Frank,
What type of steel did you use in your heads and did they heat treat them after forming? Are they stamped or spun heads? They look stamped to me, but some days I'm blind.
I could build your T stiffeners in 3D CAD models if you like so you can see them in place and have the 2D drawings to scale to cut the steel or CAD files to run a CNC aqua jet cutter, plasma cutter, or blue tipped saw.
I like your basis idea of using a tracker innertube to help with getting more freeboard. I've been thinking about a number of different types of inflatable designs for greater surface staybility and emergency buoyancy. If you could attach large volume pop off valves to the innertube you could inflate the innertube at depth if your other systems failed and once you start to assend, the pop off valves would bleed off the excess pressure. Of course if you had a inner tube at the top of your sub for this sort of emergency you would be more stable at the surface if your other buoyance systems are not working properly and it might help to keep the waves out. Most of my ideas for infatibles are in the pontoon configeration and help with keeping waves from getting to the top exit hatch.
Regards,
Brent
If quitters never win, and winners never quit,
then who is the fool who said,
"Quit while you're ahead?
From: ShellyDalg@aol.com
Reply-To: personal_submersibles@psubs.org
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] Delivery
Date: Sat, 17 Mar 2007 17:34:32 EDT
Hi Jon. The dishes are 84 inch diameter and 3/8 inch thick. They weigh 747 lbs each and will be mated to a 6 inch tube section to give me an inside height of 52 inches. The smaller dome is the hatch lid and is 20 inches in diameter. I would like to be able to get to 300 feet deep, but probably will never get below 150 or so. The windows are the weak spot, and I'm putting in an 18 inch window directly in front with at least 2 additional windows at 12 inch diameter. one above, and one below. I may put one on each side as well.For stiffeners, I will be using 1/4 inch by 4 inch with a "T" shape running from the top center hatch to the bottom, alongside the window tubes. I did a rough calculation of finished weight and came up with 8400 lbs. including drop weight and 2 passengers.I will be sizing the ballast tanks to displace enough water to give me as much free board as possible. I hope to have 24 inches of the hull above water when surfaced.I'm working on a design to add a concealed tractor innertube to the bottom, so that when I reach the surface, I can inflate the tube ( 72 inch doughnut ) and give it more lift.( Maybe get to 30 inches above water .) That will take some trial and error after the sub is wet to see if it can be done without destabilizing it. It will definitely lower the center of buoyancy, and may be prone to tipping ( and sinking!!!) OUCH!The triangular ballast tanks will be stainless, and again, will be sized to get me out of the water as much as possible. I can use the plasma cutter at work to cut the blanks, and then mig weld the 4 tanks.I considered using propane tanks as ballast tanks, but it creates too many places for things to get hung up on. My goal is to keep it as smooth as possible. I favor the round shape because I can spin it on it's own axis, and sit side by side with my passenger. I did some modeling with different shapes, and the squashed sphere is not much "less sleek" than the propane tank shape. The sketch on frappr shows a pontoon section, but I'll probably go with a full size pontoon boat so I can have more deck space. ( need room for the BBQ !) I'd like to add video inside too, but the electronics are another phase I haven't gotten to yet. Should be receiving more steel soon, and then I can post a picture of the two halves welded together and the hatch tube going in. Frank D.
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