IJN Light cruiser availability chart

[ChuckBerger]

And here are the light cruisers... following Warspite's suggestion, I've added some text indicating the fate of each ship. I'll retrofit the CA chart as well.

[SierraJuliet]

Great work again.

[SierraJuliet]

Double post.

[ChuckBerger]

In putting these charts together, I've had to make a few line calls. I haven't included brief periods of refit, ie less than ten days or so, and I haven't marked minor damage events. Generally that means damage that didn't require yard time, but there are a few exceptions.

I haven't included ships that were never commenced, as many of Japan's naval building programs were pie-in-the-sky.

I wavered on whether to include the Katori class on this chart - they were officially training cruisers and not really in the same category as full-speed and full-armament fleet cruisers, but the IJN used them in some front line roles, so in they went.

I didn't include the ex-Chinese light cruisers, as they really were more akin to escort vessels once raised and refitted, although the IJN classified them as second-class cruisers.

A few other curiosities...
1) Kitakami must get the award for the most oddly repurposed vessel of WW2. She went from torpedo cruiser to transport cruiser to kaiten carrier, a strange career indeed. And never got to use any of those toys...
2) Isuzu's refit as a CLAA is strange - anybody know why only Isuzu was refitted in this way? Most other CL refits focused on improving anti-sub capability with some AA upgrades.
3) In reading through the TROMs, it struck me just how much Japan relied on combat ships as naval transports throughout the war. These CLs were constantly ferrying troops and supplies all over the place.

[wdolson]

They would have been better off rebuilding the Oi and Kitikami as regular CLs when the torpedo cruiser thing was a failure. I think the Isuzu was the only older CL left when it went through the conversion. If Japan had more left, I suspect more would have been converted.

The US rebuilt a bunch of older DDs as fast transports and they filled the role the Japanese used regular DDs and CLs for. The Japanese also were forced to do a number of shoestring operations the US didn't have to do.

Bill

[Dragoastro]

I like this, especially the fate part. Thank you for sharing this.

[Leandros]

As this thread is discussing Japanese cruisers there is a point that has bothered me for some time: Captain Hara, in his book "Japanese Destroyer Captain", on a
couple of occasions mentions homing torpedoes as if his ship, the cruiser Yahagi, carried such on its last sortie, that of escorting Yamato. He also referred to
training with homing torpedoes. While I know the IJN experimented with own and German designs of homing torpedoes nowhere do I find any information that such
should have been used in practice. IJN officers interviewed after the war also do not mention such use.

OTH, the post-war US Controls of the Japanese torpedo facilities were somewhat lacking, not all sites were investigated. Anybody have any information on this?
Homing torpedoes used on Japanese cruisers in the last part of the war?

Fred

[oaltinyay]

I know that Mogamis were the "missing link" for modern CLs of IJN but I always wonder why not modernize those old ones to sth like Isuzu CLAA ? Put in a bunch of 3.9DPs or 12.7cm AA guns and add dozens of that 25MM mounts and there u go...I looked at the floor plans for the ships so I can say there was room there for magazines as well.

Maybe the Fire Control component ? IJN never had anything that approached Mk37 remotely, I remember reading Akagi gunners reacted fast but their computing sites did not during the last attack.

Any ideas ?

[Bullwinkle58]

Oh that subs in the game worked this well.

[dr.hal]

Interesting that only two were sunk prior to 1943 and only at the very end of '42. I suspect that many of our games see much more damage to IJN ships than is portrayed by the chart Chuck has created. It would appear that our games are far more "destructive" than what actually happened. Could this be because our sailors are electronic? Could it be reckless abandon by our players?

[jwolf]

Dr. Hal: I think it is because Japanese players typically push far more aggressively in 1942 than their historical counterparts did. For example, deep offensives in the CenPac, Australia, and/or India, pushing into areas with more Allied strength, such as it is.

Chuck: these charts are super! Any more you do would be very interesting to see, thanks very much!

[dr.hal]

Yes jwolf, I think you are right. Certainly to get troops into Oz and other places where the Japanese never went during the real war calls for MUCH more aggressive action and risk taking than was actually undertaken (although I'm sure the Japanese high command felt they were taking more than enough risk in the actual conduct of operations).

[Bullwinkle58]

ORIGINAL: dr.hal

Interesting that only two were sunk prior to 1943 and only at the very end of '42. I suspect that many of our games see much more damage to IJN ships than is portrayed by the chart Chuck has created. It would appear that our games are far more "destructive" than what actually happened. Could this be because our sailors are electronic? Could it be reckless abandon by our players?

We do. I think the USN lost a total of 70 DDs? (?check) A couple or five CVEs? Compare to most PBEMs. OTOH over 50 subs, which you don't typically see in a game after the Super-E was taken down a bit.

The USN sub war is crippled in game by the DL model, plus the EXE's direction to attack escorts first about half the time. Shooting at a PB when there were six xAKs in the convoy would get a CO relieved. It happens over and over in the game. It's not exposed in the editor either. Combined with the dud rate subs are a small fraction of their historical selves.

But few JFBs would paly past 1942 if the subs were true.

[mind_messing]

ORIGINAL: Bullwinkle58

ORIGINAL: dr.hal

Interesting that only two were sunk prior to 1943 and only at the very end of '42. I suspect that many of our games see much more damage to IJN ships than is portrayed by the chart Chuck has created. It would appear that our games are far more "destructive" than what actually happened. Could this be because our sailors are electronic? Could it be reckless abandon by our players?

We do. I think the USN lost a total of 70 DDs? (?check) A couple or five CVEs? Compare to most PBEMs. OTOH over 50 subs, which you don't typically see in a game after the Super-E was taken down a bit.

The USN sub war is crippled in game by the DL model, plus the EXE's direction to attack escorts first about half the time. Shooting at a PB when there were six xAKs in the convoy would get a CO relieved. It happens over and over in the game. It's not exposed in the editor either. Combined with the dud rate subs are a small fraction of their historical selves.

But few JFBs would paly past 1942 if the subs were true.

What you need to remember is that most JFB's aren't going to neglect ASW to the extent to which the Japanese historically did, and generally be geared towards countering the Allied submarine fleet through an aggressive offensive ASW campaign.

However, I will be the first to agree with you that the game doesn't really get sub combat quite right. Being restricted to a single target per attack, and then choosing to target the escort ships can be quite frustrating.

[Mundy]

Does leader aggressiveness impact this at all?  I'm trying to find a sweet spot with this to no avail.  It seems even sub captains with middling values still do this.

[Bullwinkle58]

ORIGINAL: mind_messing

What you need to remember is that most JFB's aren't going to neglect ASW to the extent to which the Japanese historically did, and generally be geared towards countering the Allied submarine fleet through an aggressive offensive ASW campaign.

However, I will be the first to agree with you that the game doesn't really get sub combat quite right. Being restricted to a single target per attack, and then choosing to target the escort ships can be quite frustrating.

It's the standard answer that it's all about not neglecting ASW. The IJN didn't neglect ASW; they just weren't very good at it. They did have substantial air ASW assets devoted to the task. But in RL subs had air search radar, dove long before detection, and were rarely found. In the game a DL lasts a day. In RL the datum is garbage in thirty minutes. In my game Loka has hard DLs on about ten subs every day, out to 250 miles from the search point. Ridiculous.

In the game there's no attack on multiple ships in one approach. In RL, standard.

In RL, widespread naval code reading. In the game most SigInt is about LCUs.

In the game, even in deep water, maybe half of ASW attacks after the -2 DC is fielded result in go-home levels of damage to the sub. Very rarely do I have a sub attack, hit something, be prosecuted, and stay on station. Maybe 25% of the time. In RL, not even close. Shipborne ASW in the game is driven by device slots and some by training and CO. There's no sensor factor, which was huge. IJN sonar was terrible.

I'd live with it all if the EXE could just be tweaked to radically reduce the targeting of small escorts. Combined with duds it makes the sub an unfeared weapon against the merchant marine.

[warspite1]

ORIGINAL: mind_messing

ORIGINAL: Bullwinkle58

ORIGINAL: dr.hal

Interesting that only two were sunk prior to 1943 and only at the very end of '42. I suspect that many of our games see much more damage to IJN ships than is portrayed by the chart Chuck has created. It would appear that our games are far more "destructive" than what actually happened. Could this be because our sailors are electronic? Could it be reckless abandon by our players?

We do. I think the USN lost a total of 70 DDs? (?check) A couple or five CVEs? Compare to most PBEMs. OTOH over 50 subs, which you don't typically see in a game after the Super-E was taken down a bit.

The USN sub war is crippled in game by the DL model, plus the EXE's direction to attack escorts first about half the time. Shooting at a PB when there were six xAKs in the convoy would get a CO relieved. It happens over and over in the game. It's not exposed in the editor either. Combined with the dud rate subs are a small fraction of their historical selves.

But few JFBs would paly past 1942 if the subs were true.

What you need to remember is that most JFB's aren't going to neglect ASW to the extent to which the Japanese historically did, and generally be geared towards countering the Allied submarine fleet through an aggressive offensive ASW campaign.

warspite1

I completely agree mind_messing. The Japanese - by any measure and by any definition - neglected ASW. They were hardly alone in this - the British and Americans gave ASW a much lower priority than was sensible too (and this was doubly expensive in the case of the British who of course were immeasurably more reliant upon the sea than the US who needed it more to support futures allies!).

But whereas Allied deficiencies could be made good as a) the lack of attention to, and focus on, this type of warfare did not linger for very long, b) the British started from a better position as their ASW equipment was generally better than the Japanese and c) there was the industrial capability to build more ships, more aircraft, better systems and defences, for the Japanese their pre-war neglect could not be made good.

[rustysi]

2) Isuzu's refit as a CLAA is strange - anybody know why only Isuzu was refitted in this way? Most other CL refits focused on improving anti-sub capability with some AA upgrades.

Just an FYI there are two other (that I know of) Japanese CL's that may do a CLAA conversion. These are the Tatsuta and Tenryu. Their conversions will only be available after an early war upgrade is completed.