Re: [PSUBS-MAILIST] Isn't 'Mini book review.' anymore--pressure t est

[AndrePevestorf@aol.com]

In einer eMail vom 11.04.2002 23:02:00 (MEZ) - Mitteleurop. Sommerze schreibt Asmyth@changepoint.com:


> that they put a capillary tube out of your
> sub and track the compression of the hull. As soon as the compression goes
> beyond a linear relationship with the pressure, they stop. In other words,
> they can stop when the elastic limit of the material is reached, but before
> making a loud CRUMP sound.
>
> Alec


Hi Alec,

This "capillary tube" you mentioned above ? Is it what we call DMS a little wire meander on a little plaster changing itīs resistor value due to stresses..

I suggest to Carsten to tape some off this DMS on the inner side of the hull and monitoring the stress curve during pick up the test deep ... I feel relatively secure with such a procedure to avoide complete hull failure but Iīm afraid of some local leaks particulary on connectors and hull openings and of course weldings... 

Just last night I saw "DAS BOOT" again from DVD... To make me fit for the ultimative challenge in my life ... test dive with Carstenīs CSSX  "THE PSUB" ... .-))

A unmanned test dive can mean to lose a intact sub due to a failed release automatic (see Carstens statement) but it can also mean to lose a sub due to a simple little leaking valve ... easy to seal with just two turns with the right wrench..
In a huge PSUB like CSSX I believe there is enough remaining space to manage some leaks. (see "DAS BOOT") 
But in a little box like Sgt. Pepper ... hmmm ...but the advantage is that small subs are easier to sink and easier to salvage if complete filled with water... 

Alec, would you be willing to dive with CSSX up to 325m ? Sounds my thoughts like common sense?
What preparations can be done to make such a testdive as sure as possible?
I believe itīs secure against lost of control to go to the deep only by dynamic downlift (whats the right word for the downward force from the dive plains?) and with empty hard tanks. (GABLER described such a procedure in his book) The sea bottom should be near the test deep of course. 
Any failure in the engine will cause surfacing and dive plans can only be shifted to up. At worst case with empty hard tanks, dive plans up, full spead ahead and blowing the soft tanks the sub will surface also with a greater leak like a rocket. The only problem then are vessels on the surface..... 
Thinking over this ever and ever again I believe itīs relatively safe. Maybe more then drive a car in the rushour monday morning....

A.