Re: Trolling Motors

[protek@shreve.net]

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."
>
>
>