Archive for October, 2008



Drawing on pioneering work in the field of high speed hull form development carried out in the early part of the last century and combined with the advantages of modern construction materials and lightweight engines, designer Uwe Feller has developed an extraordinarily efficient vessel.  Refined with test-tank modeling and computer aided design, the hull has been prototyped in Germany.  Preliminary sea trials have shown exceptional efficiency and unequaled ride comfort.

Dubbed “Dymax”, the hull design is a slender, stepped planing hull with deep rounded sections.  The fine entry parts water effortlessly and provides little bouyancy forward, minimizing the pitching effect of waves.  The easy, rounded sections smoothly accelerate water off the chines and ventilated step.  Air drawn under the boat by the step reduces the wetted surface and thus the resistance of the hull.  The narrow waterline of the hull is stabilized at rest by inflated tubes, which offer good protection alongside as well.

With just 33 kilowatts, the 5.3 meter prototype exceeded 60 kilometers per hour with two passengers.  Acceleration is steady with little ‘hump’ resistance and no ‘bow-high pitch before planing.  The careful placement of the step ensures the ride is level and smooth.  Cornering is tight and precise, it’s a thrilling boat to drive.

Testing continues with more engine configurations while production designs are being finalized.  An appearance at Boot in Dusseldorf is planned.  For more information, visit felleryachting.de


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Marine Catalytic Converters

The challenge of emission reduction in marine propulsion systems has in some cases been addressed in a manner of reluctant adherence to imposed government and trade standards.  To curb nitrous oxide, carbon monoxide and particulate emissions, recreational boat manufacturers are applying readily available automotive catalytic converters.  These systems are highly effective in controlled emission tests, a testament to the well-established catalyst compound applied to the substrate surface.  The most common substrate in automotive catalytic converters is a ceramic comb.  These ceramic catalyst blocks can become fragile and their lifespan in marine applications has proven short.  Faced with the high cost of replacing a failed catalytic converter, operators of recreation boats equipped with poorly designed emission reduction systems may choose to remove them altogether for a cheaper repair bill and an possible increase in performance.

If a manufacturer of recreational boats claims a reduction of harmful emissions from their products, it must be acheived in a manner that will be effective over the entire products lifespan.  If a catalytic converter is employed, it must be robust to withstand the shocks sustained in a high-speed boat.

Feller engineering has produced a patented all-metal catalytic converter for the recreational marine propulsion industry.  The catalyst substrate withstands extreme temperature and water immersion with excellent flow characteristics and even heat distribution.  Destruction testing proved impossible, with the catalyst substrate outlasting the engine in each test.  High reductions in emissions have been recorded with negligible loss of performance.

Feller metal catalyst substrate

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