Hello Steve
I do think that a bilge pumps are a good idea for wet and ambient subs that want to obtain greater freeboard or stability once on the surface. They can be used to empty flooded portions of the hull or pontoons. No air lines are required and no vent must remain sealed so the risk are reduced.
Off-Topic: I have done neg-g's in a small plane just for fun, and once we were floating around the cabin along with everything else that was not strapped down our movements had no noticeable effect on the attitude. What did you do with the brick and what effect would moving it have?
Thanks
Doug J
In a message dated 3/15/2004 3:50:56 PM Central Standard Time, cirtemoeg@juno.com writes:
Pierre and Doug,
I didn't think the idea was far fetched. If I may use an illustration I
experienced during pilot training [again]. My instructor kept two cinder
blocks just behind the forward seats. I thought this was odd and
asked him about this and was told it was for emergencies in case
the aircraft went into a flat spin or loss of control. He also stated
that
we probably would never have to use them. Hmmm, well, we DID in
one cross-country trip over the Sierras. We hit a wind shear going over
a mountain ridge and dropped 500 ft in a split second. Also, there was
no airflow over wing and control surfaces, so we were in a flat drop.
First time I experienced zero Gs. The cinder blocks floated past us and
my instructor said, quick, grab one and pushed me against the yoke
and my face mashed-up against the window. [ his also ]. We gradually
pitched forward and we got enough air flow for control and ever-so-gently
eased her back up. Good thing, the ground was coming up awfully fast!!!
My thought is why not just a mechanical ballast mechanism. Two bowling
balls on a short rail forward and aft of COG made adjustable by hand
lever or foot pedal?
Feasible ?
--Steve
On Mon, 15 Mar 2004 16:10:25 EST DJACKSON99@aol.com writes:
> Greetings Pierre
>
> I use bilge pumps on my home built ROV, and unfortunately they
> barely do the
> job and my ROV only weighs about 8 pounds. See
> http://jackson.parcabul.com/rov/index.html I am in the process of
> upgrading my ROV and converting the bilge
> pumps to use impellers but even then I don't think they would stand
> a chance
> of pushing your sub around. I am going to test a bilge pump to 150
> feet
> because I need one on my sub when it is surfaced. You might be
> interested in that.
> It could be used to give a wet or ambient more freeboard by pumping
> a ballast
> tank dry once surfaced, consuming battery instead of compressed air.
> Here is
> the pump I am going to test:
> http://jackson.parcabul.com/sub/shurflow_bilge_pump.htm
>
> How are you coming on your sub?
>
> Kindest Regards
> Doug Jackson
> http://jackson.parcabul.com/sub/
>
>
>
> In a message dated 3/15/2004 1:44:06 PM Central Standard Time,
> pipo305@hotmail.com writes:
> Hello all!
>
> A long time ago I saw a R/C sub that used small water pumps for
> movement. (I
> saw that on psubs).
>
> I was wandering, could we use that on our psubs for small position
> movements? We could use boat's pump (12V) and steer the output in
> the
> direction we want.
>
> What do you thing about that? It could be a good (read cheap) idea
> instead
> of minn-kota motors...
>
> Pierre Poulin