New A Class Catamaran by Carbonicboats – The Brief
In previous posts I expressed my motivation (why) and approach to new projects (how).
I stated the importance of clearly identifying the needs of the user, and talked about the effectiveness of working to a congruent brief.
These beliefs drive quality. They will be shared by all who value passion applied with focus to create things of beauty.
Now, on the practical side, here are the goals defining the new boat:
Fast around the course
Best time on a typical windward/return race course.
May sound obvious at first, but this requirement is vital to exclude any specialist or extreme solutions.
With reference to existing designs, we are investigating variables in hull form, foil geometry, aerodynamics, and structural arrangements, to identify the best compromises for winning races.
Controllable, simple, responsive to changes in trim
The boat must react positively, taking advantage of movements in crew weight. This is related to volume distribution and rocker profile.
The boat must be dynamically stable in pitch, overcoming a critical limit on existing boats. By addressing the pitch stability issue inherent in existing boats, the skipper will be able to push harder with greater safety.
Optimised for the most frequent conditions whilst remaining competitive in light wind and controllable so it can be pushed hard in strong winds
Appropriate weighting should be placed on prevalent racing conditions, taking into account accompanying wave states.
Having made primary gains in the target conditions, we have identified secondary gains in light winds and in top end conditions to remain competitive at all times.
Account for a crew weight of 85Kg dressed. This allows enough volume for average-to-heavy sailors to be fast.
One of the constraints on the hull shape is a tolerance for a range of crew weights.
Global stiffness is a high priority for two reasons: maintaining the design geometry (correct angles between rudders, boards and rig), and minimising energy losses.
Durable and easy to repair
Material selection should take into account toughness, durability, and ease of repair.
Given the class minimum weight rule, the available mass should be distributed to satisfy the requirement for stiffness, but also to safeguard the longevity of the boat, thus protecting the investment of the buyer.
Under this requirement, future-proofing for foreseeable foil developments and rule changes is vital. The boat should be easily retrofitted with future generations of foils with minimal modifications. Obviously we cannot foresee all eventualities, but we should make allowances for reasonable variation.
Best performance/cost relationship, achieved by investing in well thought out tooling, and optimising the production process.
Solutions will be ranked according to performance criticality, so that their cost can be factored in accordingly.
Able to take existing rigs, but with provision to accommodate longer chord masts
It is common practice in the class for skippers to carry over a ‘personalised’ rig from platform to platform. We aim to allow this on the new boat by maintaining consistent the geometry of stay attachment points, mast step, and traveler location. However we envisage investigating different rig solutions in the future.
Emphasis on reducing platform drag
We have identified possible gains in crossbeam, trampoline, and deck solutions that will be investigated during the design and prototyping process.
Aesthetically pleasing and well detailed
The boat must reflect our core values expressing them in the overall shape and in the detailing.
Styling should be elegant and use a consistent formal language.
The boat should have an integrated, unitary look.
Quality should be reflected in a pained finish to a custom boat standard.