Re: [PSUBS-MAILIST] Propane sub

["samdatl" <samdatl@mindspring.com>]

was just thinking if the ballast tanks are not open to the sae at the bottom
pressurising them with propane should not be a problem. when pressurizing
the tank to blow to the surface pressure the tank and valve off only the
water then you have low pressure gas to run the surface. if pressure gets to
low to run the engine effectivly then inject more gas to the sealed tank.
similar to blowing the sanitary tanks on a nuke. you let the tank run
completely dry and you risk blowing air out into the water making one hell
of a racket.

kinda like the new ideas
Walker
Woodstock, Ga.
samdatl@mindspring.com
----- Original Message -----
From: <CWall@swri.edu>
To: <personal_submersibles@psubs.org>
Sent: Thursday, November 09, 2000 11:53 AM
Subject: [PSUBS-MAILIST] Propane sub


> Yes we can get back to a technical discussion. I might proffer
> that while a propane engine might provide an excellent means of generating
> both locomotion and/or power, it might be better used to power a
> compressor and use air as your deballast gas. That way you aren't using
> fuel to deballast your tanks, just readily available air. Subs using
> air-breathing or even air-independent engines to power compressors at the
> surface have a long and proven track records for increasing range at sea.
> If that's your goal, you might consider looking at that option rather than
> deballast with propane. People do this with diesel already, right?
> It is totally possible that I have missed the point on this one.
> If that's the case, don't take my response as a personal attack.
>
> Thanks,
>
> John
>
> The answer I'd offer to your comment is that this sub is not designed to
go
> deep- the propane will be useless below 150 ft or so, and I don't want to
go
> anywhere near that deep- and I will have the droppable ballast to prevent
that,
>  even if I run out of propane with all ballast flooded.
>
> With dives in the 15-30ft range, it doesn't take much to get back to the
> surface, and most dives will begin near neutral ballast and surface
without
> blowing- powered submergence, in other words, so it won't be propane
intensive-
>  and when I do blow ballast for more freeboard, I'll be burning most of it
off
> for power when I want to sink again.
>
> I really think it can be very economical, IF the operator wishes it to be.
It
> does mean than the style of operation will have to be adjusted- but crash
dives
>  are not something I put a premium on in the first place in any case.
>
> Craig Wall