Subject: [harryproa] Re: Electric drive for Harryproa
From: "Robert" <>
Date: 4/3/2008, 10:47 PM

-I thought such a system as the e-jet would work really well with
efficient motors developed in Darwin for the solar car and now seen on
electric bikes,
Robert -- In, "Rob Denney"
<harryproa@...> wrote:
> G'day,
> Blind Date is getting an electric motor this winter. The 66'ter in
> and the 60' charter boat are both planning on having them as well.
> Putting them on the rudders solves the two way problem and gives amazing
> maneuverability. Would only need one if it was powerful enough.
No real
> drawings yet, but the principle is a sleeve that slides up and down
on the
> rudder blade with the motor attached to it. Lift it clear of the
water when
> not in use with a block and tackle, ease the rope to lower it. Much
> and more reliable than the African Cats system. Kicks up on impact and
> very accessible for clearing ropes and stuff off the prop. Also (smug
> grin) not usable by boats without beam mounted rudders.
> Another version is the e jet
> regards,
> Rob
> On Thu, Apr 3, 2008 at 10:26 PM, chesapeake410 <chesapeake410@...>
> wrote:
> > Hello,
> > I am planing on building a 12 m Harryproa and am thinking of using
> > electric pods. Pods would be mounted on swing arms similar to what
> > has been used on African cats. Take a look at the June 14,2007 press
> > release on website. Also check out .
> > In the Re-E-Power Forum link in the photo section is a example of a
> > pod mounted to a long swing arm.
> >
> > Has anything been done with electric power on Harryproa's ? I think
> > there was a recent reference to electric motors on rudders, does
> > anyone have more information or pictures on this.
> >
> > I think a Harryproa would be unequally suited to a solar/battery
> > electric drive system since the sail is offset on lw hull. A solar
> > canopy over the seats a center area of boat would be less obstructed
> > by sail than a cattermaran.
> >
> > The proa does have the problem of how to deal with going in both
> > directions with the electric drive. You could point one in each
> > direction and only use one in open water and lower both for
> > maneuvering in harbor or for extra power when needed. You could use a
> > prop designed for both directions but I do not know it it would be as
> > efficient as one designed for one direction.
> >
> > I would like to hear any sugjestions and comments one this ?
> >
> > One other concern would be the added weight of a battery pack which
> > could be as much as 1000lbs or more. I am hoping that newer battery
> > types will bring down the weight in the next few years to less than
> > 600 lbs.
> > Valence Technology Lithium batteries would be great but the current
> > price is prohibitive. Firerfly batteries (a new lighter type of lead
> > acit battery) sound like a good bet but are not yet available. It
> > may be necessary to start with current lead acid and switch to
> > lighter batteries in the future. After Lithium batteries get
> > established in electric cars that will start coming out in the next
> > few years I expect availability and price to improve. I spoke with
> > Bob Lutz vic chairman of General motors at a special event a the New
> > York Auto show a week or two ago and he claims that they will have
> > the Chevy Volt in production by the end of 2010 ! It will run on
> > lithium batteries.
> >
> > Thanks for any imput on this topic,
> >
> > George Kuck
> > Chestertown, MD
> >
> >
> >

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