Air-Independent Propulsion

[ASWnut101]

plus, it has to refuel very often, meaning it can't do littorial work for very long. Virginia can stay there for ~15 years, food supplies limiting it only.

[CCIP]

Originally Posted by ASWnut101

plus, it has to refuel very often, meaning it can't do littorial work for very long. Virginia can stay there for ~15 years, food supplies limiting it only.

The next step after AIP is clearly FIP - Food-Independent Personnel system :rotfl:

[ASWnut101]

ahh, robots...

[fatty]

Originally Posted by tycho102

AIP's, if I remember, are just a Sterling engine and compressed oxygen...

Some AIP systems are using fuel cells now instead, but the idea is still the same; range is still limited and recharging is still noisy as all get out.

Originally Posted by peterloo

I don't know why America don't develop its own AIP...

Why would they? As we've mentioned AIP range is limited. Most things the U.S. wants to do with its subs take place thousands of miles away, closer to political hotspots. This is okay if you want to establish forward bases or refuel along the way, but I think it's more cost-effective to operate boats that have the endurance to get themselves there. Going nuclear also allows for bigger, faster subs, with bigger armament. Of course, the new SSNs are not as quiet as diesel boats, that's for sure. But by no means does that mean they are loud.

I believe AIP can be a real silver bullet for defending home coasts. They are brilliant for smaller nations with lots of neighbours and lots of coastal interests, e.g. Sweden. They can send their subs to go splash around for a bit longer - and a bit quieter - then they would without AIP.

[Smaragdadler]

taken from my link above:

...the conventional diesel-electric plant of the U 212 class described above is rated at over 3,000 horsepower, and a typical nuclear submarine propulsion plant produces over 20,000. Since the power required to propel a submerged body varies with the cube of its velocity, it should be apparent that at least for the near future, AIP will be valuable primarily as a low-speed, long-endurance adjunct to the under- water performance of conventional submarines. There is little short-term prospect for AIP to become a primary, full-performance alternative to either diesel or nuclear power. Even the phrase "closed cycle" is something of a misnomer, because except for fuel cells, all AIP alternatives require ejecting exhaust gases overboard, which limits both depth capability and stealth.

However, this is not to minimize the dangerous potential for AIP submarines to complicate seriously both coastal defense and assured access to littoral regions. If their distinctive characteristics are exploited by skillful operators, AIP submarines can be used to telling effect for both short- and medium-range missions. AIP dramatically expands the tactical "trade-space" for diesel-electric submarines. If conditions permit, they can transit rapidly on the surface with-out unduly expending the wherewithal for superior underwater performance. Submerged, they can opt for a long, slow, silent patrol that keeps their batteries fully charged and thus capable of powering speed bursts of significant duration. And by carefully husbanding their resources, they can revert again to slow-speed operation and repeat the cycle several times over weeks of submergence. Moreover, AIP technology is evolving rapidly, and some experts predict, for example, that the power output of a typical fuel cell module could well double or triple in the next several years, allowing an even more advantageous trade-off between underwater speed and endurance.

Their tactical flexibility, their small size, their inherent stealth - and the novel operational paradigms AIP submarines introduce to undersea warfare - will make these new boats a dangerous threat to submariners accustomed to nuclear- or conventionally diesel-powered adversaries. The Submarine Force needs to understand this threat - where it's been, where it's going, what it means, and how to counter it.

[JSLTIGER]

Originally Posted by ASWnut101

plus, it has to refuel very often, meaning it can't do littorial work for very long. Virginia can stay there for ~15 years, food supplies limiting it only.

Actually, Virginia was designed to go without nuclear refueling for the duration of the 33 year career planned for her, so if one eliminates the necessity of food, she could theoretically stay on station for that duration.

[DanCanovas]

in my opinion the Type 212 is the quietest submarine in the world! if I remember rightly it submerged North of Germany and surfaced nearly 3 weeks later near Gibraltar! Awesome stuff and very very quiet! ive had the submarine as my signature for some time