[Public-list] weight distribution and electric power

[Roger L Kingsland]

Dan,

Electric sounds way cool; quiet, no smell.  Are you planning on an internal 
motor or an outboard?  Please document the project and report on the 
results.

Relative to weight, doesn't the Atomic 4 weigh about 320 pounds, plus 
another 70 or so for fuel and 50 for existing batteries?  That leaves 170 
pounds net for the electric motor and all that crazy electronic circuitry. 
Might be about a wash weight-wise.

Relative to weight distribution, aren't the gas/diesel motors mounted pretty 
high (bottom above the cabin sole) while internal electric motors are pretty 
much in line with the prop shaft.  I think more useable space for batteries 
can be had under the cabin sole by making larger hatch openings and 
modifying the "bulkheads" separating the compartments (seem to recall 
someone on the page mentioning he had done that and had photos).  Don't know 
if there would be enough space there for all the batteries but, even if a 
few have to go under the main cabin bunks or galley base, net weight 
distribution would probably be lower and further forward than the original 
A4 solution.  Some on The Page have opined that A30s tend to "squat," so 
weight a little further forward might be desirable.  If you use an outboard, 
net fore/aft weight distribution might be a wash if the batteries go forward 
of the cockpit.

I did some preliminary investigation multiple moons ago and seem to recall 
that a burst of power can be had at the expense of substantial battery drain 
but sustained cursing speed is lower unless many batteries or a substantial 
generator are part of the package.  What are the specifics of your proposed 
system?


Roger Kingsland
Managing Partner
KSBA Architects
3441 Butler Street
Pittsburgh, PA 15201
N40°- 27.83'  W79°- 57.99'

(412) 252-1500 x101 office
(412) 779-5101 cell
(412) 252-1510 fax
www.ksba.com
----- Original Message ----- 
From: "Gordon Laco" <mainstay at csolve.net>
To: "dk.campbell at sympatico.ca, Alberg 30 Public List -- open to all" 
<public-list at alberg30.org>
Sent: Thursday, September 28, 2006 9:13 AM
Subject: Re: [Public-list] weight distribution and electric power


> Dan,
>
> Don brings up valid points - a reasonably powerful engine to motor out of
> trouble with is a valuable card to play when the chips are down.  The
> electric motor is an interesting way to go but should only be looked on as 
> a
> fair weather aux for use getting on and off your dock in calm weather.
>
> Cheers - Gord #426
>
>
>
>
>
>
>> Dan,
>>   My thoughts are that you will have increased wetted surface so slower,
>> centre of resistance moved aft, so increased helm, and no power for 
>> getting
>> through waves. Don't do anything you can't change back if the motor is 
>> too
>> dangerous, because of a lack of power,  to use the boat safely. Having 
>> run
>> both LP gas and electric fork lifts, there is no question of which is 
>> more
>> powerful, and that was with 1400 lbs of battery.
>> Don #528
>>
>> dan walker wrote:
>>
>>> for many different reasons , i decided to install an electric motor. now 
>>> i
>>> need to install the batteries. i remember gordon did some scientific 
>>> weight
>>> distribution observations, so here is the question. how would the 280 
>>> pounds
>>> moved aft affect the sailing characteristics of rascal. any thoughts?
>>>   dan
>>>   rascal 145
>>>
>>>
>>> ---------------------------------
>>> Get your email and more, right on the  new Yahoo.com
>>> _______________________________________________
>>> These businesses support your Association:
>>> http://www.alberg30.org/store/A30supporters.html
>>> Please support them.
>>> _______________________________________________
>>> Public-list mailing list
>>> Public-list at alberg30.org
>>> http://alberg30.org/mailman/listinfo/public-list
>>
>> _______________________________________________
>> These businesses support your Association:
>> http://www.alberg30.org/store/A30supporters.html
>> Please support them.
>> _______________________________________________
>> Public-list mailing list
>> Public-list at alberg30.org
>> http://alberg30.org/mailman/listinfo/public-list
>
> _______________________________________________
> These businesses support your Association:
> http://www.alberg30.org/store/A30supporters.html
> Please support them.
> _______________________________________________
> Public-list mailing list
> Public-list at alberg30.org
> http://alberg30.org/mailman/listinfo/public-list
>
>
> 



 1159455464.0