Re: [PSUBS-MAILIST] Hookah Sub (First Try)

[JP <jeffpost@rawbw.com>]

Looking at the diagram, I have three pieces of input:

1) plexiglass not tempered glass for the view ports

2) I don't have enough info here, but if you want to descend to 33', how long 
will it take your compresor to raise the volume of the cabin by 1 atm? Can it 
give you the volume you need, fast enough? I'm sure other ambients use 
bottled air which would compensate the cabin much faster. I'm curious to see 
the results of your calculations.

3)How long will your supply lines be? If you want to be able to descend to 
60', you might need lines a couple hundred feet long. How does having supply 
lines that long affect the volume of air supplied? 

Here's the clincher: I have a feeling that if you simply tow the hooka, a 
slight  tug on the lines might pull your hooka under! When you use the hooka 
for diving, you obviously can't pull hard enough with you mouth to do this, 
but your proposed sub has hundreds? of pounds of thrust, and is vastly more 
massive than your hooka float.. I think this is the real spoiler with this 
particular design.

As an alternative, could you redesign your sub to put more of the structure on 
the surface? How about a small barge that tows you behind it? Maybe the 
underwater portion could have minor attitude adjusters, but to really move 
from place to place, the barge would provide the main thrust.

JP


> > Hi all
> >
> > I am trying to design a low cost
> > easy to construct,
> > 2-person dry ambient submersible for shallow lakes (60 ft). Visibility is
> > poor so speed is not important.
> > Materials must be common and not special ordered.
> > It must be able to be constructed using only hand tools and a welder.
> > I want to be able to exit the sub while it's down for dives. The cabin
> > cannot flood (much) when I exit to dive,
> > and I want a second egress that allows me to stay relatively dry.
> > It also has to weight less that 1 ton so its easy to tow, launch and
> > recover.
> > The primary air supply will be 3 air lines coming down from the surface
> > where my towed hookah system will be following along. One of the line
> > will be used for cabin air and ballast contorl the other 2 will have
> > regulators and enter the sub through the dive hatch.
> > Hookah means I can exit the sub without a BCD or scuba tank and very
> > little weight. The hatch can therefore be relatively small.
> > You can see my 1st design "H1" at
> > http://members.cox.net/djackson99/sub/Sub_H1.htm
> >
> > I would love to see other designs that meet some of these requirements
> > and I welcome any suggestions from the group.
> >
> > Thanks!
> > Doug Jackson