Japan Military News, Reports, Data, etc.

FairAndUnbiased

Brigadier
Registered Member
Agreed. If thermal runaway begins, nothing is going to stop it short of dumping the entire thing into a tank of water. And at that point, you've just lost your entire battery pack anyways. One way around this is to use a large number of smaller battery packs distributed throughout the submarine, with automated systems for jettisoning them into a water tank. When the thermocouple reads beyond the threshold, the system can go ahead and do its thing. You'd lose some of your total capacity but preserve the rest.
Then they either have to be outside the pressure hull, necessitating water tight high pressure hull feedthroughs, or have a door mechanism for ejection, which also requires a hull feedthrough. Hull feedthroughs are structural weak spots and difficult to manage, you try to have as few as possible.
 

CMP

Senior Member
Registered Member
Then they either have to be outside the pressure hull, necessitating water tight high pressure hull feedthroughs, or have a door mechanism for ejection, which also requires a hull feedthrough. Hull feedthroughs are structural weak spots and difficult to manage, you try to have as few as possible.
Nah. I am thinking internal tanks of water.
 

CMP

Senior Member
Registered Member
but that's dead volume. why the complexity? Just use lithium iron phosphate... cost of batteries in a sub is low compared to the cost of the sub specific systems like the pressure hull and sonar.
Yeah I agree. That's why my very first recommendation was lithium iron phosphate. The downside of that chemistry is much lower energy density than the much less stable ones common everywhere. Please refer to my original posts.
 

Virtup

Junior Member
Registered Member
Yeah I agree. That's why my very first recommendation was lithium iron phosphate. The downside of that chemistry is much lower energy density than the much less stable ones common everywhere. Please refer to my original posts.
You wont be losing too much on enrgy density on the pack level since lithium iron phosphate doesn't need as much cooling as other lithium chemistries.
 

Stealthflanker

Senior Member
Registered Member
The question now is how actually the Japan design their Lithium ion battery to be safe and can run the submarine in the first place. There is no real point to argue choice of design without actual knowledge on the design tradeoff in the first place. If the Japanese know what they are doing, they'll include safety features. If they messed up.. we might hear Fire incident soon.

The thing is that there will be no real place for any fancy safety like battery dumping or anything like that in a submarine in the first place.

Just like AIP... let's take example of U-214.. which have INTERNAL LOX Tank.. if the tank ever got punctured or leaked.. how one can expect to deal with Liquid Oxygen fire in a closed enviroment such as Submarine. Or if there is no fire.. the cryogenic LOX may embrittle the internal structure.

It's kind of either you work to make it safe or not building it in the first place.
 

Pmichael

Junior Member
There is something way more important. Japan never developed anything in the AIP department, the AIP of the Souryuu-class was Swedish. So the reality of the domestic industry forces Japan to double dip on batteries
 

Helius

Senior Member
Registered Member
Interview with a female ex-JGSDF member who was inspired to join up after witnessing rescue efforts by the Self-Defense Forces in her home town during Tohoku 2011.

As soon as she finished training, however, she was subjected to daily sexual harassment, abuse and direct assault from her peers and superiors, to the point she nearly committed suicide, only to be interrupted by a call to duty as an earthquake struck.

Reports were brought up, and dismissed on grounds of being "part of the training". Charges were subsequently filed, likewise dropped on grounds of "lack of evidence" as witnesses were "ordered" not to testify.

The JSDF has a high suicide rate due to the extreme hierarchical and conformal structure within the forces.

The mental and physical "toughness" that are expected from service members mean that abuses that would otherwise be illegal are often unreported, outright ignored and tolerated in order to preserve "unit cohesion".

Enable CC for Eng subs -


To follow up, the woman's case is now making national news, and the MoD has opened a new investigation into the matter -

Please, Log in or Register to view URLs content!

That was quick, like everything they were looking for was already there in plain sight -

Please, Log in or Register to view URLs content!

Probe confirms ex-female Japan defense forces member was sexually assaulted​

TOKYO - Japan's Defense Ministry on Thursday apologized to a former female member of the Ground Self-Defense Force after an internal probe confirmed that she had been sexually assaulted by colleagues.

The investigation found that Rina Gonoi, 23, had been subjected to sexual harassment, including sexually explicit comments, on a daily basis, and been the victim of other forms of abuse from fall 2020 through August last year, including being forced to the ground at a dormitory during training.

The ministry said it will identify the perpetrators and promptly take disciplinary action against them.

"I deeply apologize on behalf of the GSDF," Gen. Yoshihide Yoshida, the ground force chief of staff, said at a press conference on Thursday, adding that he decided to make an apology before taking disciplinary action in light of the fact that Gonoi went public with the allegations.

photo_l.jpg
Gen. Yoshihide Yoshida, the Ground Self-Defense Force chief of staff, bows in apology at a press conference in Tokyo on Sept. 29, 2022. (Kyodo)

Some SDF members who had initially denied involvement later admitted to their actions during the probe, according to the ministry, but Yoshida said they had "lacked any sense of guilt."

Defense officials also directly apologized to Gonoi in Tokyo the same day.

"It's come far too late," Gonoi responded in tears. "I hope fundamental changes are made so nothing like this ever happens again."

According to the ministry, the commander of Gonoi's unit received a complaint from her after an incident in August last year, but failed to report it to his superior.

Gonoi had also been told to keep quiet about the incident, but the case was reopened this month after the Koriyama Committee for the Inquest of Prosecution decided to challenge a decision not to prosecute the three suspects on charges of indecent assault.

Gonoi belonged to a unit at Camp Koriyama in Fukushima Prefecture. The probe found that several other female members of the unit had also been sexually harassed.

The Defense Ministry is also conducting a special investigation into various forms of harassment, including abuse of power, covering all SDF units to determine whether appropriate measures are being taken.

The GSDF's Northeastern Army led a probe that began at the end of August last year, and investigators spoke with Gonoi several times while also interviewing around 100 members, according to the ministry.

Very brave of the woman to have brought her case to light indeed, esp. now that it's been "discovered" she wasn't the only victim in her unit, let alone the entire force -
[...] that several other female members of the unit had also been sexually harassed.
 

Helius

Senior Member
Registered Member
Kaga progress. The first deck module for the enlarged bow has been installed -


Curiously, the aft catwalk at the stern has also been removed and replaced with what looks to be a sturdier one that conforms with the CIWS sponsons on either side, though for what reason to go to this extent for a catwalk, is unknown -

Kaga mod 2022-10-10.jpg
DDH-183-JS-Izumo-028.jpg
 
Top