Keeping the blogosphere posted on the goings on of the world of submarines since late 2004... and mocking and belittling general foolishness wherever it may be found. Idaho's first and foremost submarine blog. (If you don't like something on this blog, please E-mail me; don't call me at home.)

Thursday, September 08, 2005

Next Generation Sub Update

Joe Buff has a good article on the current vision for the proposed Virginia-class follow-up, Tango Bravo, over at military.com. I agree wholeheartedly with this statement from Joe:

"So a bit of healthy disbelief seems advised when TANGO BRAVO's goal is labeled as “the same or better mission capabilities for half the money,” or claims are made that “with concerted effort, an SSN design derived from TANGO BRAVO would be ready for procurement in 2011 or -- under ideal conditions -- even earlier.” On the other hand, we can't afford to not do TANGO BRAVO, or our own expertise base will wither irrecoverably, and we won't have a good follow-on class beyond the Virginias."

Initial cost estimates for Virginias back in the 90s were something like $1.3B per boat, which was only slightly more than an LA was going for at the time -- this was clearly unrealistic, but Congress signed off on it.

I'm especially interested in the concept of "shaftless propulsion"; so interested, in fact, that I did some research on it before I left the service, so I can't really talk about it. Here's what Joe has to say:

"The propulsion shaft of current SSN designs is long and rather heavy, causing center-of-gravity (trim) difficulties for naval architects, and the shaft requires a large hole in the stern of the pressure hull. Moving to all-electric propulsion, with the drive motors encased in pods outside the people tank, and with hull penetrations needed only for power cables that don't rotate, is a very attractive alternative. A word of devil's advocacy, though. A commercial ship with a similar arrangement recently suffered a serious fire in one such pod; no one was injured, but the ship was crippled. And this was on the surface with help nearby -- not deeply submerged during battle maneuvers. The tech for submarine use will surely get there, but the point is it isn't there yet and it won't be cheap."

An advantage of "shaftless propulsion" with electric drive is that all of the reactor's usable output could go to generating electricity; in theory, you could divert that electricity to other interesting things when not needed for propulsion. (Right now the other interesting things are most usable for surface ships, but I'm sure some smart submarine guy could figure out how to make subs use the extra power as well.)

Anyway, read the whole article -- and check out the rest of Joe's archives if you get a chance! (At this point, I should point out that in my last post about one of Joe's articles, I kind of got on him about HF sonar; I realized in hindsight that even a civilian writer has to operate under a lot of restrictions that we sub-bloggers are bound by, and I'm sure Joe knew what he was talking about.)

5 Comments:

Blogger BEHUMP said...

Similar article here.

9/08/2005 1:41 PM

 
Blogger Skippy-san said...

I read the links. All the while a little voice in me was saying," remember the A-12!"

Lot of similar promises were made and when the program got canx, it took over a decade for Naval Aviation to recover.

9/08/2005 2:51 PM

 
Blogger Vigilis said...

The equation for Virginia's successor also involves the life cycles of remaining boomers (and their conversions). They are a strategic necessity that will continue to absorb major bucks from the shrinking pie remaining for other subs to slice.

SSNs are now ideal only for certain submarine operations. A mothership (submerged replenishment and crew) concept reduces the total number of SSNs needed even further (my guess, perhaps into single digits).

AI type subs might fulfill remaining submarine roles handily and with three major advantages: shorter production lead times; lower, more contollable aquisition costs; and reduced manning, and operating costs.

Things are going to get very interesting with respect to basing any new SSNs, which are probably going to be scarce and more secretive than ever, in my opinion.

9/08/2005 5:36 PM

 
Blogger JoeBuff said...

If you want to see how far back the ideas go of small sub crews through automation, and big payloads towed on undersea barges, check out the novel by famous science writer Frank Herbert called "The Dragon in the Sea" which first came out in 1955(!). I think it's long gone out of print, but Amazon has a few used copies for as little as barely $1, and www.abebooks.com is another good source for used books. Herbert's is a short and good novel; I've read it twice myself. It's something more of a psychodrama than a typical submarine action story, but it's definitely suspenceful and has some very kewl tech ideas -- and even touches a lot on the (surprisingly modern) issue of religious faith in the military, too. Check it out!

9/09/2005 9:15 AM

 
Blogger Bubblehead said...

Thanks for stopping by, Joe! (Sweet... a big time writer noticing my little blog!) I'll have to check out that Herbert book...

9/12/2005 1:11 AM

 

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