JEC COMPOSITES MAGAZINE - Issue #110 - January/February 2017 - 44

SOLUTlONS marine

Diagram of the functionality of foils

light. Over the past twenty years,
new high-tech manufacturing
techniques have helped remove
as much as two metric tons from
the boats. Carbon fibres are
increasingly technical and the
resins are reinforced with nanotubes. The sails are also made of
composite materials, and weigh
only half as much as they did
fifteen years ago. "What is being
accomplished today wouldn't have
been possible four years ago. We see
progress every day in this field in
terms of both research and manufacturing."
Each skipper comes with a set
of precise specifications that are
established based on his racing
experience. To meet these specifications, architectural teams carry out numerical simulations of
the round-the-world route: based
on ten years of wind data along
with swell data, they programme
about a hundred Vendée Globe
races to test the foil-equipped
boats and conform to the skipper's wishes as closely as possible.
An odyssey
Out of the 29 competing boats,
ten can aspire to victory, ten can

improve, and ten are present for
an extraordinary experience -
an odyssey that is an extremely
tough challenge from a mental
point of view, and which requires
passion and a competitive spirit.
It entails being in exceptional
physical shape: sailors spend
their time lugging their equipment from one side of the boat
to the other for tacking purposes.
They carry up to 20 metric tons
during the sea crossing. Rest is
another knotty issue, as it always
means loss of speed. Skippers
always feel guilty about getting
some rest. The best sailors are
those who are adept at catnapping, and only when the sea conditions permit.
The hull of an IMOCA boat
is all carbon fibre, with a very
complex structure. Its skin can
vary in thickness from as little as
0.25 centimetre in some places to
as much as 3 centimetres in the
thickest parts. The structure resembles a skeleton with ribs and
backbone, over which a very thin
carbon-fibre skin is placed. The
outer prepreg skin is laid up in a
female mould, then the Nomex
core material is placed where

more flexural strength is required
and the second, inner skin is laid
over that. Cure with polymerization takes place in a vacuum
oven.
This complexity makes for boats
that can be brutal on the sailors,
as the materials are much stiffer.
In squall conditions, the rigidity
translates into speed, making for
a bumpy ride. The boats may be
much faster and responsive, but
they are also very noisy, with a lot
of vibrations from the keel, centre-board and rigging, making it
hard on the ears. A sailor needs
to be one with his boat. It would
be dangerous to wear earplugs all
the time, since he must be able to
react to any strange noise on the
boat. "The round-the-world race
demands a good sailor who knows
when to accelerate or slow down
at just the right moment to avoid
damaging the machine." He must
be capable at every moment of
anticipating a manoeuvre and
carrying it out before it is too late.
It is not easy to allow for weather
conditions and figure out phenomena two hours before they
occur. Skippers need to use all
their ingenuity in these races, to
channel their inner MacGyver!

jec composites magazine / N 110 January-February 2017

Twelve boats, twelve
skippers, twelve teams
Performance is invaluable, and
teams are willing to pay for it in
order to gain speed. They have to
find the right assembly partners,
manufacturers, shipyards and infrastructures - and all in France if
possible.
None of the six boats with foils
have exactly the same ones. As
mentioned before, each skipper
has his own set of specifications.
It takes extremely precise calibrations and adjustments to increase
the effectiveness of the foils and
make the boats more versatile.
Managing all twelve IMOCA
boats simultaneously was very
complicated for the naval architects and engineers. The different boat teams were very wary
of each other, from the skipper
to the sponsor. There can be
no communication on performance, that information is jealously guarded by each one. On
the other hand, true to the spirit
of sailing buffs, safety issues are
discussed freely - no one wants
to win due to rotten luck on the
part of another competitor, who
is also a pal.
"We have stepped into a new era,"
Quentin Lucet tells us. "We're still
learning about these foils. There
have been some really promising
phases, and we now need to continue sailing to fine-tune their use."
As this article is written on
Thursday December first, British
skipper Alex Thomson on the
Hugo Boss has overtaken Armel
Le Cléac'h on Banque Populaire,
but has only a tiny lead of 0.65
miles. The toing and froing between these two VPLP-Verdier
foil boats has no doubt only just
begun!
More information:
www.vplp.fr

http://www.vplp.fr

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #110 - January/February 2017