44
SVN Solovelanet Global
With two blades mounted on the sides of the stern,
when the boat lists one of these comes out of the
water, while the other blade, which is significantly
smaller than a single blade, remains underwater. So
the wet surface of the rudder is significantly reduced.
When the boat lists, the inclination of the immersed
blade decreases too, because the blade is inclined
outwards to begin with, therefore when the boat lists
it returns perpendicular to the bottom and is more
efficient.
SVN - So a big boat, where the width/length ratio
is not excessive, does not need a double blade so
much, and might indeed sail better with a single
rudder blade. Then why did you provide a double
rudder blade for the First Yacht 53? That boat is
wide, but not excessively so.
R.B. - That boat is indeed not remarkably wide. A
single rudder blade would have been equally suita-
ble for that hull, but the reasons for equipping that
model with a double blade are different. Bénéte-
au wanted her to be fitted with a large aft garage,
suitable for accommodating a tender longitudinally.
This is impossible if you fit a single rudder blade,
Better manoeuvrabili-
ty on boats with large
sterns
Less wet surface when
listing
Possibility of storing
the tender in a garage
in the stern
Pros of double rudder
blade according to
Roberto Biscontini
Roberto Biscontini
Biscontini Yacht Design
At the top right the new Hallberg Rassy 44, one of
the first models of the Swedish shipyard featuring the
double rudder blade, and just below, a rendering of the
stern of the same boat, where you can clearly see the
two rudder blades and the shaft line of the propeller. The
stern of the Hallberg Rassy is not so flat and wide as
to justify the use of the double blade. In all likelihood,
the choice to install a double blade was influenced by
reasons linked to the yard's marketing policy
