48
SVN Solovelanet Global
The double-skinned mainsail
Another major change in this America's Cup is
the return to the traditional mainsail; however, this
change is everything but a step back. According to
the racing rules, the mast must have a "D" section
and should be able to rotate along its axis. Each of
the two edges of the "D", pointing aft, will be con-
nected to the hoist of its own semi-battened main-
sail skin. On so doing, the two mainsails are basi-
cally independent from one another. This implies
multiple advantages. First of all, this system allows
air to run more smoothly from the mast to the sails,
reducing the turbulence that a mast would induce
over a traditional single mainsail (see Figure 4).
Another source of inefficiency is due to the ten-
dency of the air on pressure-side to slip under the
boom, being "sucked" by the suction-side. The
same phenomena affect the aircrafts too, where
the wings rarely end with an abrupt cut. On the
contrary, the wing tip presents those facing-up
"horns" called winglets, whose role is specifically
to hinder this spill-over and to optimize the wake.
In sailing, this problem can be mitigated only
marginally by using a very wide and flat boom.
Mast Height = 26,5 mt/ 86,94 ft
Boat lenght = 23,00 mt/ 75,45
Mast Height = 23,6 mt/77,42
Boat lenght = 15,00 mt/49,21
Weight = 6,5 ton/14,330 lbs
Weight = 2,5 ton/5,511lbs
AC 75
AC 50
Bermuda 2017
36° America's Cup
