Boat International US Edition - June 2018

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ON BOARD

JUNE 2018

Cutting-edge sail power

There’s a new twist on reaching sails;

the fastest ones may not be hard and lat

after all, discoversMarilyn Mower

Because the sail

isn’t fixed along the

entire length of the

luf, the sail can be

trimmed for more

mid-section depth

when desired

These vertically oriented

panels (in blue) are what

Doyle calls the load lens.

Filaments in the sailcloth

(the darker lines) control

the amount and direction

of stretch possible,

making it feasible for the

sail to project this

increasing drive in the

forward part of the sail,

giving it power through

a wider range of

apparent wind angles

The line shown in red

is the concentration

of uni-directional

fibers taking the

tension load instead

of a cable or

attachment to

a fixed forestay

W

hen an eight-year-old yacht wins every race in her class and

the St Barths Bucket fleet trophy too, curious minds look

for the boat’s edge. Of course there’s more than one piece

to the puzzle, but when she has one of the latest advances

in sail technology on board, it seems worthy of investigation.

The yacht in question, Nilaya, is a 112 footer launched by Baltic in 2010

to lines by Reichel/Pugh and fresh from a refit at the hands of her builder.

She raced at the Bucket with a headsail called a Cable-less Code Zero –

the largest one Doyle Sails has built since the sail’s introduction less than

two seasons ago. Cable-less Code Zero is pretty much what the name

says: a gennaker that doesn’t fly of a forestay. But, the thing is, it’s

an upwind sail. The luf edge structure is developed by a proprietary

membrane oriented on the load path at the forward part of the sail.

“It’s designed to project rather than hang of a cable,” says Mike

“Moose” Sanderson, Doyle’s new CEO and majority shareholder.

“It’s 30/40 percent more eicient than a Code Zero hanging of [a stay],

is lighter and has more longevity.” Easy to say, but how does it work?

“The sails have what we call a luf lens in them. These are either three

or four full-length vertically shaped panels that generate the entry

of sail, carry the luf tension and at the very front there’s a high

concentration of uni-directional fibers that create a band that’s used

to furl the sail.”

For racers used to having a container full of headsails for diferent

conditions, this sail may be a wild card, as it provides power over a wider

range of apparent wind angles and can be trimmed deeper in the

midsection. “The range comes from the fact that the luf can fly forward

whereas a conventional tight-lufed cable sail actually gets held back by

the cable,” adds Sanderson.

“We can easily change the mode of the sail and in many ways it’s quite

automatic. At wider apparent wind angles, the luf just projects without

the crew having to do anything.” doylesails.co.uk

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