|Subject: [harryproa] Rudder Harryproa|
|From: Doug Haines |
|Date: 4/4/2008, 5:48 AM|
Blind Date is getting an electric motor this winter. The 66'ter in Portugal 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 cheaper 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 http://www.e-
On Thu, Apr 3, 2008 at 10:26 PM, chesapeake410 <chesapeake410@
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 Africancats.
com website. Also check out RE-E-Power.com .
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
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
Thanks for any imput on this topic,