How to Replace Sailboat Lifelines with Dyneema or Swageless Wire Terminals

Before removing anything, photograph every gate, terminal, turnbuckle, pelican hook and attachment point, as West Marine recommends. Label each line (port upper, port lower and so on) and note which end goes to the bow pulpit, gate or stern rail. Then remove one side only, keeping all hardware in order. Leave the other side up until the first side is finished.

With the lines off, check each stanchion and base (see the lifelines and stanchions guide): movement with the deck, cracks, loose fasteners, bent tubes. Then look inside the holes the lifeline passes through. Practical Sailor says burrs in these holes are what chew through rope lifelines. Smooth every hole with a rat-tail file or small sanding drum and work up to 400-grit paper, then polish. Don't skip this for wire either; rough holes wear wire too.

West Marine recommends replacing turnbuckles that show corrosion, thread damage or distortion, and any doubtful pelican hooks, toggles and split rings, at the same time as the lines. A new lifeline on worn hardware isn't a safe system. Newer over-center pelican hooks are an option.

West Marine warns that lifelines need very exact measurements and that different terminals are measured to different points. A reliable method:

• Measure between the attachment points on the boat (pulpit eye to gate, gate to stern rail), not the old line, which may have stretched or been shortened by bent fittings.
• Decide how much room each end needs: a turnbuckle's adjustment range, a lashing gap, or the length of a terminal. Turnbuckles should be set near the middle of their range so there's room to tighten later.
• Write a simple sketch with every length, terminal type and fitting. If any of this is unclear, use the rigging shop's measurement form or have them make the lines.

Mechanical terminals (Sta-Lok, Hayn Hi-MOD, Norseman and similar) grip the wire with an internal wedge or cone and a threaded body, so they can be fitted with hand tools instead of a swaging press. Practical Sailor's pull tests found well-made fittings of this type equal or better than other end fittings. Marine Fabricator and Practical Sailor note they can be taken apart for inspection and reused with a new wedge or cone.

• Buy terminals made for your exact wire size and construction. Practical Sailor notes Hi-MOD fittings don't work with Dyform (compacted) wire.
• Cut the wire cleanly and square with a proper cable cutter.
• Follow the terminal maker's instructions to the letter: how far to slide the parts on, how to lay the strands around the wedge or cone, any sealant or thread-locker, and how far to tighten. Arranging the strands evenly is the step that decides the strength.
• Take the terminal apart once after first tightening if the instructions say so, check the strands are evenly formed, then reassemble.

West Marine notes hand-crimped lifeline terminals can be owner-installed with the matching hand swaging (crimping) tool and give a strong, if lumpy, result. Use only terminals made for lifeline wire, crimp with the tool specified by the terminal maker, and check each crimp with the maker's gauge if one is supplied. Never use household wire-rope clips or hardware-store cable clamps on lifelines.

• Pick the line. Practical Sailor has used a larger size than the minimum on its own boat to leave a reserve against UV and wear, especially for the top line.
• Make the eye splices. Practical Sailor favors a simple bury splice with a smooth, tapered tail, lock-stitched with whipping twine using a blunt needle, following the rope maker's (Samson's) instructions for 12-strand class 2 rope. It reports a lock-stitched bury is as strong as a Brummel lock splice.
• Allow for shrinkage. Each splice shortens the rope. Practical Sailor's tip: make the first splice, pull it firmly to settle it, measure how much it shortened, and allow for that on every other splice.
• Fittings. West Marine sells splice-on fittings that let rope lifelines use standard gate eyes and turnbuckles. Practical Sailor warns against ordinary wire-rope thimbles, whose sharp cut ends can cut the rope; use a sailmaker's thimble, a smooth low-friction ring, a webbing cover, or no thimble.

Many rope lifelines (and some wire ones) attach at one end with a lashing instead of a turnbuckle. Practical Sailor's testing showed lashings share load unevenly between passes, so it recommends sizing a lashing at twice the calculated strength of its passes, finishing it with a long series of half hitches around the whole bundle, and not cutting the tail short. A lashing has less redundancy than the line: one cut pass can let it all go. BoatUS says lashings should be as strong as the lifeline, no more than about 4 inches long with the line tensioned, given a couple of extra turns for margin because every bend weakens the line, and replaced every year. Practical Sailor likewise says to renew lashings far more often than the lifelines: every few years, and at about the halfway point of the line's life (2 to 3 years) to be safe. Pick the shorter interval if you're unsure. If a lashing is meant to be cut to drop the lifeline for a crew-overboard pickup, make sure everyone aboard knows which one.

Slide tubular webbing or a chafe sleeve over splices, lashings and any spot that rubs, keeping it loose enough to slide aside for inspection, as Practical Sailor suggests. Where rope passes through stanchion holes, a plastic or textile sleeve helps. Don't let the crew hang over rope lifelines while racing or use them as a backrest; that's what wears them through in the stanchion holes.

Fit the new lines, starting at the fixed ends and working toward the gates. Tighten turnbuckles or lashings until the lines are snug without bending the stanchions inward (see the lifelines and stanchions guide for a simple tension check). Lock every turnbuckle, fit cotter pins or rings, and tape pins, ring ends and pelican hooks so they can't snag or open. Open and close each gate: it should latch firmly and the hook shouldn't open by itself.

New rope lifelines settle in as splices bed down and the fibers stretch slightly. Check and retighten them after the first few outings and again after the first season. Recheck mechanical terminals at the same time.

Repeat for the other side. Then set an inspection routine: West Marine and BoatUS suggest checking every season, looking for fuzzy or flattened spots where rope passes stanchions, faded stiff rope from UV, creeping or opening splices, and on wire, rust or broken strands at the terminals. BoatUS's trick for bare wire: run a loose wad of tissue paper along the whole length in both directions; a broken strand ("fishhook") snags the paper before it snags your hand. Practical Sailor notes that swapping a rope lifeline end for end can buy some extra life if chafe shows at the stanchions.

Record in BoatMend the date, material, size, terminal type, who made each line, and when lashings are due. That date is what tells you when the line is due for replacement.