Re: [PSUBS-MAILIST] VBT's & The Apology

["Sean T. Stevenson" <cast55@telus.net>]

Ken - the difference here is the significance of the buoyancy change.  In a 
naval submarine, a few divers and/or equipment exiting the sub does not 
significantly change the trim of the vehicle with respect to its inertia.  
VBTs in a military sub have more than enough capacity to handle the 
difference, and can achieve neutral trim before the difference has an 
opportunity to adversely affect the trim or depthkeeping of the boat.  A sub 
this large responds very slowly to buoyancy forces.  In a psub, or 
commercial / civil submersible, this is not the case, and is the reason why 
regulations exist to prohibit the practice of midwater lockout in commercial 
ops - that, and the fact that accidentally killing divers in a civil context 
is frowned upon.  In the military, it is a risk assumed when you sign on the 
dotted line.  That is why Vance mentioned two exceptions to bottom / negative 
lockout:  physical restraint to a solid fixed body, or high mass / military 
subs.  In the latter case, the military subs operate outside the law anyway, 
and civil regulations do not apply. 

-Sean


On May 26, 2007 10:09:39 Ken F wrote:
> Vance,
>
> Almost purely for the sake of argument at this point.
> It's not un-heard of for a Naval Submarine to dispatch a squad of SEALS,
> and all of their equipment, out through the TORPEDO TUBES, as well as
> undocking an SDV (submersible diver vehicle) from the deck of the
> submarine.  With the weight off all the men, equipment, and SDV, I'd figure
> it at roughly 2000 to 3000 pounds.  So you're telling me that a Naval
> Submarine intentionally grounds itself if it's going to offload a ton to a
> ton and a half of mass, because there's no safe way of doing it otherwise?
> I wanted the *method*, which is where I think you're missing the point.
>
> Ken
>
> vbra676539@aol.com wrote:  Age and evil intentions will outdo youth and
> smug every time. Deal with it. What you are suggesting is not new, merely
> dangerous. Figure a way to "anchor" in midwater, or perform underway with
> enough mass (as in military subs) and you'd be fine. Otherwise, problems
> compound. Don't take it personally. I was 23 once, as well. The difference
> between us is that you're coping with it and I'm merely glad it's over.
> Vance



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