WB-News will follow in a series of articles
the building of a 6,5 m long Mini-Transat boat.
This article is the introduction to the series.
Reima Alander, sailmaker
at WB-Sails, has launched his Mini-Transat project. With a little help from his friends,
Reima plans to finish his boat by the end of
summer, to sail the first trials at the beginning
of September. WB-News will follow closely the
building of the boat. in a series of articles
on these pages.
the mold with a robot
process, which uses the latest CAD-CAM technology
throughout, is rather unusual and novel. The mold
was carved by TwinCam Ltd,
in Styrofoam with the help of a computer controlled
milling machine. The entire process took some
40 hours, for the deck and the hull mold together.
A rough contour of the boat is first built from
15 cm thick blocks of Styrox. The crafting robot,
which can handle pieces of 3x5x10 m at one time,
then accurately sculpts the lines of the 6,5 m
long and 3 m wide little boat, first at speed
with a coarse blade and then with a finer blade
to produce a perfectly smooth surface. Once the
robot has done its job and the milling is completed,
the boat builder, RTM- Composites,
finishes off with a plastic covering (exactly
how this is done is RTM's big secret) and voilà,
the mold is ready for lamination. A substancial
saving in labour & construction materials, Stryrofoam
is cheap. Of course, at over $100 an hour, the
milling is not inexpensive, but the accuracy is
drew the lines with the help of MultiSurf
a relatively new and particularly user-friendly
program by Dr. John Letcher. TwinCam's Silicon
Graphics workstation had no problem in digesting
Kamu's DXF-file. The production method cuts down
manufacturing time dramatically: the molds were
done in two weeks time after Kamu had completed
We will look closer at the design in a future
|Frames cut with
Another area of time, labor
& materials savings: the frames and girders were
cut directly from Divinycell foam with the sailloft's
laser cutter. The PC- produced frames were transferred
into Plotmaker, a Macintosh- based sail cutting
program by Sails Science. In Plotmaker, the 30
or so pieces of Divinycell were nested to minimize
material wastage, much the same way as is done
with panels & corner patches that form a sail.The
cut-out foam cores are then covered with epoxy
draped E-glass and vacuum bagged, to form the
frames, bulkheads & stiffenings.
With the help of the sailmaking software, the
pieces of the frames and bulkheads can be nested
into the smallest amount of Divinycell, resulting
in material savings. Even more important is the
time savings: the cutting process took some 20
minutes, as opposed to several days of hand plotting
& cutting from offset tables provided by the designer.
is the Mini-Transat
race goes over the Atlantic in two legs: first
from Brest, France to Funchal, in Madeira, and
then after a stop at Madeira across the Atlantic
to St. Martin in the Caribbean. Single-handed,
in a 6,5 m (21 ft) long boat!
The rule for the boat is most simple: Length
not more than 6,50 m, max. beam 3,0 m, and maximum
height from the bottom of the keel the the top
of the mast less than 14 m. There are other rules
regarding stability, structures & safety equipment,
but it could not be more simple.
have water ballast tanks of 200 liters on each
side, and some even use canting keels. The size
of the asymmetrical masthead spinnaker is some
80 sqm, and the fully battened mainsail sports
a huge roach. The boat is completely over- canvassed,
to make the best of the calm moments on the Atlantic
crossing, and needs to be reefed almost immediately
as the wind starts to build up.
The winner of the -93 edition of the race, Frenchman
Thierry Dubois in his boat Amnesty
International, reached an incredible average
of 8,2 knots across the Atlantic, with a best
24 hours run of 254 miles - alone, in a 6,5 m
long boat. On the first leg of the race the fleet
was hit by a deep depression 12 hours after the
start from Brest. The race committee decided to
cancel the race, but not all of the competitors
received the canceling notice through their radios.
Most turned back at their own will, but three
boats sank and their skippers were lost, and masts
broke in numbers.
Amnesty International never knew about the canceling
but continued beating upwind towards Madeira.
The astonishment of the skipper was great when
arriving to Funchal, he saw the rest of the fleet
awaiting him, transported there by a cargo vessel.
²It was tough all-right, but why should I have
given up - this is no picnic anyway², commented
the exhausted skipper.
the wannabee Minitransit
from behind the sewing machine to the South Atlantic
is long and winding, and Reima is in need of many
more sponsors before he can fullfill his dream.
He hopes to complete the boat by the end of the
summer, to do some practicing before setting sail
south - away from the cold winds of Autumn that
will by December cover our little Gulf of Finland
The Mini-Transat race itself starts in September
-97, so Reiska
TwinCam Ltd Lohja-Lojo, Finland
RTM-composites Ltd Valimotie 11, 00380 Helsinki, Finland
Karl-Johan Stråhlman Björnviksvägen 7 A 11, 02110 Esbo, Finland
Copyright © WB-Sails -96
All rights reserved.