Farr Yacht Design’s latest offering is a 55 foot IRC racing design with boats currently under construction in New Zealand and Turkey. With a large presence of TP52’s optimized for competing in many IRC fleets, Farr Yacht Design’s was to design a boat that could race in the same class; faster with a relatively better handicap.
The 55 foot sailing yacht length produces the desired performance leap and moderate increases in displacement, draft and sail area limit the increase in handicap. The hull was developed using the knowledge gained from our recent extensive CFD research on Volvo 70s and GP42s. A unique feature with a large impact on the hull design is the twin rudder steering arrangement. The twin rudders generate much less stern up force allowing the bow to be finer forward for less drag in waves and chop.
Because the stern lifts less at high speeds the effective sailing length can be maximized over more of the speed range without incurring handling problems in extreme conditions. Ease of handling in reaching and running conditions was a prime driver in our design process as we worked to ensure that this boat can be just as dynamic as the smaller and marginally lighter TP52’s that it will compete against.
One of the unique features of this design is the twin rudder steering arrangement. These arrangements are now commonplace on many of the relatively beamy ocean racing yachts like Volvo 70’s and Open 60’s but have only been applied on a limited basis to IRC racing designs. Farr Yacht Design’s extensive experience in rudder arrangements on these other classes of yachts has equipped us with a wealth of valuable knowledge, which we have applied to the design of the IRC 55.
The yachts twin rudder arrangement vastly improves handling in critical breezy reaching and upwind conditions. In these conditions the leeward rudder becomes deeply immersed under the hull and hence is extremely efficient at providing the side-force necessary to steer the yacht effectively. This allows the rudders to be of a very small sizing, thereby minimizing the drag in all conditions.
