If you would consult a naval architect, or minimally, a competent prop shop, they will do the calculations to tell you what hp and prop size you will need to move the boat at the desired speed within the limits of a displacement hull of a given length as opposed to planing hull. You do not need 160 hp to achieve the desired result. Torque is the figure to pay attention to. Size the electric motor to the torque developed by the Lehman at the RPM that produces the desired 10kts.
George
I have a hydraulic generator, not set fully up, but the system already turns a shaft off the hydraulics, I already have duel AC units and a large freezer and fridge, ac inverters, and a gen set.
The prop wont do regen energy, its a full feathering prop, this means its absolutely without drag when not producing thrust.
I do like the fact that the idea has the capability to motor on electrics, but I haven't found even one motor that is electric that can produce the same power as the 160 hp turbo, and not burn up the battery bank in a matter of minutes.
Nicholas
--- In electricboats@yahoogroups.com, Daniel BUSH <lostboys81@...> wrote:
>
> Have you considered getting a controller and motor capable of rgenerative
> braking-?In essence you put the electirc afeter the fueled engine and use it as
> both a generator and power supply. You can use a transmission that has an
> auxialary power shaft. Some of the boat transmissions will run backwards i.e.
> turning the output shaft will push power backwards through the system Going at
> it from this drection would allow you to probably keep your current motor(
> probablly have to shift it to enable installing electric motor) and end up with
> a single system rather than several systems that you would then have to
> integrate. Look into ac motorsrunning at 110 or 220 and you should be able to
> equip the rest of your boat with regular "real' electric refrigerators,a/c and
> other equipment which is far more common,and as far as I am concerned far more
> reliable than most dc equipment. In my experience the life expectancy of most dc
> equipment is either far shorter or you pay far higher to buy the same quality.
> Dan from Lostboys
>
>
>
>
> ________________________________
> From: ibles_world <ibles_world@...>
> To: electricboats@yahoogroups.com
> Sent: Wed, January 12, 2011 5:21:16 PM
> Subject: [Electric Boats] Re: Repowering a 65 motor sailer
>
> Â
> 6-8 motors.... I would like to start with 4 but it doesn't seem like enough
> power, Maybe 6 would work.. don't know... I do know at max output its
> unrealistic, but what is it a cruise speed? I have to make a excel calculator
> for this, and it would be easier to run the numbers, or is their a excel
> calculator already? I know your right, it would take an enormous gen set, or
> equal to the motors I have to power... Right? but its no difference than a
> hybrid system, just each one contains a motor and gen set in to each one. I
> might be missing something... usually do... but I'm approaching this like as if
> it was a 30ft boat with 10k-12k weight and just have to have 6 times the motors
> and systems to power it. would you agree?
>
>
> In reality its close to those numbers, a 30ft has about 30hp motor, pushing a
> 10k-12k hull around, I am 68k displacement hull and have a 160hp so at 6 times
> them I would be the equivalent of 60k-70k hull weight, 180hp worth of motors, So
> what a 30 ft boat needs I need 6 times those systems, now does each one need a
> 12k gen set? some are running just off batteries and solar. I know splitting up
> my gen set amongst 6 banks of batteries and motors gives me only 2k of power. I
> know this seems simplistic way of thinking but its really in all likely hood the
> same, even with boat expenses its 6 times the cost of a 30 foot boat. Hull
> displacement is in direct correlation with the amount of HP needed to move the
> boat, other items that affect the result would be beam and keel type, but that's
> another argument.
>
>
> So with this what size electric motor and gen set is needed for a 30ft at cruse
> speeds?
>
> Solamon, thank you for your emails, I wish I had the time to go to Florida, I
> run a company here and have a hard time just leaving for lunch...
>
> --- In electricboats@yahoogroups.com, Steve Dolan <sdolan@> wrote:
> >
> > Ok I'm really confused. (not unusual)
> > You're even considering 8 motors and talking about KISS?
> > Belt Drive on a system this big?
> > Why water cooled?
> > Why are you set on a 48V system?
> > As an example the GMS system below uses 384A at 4300RPM and 48V (then at 85%
> >E). Let's see 384A x 8 motors = 3000A at 48v with an 8 pack (2 strings of 210
> >AH, 50% SOC = 100A). You should be able to run for ooh... what 30 seconds?
> > You would need a 144kw Genset.
> >
> > I'm sure I screwed up the calcs some place so educate me, it's early and I'm
> >still sleepy. :o)
> >
> > Redundancy...
> > My motors are actually 2 motors in one case each side. I have 2 controllers for
> >each side. If ½ of a motor goes I can run at 50% on the remaining ½ and full on
> >the other side.
> >
> > I have reverse
> > Direct drive = Motor, shaft, prop.
> > I'm at 144v system = much smaller wire sizes.
> > I draw a theoretical max AMPS of 150A per side (as tested by the Eng. To see at
> >what point things smoked) Never tried nor plan to but the hull speed is reached
> >at 40A per side so I don't need to go there.
> > I have a 16KW Genset (would really like a 20 or 22kw) providing 80A.
> > At 60A total I can motor all day long at around 8 knots with the genset and put
> >20A back in the batteries.
> >
> > KISS...
> >
> > Steve in Solomons MD
> >
> >
> >
> > The dual version in interesting:
> >http://www.greenmotorsport.com/green_motorsport/products_and_services/3,1,388,17,27462.html
> >l
> >
> > Just two of them cost $11,000 dollars. Eight would set you back about $45,000.
> >They seem to get two of the controllers to work together. I wonder how much more
> >work it will be for you to get 8 of them to work together?
> >
> >
> > On Jan 11, 2011, at 11:11 PM, ibles_world wrote:
> >
> >
> >
> >
> > I am looking into Green Motorsports, The motor they produce weighs in at 37lbs
> >and is 21 hp each They are water cooled Brush-less and completely sealed for
> >marine environment, 48 volts, Ac not sure if its 50 or 60 cycles, 4000 rpm. I
> >may need 6-8 of these motors, The question now is how big of a gen set would I
> >need to continually run them at half speed? Has anyone used them or done
> >research on them?
> >
> > --- In electricboats@yahoogroups.com<mailto:electricboats%40yahoogroups.com>,
> >Matthew Geier <matthew@> wrote:
> > >
> > > On 11/01/11 16:57, ibles_world wrote:
> > > >
> > > > I also was on another site and it looked as if multiple motors could be
> >setup in tandem with one another, This looked like a valuable option, I could
> >mount 2 or more smaller drive motors with clutches to a single shaft,
> > > You don't need the complication of clutches to disengage motors. You
> > > just leave them all connected and run them in parallel at lower power in
> > > each motor.
> > > Motors are often ganged to get extra power.
> > >
> > > Even if it became necessary to cut the power to one motor (say due to
> > > an electrical fault) unlike an ICE there isn't much mechanical
> > > resistance in leaving it in line and spinning it dead. (unless it's
> > > shorted out and acting like a generator with a shorted output, but that
> > > would be unusual.) Having a motor mechanically jam would be very rare.
> > > Your clutch arrangement would be more likely to fail.
> > >
> > >
> > > Electric motors also have very large operating speed that produce full
> > > torque. A variable gearbox isn't generally needed. Forced cooling might
> > > be needed if high torque at low speed is needed as the motors may not be
> > > spinning fast enough to self-ventilate. Rail applications all have fixed
> > > gear ratios and look at the loads railway locomotives drag.
> > >
> >
>
--
George Johnson
GeoMar Logistics
Jomtien, Chonburi
Thailand
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