Exo   /   46m sloop

LOA46 m
NAVAL ARCHITECTSDykstra Naval Architects
TOPOLOGY OPTIMALIZATION Alfred Wegener Institute in Germany

Seeing the world differently from the inside and out…This is what Exo, the new 46 metre concept sailing yacht developed in partnership between Claydon Reeves and Dykstra Naval Architects is all about.

With the primary focus to let far greater amounts of light into the interior and provide ground breaking views from within, the team redefined the hull's traditional sense of enclosure creating an innovative modern design aesthetic as a result. Huge glass windows wrap over the deck allowing unparalleled views of the passing external and underwater environments and a convex wall of glass separates the saloon from the aft beach club. Complemented by a strong organic curving chassis, her "exoskeleton" divides and dissipates the majority of forces with an appropriate beam maximizing the focal view from within and adds a new element to the experience of performance cruising.

A more recent research program is looking into the potential applications of so-called 'topology optimisation' in yacht design and construction of the Exo concept. Topology optimisation is a mathematical approach that optimises material use within a given design space for a given set of loads and boundary conditions, such that the resulting layout meets a prescribed set of performance targets. It is a method by which designers and engineers can find the best concept design that meets the design requirements, which is then fine-tuned for performance and manufacturability.

The designers introduced a more organic and natural approach to this project inspired by shapes and forms not usually found in traditional yacht design with its linear form language. This, in turn, led to a study in conjunction with the Alfred Wegener Institute in Germany that took Nature as the source of inspiration. The study analysed the exoskeletons of microscopic marine creatures to discover whether the same functionality, efficiency and aesthetics could be transferred to yacht design using a dedicated software program. The basis of any optimisation is the definition of a specification with information on the materials, the manufacturing process, the restraints and the loads. Optimisation variables such as weight, maximum stress or displacement are also defined. In some cases a topology optimisation can already give first clues for an intelligent positioning of the material, so that 'superfluous' material can be eliminated. The principles of the archetypes are translated into technical component designs with the aim of simplifying the geometry while retaining its functionality. In the case of the composite EXO concept, this involved entering data on load paths through components such as the fore- and backstays, shrouds and keel box, into the software program. The resulting 3D 'skeleton' design basically mirrors the loading on structural stiffeners and truss members in the hull, as well as the deck and bulkheads.

"Because the spaces in between the load paths are non-structural, you can then create shapes in the hull that would not be possible with traditional frame construction," says Thys Nikkels. " In the case of EXO, for example, the large organic windows set into the hull are the direct result of this process insofar as they are designed around the loads on the hull structure, not the other way around." The research is still in its infancy, but in theory an 'organic' composite structure could be manufactured in a female mould that is then clad to create the hull form.