#428 IMS 49
gleaned from our extensive tank testing in support of IACC
and Volvo Ocean 60 designs combined with continued analysis
of the evolving IMS rule have yielded this advanced shape.
Like BEAU GESTE, this hull has a removable stern extension.
It is installed for regattas with big seas and removed for
regattas in sheltered waters. At the beginning, IMS hull measurements
were made of both configurations to allow simple swapping
of the offset files for rating purposes.
428 will benefit from the significant investment Farr Yacht
Design has made in the installation of the surface-modeling
program Pro/Engineer. Reproducing the design airfoil shape
is critical to the performance of the boat so the keel and
rudder surfaces were machined using Pro/E 3D models supplied
directly to the builder. The keel is a refinement of the style
first used on the highly successful Farr 45, BIG APPLE. The
draft is somewhat less than the preceding designs because
the IMS rule now is less favorable to extreme deep draft and
the boat will first sail in the rock-strewn waters of the
Solent and English Channel. The stability of the boat can
easily be varied by swapping portions of the keel with different
densities while maintaining the original shape of the fin.
rig and deck layout are adaptations of the previous designs
but have been fine-tuned to meet the owner’s requirements.
Every detail of the deck and interior is designed to function
efficiently using the least amount of weight while meeting
the requirements of the IMS rule. The coachroof is of minimum
size while the cockpit length is maximized for ease of maneuvering
and sail handling. The sailplan has overlapping headsails
for flexibility in the wide range of expected weather conditions.