Pearl Harbor WI

Hyperion

Banned
What if, on the evening following Pearl Harbor, a USN submarine found and torpedoed one of the Japanese carriers, say the Kaga, and sent it to the bottom, with over 3/4 of her crew. How would this effect the Pacific War, specifically the first few months?
 

NapoleonXIV

Banned
Japan had 10 carriers. One would have been a loss but probably not really affected much.

The problem would come in getting it replaced.
 
The US gets a morale boost, and the operation to relieve Wake Is. might go ahead. But Japan will be much more cautious, making further victories a bit more difficult.
 

CalBear

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NapoleonXIV said:
Japan had 10 carriers. One would have been a loss but probably not really affected much.

The problem would come in getting it replaced.

Actually they had 6 full sized decks (Akagi, Hiryu, Kaga, Syokaku, Soryu, & Zuikaku). The rest were light carriers (Ryujo, Ruyho, Zuyho) roughly the same size & capacity as the USS Ranger (14-16,000 tons) & the Hoshu which was the Japanese equivalent of USS Langley (7,600 tons, converted tanker). Several other light carriers were launched or commissioned in early-mid 1942.

Loss of a full sized carrier, and just as importantly, any of her highly trained aircrews, would be a blow to Japan's offensive plans. As stated earlier, it may also have had a serious impact on the IJN's willingness to go into harm's way. At the least it would have radically altered the Midway Battle Plan, since there would have been one less deck available.
 
The sub skipper gets the Medal of Honor.

FDR hails it as the "first great victory on the road back".

And the U.S. doesn't bother with the Doolittle Raid.

Though how an American sub with those pitifull torpedoes they had early in the war manages to sink a Japanese carrier is beyond me.
 
Sinking the carrier...

I can think of a couple of ways that the sub could sink the carrier.
1. It's an older sub, perhaps an S-boat--and her skipper got stuck with a load of Great War torpedoes. Some of them were still around, and tended to explode. I'm not sure if any were on subs, or just a few old destroyers destroyers. Sometimes, the explosion would be less powerful, as the warhead had deteriorated--but perhaps not, also...

2. The sub has a poor angle, but it's the best shot he'll get--and the fish all strike at an oblique angle--much better chance of detonation.

3. Sometimes, although not as often as hoped for, American torpedoes would detonate.

3/4 crew casualties is perhaps unlikely, often, a warship sunk by submarine torpedos lingers a bit. Still, the right hit could start a fire close to the magazines--one oopsie on damage control, and kaboom!
Barham and Royal Oak come to mind as sudden explosions, while Ark Royal, Yorktown, and Audacious are the first slow motion sinkings to come to mind--either way is quite possible. Of course, how many hits plays a role as well...

Dayton Kitchens said:
The sub skipper gets the Medal of Honor.

FDR hails it as the "first great victory on the road back".

And the U.S. doesn't bother with the Doolittle Raid.

Though how an American sub with those pitifull torpedoes they had early in the war manages to sink a Japanese carrier is beyond me.
 

Hyperion

Banned
It would probably help If I'm more specific. Lets say 7 torpedoes are fired. 4 hit. 1 bounces off and does nothing and sinks. 1 fails to explode but rips a 5 by 6 hole in the hull, flooding a couple of compartments. 2 hit and explode.

On the casualties, now that I think about it, maybe loosing half the crew while the other half survives would be more reasonable.
 
Well, if the attack is a complete surprise its possible the Japanese carrier doesn't get its watertight doors closed.

That has happened in the sinkings of a few ships.
 
I just thought of something.

Its possible that things go pretty much the way they did until Midway.

Then, its possible that without the services of one of his best carriers that Admiral Yamamoto doesn't decide to divide his forces prior to Midway with the worthless "Aleutians diversion".
 
One long term effect could be that the japanese take anti-submarine-warfare far more serious
Improbable. IJN DD sailors wanted nothing more than fleet action. (They weren't alone...) And IJN ASW doctrine, training, & practise was absolutely awful.
and use their own subs better.
Extremely improbable. IJN (like USN & RN prewar, too) was in the grip of Mahanian doctrine: subs were fleet scouts, to be used against men of war, not on guerre de course.
Its possible that things go pretty much the way they did until Midway.

Then, its possible that without the services of one of his best carriers that Admiral Yamamoto doesn't decide to divide his forces prior to Midway with the worthless "Aleutians diversion".
I find that doubtful. Yamamoto expected, planned on, losing as many as half his CVs on the op.

And to clarify, it would've had to be a fleet boat, firing Mk 14s & getting a miracle. The Sugar boats were based in Manila, & the Mk 6 was liable to get 4-6 prematures &/or 2-3 duds (of 6 bow tubes fired), per Brockman (Nautilus) at Midway; there'd be no "oblique" contact explosions, since that only applied if magnetic feature was deactivated (or the contact feature activated), which it wouldn't have been 7/12/41, since everybody expected the d*mn thing would work correctly...
 
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Well, if the attack is a complete surprise its possible the Japanese carrier doesn't get its watertight doors closed.

Doubt it. If anything, it would simply validate Japanese strategy of using submarines with the fleet/against the enemy battle fleet, and no perceptible change of strategy will occur. Yes, they may consider submarines more serious, but the most likely result is they just let their own attack a little more often.
 
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