Recent Applications of Hydrofoil-Supported- Catamarans - Boat ...

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16It is reported that the trim can be fast and easily adjusted to the helmsman’s wishes andthe running attitude of the boat be adapted to the prevailing sea conditions in the bestway. The photograph in Fig. 9 shows the Molly with foils at about 30 knots during theinitial trials.Figure 9 : Molly with foils during the initial trial runs
173. CONCLUSIONThe hybrid of a catamaran hull in combination with lifting hydrofoils improves the hullefficiency considerably and this has now been proven in many applications. The liftcarrying capability of hydrofoils when designed for optimum condition is so much betterthan the one of the standard fast ship hulls that still further improvements seemfeasible.However, not only the resistance improvement alone is important but all otherperformance parameters of a craft as the dynamic trim, course-holding, transverse andlongitudinal stability at all speeds, broaching and porposing behaviour, seakeeping etc.must not be negatively off-set by the addition of a foil system. This makes the design ofa Hysucat a formidable and sophisticated task which very few designers are able totackle without extensive use of model- or prototype testing.The progress in the Hysucat development is therefore very slow. The use of supportinghydrofoils for catamarans was first thought to be of advantage for the smaller craft onlyand 20m long craft were thought to present the optimum. However, on request largercraft were investigated and new foil systems developed which were optimal for the newconditions and also considerable improvements were achieved. The largest foil systemdesigned to date and under construction is for a 72m car ferry weighing 630t.The gaul in this project of a Diesel driven ferry is a speed increase from todays 48 to 50knot to nearly 60 knots with foil-support. The advantages of foil assistance do not endhere and the application to the fast and larger gas turbine powered ferries might proveeven more fruitful with reduced resistance and propulsion power per weight unit,reduced consumption and emmision.Such new designs are not easily reached by simple conversions of existing ferries tofoil-assisted catamarans but have to be designed from the beginning on as anintergrated entiety including the propulsion system. The author has the strong beliefthat considerable design improvements will follow in the near future. So far all Hysucatand Hysuwac foil systems have been designed by Foil-Assisted-Ship-Technologies c.c.(FASTcc). For further information please visit the Webpage of FASTcc,www.FASTcc.co.zaFor further questions please contact Prof. Karl Gunter Hoppe at FASTcc on:Tel: +27 21 8552116 / 8555478Fax: +27 21 8555477email: fastcc@hydrofoildesign.comwebsite: www.hydrofoildesign.com
Page 1 and 2: Newsletterwww.tsbp.state.tx.us FALL
Page 3 and 4: 3Making use of the so-called hydrof
Page 5 and 6: 5The avion type Hysucat foil system
Page 7 and 8: 7A hydrodynamic stabilizer system w
Page 9 and 10: 9tunnel between the demi-hulls give
Page 11 and 12: 11Figure 6: The E-Cat foil at speed
Page 13 and 14: 13Another foil system was developed
Page 15: 15However, the trials in Chile only
Page 19: 19Stumbo S. (2000), Wake Measuremen

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