Re: [PSUBS-MAILIST] Center of gravity Vs. Center of Bouyancy

[Ed Greany <crest25@attglobal.net>]

That's progress, isn't it? I once rode beneath a hurricane spproaching
and it was interesting. At 300+ (classified) feet deep, we simply
maintained our patrol with very little if any sense of motion due to the
current.

That's the nice thing about nukes.

Ed, STS-2(SS), Plankowner
USS Will Rogers SSBN659(Gold)

Greg Cotton wrote:
> 
> The Navy took the problem seriously enough that, except in emergencies, we
> didn't surface or submerge during heavy weather. This resulted in lots of cold
> wet nights on watch off of the Virginia Capes, taking waves over the low
> bridge of our stepped sail. When the weather got heavy enough, we ended up
> standing watch on the periscopes, with the Conning tower upper hatch closed.
> Submerging would have been nice, but since we didn't have the power or air
> to get out from under the storm we rode the whole thing on the suface. Nukes,
> of course, don't have that problem and mostly stay submerged. On the Polaris
> boats we only surfaced and submerged once per 60 day patrol.
> 
> Greg
> STS3 (SS) N0WEK
> www.usstorsk.org
> 
> Date sent:              Sun, 12 Aug 2001 09:58:26 -0700
> From:                   Ed Greany <crest25@attglobal.net>
> Organization:           Dopplers by Greany,KB6DOL
> To:                     personal_submersibles@psubs.org
> Subject:                Re: [PSUBS-MAILIST] Center of gravity Vs. Center of Bouyancy
> Send reply to:          personal_submersibles@psubs.org
> 
> > Hi Doug,
> >
> > Honestly, I don't even remember Sub School particulars. I didn't get
> > serious until I got OUT of Sub School and on a boat when I really began
> > to understand and WANT to understand what boats were all about. Sub
> > School to me was just another Boot Camp with it rigidity and rules and
> > etc. We also could not take notes and keep them since everything was
> > classified. So,
> >
> > my experience on the boat was limited to a "boomer". Of course, our
> > ballast tanks were 12 in number (3 port fwd, 3 port aft, 3 stbd fwd, 3
> > stbd aft) but were not isolated from their port/stbd partners. In other
> > words, ballast tank 1A on the stbd side forward had a hole at the top
> > and one at the bottom with ballast tank 1B. So you could actually say,
> > there were 6 ballast tanks and each was split port and starboard but
> > they went all the way around from keel to keel instead of saddle tanks
> > which infer only partially around the bull.
> >
> > Subbing on a SSBN boat that weighs over 7,000 tons submerged is going to
> > be considerably more different than say the Tang with only 2400 tons
> > submerged and your premise of a hazard of a broadside wave is pretty
> > much not even a consideration. I liken it to a sailboat where a strong
> > wind can blow the sail over and actualy capsize the boat. The sail on
> > the sub is much smaller in comparison to the hull and weight
> > differential is no where near the same proportion.
> >
> > Ah, yes, the Trigger trainer. I remember it well. Let's see, "Harder,
> > Darter, Trigger 'n Trout; always in and never out!" used to be the
> > saying. The actual Trigger was the first boat I took a dive on.
> >
> > As for the theory of blowing entirely, that was routine anyway but I
> > can't disagree with the physics you present concerning the CG and CB
> > cross. I'll leave that up to the engineers. That is beyond the scope of
> > my "need to know."  ;) I'm not sure it necessary has to do with ballast
> > tank design however. As long as the ballast tank blows inside to the top
> > of the tank forcing water out the bottom, I don't think there is any
> > problem with a wave. You might incur a roll but not a threatening
> > situation unless you are in the surf.
> >
> > By the way, out guys raising havoc with the Diving Officer didn't have
> > to go thru Control since Control was on the upper deck and we were in
> > the Middle Deck so no one was the wiser. Lots different on a boat 425'
> > vs 300' long.
> >
> > "Straight board; even bubble".
> >
> > Ed
> >
> > Doug Niessen wrote:
> > >
> > > Ed,
> > >
> > > If I remember correctly from sub school (1964), doesn't the center of
> > > buoyancy move up and down the vertical axis of the boat as the ballast
> > > tanks are blown or flooded? Seems that in the Trigger trainer they
> > > stressed the point of quickly and completely blowing the ballast tanks
> > > during surfacing. There is a point when the center of buoyancy and CG
> > > cross during diving and surfacing and at that point a big wave broadside
> > > to the sail could capsize the boat.
> > >
> > > This may not be a problem for small subs if the ballast tanks don't
> > > encompass the hull.
> > >
> > > Or..... I may be making all this up and am completely wrong.
> > >
> > > We have done the same thing, moving ten or fifteen guys for to aft to
> > > play with a fresh diving officer. The giveaway is these guys streaming
> > > through control like a line of ants.
> > >
> > > Cheers,
> > > Doug,   K6STS
> > > ex-STS2 (SS)
> >