I'd want to work them without ribs, I think. The Cousteau saucer is 3/4" nominal and was calculated to buckle at 1000 meters. DS-1 survived that depth, in fact, for seven years. They snagged a cable during the test and lost the hull, but steamed over it several times a year to keep an eye on their baby, and it was seven whole years later before the hull settled to the bottom (for whatever reason). I'm looking at a different configuration at the moment; 54"ID, a hemi in the bow with the big window, and about 6 1/2 to 7 feet long overall for the pressure hull. What I would want is the same ability that Aquarius offers--lay down, sit up, stand on your head--whatever. The saucer was designed starting about 1953 and what they wanted was armor for a diver--so having the pilot on his belly was a natural extension of that. The nice thing about DS-2 is that extra height (she's about 4' 10" high inside). With bigger viewports, you could sit up as you are planning to do, but it's nicer to do both given the opportunity. There's nothing like getting down to that viewport for a close squint at something outside.
Vance
-----Original Message-----
From: ShellyDalg@aol.com
To: personal_submersibles@psubs.org
Sent: Sun, Oct 25, 2009 11:56 am
Subject: Re: [PSUBS-MAILIST] elliptical heads
In a message dated 10/23/2009 5:09:04 P.M. Pacific Daylight Time,
vbra676539@aol.com writes:
Never mind, I just went back through the projects page and got most of the questions answered. May I assume that the cylindrical extension was used due to the fact that you COULDN'T find a supplier for deeper heads?
Next question: George always told me I could weld anywhere through the head except in the knuckle. You, on the other hand, put that bloody great window right through that baby. How does that look on the calculation sheets for additional stress?
Sorry for the late answers. I've been out on a couple of bike runs for the last few days.
The outfit "Fort Worth F&D heads" could have made a 3 inch straight leg (max) on my heads but I didn't think to ask at the time, so I added a 6 inch ring to give me more height.
George is right to warn against cutting at the knuckle, on a K boat design. The K boat has no ribbing on the heads. My hull is ALL heads so I'm adding beefy ribbing around the window area.
As for the calcs, I had an old retired NASA engineer run them for me. He didn't include any window openings so it's just the bare hull that I have numbers for. I couldn't get the Hull calculator to work so I gave it to him. He couldn't get it to work either so I'm not sure how he came up with the numbers but he's way smarter than I am. He's going to help me with the ribbing design too, so I can get a buckle depth around 1500 feet.
Frank D.