OSSA POWERLITE^{®
Diesel-Electric Marine Propulsion Systems and Accessories}
 

Project Description:

Despite its traditional appearance, this aluminum long-distance cruiser (designed by Greg Marshall Naval Architects Ltd of Victoria, BC Canada) is about as innovative as they come.  The boat is designed from the ground up to take maximum advantage of the benefits of the OSSA Powerlite system.  In addition to making full use of OSSA Powerlite, the designer and builders have evolved a construction process which speeds reduces time (and cost) which improving quality and precision. 

The vessel is fully diesel-electric with five separate generators feeding an 800vdc main power bus.  This main bus provides power to the propulsion motors as well as thruster (bow and stern) motors and hydraulic stabilizers.  By combining multiple smaller generators, the Snowbird is applying the same systems approach used by the newest tankers and cruise ships.  Running multiple generators offers benefits beyond the obvious one of redundancy.  These benefits include maximizing throttle response, minimizing engine run time, allowing for routine maintenance underway and, most importantly of all, dramatically improved fuel efficiency.

To power the house loads underway, a 40kw OSSA Powerlite electromechanical DC/AC converts the main power (800vdc) to 240vac.  At dockside, shore power feeds into this same circuit.  To eliminate the need for shore power conditioning, all of the appliances (except for the washer/dryer) operate from 240vdc.  While a 240vac power circuit is maintained, most of the power is converted to 240vdc and distributed through the OSSA Powerlite Power Distribution System to feed the major accessories including HVAC, cooking appliances, water heater and battery chargers.  Running these appliances from DC power (rather than directly from AC) makes them immune to voltage fluctuations (up to +/ 50%) and frequency changes.  Not only does this make the electrical system more reliable, it also reduces cost and weight.

The 24v house battery bank provides power to refrigeration and traditional low-voltage DC loads. A 24v - 12v DC/DC converter taps power for the house bank to feed a separate 12v circuit to permit the use of 12v electronics.  The minimal load of the few 115vac appliances is handled by 24vdc - 115vac inverters with the battery chargers acting as power supplies to prevent battery drain.  By keeping the 115vac circuit isolated and electronically supplied, power sensitive electronics (such as computers and entertainment systems) are assured of ultra-clean power anywhere in the world without resorting to expensive shore power conditioning.

Project Photos