The pressure hull would have to be a component to the whole. However, it seems a fair exchange to reduce displaced volume from a purely spherical hull form, which is why Cousteau and company chose that shape. The DS weighed just a touch over 4 tons all up. A 6 1/2 foot sphere displaces 4.6 tons all by itself, weighs proportionally more and would probably go 5+ tons all-up similarly equipped. Those are important numbers for a ship as small as Calypso with her limited storage and handling equipment.
Of course, the design work on the DS was done in the middle 1950s (hulls manufactured in '57-8, #1 lost in 58-9ish in the Med. and #2 outfitted for its launch in Puerto Rico during the summer of '59). It's pretty hard to beat the service record on the DS. 1500 dives isn't many by Perry/Hyco/Delta/WHOI/Nuytco, etc. standards, but it is still pretty good service considering the sub was an adjunct tool, rather than the center of Calypso's universe.
Modern experience has demanded better surface behavior. Mike Adams always said that Perry and crew made sure their subs operated well on the surface (like a boat) FIRST, then took care of the underwater stuff, figuring if it did well on top, then any fool could dive it. Which turned out to be true in my case, of course. That said, I think the nearest comparison we could make today to the saucer is Dr. Professor Mr. Nuytten's Deepworkers (or a dual, if you like). Not in specifics, but rather intent.
The DS and the DW are both geared to work underwater, with little concession for the surface other than the evil necessity of going through it on the way to work or on the way home. The saucer, of course, was more for observation, and put the Mark I Human Eyeball low and up front. I think they did something like Phil did with the airline seat, only they wanted their faces right up front and started out with a crew on its belly and built the smallest submarine around them that they could, which turned out to be the saucer.
The DWs really are workers, with less emphasis on spot-on observation (feet the the seabed instead of inches). They are based on a lot of things, but experience working underwater was a primary. Working, not just mooning around looking. However, one of the most endearing Aquarius features is that ability to press your nose right against the window and be THAT far from what you are looking at, reducing backscatter and attenuation to a minimum. I don't know if you could combine the two (saucer/arc segment port) but it is interesting.
My experience tells me that a short, fat cylinder with a big dome in front would do the same thing, to the same depth, and with less displacement. That's what I have, and that's what I'll be building next. But my heart likes the old saucer. Can't help it. That said, I'd love to have had the opportunity to put JYC in a Deepworker or Aquarius (or Antibodes, come to that) and turn him loose. They have the same sort of magic as the aqualung--practical, unadorned, unapologetic and fun as hell. You can't beat that combination. The DS was like that, too.
Vance
-----Original Message-----
From: Jay K. Jeffries <bottomgun@mindspring.com>
To: personal_submersibles@psubs.org
Sent: Sat, Oct 24, 2009 9:06 am
Subject: RE: [PSUBS-MAILIST] elliptical heads
Vance,
My issue is not that they survived but it is my feeling that there are stability and maneuvering issues. This is an opinion that I don’t have the time to work out the calculations to support. Would think that if it was a successful hull form that there would be many more built due to the economy and innate strength of this shape. The ride on the surface would have to be particularly obnoxious due to pitching and heaving.
R/Jay
The FIRST saucer pressure hull was lost at sea, along with an expensive set of strain gauges. Sat 10 meters off the seabed at a thousand meters for over seven years before finally leaking down and settling into the grave.
From a historical point, how many saucer-shaped submersibles were operational successful (and this is not to be negative on Frank’s extensive effort…I am praying that it is successful after all of his hard work)? There is Cousteau’s saucer (the 2nd saucer was last at sea) and the unsuccessful Boston effort the I am personally aware of. Past history is not real supportive of saucer-shaped submersibles.
When you were looking for hull bits, did you find a fabricator who could and would do non-standard elliptic heads? I'm fiddlig with the old Diving Saucer shape, which was 1.5 meters by 2 meters, give or take an inch, and was 3/4" thick. I like the space and payload available with that shape. A 2:1 head gives you, what, four feet in height? I don't remember the thickness of your hull. What does the shell weigh and what depth are you figuring for test and operating?