it back on itself. Measure 20 cm back from the bitter end and mark the other line at the corresponding point.
 Inserting fid through line
 
2. Ease the Dyneema fibers apart at this point with your fid and thread the bitter end through. Leave enough of a gap between the fitting and the join to enable you to thread the fitting back on itself and through the line (this is much easier to follow on a video than in written instructions).
 
First pass completed
 3. Now ease apart the fibers at a point on the bitter end, as close as possible to the join while still enabling you to feed the fitting through it. Feeding the fitting through the Dyneema is challenging – I found the end of a fid could be used shoe-horn style to help ease it through. Smooth the splice back on itself. When you pull the line tight at this stage, the splice is locked.
Working Johnson fitting through line
 
4. Now feed your fid down through the centre of the line, just below where the bitter end protrudes. Work it down for at least 10 cm, exit the line, then feed the bitter end through using the fid. This should create quite a neat finish with the end inside the line. Trim it if necessary.
Final tuck of bitter end
 
Make sure you keep checking the lines against their positions, keeping in mind that you will be using the turnbuckles to tighten the lines to their final tension.
 
 The final result looks quite smart, compared to the rust-spotted wire that was there before. These will stretch and need replacing some time in the future, but then so would wire and at greater cost. Overall, we are quite pleased with the outcome. –Terry and Carol Hogan

 




Plus, discover more articles in the Winter 2016 issue!


COLUMNS:

CHANGE OF COURSE by Jessie Mackelprang-Carter & Neil Carter [CM440]

VIEW FROM THE BRIDGE by Nick Caballero [C36]

SAFE JOURNEY by Bill Martinelli [C350]

 

FEATURE:
A JOURNEY BACK TO MYSELF:
SINGLEHANDED TRANSPAC By by Margie Woods [C34/355]
Six months before departing on the Singlehanded Transpac (SHTP), I was on the docks in Marina Del Rey shooting photos of a fellow singlehanded racer’s very high tech carbon race boat. The dock was abuzz with the banter of interested racers. A friend introduced me to two of them and he spoke of my plans to race in the 2016 SHTP...

 

TECH NOTES:

A Mainsheet exclusive! Technical information for your boat that has been approved by Catalina Yachts for accuracy.

 

ASSOCIATION NEWS:

Stories and news that’s specific to your Catalina sailboat.




SUBSCRIBE TO MAINSHEET TODAY!