Lifeline failure usually arrives as a shocking surprise, sometimes with disastrous consequences. Metal fatigue and crevice corrosion are hidden from sight in traditional lifeline construction, with potential danger lurking under white plastic coating and inside wire swage fittings. Adding to the worry, flimsy lifeline turnbuckles are notorious for failure and find their way into many gear graveyards.
The solution? Get rid of the metal and go with Dyneema rope instead. Dyneema lifelines are corrosion-free, easy to inspect for wear, and more than twice as strong as comparable stainless lines.
Dyneema is a common brand name of the incredibly strong and durable high modulus polyethylene (HMPE) category of rope. The suitability of this product for lifelines has been debated for years, and its approval for use on the racecourse by various governing bodies of sailing has been in near-constant flux. Susceptibility to corrosion and metal fatigue is the weakness of stainless lifelines; with Dyneema lifelines, the weakness is chafe—especially with rail meat hanging on them during a race.
The major difference between the two shortcomings is inspectability. It’s easy for a sailor to spot the onset of chafe in Dyneema, while it’s often impossible to see corrosion or metal fatigue brewing in a stainless lifeline. I don’t race my boat, so I can use my own judgment on this choice. Those who do race should check with the current state of regulation for their category of boat in their slice of ocean or lake before installing Dyneema lifelines.
I made my decision and recently transitioned the lifelines from stainless to Dyneema onboard Sundance, my 36-foot Morris Justine. After considering the various options for line and hardware, I decided to go with a custom kit from Colligo Marine consisting of Hampidjan 5mm Dynice Dux rope, lashing line, and all the required gate hardware.
The Dynice Dux product is Dyneema cordage that has been heat-stretched to increase strength and reduce creep. It’s easy to splice and a joy to work with. John Franta at Colligo has been encouraging the sailing world to embrace Dux as an alternative to stainless for more than 20 years and has extensive experience with the material.
Building synthetic lifelines is a manageable DIY project. Colligo provides good instructions for building the necessary locking brummel splices, and the work requires only a small assortment of common hand tools. Once I got into a good rhythm, I found I could measure, cut, and complete the install of a lifeline section in under an hour.
For lashing, I used the 3mm Dyneema cordage recommended and provided by Colligo. Instructions called for knotting off the lashing with a spiral of half hitches. I strayed from this aspect of the directions and instead used a dozen reversing hitches in a manner that I find to be a superior way to lock down a lashing. The set of reversing hitches also provides a handy channel in which to bury the bitter end.
John at Colligo has developed a good system for measuring for supplies for this project. He shipped all the needed hardware alongside adequate lengths of Dynice Dux. However, John assumed that my splicing work would be flawless, and John was wrong. I snagged my fid while burying a tail in one splice and had to cut that fid out. That was the end of that lifeline. I also made one of my end loops too small and couldn’t force the thimble into it once complete. That was the end of a second lifeline. This wasn’t my first splicing project, but the work is fiddly, and with 20 splices to build, mistakes are likely.
To hedge against running short of rope stock, it would be wise to build the longest sections of lifeline first. That way, if you mess up a measurement or a splice, you can cut away the offending end and still be left with a long enough bit of Dux to use for a shorter section of lifeline elsewhere on deck. A second obvious hedge would be to purchase more rope than you need at the outset.
I suggest you simply double what Colligo recommends for lengths of both the 3mm lashing line and the 5mm lifeline stock. This purchasing strategy will not only leave you with spare rope for the initial build but will also equip you with adequate supplies to make up a replacement lifeline or two down the road. Lastly, that 5mm and 3mm rope is nice stuff to have around, and you will likely find yourself happily pirating your spare lifeline stock for other projects on the boat. I know I have.
The Colligo kit including all supplies for this project on my 36-foot boat cost a total of $981. But, as I mentioned, I went back to the well for additional cordage before the project was complete. If I had doubled the recommended cordage total at the outset, that complete kit would have cost $1,416.
It’s fair to say that the cost of building lifelines with Dux is comparable to building with stainless. Dux cordage is considerably more expensive than stainless wire. But there are other ways using the Dux system makes up the difference.
For one, labor costs. Building most stainless lifelines requires a swaging machine in a rigging shop, which requires a professional who knows how to use one. If you make your own with Dux, you eliminate that cost.
If you did hire a rigger to build your Dux lifelines, labor costs could flip back in favor stainless. But hiring someone to make your splices is a bit like hiring someone to tie your shoe; you quickly realize that the hassle of outsourcing the work outweighs the luxury. I appreciate the independence I’ve gained by being able to do this work myself anywhere and anytime.
The other savings comes in hardware. We used luggage tagging at the pushpit and pulpit and soft lashing at the gates, eliminating eight turnbuckles and other associated hardware components that stainless lifelines required for our boat. In addition to lowering costs, ditching these bits of hardware removes potential failure points.
One unexpected downside to the synthetic lifeline is its ability to tenaciously hold a stain. An accidental splatter of turnbuckle grease, varnish, or wax will be far more difficult to clean off Dux than it would be from stainless. On the flip side, if you do mess up with a careless stroke of the varnish brush, it will be easy to simply build a new section of lifeline with the tools and supplies you have aboard.
Same goes for worn out lines. You can expect new Dynice Dux lifelines to last for five to eight years. When they do show their age with tell-tale fuzzing or signs of chafe, the task of building replacements can be completed quickly.
Soft-attach blocks and fittings using modern cordage are becoming more and more common on sailboats for good reason: They are light, strong, adaptable, and immune to corrosion and metal fatigue. Dynice Dux lifelines are a welcome a part of this revolution.
June/July 2024
