Boat International - June 2018

http://www.boatinternational.com | June 2018

DESI

G

N

R

A

D A R

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 34 metre 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
is 30 to 40 per cent 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 the sail, carry the luf tension and at the very front there’s
a high concentration of uni-directional fibres 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

ON BOARD

Cutting-edge sail power

There is a new twist on reaching sails;

the fastest ones may not be hard and flat

after all, discovers Marilyn Mower

Because the sail

isn’t fixed along the

entire length of the

luff, the sail can be

trimmed for more

mid-section depth

when desired

The line shown in red is

the concentration of uni-

directional fibres taking

the tension load instead

of a cable or attachment

to a fixed forestay

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