Re: [PSUBS-MAILIST] Ambient / 1ATM Q?

Hi Bill,

It's mainly about where I will be using the boat. Biscayne Bay is a large mostly shallow body. There are some areas in the south which are outside of the channel where I could test her in about 15' but, the bay would be surfaced running for sure, too shallow and too much traffic.

It's Hawke's channel just off shore where I plan to dive, miles wide, follows the Keys south and 15 to 50' depth. Lot's of clear water, relatively light traffic, and nice bottom topography.

The very simple constant flow system I chose is for those times I may want to bottom the boat briefly to take a look at something interesting. My boats control profile will not have station keeping capability like say a nice stable K-350 or an ambient Sportsub with thier electronic auto hover system (too easy to break in my opinion). Two steel 100cf cylinders are going to be a lot, four of them and I would need to take my shaving kit with me. :)

Another reason for operating at snorkel depth is traffic. This boat will be independent of surface support and traffic avoidance is squarely on my shoulders. Submarines do not have the right of way. In fact, this boat will have a very simple directional hydrophone to take bearings on prop noises for those times I do bottom the boat. I already bought plans for a simple unit. I do the same thing with my ears when I'm diving, if it sounds too close, I stay down.

The boat will make it's biggest impact on the surface, mean and military complete with kill silhouettes, where the question will always no doubt be...Doe's it really dive? The answer will be yes.

I am not familiar with the David's (Iv'e heard of them) but know nothing about them, I will have to take a look.

I hope this clears up what I'm up to.

Joe

From: "Akins" <lakins1@tampabay.rr.com>
Reply-To: personal_submersibles@psubs.org
To: <personal_submersibles@psubs.org>
Subject: Re: [PSUBS-MAILIST] Ambient / 1ATM Q?
Date: Fri, 20 Jan 2006 03:44:35 -0500

Hi Joe.

Good ideas on making the snorkel do all it can do Joe. But what about your air loss from your constant flow system when you are below snorkel depth?

Are you saying that you intend to remain at snorkel depth MOST OF THE TIME and intend to only dive deeper for short intervals so as not to deplete your

constant flow air tanks as quickly? If that is the case then it sounds like you are designing a boat that will live most of its life near the surface barely submerged with only short

periods of diving deeper. It sounds similiar in concept to a civil war confederate David boat, except for short periods of going deeper. I do wonder why you selected the

constant air flow system instead of using an equalization system that would activate only when there was pressure differentials and thus save more air. Why did you?

Bill Akins.

. .

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

From: Joseph Perkel

To: personal_submersibles@psubs.org

Sent: Thursday, January 19, 2006 8:11 PM

Subject: Re: [PSUBS-MAILIST] Ambient / 1ATM Q?

Bill, Patrick, & Chip

Yes, a lot of ways to skin that cat. Mine is only one way and as I have chosen it, I neglected to mention the others. That's your job Patrick or anyone else, to gather information from various sources and independently verify the validility of that information. (The fork in your eye ethos).

I came up with a way to minimize that waste of air you mentioned Bill. I will use a 12v centrifucal blower at snorkel depth for air flow and save the tanks. I stole (ah...borrowed) the idea from two places. The 10 psi blower system on the fleet boats, and I believe the Aquasub pontoon semi-submersible uses a blower in the ventilation system on the port float. The 12v blower may be able to blow ballast as well, I don't know yet. I have to look into the blowers specs.

There was a discussion some months back regarding the use of LP air at the surface for blowing ballast. That discussion caused me to think about, how many things can I get the snorkel to do? So far,... cabin ventilation / compensation at snorkel depth, engine air induction / ventilation, and surfacing the boat.

I am (borrowing) Ricks use of the second stage regulators for use in the engine compartment only to feed the diesel a little air should the flapper valve close on the snorkel intermitenly from say, wave action or sloppy depth keeping. Otherwise, your eardrums become that membrane you mentioned Chip.

Someone said to me not long ago, why bother, that I would end up with a deep draft boat. Well, it's a facsimile of a military sub which is designed to simply appraoch it's target by stealth. Simply submerging does that. Besides, bouyancy and rate control in an ambient are a bit dicey at depth. This way keeps me out of trouble.

Joe