FORM FOLLOWS FUNCTION
A high performance multihull needs low weight, high slenderness ratio (SLR), powerful sail plan, and very high structural integrity.
|
| > |
High SLR = low wave drag = liberation from normal hull speed
|
| > |
Low Weight = low wetted surface, low momentum |
| > |
Very High SLR is very sensitive to very small weight changes |
| > |
Structural Integrity = very stiff hulls and platform |
| > |
Stiff Hulls = protection against micro-cracking = long lifespan |
| > |
Stiff Platform = low energy loss = faster acceleration |
| > |
Sailplan Loads = very high because they vary with the square of the apparent wind speed |
It is a challenge to build a multihull with a very high SLR, very low weight, and very high structural integrity.
QUALITY DELIVERS PERFORMANCE
Top quality materials and construction provide the answer. And, extra benefits: longer lifespan for the boat and lower total
cost of ownership.
Top quality monohulls and multihulls are built using epoxy laminates, regardless of whether the reinforcement materials are fibreglass or carbon fibre.
Epoxy laminates are superior to polyester or vinylester laminates in 5 major areas:
| > |
Adhesive properties |
> |
Strength and stiffness |
| > |
Resistance to osmosis |
> |
Resistance to water ingress |
| > |
Resistance to fatigue and micro cracking |
The stiffness and resistance to micro cracking advantages increase dramatically when a core material is used in the laminate,
because stiffness is proportional to the cube of laminate thickness.
QUALITY DELIVERS LONG LIFESPAN
Top quality cored epoxy laminate hulls (e.g. the Marstrom Tornado, M-20, many 505s) achieve levels of stiffness that never suffer
fatigue and micro cracking.
As a result, these hulls have a very long competitive lifespan. The lifespan of an average Marstrom Tornado is more than 10 years at the highest level of competition.
It is no surprise to Tornado sailors that Roman Hagara and Hans Peter Steinacher won both their Olympic Gold Medals in 2000 and 2004 using the same boat. Or
that 15 year old boats are still minimum weight.
The lifespan of epoxy/carbon laminate boats has moved even further. The competitive lifespan of a carbon prepreg A-Catamaran may be limited by design innovations,
but it effectively has no structural lifespan limit.
COMPROMISE GETS EXPENSIVE
Most recreational boats and many small racing boats are still made with polyester and vinylester laminates.
These boats suffer micro-cracking sooner and more frequently than epoxy laminate boats. When this happens, weight and displacement increase; and performance
progressively degrades.
At the Olympic level, this signals the end of a boat's competitive lifespan and its re-sale value collapses.
The major beneficiary of short lifespan boats is the manufacturer.
