Hi Pierre;
I'd like to give you some "food for thought" on your decision.
If you are going to pressurize compensate your motors, there's no
real problem to pressurize your battery box as well... it's simply more
volume. The weight of your sub is determined by the size (volume) of the
bubble you're trying to sink.
In my judgement, the PVC is a much simpler solution, widely available,
easy to work with, inexpensive, non-corrosive, strong, lightweight, easily
capable of withstanding minor pressure variations. Simply
put, PVC is ideal for an ambient sub.
If you are going to build big heavy steel battery boxes (tubes?) filled
with batteries and lead, can you jettison them in an emergency? I would
hope so. That's a lot of weight. Steel rusts anyway... but
add oxygen from electrolysis, add salt water, add electrical potential for
galvanic action, the conductivity of steel, and.... well, I
like the plastic idea better for an ambient sub.
But that's just my opinion.
Stan
In a message dated 1/18/2005 7:50:34 A.M. Eastern Standard Time,
poulin.carrier@videotron.ca writes:
Hi Bill,
Sorry to take so long to respond. I had to make
a decision before i reply. I have choose to go with all steel pod. One of my
friend have access where he work to a rolling machine. So we will roll the
tube and I will use 5/8" steel plate as end caps. I will also place plates
inside the pods and fill the empty places around the battery with lead
so the pod will also serve as weight. To reduce over-all weight of the sub.
Which i want to keep at around 1000 pounds. the removable end-caps will be
similar to what Dan explain except that i will have 2 bolts and they will
thread directly on each side of the battery in a permanent side
plate.
As for the battery, I presume that since my
battery have about 3/4" of air on the top, the plastic case will be under
pressure. And it may crack. I'm by no mean an expert but I'm still not
convinced about air-compensation the battery pod. I'll built a pod that can
bear the total pressure.
Yes i will compensate the motors. I'm using 2
minn-kota endura 30 motors. The only reason to compensate them is because of
the seal. The rest of the motor is capable, I think, to resist much
pressure! I will compensate them from the carbon tube directly. this tube
will stay open inside the cabine of the sub.
Thank you again for your much appreciated
input!
Pierre Poulin
Québec
Canada