Submarine Launch

[Subscuba@aol.com]

Hello Psubbers,

I finally got the chance to launch the Sub! I launched it in my Pond and found
the following:
 
1) Buoyancy was almost perfect, the bow is about 5 pounds positive with the
stern about 3 pounds Positive. That's in fresh water not wonderful seawater.

2) The trim, that's the Sub buoyed in an upright orientation, was again almost
perfect.

3) The motor controls worked fine with no problems. Looks like I'll have as
much power as I need.

4) Pressure compensation looked OK although I didn't submerge the Sub more
than about 1 foot. No leaks have been noticed.

5) I couldn't really test the controls due to the size of my small pond. The
little bit I did they looked OK but a little slow, I think because I couldn't
get up to speed in the pond. I am going to try to do more testing in a much
larger pond in the next few weeks.

6) The biggest problem was with my truck. It got stuck when I tried to pull
the Sub out. The second biggest problem was the water in the pond was cold.

All the buoyancy calculations, moment arms, motor controller design, and other
calculations, paid off. The Sub sits beautifully in the water. I may have to
add a little lead ballast but not much. Trim as it is without any changes is
perfectly adequate. Even the motor torque is balanced by the flotation
positioning, thus the Sub doesn't rotate when power is applied. Luck with a
little math skills.

I had put off the initial launch due to anticipated problems of trim and
buoyancy and I didn't want any more problems at this time. I should have had
more confidence in the calculations. Results at this time have been much
better than I had expected. The total time I have spent has been 3 years 11
months and 22 days. A long time.

I am looking forward to this summer.

I hope all of you had a good holiday season. Best wishes.

Ken Martindale (Have Submarine, will travel)