Trimming a Sub - Reference SCR June 2003 article....

[don prince]

I read through the excellent article by Volker Klein and learned a great deal. Hower, I have a question about the final steps. Do I want a negative downward force at 70 percent of ballast flood. That would mean at 100 percent the boat would be highly biased downward. If there was a loss of power or some other catastrophic failure the only direction for the boat to go is further DOWN! I have a problem with that concept... Can someone help me with this delimma?

Regards,
Don_

[raalst]

Hi, maybe there is, but

Hi, maybe there is, but it might not be what you want to
hear.

One solution is to make sure that fully ballasted the
sub still has a tiny amount buoyancy.

what you have made then, is a dynamic diver (you will
need forward speed and dive planes to go under) instead
of a static diver which can submerge with zero forward
speed.
on the plus side, left dead in the water it will surface (a bit)
if not stuck to plants or debris or heavier than normal
(i.e. if water gets into the dry compartment outside of the
ballast tank.)

the latter is more like the real thing, the former is the
safer way to keep your boat....


if space allows, you can use separate batteries for the
ballast tank motors and/or battery capacity monitors
to detect empty batteries before they become a problem.

another good idea is to have a way to detect loss of
received signal and then blow immediately. several
vendors built this into their control chips.

and last but not least maybe you should put a few elka-
seltzers in the dry compartment. if wet they release gas,
which *might* push out the water from the dry
compartment. It will probably not be enough to surface
the boat, but it keeps your electronics dry while
scubadiving for it.

hope it helps ! current value is 2 cents



Edited By raalst on 1054885899