End view of braided polyester line
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The beginning
Everyone who's not a teenager remembers line like the Samson double braid, its twin by German cordage manufacturer, Gleistein, or the Yale Yacht Braid. All featured cores and covers made of polyester which matched the deck hardware and could handle the rigging loads because line, sails and building materials all stretched or flexed to absorb some of the energy.
What's Changed
Crew want clean decks with as few winches as possible.
Photo:
Sharon Green |
A standard deck layout used to have winches, purchases or cleats for every maneuver. Today, crew want clean decks with lines led to as few winches as possible. Because line is no longer secured on individual winches, this puts more strain on the other hardware: clutches, cams, turning blocks, deck organizers.
In addition to distance racing, Big Boats are now course racing. The number of tacks and jibes are greatly increased, and the time to finish a maneuver dramatically decreased. For example, crew can take two minutes to hoist a headsail in a distance race, while in course racing, time is of the essence. A 30 second hoist can make the difference between winning and losing. This new type of racing forced manufacturers to develop a new generation of line materials that could handle high loads and wouldn't twist or stretch like polyester. With the introduction of exotic fibers like Kevlar®, Spectra®, Dyneema®, and Cordura®, winch surfaces, block sizes and clutches also changed to accommodate the new types of line.
OverHeating
Care should be taken not to overheat and abraid line.
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A key consideration with deck gear is to avoid overheating. When using line on a winch or clutch, care should be taken to avoid releasing line at high speed while the winch drum is rotating or the clutch is in release mode. The friction from this slippage causes localized overheating which can melt or fuse synthetic fibres, resulting in severe loss of tensile strength.
Early Overheating Solutions
Kookaburra. By wet sanding the drums on the runner winches, the runner (tail lasted more than one race! This 'do it yourself' method was risky. If the drum was sanded too much, the runner line would slip when loaded.
To solve the melting and slipping problems an additional 'sacrifice' cover was sewn onto the runner tail where it wrapped onto the drum. However, this cover made the line stiffer, bulkier and less handy to use. Even if the cover was firmly stitched, there was still a noticeable 'step', changing the load point on blocks and self-tailing arms. The answer was to bury the tapered tail of the sleeve into the line. However, this was costly because it took a skilled rigger time to make the transition. In addition, a tapered line couldn’t be replaced like a sewn-on sacrifice cover.
Cordage solved the problem with a breakthrough innovation called Yale Tail, line specifically made for runner tails. The cordage was a blend of Kevlar® and polyester woven in a W-shape. Despite Kevlar® being prone to UV degradation, the material proved durable and able to withstand the rough texture of the winch drum and the speed of uncontrolled line release.
Matching Line to Primary Winches
This w-shaped cordage was specifically woven for runner tails.
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Matching line to primary winches was another benchmark. When the skipper of a Baltic 64’ told Fabbroni & Vongher Yacht Riggers he didn’t want heavy wire-to-rope afterguys,
we developed an afterguy made with line found in Samson’s industrial catalog. It was called Spectron 12. This single braid Spectra® line was jacketed with a silver urethane coating that stopped yarn from catching and snagging. Because Spectron 12 is slippery, the line was sleeved with a polyester cover so it could be held firmly by the winch’s self-tailing jaws.
However, when an exotic core and polyester cover are joined, the polyester cover and exotic core have different stretch characteristics. This results in the cover becoming longer over time. A loose cover snags on gear, damaging line which could prevent a sailing maneuver. In addition the core is made of slippery material and is hard to bond to a polyester cover. The cover tends to creep in the direction of the load and is unable to transfer the entire load onto the core. To solve this, line manufacturers added a third braid between the cover and the core. However, this complicated splicing method reduced the amount of Spectra® core and resulted in a weaker splice.
Minimizing Line Creep
Yale and Southern Oceans Ropes were the first to minimize line creep by hard coating the Spectra® core with a chemical dye to make it more abrasive, produce a stronger bond, and help the cover transfer the load to the core.
Something to consider when choosing halyards is cold flow. This type of creep is often seen in and lines that are under a consistent static load. For example, over time, a halyard on an offshore racing boat will become elongated due to molecular creep. With Spectra® and Dyneema®, the point of no return with this type of creep is relatively easy to reach because the materials have very low melting points—critical is 150 F, while the melting point is at 297 F.
Slippage
With line becoming smaller and smaller and reaching diameters not manageable by self-tailing jaws or clutches, the result is slippage. An early solution for clutches was to sleeve the line on the most loaded areas by hard stitching a tiny piece of line inside the core so it would keep its shape. But this created a hard spot. Today, blends of materials like Cordura®, Kevlar®, Vectron® and Technora® mixed with polyester give a better result, eliminating the 'step' in the reinforced area of the halyard.
Today's State of the Art
Today, state of the art cover material uses Pbo Zylon®, first pioneered by Gottifredi & Maffioli. This space age material has near zero stretch, optimal heat dissipation, and is abrasion resistant. Ideal for lines that bear high loads and are subject to intense heat build up from winch friction.
Reference:
Spectra® and Dyneema® are all regestered trademakrs of American Allied, Japan based Toyobo and Holland based DSM.
Yale Cordage: www.yalecordage.com
Samson Rope: www.samsonrope.com
Kevlar is a registered trademark of Du Pont de Nemours.
Gottifredi & Maffioli: www.gottifrdimaffioli.com
Vectran® is a registered trademark of Hoechts Celanes
Technora® is a registered trademark of Tejin
Pho Zylon® is a registered trademark of Toyobo
Harken Italy Custom Sales and Tech Service Manager Danilo Fabbroni has been sailing since he was 14. An admitted addict, he raced in countless one-design regattas before graduating to Big Boats, where he successfully competed in the Sardinia Cup, Admiral’s Cup, SORC, One Ton and Two Ton Cups. In 1984 he founded: DF Rigging + Photo, and specialized in rigging and architectural photography. The company became well-known in European rigging circles and eventually changed its name to Fabbroni & Vongher Yacht Riggers. Fabbroni has written articles about rigging in Vela, Farevela, Nautica and Bolina magazines. After joining Harken Italy in 1999, he wrote Rigging, a leading book on the art. Published by Incontri Nautica, Rigging has sold more than 2000 copies in Italy. 