Re: [PSUBS-MAILIST] Ambient vs. 1 ATM: the historical perspective

[VBra676539@aol.com]

Mike,

The Hunley did indeed have open topped internal MBTs but it was NOT an ambient boat. The water was valved in as if the tanks were Variable tanks, and pumped out, while the hull, aside from water volume changes, stayed the same. The definitive book on the Hunley is Mark Ragan's. He was a technical advisor for the movie, is a commercial diver, and is a submersible pilot and pilot instructor from Maryland. He's got a 2-passenger K250 and did his own research and physical search for the Hunley before collaborating with Cussler.

I've got a bone to pick about this running discussion about never diving past BLANK feet. 20. 50. Whatever. Losing depth control is a fair old possibility, especially in lakes with slow currents that tend to stratify into temperature layers. Build a sub out of tin cans if you want, or a couple of layers of glass fiber, but make sure the thing is tested for good safety margins. The "I'll never dive past 20 feet" school of thought might lead someone to believe that they would never actually dive deeper than that. Trust me, they will. We need to think in terms of 3 to 1 or 5 to 1 safety factors for these shallow vehicles--especially for the new guys who are converting day dreams into reality.

And the reality is that once the submarine is built, it becomes secondary to its capabilities and to its pilots desires. Once you start diving, then what you want to do is get down there and do it. And the more you do, the more you want to do. If somebody dreams up a 10 knot submarine, that's fine. But eventually they will want to slow down and look out the window. Then they'll need to steer in VERY small increments, which the submarine won't be designed to do. Then they'll want to check that little ledge out right over there, only it's 70 feet deeper and the sub isn't tested beyond 20.

The fact is that it is just as easy to build a strong submarine as it is to build a flimsy one (or just as difficult, depending on perspective). There really isn't any easy way out.

The Nautilus job has the submarine hidden inside a fantasy shell, but the submarine is there, first and foremost. My submarine is more pragmatic, as I will trade function for form more often than not. That's a matter of personal choice, based on experience and preference, and made AFTER the submarine part is done. Not as an afterthought.

Best Regards,
Vance