Japan badly damaged at Pearl Harbor

[Derek Jackson]

Now there were strands of intelligence that MIGHT have let the US leadership know of Japanese plans.

Suppose the possibility was taken seriously. Suppose further there was a sensible plan (being able to seal watertight doors on ships, and being able to get the aircraft in the air quickly. Suppose the radar detection was then acted on and that Japan's declaration of War came, as intended, minutes before rather than after.

The attack on Pearl could have resulted in lots of Japanese planes being damaged.

I know it is pushing luck but maybe the Japanese force would have been located.

Now, if the Japanse forces were damaged by air attack it might be that the US Battleships would have reached range

Might all this mean that Aircraft carriers are not seen as the key capital ships???

 

[NHBL]

Not a battleship day

Based on your proposed POD, I'd say there's no way the American battle line could have got into range. The ships are too slow. If the Japanese had some carriers damaged, and couldn't conduct flight opperations, I think they'd abandon any carriers that couldn't keep up. They'd know they were located, and couldn't stand up to battleships.

Results, IMVHO, from your scenario might be, at worst, one or two carriers lost to air attack, or a sub that gets lucky with both getting a shot, and having a torpedo explode--but the loss of trained aircrews would have been BAD.

 

[Astrodragon]

Main options if the US had been alert is the fleet sorties.

It wont catch the japanese carriers - the old BB's are far too slow - so either they simply wander around for a while, or the Japanese locate them and sink them with no hope of recovery.

The Japanese will lose more planes if PH is alerted, but they'd planned for that, so I dont see it would have affected much.

 

[Bearcat]

The Japanese can't lose outright without ASB. Their pilots are just too good, and the USN is just too unprepared.

But, the Japanese can lose a lot more planes, instead of losing them months later at Midway. So the Chain Reaction of Aviator Doom starts a little sooner. The Japanese desperately keep their remaining pilots in combat. They get flamed. there are no replacements.

Operationally, no Darwin, no Trincomalee. Wake can't be attacked by Hiryu and Soryu and may not fall (depends if the Americans respond in time). Midway is still possible as Yamamoto will believe he must roll the dice with everything he has before the USN launches the Essex's. Paradoxically, the lack of Victory disease means the IJN search plan is better thought out and the battle is less one-sided, but falling pilot quality means the US still gets a win, or a draw, which is almost as good.

Now things turn to Guadalcanal. The Japanese Army begins to bleed too.

All in all, the timeframe of things doesn't change that much - the US can't start advancing in force until it has the ships and trained men it needs. But a lot of interesting changes in detail.

 

[Hyperion]

I have to agree that the battleships aren't going to get a chance to use their heavy guns.

Best thing you can hope for is to double or triple the number of enemy planes shot down and damaged.

The big thing that might help however might be having some of the handfull of cruisers and destroyers and support ships that where damaged coming away in better condition.

Best thing I can think of is maybe the Nevada has a chance to get out of dodge, unless of course they catch her in the channel and sink her outright. That and maybe Pennsylvania gets ignored completely as she was off from the others a bit, setting in drydock at the time.

 

[Geekhis Khan]

Well, assuming some notice, say a seaplane or sub spots the fleet, then the fleet's still stuck in port, but the alarm is sounded, aircraft can be scrambled, and antiaircraft guns can be manned on the ground and on the ships. While the Japanese will still outclass the Yanks in pilots and planes, there's a lot of rugged and hard-hitting P-40s capable of doing some damage, particularly to the slow-moving torpedo bombers. Plus a screen of AAA fire.

The IJN will still have strategic surprise, but not tactical. They'll win, destroy many US planes and down a few ships, but they'll take some serious losses in the process, losing irreplacable pilots.


With a lot of notice (Intel coup?) the US fleet scrambles, carriers included, but leads with the BBs. The US fleet is probably devastated, and out at sea where lost ships can't be raised or salvaged. The US carriers may score some points, perhaps the IJN loses a carrier or two, many ships will likely be damaged, but in the end this may prove worse thanPH OTL as the US may lose its flattops earlier and won't get to salvage any ships.

Perhaps Japan takes Midway?

 

[Grimm Reaper]

Japan anticipated losses of up to 50% historically and one reason Nagumo didn't launch his third strike against the oil farms and other key installations was that he had achieved most of his mission with losses vastly less than expected and didn't believe the remainder of the mission would be worth the risk.

He had also realized that one or more American carriers were not only at sea but somewhere in the vicinity...

If he's already taken heavy losses he might feel a greater need to achieve every last item on the agenda.

 

[David S Poepoe]

From Avalanche Press

Avalanche Press in July had an article about a much more prepared US defense on December 7th 1941. The article is related to their game Second World War at Sea: Midway.

Enjoy.

http://www.avalanchepress.com/Midway_PH.php

 

[xchen08]

Is there any reason to believe that the Japanese would be able to actually inflict any major damage against a fully roused fleet? It shouldn't matter that the Japanese had better pilots and planes when the USAAF will greatly outnumber the escorting Zeros. No way the escorts would be able to keep the all the Americans off the bombers.

 

[jotheberlock]

I have to agree that the battleships aren't going to get a chance to use their heavy guns.

Best thing you can hope for is to double or triple the number of enemy planes shot down and damaged.

The big thing that might help however might be having some of the handfull of cruisers and destroyers and support ships that where damaged coming away in better condition.

Best thing I can think of is maybe the Nevada has a chance to get out of dodge, unless of course they catch her in the channel and sink her outright. That and maybe Pennsylvania gets ignored completely as she was off from the others a bit, setting in drydock at the time.

On the other hand, if the fleet does get out to sea and is hit by the Japanese anyway, it might actually be worse off, since historically many of the sunk ships were in shallow water and could be repaired whereas now they'll be gone for good.

 

[Dathi THorfinnsson]

Is there any reason to believe that the Japanese would be able to actually inflict any major damage against a fully roused fleet? It shouldn't matter that the Japanese had better pilots and planes when the USAAF will greatly outnumber the escorting Zeros. No way the escorts would be able to keep the all the Americans off the bombers.

It does seem that the US had more planes available, certainly than either individual wave of Japanese planes. OTOH, what was the composition of those planes. A P40 would be of some use, especially against the bombers, but there were P36s, and maybe Buffalos. Since the US hadn't learned that they couldn't dogfight against Zeros, mightn't they just be hacked out of the sky (Great Marianas Turkeyshoot in reverse?)

 

[xchen08]

It does seem that the US had more planes available, certainly than either individual wave of Japanese planes. OTOH, what was the composition of those planes. A P40 would be of some use, especially against the bombers, but there were P36s, and maybe Buffalos. Since the US hadn't learned that they couldn't dogfight against Zeros, mightn't they just be hacked out of the sky (Great Marianas Turkeyshoot in reverse?)

There were 45 Japanese fighters in the first wave, compared to about 100 American P-40, and half that number of older fighters. If they are all scrambled, wave one is going to get chopped up real bad before it reaches the AA line. The Turkey Shoot had a large American numerical superiority to go with the superior technology and training. I don't know how well even the best pilots in the best aircraft can handle being mobbed 2 or 3 to 1.

 

[Derek Jackson]

And of course the Japanese would be fairly near the limit of their range whereas the US planes above their own base.

 

[Bearcat]

The zeroes will give as good as they take. But the Vals and the Kates...

Even a couple dozen fighters getting to those bombers - inevitable with the American advantage in numbers - will be catastrophic.

At a guess, I'd say wave one loses 12 fighters and 40 bombers to P-40s before it reaches the AAA. Then it loses another 20-30 planes, with a total of over 100 of the remainder damaged to some degree. Many of those will be write-offs on landing on their carriers.

The Kates with torpedoes of course, take disproportionately high casualties - no maneuverability.

Wave two may have it even worse, as Pearl is now an aroused, enraged hornets' nest.

The US still loses some battleships. But when the IJN totes up the cost, they will wish they had never listened to Yamamoto.

 

[Markus]

On the other hand, if the fleet does get out to sea and is hit by the Japanese anyway, it might actually be worse off, since historically many of the sunk ships were in shallow water and could be repaired whereas now they'll be gone for good.

I don´t think so. Force Z was two capital ships with weak AA and four DD with lousy AA. The Fleet at PH were 8 BB with 5´/25 AA guns, six modern cruisers with the same guns, 25+ modern DD with 5`DP guns and they did have vastly better fire control systems. And last but not least, the Japanese scored relatively few hits on PoW and Repulse, so the US fleet might be safer at sea than in port.

And I concur with the statement that US fighters were sufficient and quality and numbers to inflict significant losses on the first wave.

 

[sloreck]

Also need to factor in that damage to airfields will be much less, and US planes will get a chance to land & re-arm. In reality, most of the battleships that were salvaged were not back in service until 1943 or later and ended up being used for gunfire support. If sunk in deep water, it hurts but does not really change the balance of power as the war goes on. If some of the fleet exits PH and turns away (south) to regroup for a later riposte, they will be perfectly safe as the strike force did not have the fuel to go looking for them even if only 10-15 miles away.

Here's a thought - if the PH commanders (Kimmel & Short) do respond to intel/recon/radar promptly and effectively and MacArthur still screws up the PI response, what happens to Mac - he is alone out there in clownland.

 

[Bearcat]

I don´t think so. Force Z was two capital ships with weak AA and four DD with lousy AA. The Fleet at PH were 8 BB with 5´/25 AA guns, six modern cruisers with the same guns, 25+ modern DD with 5`DP guns and they did have vastly better fire control systems. And last but not least, the Japanese scored relatively few hits on PoW and Repulse, so the US fleet might be safer at sea than in port.

And I concur with the statement that US fighters were sufficient and quality and numbers to inflict significant losses on the first wave.

Remember though, the Betty pilots of Force Z weren't Kido Butai. In pre-war training, the Kate and Val pilots were hitting around 70% of moving targets. A fair number would get shot down, but without the VT fuse, it won't be enough. In port, American fighters could swarm them and cut losses down. But at sea... most P-40 pilots weren't trained for over water flights and air cover over the battle line would be far less imposing.

 

[Bearcat]

If Kimmel hunkered down at Pearl, and had support from the P-40s, the US takes a bitter toll of IJN pilots and air crew. Say slightly upwards of 100 aircraft KIA total for both raids. Another 100 or so damaged enough to be out of action for some time or even pushed over the side. Another 50-100 with lesser damage.

Nagumo knows there are still carriers nearby - he thinks maybe 3. He has equivalent to two healthy air groups left, and a third battered. He is by nature cautious.

Nagumo is hauling ass for home, and tells Yamamoto to politely go screw himself if he is asked to hit Wake.

The Wake plan is delayed because of the change. Saratoga and tangier get through and the island is resupplied. The new fighters, aided by the Sara's Wildcats, give a nasty surprise to the Nells coming up from the Marshalls. The IJN abandons the Wake plan for now...

The IJN carriers are out of action for much of the next three months as the air groups are rebuilt. Quality declines significantly as replacements are poured in.

Once the Carriers are ready, they look for a fight with the US. The Indian Ocean excursion is stillborn. Coral Sea is a Japanese victory but again costly in aircraft.

Either a new Wake or Midway looms on the horizon. The US is reading the IJN JN-25 and will be waiting...

 

[Astrodragon]

One point on the wonderful efficiency of the USAAF in shooting down Japanese planes...

The USAAF record in SE Asia after declaration of war was less than stunning. It isnt surprising, you just dont move from being at peace to being at war when you're the defender. I suspect that while Japanese air losses would be higher (around what they actually expected), it wouldnt stop them doing what they did.

But it wouldnt be the efficient hornets nest supposed by some replies.

 

[xchen08]

One point on the wonderful efficiency of the USAAF in shooting down Japanese planes...

The USAAF record in SE Asia after declaration of war was less than stunning. It isnt surprising, you just dont move from being at peace to being at war when you're the defender. I suspect that while Japanese air losses would be higher (around what they actually expected), it wouldnt stop them doing what they did.

But it wouldnt be the efficient hornets nest supposed by some replies.

Yet the handful of American fighters that did manage to take off at Pearl Harbor were able to inflict impressive damage for their numbers. There's no need to assume some highly efficient response, but simply having 150 fighters in the air is going to seriously mess up the Japanese attack groups, especially the torpedo bombers, which I'd expect to suffer near total losses as they fly slow and steady in their attack runs.