Come on Fella's, the Mod's are listening.
HP is a fixed amount.
Typical diesel installations drive through a gearbox
, lay shaft in bearings, to a prop that is sized for shaft revs and a target boat speed.
Typical Electric installations the prop is selected for the wattage chosen, which is electrical
HP (torque actually) then bolted
to a motor that will deliver that power at the right revs.
For a single
speed diesel generator
driving the electric motor this will deliver more push than the normal prop on a normal diesel installation
If you gear
down the diesel driven prop you lose some horse power to get a bit more push from the prop. If you don't gear
it down you lose push at the prop because it's spinning too fast.
My drive leg, a double 90 arrangement, has a 1.6:1 ratio built into it. It costs HP but that's already lost
by having the engine well above the water
line. But I get a big prop. It sure does push but can run out of revs when motor sailing, so it's on a system to haul it out of the water. You can do this so easily with an electric drive, not thro the hull
but slung over the back, hinged to lift
clear when sailing, reducing drag, growth on the prop and lobster rope/net snagging.
Search Sillette ffor details, but it's not the best way now. A prop fitted direct to the submersible (water cooled) electric motor and mounted on a retractible system is the right way.
Battery will get you out of the Marina, a genny will take you a long way. Sailing is even better, especially without the handbrake on (prop being dragged).