Re: Trolling Motors

[Marcel Michaud <michaudr@telusplanet.net>]

protek@shreve.net wrote:
> 
> Rick,
>    Believe it or not my main line of defense for surfacing is a set of two
> "soft" tanks.  And the answer to your next question is "Yes, I have blown
> ballast at some depth and Yes, it is a wild ride."  I actually sort of like
> the effect.  You just got to be reasonably sure that there is not a boat on
> the surface above you.  I like blowing the bow tank with full speed and
> power and then when well on the way to the surface blowing the aft tank.
> If you have ever seen Hunt for Red October where the sub does an "On the
> top" surface, it looks something like that.  The angle seems greater than
> 45 degrees and much of the hull is above the water line for a second or so.
>  The surface is far faster than propulsion is going to take you up.
>    One note here about drop weights;  People should be very very careful
> with designing a sub with drop weights due to the possibility of the sub
> rolling due to the Center of Lift being below the Center of Gravity.
> Remember I do not use dive planes at all.  I shift 325 pounds of weight.
> To get the steep angles that I require my CB and CG are closer than most
> subs.  This causes my boat to not be as surface stable as most in waves
> etc.  But under water it handles very well.
> 
> Gary Boucher
> 
> At 09:03 PM 10/26/98 -0800, you wrote:
> >> [snip]      Also concerning safety is the statement that I made earlier
> that if you
> >> are relying on motor propulsion as your primary emergency means of getting
> >> to the surface you are making a major safety mistake.  Do I think you are
> >> safer with failure proof shaft seals?  The answer is yes.  But I will tell
> >> you that my 6.7Hp is not my security blanket.  My tanks are.
> >
> >There ya go . . . As I mentioned in one of my posts to this thread, any
> upward movement through the
> >water column from your main motor will be due to a vectored force and, by
> definition, secondary in
> >effect.  However, I'm curious as to whether your first line of defense is
> a hard tank or soft
> >(ambient) tank.
> >
> >-----------------
> >Rick Lucertini
> >empiricus@sprint.ca
> >(Vancouver, Canada)
> >
> >"You have a very interesting face, but, you should drain it once in a while."
> >
> >
> >
Gary,
	I have a 100# drop weight on my sub, when I run calculation for my
weight and buoyancy, I find only a small diffrence in my VCG it increase
or rise a bit not very much when I drop the weight even though I am a
100# lighter. If I may ask a question. What is the distance between your
VCG and VCB submerge and on the surface? Thanks

Marcel Michaud