Re: Unmanned test dives

[Jonathan Wallace <jon@zk3.dec.com>]

"Morrisson, Richard D" wrote:

> For the viewports I would suggest facing the port into a pipe with a cap on the end and a machined flange on the other similar to your sub's port receiving hole.  The pipe can then be flooded and pressurized to the depth you want to test to.  Pressure cycling and/or long term exposure is then very trivial, it could even be automatic with a little ingenuity.  In addition, a dial indicator can be positioned on the port to measure deflections.  This may help predict failures or show non-elastic deformations.  A 3000psi scuba cylinder with a regulator can provide the pressure for an air over water charge line to the pressure vessel good to any depth up to 6000'.  Using a small orifice can prevent most of the explosive problems with this setup.  Make sure your pipe and the flanges have the capacity for the pressure you will be using.  You can even make this double ended to allow testing of two ports at the same time.

I'm not familiar with "air over water" charge lines, but this sounds like a feasible
alternative to field testing the viewing ports.  Is a piston needed to separate the
air from the water to prevent dissipation of the air into the water (to provide an
evenly distributed PSI over the entire view port)?  Could you provide more details
about the design of such a unit or provide a reference where I can view a similar
device?

Jon