The last frontier of sails: goodbye twist-resistant cable

The anti-twist cable for years has been one of the basic components of sails such as Code 0s, A0s, and all those non-infertile sails that can be furled with a “whip.” Today, however, we are about to enter, and in part we already are, a new era, that of sails referred to as “Cable Less,” without anti-twist cable. Numerous sailing companies are experimenting with this solution in racing, and its advantages, as you will read, are not insignificant, so as to justify its forthcoming large-scale use not only in the racer world.

The first to experiment with “Cable Less” technology were Doyle ‘s sailmakers on the Maxi 72 Bella Mente, a boat with two legends on board, Terry Hutchinson, vice president Quantum Sails, and Mike Sanderson, Doyle CEO. The boat was outfitted with a mixed outfit provided by the two sailmakers, but with Doyle’s signature Tails and the like.

THE IDEA.

Doyle’s idea was to replace the cable with a series of integrated unidirectional stiffeners that would stiffen the leading edge of the sail, which then goes to work in the winding process. As an alternative to this solution, reinforced fabric panels, which are heavier than the sail construction, are also used. A need that initially arose for a simple reason: to make the wing more efficient in certain conditions.

On Code 0 type sails and the like, and generally as a principle, when you slightly widen the angle to the wind you need to soften the halyard to make the sail more powerful, same thing in light wind. In these situations, the effect of gravity caused by the anti-twist line adversely affects, causing the luff to fall downwind more than it should and forcing too much halyard tension, which is not justified by the wind speed and intensity. Same thing in tight corners or tighter breeze, the halyard must be able to stretch not only the sail shape but also the anti-twist line, and the result is toalways have higher loads than needed for the conditions. This caused the design sail shape to be a little leaner than it should be on the leading edge, just to predict the hollow factor.

As he further told us Vittorio D’Albertas of Quantum Sails Italy: “For IRC and ORC rating reasons, Code type sails have a limitation: to avoid being considered by the regulations as “super genoas” that would greatly penalize the rating, the measurement between mid leech and luff must be 75 percent or more of the length of the base. Since they cannot add inches of curvature in the luff, which would worsen the gravity effect of the cable, these are added in the leech, with the annoying result of sails with often “billowing” leech because they are made “rounder” to stay in tonnage. Something unsightly and inefficient. Without the cable, with the Cable Less, some of this curvature can be carried to the leading edge, projecting the luff forward, improving the overall shape of the sail, and offering more precision in adjusting the luff angle.”

A QUESTION OF LOADS

As Matteo Reboli of North Sails, a company that renamed its cordless sails Helix, explained to us: “The breakthrough with Helix sails is the redistribution of loads, which allows for a significant reduction in stresses on the attachment points (tack and head) by transferring the stress vectors to the front of the sail, making the profile more effective and improving the furling, this is reflected in transferring less stress to the boat, mast, rigging and bowsprit/fittings required (essential elements in the design and implementation of custom/regatta-offshore projects). In addition to that valid application for our 3di construction technology, North Sails continues to develop optimization of Helix sails in triradial cut to try to be able to fully address all market needs.”

Of the same opinion is One Sails, which was instead the first to experiment with this technology, which the company has named IFS, even on gennaker-type nylon sails: “Thanks to a halyard tension that is 30-35% less than on an anti-twist cable sail, it is also possible to simplify rigging by not requiring the adoption of a demultiplied halyard and significantly reducing the structural load on bowsprit or definiera, all to the benefit of safety. Wrapping and unfurling the sail therefore does not require much tension on the halyard, just the minimum to make it almost straight. The furled sail then, without the anti-twist cable, is light and easy to handle and folds easily on itself.” Currently, this technology is being used successfully in the world of racing boats, but soon its use will be on a wide scale, moving closer and closer to the cruising world as well.

Mauro Giuffrè