Bill, I luv ya, Baby, but, every time you post a reply about ambients, I
get this crick in my neck and my hump changes sides ;-)
I am taking exception to a few of your points to the new guys. Permit
me to adlib. Fling mud as appropriate!!!
----- Original Message -----
The three basic types are wetsub, where you wear full
scuba gear and the boat is fully
flooded, 1 atmosphere sub, where the interior is
completely dry and your hull atmosphere
is the same as at the surface, and ambient, which can
be partially wet, or mostly dry.
Ambients are either semi-dry or bone dry. Magical Child, my Typhoon
look-alike, will be as dry as an Idaho tumbleweed, especially with
dessicant.
The wetsub is used basically as a diver propulsion
vehicle
With a proper "windshield", lots of air and batts, and a dry
suit you can tour for miles.
The ambient sub has either openings or a valve to let
the water
pressure into the sub and then that water pressure is
kept out of the sub by superior air pressurization of the
sub's interior.
Eez no so, Senor . . . well, ok, a semi-dry ambient is USUALLY open to
the surrounding water, but, doesn't have to be. A semi-dry (Markham
boat, SportSub) uses its cockpit as a variable ballast tank to
control buoyancy. A dry-ambient is COMPLETELY sealed from the
surrounding water. It has to be or the air compensating regs WILL
NOT WORK. You can admit water into a VBT that is compensated, as
well, but I suggest you keep it out of the cockpit proper.
The Markham sub uses the inverted cup principle to keep a bubble of air
in the canopy. The SportSub was initially designed with an electronic
sensor designed by Hugh Daskin of Vancouver that controlled the water level in
the sub. Both were/are open to the sea.
Magical Child, a true dry-ambient, will be totally isolated from the
ocean. Not only will it serve my needs as a touring vehicle but
it will also be fully automatic in its depth keeping. I want to
look outside and admire the view, not manage a machine (obviously I'll be
managing depth dynamically)
Your operating depth for an ambient sub can not
exceed normal scuba diving depths.
Por que? As long as you have taken the usual precautions (and keep
your hand away from the hard ballast jettison handle) a decompression dive is
appropriate. There would have to be an accurate way of maintaining
stops, preferably on an anchor line, not moving. A sub is just a
vehicle. Mixed gases on the other hand . . .
So the first thing you need to
find out is which of the three types do you want to
build. None are easy.
If you've ever put together a strip-built kayak or canoe, then a wet or
ambient sub isn't much more complicated. If you're not a diver, haven't
used compasses, depth gauges, pressure gauges, regulators, BC's, weight belts,
or dry suits, then, yes, putting a dry-ambient together can be intimidating
because you just don't know what the heck to put into it.
By the way Patrick, an ambient sub does not require
any special type of framing other than for
it to be reasonable sturdy. [snip ] As long as it is
strong enough to hold together and take the weight of whatever equipment you
put on it, it should be strong enough.
True enough. My dry-ambient will be a monocoque construction using
epoxy over ply. Magical Child will be used for touring and her hull
needs to be able to handle a rigorous seaway. We get twelve foot
seas out here, and the water can be very confused with changing wavelengths in
a matter of seconds.
A further note on ruggedness: a semi-dry ambient, if open to the sea,
does not have to have a particularly strong cockpit. A dry-ambient, on
the other hand, has to have a strong cockpit because of lag time in the
compensating regulators. If you are plunging in an uncontrolled descent,
you need to give the regs time to respond.
But be aware that an ambient sub will only let you go
to scuba depths
and you have to be a certified diver and follow dive
tables to avoid getting decompression sickness, and why
bother when you could just go to those depths with
scuba anyway?
Well, I never!!! Bill, Bill, Bill - I want to TOUR. I've been
diving since 1974. I'm tired of just seeing fish. I want to sit on
the deck and watch the sun go down, see the water rush over the canopy, cruise
through canyons, skim over wrecks, hover off walls, and look for interesting
things like nude beaches outside of scuba swimming range.
AND, I want to do it dry and comfy - remember my latte?
It has been pointed out in the past here
that it is almost as much work and trouble to build
an ambient sub as it is a 1 atm sub that can dive much
deeper. The main difference is that one has a
pressure hull and the other does not. The propulsion
systems are still required by both. Ballast and
buoyancy systems are still required by both.
And exactly what do all those Lloyd's of London folks do out there - play
cricket? A one-atm boat is orders of magnitude more complex than a strip
built kayak that can sink. Magical Child will simply be a wooden boat
that can indeed sink and will have a fantastic view. Period.
A few basic instruments and controls. The only pressure type item will
be overpressure valves that will be installed in the cockpit and cylinder
storage areas in case of either an LP (or HP) line failure or
an uncontrolled ascent. I doubt the exhaust ports on the regs
would be able to dump fast enough.
So there.
Rick L
Vancouver
----- Original Message -----
Sent: Tuesday, January 17, 2006 9:12
AM
Subject: Re: [PSUBS-MAILIST] I will
build it!
you're kidding me...I can make that with a trip to Home Despot!
maybe I won't have to wait till I'm older and wealthier to build a sub
afterall!
are there any plans or design guidelines on the psub site or elsewhere
for
this type of vessel?
What should it be framed with?
What would the safe operating depth be?
~suddenly very excited,
-patrick
----- Original Message -----
Sent: Monday, January 16, 2006 6:10
PM
Subject: [PSUBS-MAILIST] I will build
it!
Hello all, I'm new to the group. I spent 6 years in the US naval
submarine service. 4 years 10 months on board the USS Baton Rouge (SSN
689). Now middle age has me by the b#$%s, and I want to build a boat of my
own. I figure I won't have the time/money/space for at least 5 years. I
count that as a benefit, as I should have a pretty good plan by then. in
the mean time, I'll learn and share what little I know.
Jim