A brief note on Japanese Cruisers

Werner · Post by **Werner** » Sat Jun 30, 2007 1:23 am

When looking at these ships, one has to remember, the engineering plant extends from before the bridge structure to the "Y" turret foundation, and from the middle deck (British upper deck) to the keel. One of the reason certain heavy cruisers appear to have excessive superstructures is woven into them are immense uptake and downtake spaces to supply air and remove exhaust for the boiler rooms forward and beneath the navigation spaces. In this sense, although they are cumbrous, they really don't weigh much.

The US and some other cruisers were able to have very much smaller engine spaces because the boilers produced a hotter, higher pressure steam, and therefore could fit in the space of four of the twelve boilers in other ships.

The last generation of US ships had so improved this relationship that each motor had it's own boiler in the same space -- called the unit principle -- making it much harder to hurt.

Atago for example is vulnerable to hits from the chain locker to the steering engine. There is simply no length or width between these spaces not given over to boiler, magazine, turbine or auxiliary machinery.

This doesn't count the dangers of oxygen fueled torpedoes or light skinned turrets. They are simply cruisers of a different description all together.

Guest · Post by **Guest** » Sat Jun 30, 2007 9:05 am

Interesting comment on dangers of oxygen fueled torpedoes, Laicoux and Wells note that these torpedo caused a lot of damage to there own side when there ships were hit. I lot more I thing that was generally recognized at the time .
I haven�t seen anything on the damaged that these torpedoes cause to there own destroyers when they where hit but I suspect that they may have caused quite a lot of self inflicted damage. a bit of a two edge sword ! in the later part of the war when the IJN passed to receiving end of the deal

graham murdoch

graham · Post by **graham** » Sat Jun 30, 2007 9:09 am

Must Login log

in login

Werner · Post by **Werner** » Sat Jun 30, 2007 1:32 pm

Would have to look to those few engagements where the Americans fired while the Japanese torpedoes will still in their tube. The Battle of the Bismarck Sea might have some incidents.

Guest · Post by **Guest** » Sat Jun 30, 2007 3:41 pm

Takao survived 2 torpedo hits and limped home on her own power. Name any US cruiser that benefited sufficiently from the supposedly significant effects of the better layout to duplicate this feat.

Dick J · Post by **Dick J** » Sat Jun 30, 2007 3:58 pm

Anonymous wrote:Takao survived 2 torpedo hits and limped home on her own power. Name any US cruiser that benefited sufficiently from the supposedly significant effects of the better layout to duplicate this feat.

Minneapolis survived 2 long-lances, limped home, AND returned to service. Takao made it to Singapore, but couldn't get home for repairs.

chuck · Post by **chuck** » Sat Jun 30, 2007 4:37 pm

Dick J wrote:
Anonymous wrote:Takao survived 2 torpedo hits and limped home on her own power. Name any US cruiser that benefited sufficiently from the supposedly significant effects of the better layout to duplicate this feat.
Minneapolis survived 2 long-lances, limped home, AND returned to service. Takao made it to Singapore, but couldn't get home for repairs.

Ahhh, but she was listed as operational while in Singapore, and formed part of "Southern expeditionary force" with other stranded Japanese cruisers.

Werner · Post by **Werner** » Sat Jun 30, 2007 5:07 pm

chuck wrote: Ahhh, but she was listed as operational while in Singapore, and formed part of "Southern expeditionary force" with other stranded Japanese cruisers.

She was as "operational" as Centurion off the Mulberry during the D-Day ops.

Two US CAs had their entire bows blown off; one to A turret and the other to B turret; both returned to Pearl Harbor from the Solomons under their own power after some local jury rigging.

I think there are 7 cases of US cruisers torpedoed by the Japanese. Only one sank after a single hit (a four-piper at Pearl).

Believe it or not, surviving two hits was not a design criteria for US cruisers. If possible, it was incorporated into the design, but about half the cruisers were considered likely to lose their entire engineering plant after a single, well placed hit (at the junction between the forward engine room and the after boiler room. That's why the main diesel generators were on the 1st Platform Deck for and aft of the machinery spaces.

The CL Houston took two hits, one which nearly tore her in half because she was in a tight turn and it went exactly to the keel and exploded, and another in the stern that tore most of it off. You can see the pictures at Navsource. She sagged so visibly that the bow and stern were pulled together by running anchor chain from the fore bitts to the stern and tightening them.

Laurence Batchelor · Post by **Laurence Batchelor** » Sat Jun 30, 2007 5:14 pm

Wasn't Takao also sitting partially on a sank bank in Singapore harbour?

I remember reading something along those lines when I read the Captains report of his X-craft attack on her.

This suggesting she was about as operational as Werner suggests?

Werner · Post by **Werner** » Sat Jun 30, 2007 5:16 pm

Her stern (including rudders and propellors) was blown off. Can't be very active after that.

Laurence Batchelor · Post by **Laurence Batchelor** » Sat Jun 30, 2007 6:10 pm

I meant she was sitting on the sand bank before the X-craft attack.

I remember reading the Captain had trouble getting underneath her due to her sitting on it.

The X-craft attack then just compounded the issue still further.

Filipe Ramires · Post by **Filipe Ramires** » Sat Jun 30, 2007 6:14 pm

Werner wrote:Her stern (including rudders and propellors) was blown off. Can't be very active after that.

Myoko suffered the same kind of damage and was also at Singapore by the time. The last good known photos of her show the cruiser in a failry good level of shape, though you can't see the stern which wasn't there anymore. In other words they were mere floating batteries.

Werner · Post by **Werner** » Sat Jun 30, 2007 7:36 pm

As the Kriegsmarine would tell you, the main guns, even the anti-aircraft battery, of an immobile, partially flooded ship are useless against an enemy with complete air superiority.

The Japanese did not discard these ships simply because there was too little time.

These ships as well as Aoba were worthless as fighting ships or anything else but razor blades. Even Tone had tiny value when she anchored near Hiroshima. Once found by TF38 she was completely wrecked and flooded.

After the war the British determined the two cruisers had no ammuntion aboard.

Guest · Post by **Guest** » Sat Jun 30, 2007 9:24 pm

Werner wrote:
Believe it or not, surviving two hits was not a design criteria for US cruisers.

Sorriest excuse I've ever heard.

Guest · Post by **Guest** » Sat Jun 30, 2007 9:27 pm

Werner wrote:Her stern (including rudders and propellors) was blown off. Can't be very active after that.

Not Takao. You are thinking of Myoko, whose stern was blown off by British destroyers. Takao was structurally intact. 2 of her 4 shafts were not operational as result of torpedo hits sustained during Leyte gulf, but the ship was still capable of navigation. It would have been a miracle if she had made home on her own power if she had neither propellers and rudders, don't you think?

While in Singapore the British limpet mines hole another boiler room, but she was still capable of navigation.

Werner · Post by **Werner** » Sat Jun 30, 2007 9:57 pm

Chuck wrote:
Werner wrote:Her stern (including rudders and propellors) was blown off. Can't be very active after that.
Not Takao. You are thinking of Myoko, whose stern was blown off by British destroyers. Takao was structurally intact. 2 of her 4 shafts were not operational as result of torpedo hits sustained during Leyte gulf, but the ship was still capable of navigation. It would have been a miracle if she had made home on her own power if she had neither propellers and rudders, don't you think?

While in Singapore the British limpet mines hole another boiler room, but she was still capable of navigation.

You're right. She was the one (of the two) that had part of her stern, although she was immobile.

To quote LaCroix, P. 346, "Takao was hit at 0634 (23 October 1944) by two out of four torpedoes fired from 1,400 m by the stern tubes of Darter, which had swung hard left after firing the bow tubes at Atago. Of the two 53-cm torpedoes that struck to starboard, one hit in the vicinity of frame 180 flooding No. 4, No. 6 and No. 8 boiler rooms. The other hit near frame 335, destroying the rudder and both starboard engines by reducing their rotation abruptly." As far as I can tell, she reached Brunei only because of tow or tug actions by Asashimo and Hiyodori.

Takao is marked as "heavily damaged" before a B-29 raid of over 100 aircraft. After the raid she was listed as "impossible to tow to home waters" and attached directly to First South Expeditionary Fleet on 5 February. She made no further movements from Singapore after this date.

chuck · Post by **chuck** » Sat Jun 30, 2007 10:19 pm

The impossibility of towing Takao home was due more to the limited resources available, the military situation likely to be encountered en route, and the general inability of Japan to either provide the material for her repair or to man and operate her should she be repaired, then to the extent of damage. In normal situations, much worse damaged ships have been towed and repaired.

In Situ repair was done in Singapore so she could sail at 10 knots, but nothing could be done to repair the damaged engines or boilers. Right around the same time that Takao was stuck in Singapore, all remaining major Japanese naval vessels except for units of 2nd fleet were effectively decommissioned to conserve fuel and free their crew for other work ashore. This policy has more to do with Takao's stationary status than her seaworthiness.

Werner · Post by **Werner** » Sat Jun 30, 2007 10:21 pm

Well, a ship with 1/4 of her boilers wrecked and her rudders not working can hardly be rated an effective combat unit.

As I said, the British found no ammunition aboard, so she could not have served as a shore battery or even as an AAA unit.

Guest · Post by **Guest** » Sun Jul 01, 2007 11:12 am

More valid criticisms of Japanese cruisers includes:

1. Awkward layout of main armament

2. Relatively modest secondary armament

3. Awkward layout of secondary armament directors

4. Excessive midship length devoted to float planes and prevented from being used for close range AA

5. The long horizontal trunking of funnels have potential for making the bridge untenable if a shell were to tear it open

6. Poor living conditions

7. Lack of main turret armor

It is interesting the Japanese never developed a triple 8" turret for their heavy cruisers. It would have vastly improved the layout possibilities.

-Chuck

The Ship Model Forum

A brief note on Japanese Cruisers

A brief note on Japanese Cruisers

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