The Tetra superyacht concept, a 70ft HYSWAS tetrahedron vessel, has moved one step closer to reality. Designer and architect Jonathan Schwinge has teamed up with Marcel Müller, owner and director of marine industry consulting INMAINCO, to pursue the construction of the project. A German shipyard has also joined in the development effort.

Müller, former MD of carbon fibre racing yachts manufacturer Green Marine, is a qualified boatbuilder and holds a degree in aeronautical engineering.

“Partnering with Marcel Müller from INMAINCO on the Tetra-Superyacht project is a perfect match,” Schwinge told SB. “Marcel’s aeronautical and super-lightweight carbon fibre superyacht construction experience matched by his dynamic out-of-the-box approach is very much what the project is about.”

EL0200_005The pyramid-shaped vessel uses a hydrofoil small waterplane area ship (HYSWAS) comprising a single retractable vertical strut onto a single submerged ‘torpedo’ hull.

This hull form has two working ‘waterlines’ for its operation. At low speed the tetrahedron sits gently onto three underbelly hulls. At high-speed the hydrofoils rotate on the lower submerged hull, causing the effect of raising the triangle out of the water.

An auto-pilot ‘fly-by-light’ system from the aviation industry would take control of roll forces and maintain ‘foil-bourne’ speed. This would also control pitch and heave.

The concept

Conceived by Schwinge and presented to the public in 2010, the HYSWAS tetrahedron superyacht design is “instigated by the re-thinking of the form, superstructure and propulsion of the modern superyacht into a radically simple enclosure and an elevated mode of travel above the water line,” Schwinge says.

The HYSWAS concept was originally conceived in the 1970s by John Meyer at the U.S. Navy David Taylor Model Basin.

MAPC_Quest-01-sbUnder a Small Business Innovation Research (SBIR) contract, Maritime Applied Physics Corporation (MAPC) designed and constructed a prototype vessel named QUEST during the 1990s.

MAPC subsequently designed three larger HYSWAS vessels up to 85m in length. These vessels went through extensive towing tank testing but were not built.

Lightweight construction

MAPC_Quest-02-sb“Finding the best possible balance between volume and weight without moving away from Schwinge’s design directive has been the main challenge of the project,” Müller told SB.

The HYSWAS hull has been chosen for this superyacht concept for three basic reasons including the capacity to reach long distance and a smooth travel through rough water at high speed.

“Once elevated on its narrow strut and controlled by its underwater foils, the drag on the vessel drops dramatically thus allowing it to achieve higher speeds with lower amounts of fuel use,” Schwinge explains.

In addition, the elevated hull cuts through the sea surface without being influenced by the waves. Schwinge says this produces a very smooth ride in seas to three metres.

The successful operation of the vessel requires the use of lightweight construction materials.

The haunch, upper hulls and wet deck of the tetrahedron superyacht will be constructed out of carbon fibre. The lower HYSWAS systems are duplex stainless steel.

The placement of the propulsion machinery and auxiliary systems in the lower hull allows more room for outfitting the yacht.  “The isolation of the machinery also allows very low noise levels in the upper hull,” he adds.

Müller also reveals that the project could provide certain degree of interior customisation. “The main constraint is weight. Within the weight budget interior and equipment can be customised like in a ‘normal’ lightweight yacht project. The unique design language Jonathan is introducing with this project sets the theme for the interior.”

“The target weight is 95 tonnes,” Müller explains, adding that classification will depend on specific client requirements.

Tried and tested

Schwinge’s project has gone through extensive design reviews and the concept has matured to a stage where further design refinement will be done by means of computer simulation and testing.

A German shipyard has joined the development effort in this area, Müller told SB. He declined to disclose the name of the yard.

“We went through various analytical iterations together with this German yard. Based on the testing MAPC has done with HYSWAS prototypes, they established unique analytical tools to simulate different operating modes. As a result of this we are very confident that the main parameters we set e.g. weight, speed, propulsion power, etc. will work,” Müller explains.

The project has moved to the next phase aiming to establish a generic specification and GA, which is based on the latest results.

“MAPC is the world leader in HYSWAS technology. No doubt, there will be challenges, but we understand the technologies that are required to make this yacht a success,” Müller concludes.