Re: [PSUBS-MAILIST] Practical motor

["Alexander Foreman" <alexforeman@mailworks.org>]

On Wed, 31 Mar 2004 07:24:08 -0800 (PST), "irox" <irox@ix.netcom.com>
said:
> 
> Electric trolling motors filled with oil.  On ebay you can find all sorts
> of trolling motors and just about all costs (from ~$100 to $1000).
> 
> Ian.
> 

Those look ideal - thanks.


> -----Original Message-----
> From: Alexander Foreman <alexforeman@mailworks.org>
> Sent: Mar 31, 2004 4:09 AM
> To: PSubs Mailing List <personal_submersibles@psubs.org>
> Subject: [PSUBS-MAILIST] Practical motor
> 
> Does anyone know if there is a low cost elecric motor that needs little
> or no modification (except for pressure compensation) that comes with a
> waterproof housing and can be used down to 100 feet?
> 
> On Mon, 29 Mar 2004 07:45:35 -0700, "Coalbunny" <coalbunny@vcn.com> said:
> > Why not have an additional air tank and inflate "ballast tubes", raising 
> > the sub a few inches?  He'll be on the surface, so he can refill his 
> > tanks with a small 12vdc compressor (if he wants), and if in a crisis 
> > underwater, he can also inflate the same tubes and add to his bouyancy.
> Inflateable ballast bags - I think the problem with these is deflating
> them cleanly and storing them when diving. The bags will nead to be
> inflated when entering the sub prior to diving - to maintain hatch
> clearance.
> Maybe the bags need to be stored in a fairing of some kind, but them
> might as well have bigger ballast tanks.
> 
> > Otherwise, I'd suggest not flooding the sail.  That's the part I fail to 
> > understand.
> > Carl
> I presume you're a 1ATM oriented submariner.
> Because the 1 ATM boat will be very heavy anyway, adding a conning tower
> makes only a small difference to the boat's overall weight.
> In some ambient designs, weight is critical. The structure of the boat is
> light so overall weight is determined by lead ballast added to compensate
> for displacement.
> If the conning tower is NOT necessary for submerged operation, but IS
> necessary for surface operation, then flooding the conning tower when
> submerging seems the logical option.
> Flooding the tower reduces the amount of water the boat must displace,
> and therefore reduces the amount of lead ballast required.
> The difference can be measured in pain and hardship whilst launching a
> heavier sub.
> 
> Of course, this is only one of many options, as you and others have
> pointed out.
> -- 
> Alexander R Foreman
> Port Lincoln, South Australia
> Sub - Research stage only
>     - Small dry ambient
> 
> -- 
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> 

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