|
Me again Allen. The pressure inside the sub doesn't change, because it's a
"one atmosphere" pressure vessel.
There is no real build-up of pressure under the hatch. As the sub gets
deeper and the hull compresses a tiny bit it may go up a tiny bit, but not even
measurable.
An ambient sub is different. There is a change in pressure as
you first descend, and the bubble inside is always trying to "blow the hatch".
The pressure under the hatch is equal to the outside but the air bubble is
trying to go up because of gravity. The water is heavier than the bubble so the
water is trying to get into the sub. The upward pressure on the hatch would
be more or less equal to the displacement weight of the dry portion of the
ambient sub. ( I think )
Haven't really thought much about this before so I could be way off.
Frank D.
|