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Hi David. Some times "easy" is a little misleading. The nice thing about
having the manual valves inside is you never wonder if it's working or not.
There's a guy in Michigan with a real nice red sub. He's got electric dump
valves on his ballast tanks.( or maybe pneumatic ) I don't think he's
ever had a problem with them, but if he did, he's gonna be real screwed. I
considered buying his sub at one time. It's very beefy, and the work is nice. He
said he had about $100K into it, and I believe him. He was asking $70K for it on
ebay.It just didn't quite fit my purpose, and the modifications would have been
extensive.
I'm no computer whiz, or even a competent electrician, so I like things
real simple, with a fail safe system on every thing. Some things have fail safes
on the fail safes. ( Ya , I'm a little paranoid when it comes to taking my kids
to a place with inherent danger.)
Ask the other guys about how they're plumbing the ballast tanks, and how
they operate. I think most will agree that simpler is usually "easier."
I see in my head what type of valve you're contemplating, and although it
will definitely work, there may be some problems that could arise. I don't mean
to be a know-it-all, just trying to put my own two cents in.
First....The air pressure in the ballast tanks at the surface is very
small, and air can get out some really tiny spaces. If a little piece of crap
from the water was to get lodged in the valve, you could be docked and at the
bar for a drink, or maybe lunch, and come back to find your boat sitting at the
bottom of the harbor.( bummer ! )
Second....A screw mechanism generally doesn't snap shut, but must be
powered closed. Could be a problem if there's an electrical failure any where in
the system. Hydraulics would be better in that scenario so you could relieve the
pressure and the valve would close by itself ( maybe with a spring ? ) so if
something goes wrong, blow ballast and surface.
Still, you're relying on a device that's outside and can't be reached until
you get to the surface.
If speed of dumping is the concern, put a bigger valve inside the sub. The
labor is the same, and the cost difference minimal. I will be using 1 inch
valves on mine, but 1 1/2 or even 2 wouldn't be much more work/cost.
Third...... With the valve inside, you need two holes in the hull per
tank. One for air to come out of the tank, and one for that air to be
dumped outside. Add an air line to that loop, and you can blow ballast through
the same holes. If you have a hydraulic line or electrical cable going to the
ballast tank, plus an air line, you still have just two holes per tank in the
hull. That's a wash.
Fourth...... If there's a leak, you know it right away because it's
right there and will drip. If the valve is outside on the tank, how do you
tell if it's leaking ? That's not a big deal if a little air leaks out
while submerged, because its full of water anyway, but if the valve or related
systems fail for one reason or another, can you still blow the tanks to surface
?
Ask the guys who have finished subs. I'm certainly no expert, and in fact,
have only been in one of these things down under once, and I wasn't even driving
! ( Dan took me on a night dive in his. What a blast ! )
Like most things, I try to keep it simple, and rely on what the more
experienced guys tell me.
On the steering thing, Ya, you got the idea. It could
work very much like that. A wheel for turning the rudders,( rack and pinion to
the master cylinders ) and a push/pull for the dive planes. I
was wondering if there would be any advantage to having the dive planes
operate separately. Maybe the left one pointing up, and the right one pointing
down. Would it be possible to tilt the sub slightly on it's side while
cruising the depths ? Would it be of any use ? Certainly would add some
complication to the control plumbing. OOPS! getting complicated again !
When you get to the convention, ask lots of questions. This is a great
bunch of guys and they all have their area of expertise. They're all way
smarter than I am, and I wouldn't be any where near where I'm at with out
them. Frank D. Wondering what's for Dinner Tonight? Get new twists on family favorites at AOL Food. |