Re: [PSUBS-MAILIST] hard balast

The easiest way to deal with hard ballast is just have some colored been bags that you put in the sub with you, Example. Green is 5 pounds,,,blue is ten pounds,,,yellow is what ever you want it to weigh, And my personal favorite is red tartan fabric for the 2.5 pound bags. I guess I just cant get all those size 4 plaid skirts out of my mind......Dave

"Dan H." <jmachine@adelphia.net> wrote:

Rick,

Are you sure you haven't done one to many of your "fast bounce dives to 200 feet"?

I don't see any connection to your original question I replied to, and what your talking about now.

Please try to be more specific in your future posted questions.

Dan H.

----- Original Message -----

From: rick miller

To: personal_submersibles@psubs.org

Sent: Tuesday, October 11, 2005 3:33 PM

Subject: Re: [PSUBS-MAILIST] hard balast

Dan

The primary question was about the hard ballast and maintaining a resonable decent speed. As a long term diver i allways start a dive about 12 lbs heavy. This allows me greater control over students and some really spectacular decent speeds on deep boounce dives. i am alot more hydrodynamic than a sub. This wieght equates to about 4 gals of hard ballast in a 4000 lb sub, so i guess that about right.

rick miller

note: to all the divers out there. yes i know that the recommended decent speeds are 60 ft a minute. I do not recommend anything faster. But if your ears can handle it, a high speed bounce dive to 200 plus is a blast.

----- Original Message -----

From: Dan H.

To: personal_submersibles@psubs.org

Sent: Tuesday, October 11, 2005 5:03 AM

Subject: Re: [PSUBS-MAILIST] hard balast

Rick,

Your question is kind of brief. I assume you know the difference between hard and soft ballast tanks.

There really isn't much of a relationship at all. Soft ballast is only used on the surface to lift the sub out of the water, to gain adequate freeboard to enter and exit the sub without flooding it. If you have air in the soft ballast tanks when diving, it will compress and as you go deeper and so you get heavier the farther down you go. Not a good thing if you ever plan to resurface.

Hard ballast, on the other hand, is as it implies. A hard, pressure tight, tank that is used to set buoyancy for diving the sub. Since it is hard, it doesn't matter how much air or water it contains while diving. Your buoyancy won't change in relation to your depth.

Your sub should have sufficient soft ballast to lift the conning tower high enough out of the water for it to be safe to open the hatch. Your hard tank should be of sufficient displacement to allow you to make fine adjustments in buoyancy. There is no substitute for the soft ballast. You have to calculate how much water you have to displace to push enough of the conning tower to a sufficient height. You must have enough.

On the other hand, having to little hard ballast tank only means that you have to do a better job of guessing the proper amount of fixed ballast (lead weights) to put in the sub before starting your dive. The more soft tank, the more adjustment you have before you have to add or remove lead weights. To much hard tank requires to much air consumption if you need to blow some ballast at depth. For starters, I'd consider about five gallons of hard ballast.

Dan H.

----- Original Message -----

From: rick miller

To: personal_submersibles@psubs.org

Sent: Monday, October 10, 2005 6:03 PM

Subject: [PSUBS-MAILIST] hard balast

does anyone know the prop realtion between soft balast hard balast and displacement?

thanks

rick miller