@Skywatcher
That is correct, but since we are on it, even with the advanced snorkeling, and advanced sonar operation at snorkel depth...Samurai, can you give us some idea of why the last two Soryu, and these new Taigie subs appear to have abandoned AIP?
It seems that, at least IMHO, that AIP is less risky, and at least that if necessary, having these new systems compliment it when needed would have been a better course. That is unless they were having problems with their particular AIP implementation.
The explanation I found was this:
Lithium-ion batteries have almost double the electric storage capacity of traditional lead-acid batteries, and by not only replacing them in the existing battery storage areas but adding to the already large battery capacity by also filling the huge space (several hundred tons displacement) inside the hull previously occupied by the AIP Stirling engines and their fuel tanks with these new batteries, the amount of (more powerful) batteries carried overall is massive. This has improved the underwater endurance significantly and is felt will be an advantage over the slow recharge capability of the AIP system. In any event, JMSDF believes that lithium-ion is the way forward and intends to 'trial' this new system and compare it to the previous AIP system for operational effectiveness.
So, in effect it seams like a trial. They must be happy with it thus far to have four subs committed to it...and the slow change rate of the Sterling AIP must have been intolerable to the JMSDF.
But with the massive Lithium-ion storage, I wonder how long the snorkeling re-charge takes when needed. It would be nice to see a comparison of recharge time and underwater endurance for both of the two equipment implementations.[/I][/I]