WI Decisive Japanese Victory at Coral Sea?

[EnglishCanuck]

Forgive me f this has been asked before but I've seen so many alternate Midway scenarios that I figure I might as well ask about a different battle. The Japanese scored a tactical victory at Coral Sea, but what if they managed to decisively defeat Task Force 17?

What effect would this have on Japanese operations in 1942? How long could this extend the Pacific War by?

 

[Brother Stormhammer]

A lot is going to depend on what the win costs the Japanese.
How many ships, aircraft, and airmen did they lose? How many ships were damaged, and how badly?

Their production rate for replacements is low (honestly, it's abysmal), so the answers to those questions will shape their future operations to a much greater degree than American losses. Assuming that they don't pay too high a price for their win, the Japanese will definitely have a short-term advantage in the Pacific. In the long term, though, I don't think this POD would prolong the war very much, simply because what the American capacity to make good on lost ships and planes.

I can even think of one scenario where a decisive Japanese win at Coral Sea could shorten the war...the Japanese, determined to draw out the remaining US carriers, goes ahead with the Midway attack, and the weaker USN simply lets them have the place after evacuating everything they could, and destroying everything they can't. The USN submarine force then has a field day picking off supply ships trying to support the Midway garrison. If they lose enough shipping, the Japanese navy's performance will be degraded badly, leading to a shorter war.

 

[Cryhavoc101]

Forgive me f this has been asked before but I've seen so many alternate Midway scenarios that I figure I might as well ask about a different battle. The Japanese scored a tactical victory at Coral Sea, but what if they managed to decisively defeat Task Force 17?

What effect would this have on Japanese operations in 1942? How long could this extend the Pacific War by?

I am assuming a decisive victory = fewer planes lost as they had already beaten the Americans - quite decisively

In OTL the battle became a US Strategic victory after the Japanese invasion force retired

This was due mainly to the amount of fuel IJN ships had used up in the battle as well as the heavy losses in Aircraft and Aircrews

Fewer air losses and greater resrerves of fuel across the fleet allows the landing to go ahead.

After that???

Is Yorktown lost?

 

[nbcman]

Forgive me f this has been asked before but I've seen so many alternate Midway scenarios that I figure I might as well ask about a different battle. The Japanese scored a tactical victory at Coral Sea, but what if they managed to decisively defeat Task Force 17?

What effect would this have on Japanese operations in 1942? How long could this extend the Pacific War by?

See Combined Fleet. A decisive win at Coral Sea would have resulted in the loss of a second carrier which would impact the US's decision whether to fight over Midway. Additionally, it would have led to the probable loss of Port Moresby which would have further extended the Japanese defense perimeter and maybe emboldened them to try for Fiji, New Caledonia or Samoa. But overall, it would not have had made a bit of difference. The Japanese would be further strung out and the USN was going to break even with the number of carrier decks in September 1943 even if they lost Enterprise and Hornet during an ALT Midway. Plus the Manhattan Project is not going to be impacted by a loss in the Coral Sea so Japan would still receive nukes in August 1945. Japan was doomed the minute the bombs started falling at Pearl Harbor.

 

[TFSmith121]

It's worth making the point the

Forgive me f this has been asked before but I've seen so many alternate Midway scenarios that I figure I might as well ask about a different battle. The Japanese scored a tactical victory at Coral Sea, but what if they managed to decisively defeat Task Force 17?

What effect would this have on Japanese operations in 1942? How long could this extend the Pacific War by?

It's worth making the point that historically Lexington's loss was largely due to mistakes made in damage control, at a point in the battle when Shokaku was already out of action and Zuikaku had suffered significant losses to her air group, and Shoho had already been sunk.

So to get a "decisive" victory for the Japanese, one needs a significantly different 7 May, which given the state of carrier operations and strike tactics in both navies at that point, is asking rather a lot.

The question of the Japanese invasion force is almost an entirely separate issue; even absent the naval forces, the chances of a Japanese assault on Port Moresby are open to some question; this is the same army that was defeated at Milne Bay, Imita Ridge, and on Guadalcanal later the same year in straight up infantry assaults...

Both sides could have escaped with less damage from Coral Sea; given the realities this was the first ever carrier vs carrier action, it's open to question whether either navy necessarily could have inflicted all that much more damage to their opponent, absent the realities of incidents like the Japanese hitting Neosho and Sims and the Americans clobbering Shoho with enough firepower to have sunk Yamato, practically.

First battles are like that, generally.

As far as numbers go, the USN had seven fast fleet carriers in 1942, the British had five, and the Japanese had six ... Even given the distances the Allies had to cover, 2-1 odds (not even counting the smaller, slower ships, including the CVEs that totaled ~20 by the end of 1942) makes the strategic problem for the IJN pretty clear.

Best,

 

[Catspoke]

Its pretty easy to get a moderate Japanese victory where:

Both Lexington and Yorktown are sunk on the USA side:

And the following Japanese losses.
(Shoho is sunk)
with OTL damage and aircraft losses to the other Japanese carriers.

(with just different sighting luck)
Those losses likely means the Japanese have to turn back still do to lack of air support so Port Moresby is safe.

USA will have to rush to get carrier Saratoga back to Pearl.

So likely USA will let Midway garrison defend itself and it probably will be able to repulse an assault since its pretty fortified, when Saratoga is ready USA will launch a counterattack.

----------------------------------------
A decisive Japanese Coral sea victory means the Japanese carriers are intact with a decent amount of remaining places and both USA carries are sunk, Japanese proceed to Port Moresby and are drawn into a nasty fight with land based error and the Australian garrison which could get messy and drawn out which might preclude Midway from happening.

Regardless Japanese might end up in July 42 with more fleet carriers not sunk which probably precludes a Guadacanal counterattack but a New Guinea counter attack is still likely.

 

[mack8]

One of the most clear opportunities for Hara to destroy the US force is on the morning on the 7th (another chance was couple of days earlier when Fletcher was fueling i think, have to recheck again). As known the scout from Shokaku mistakenly signalled "one CV and one cruiser" to the south (Sims and Neosho), prompting Hara to send everything he got. The real sighting of Fletcher came after the strike was launched, about half hour or so (again, have to re-check).

If that scout had his damn eyes opened and sees Neosho for what it is (a lowly tanker), Takagi launches a bit later but against Fletcher, in the perfect setup, attacking the enemy force while the enemy does not know his position. I've played with this scenario in my head many times, the japanese will send 18 Zero, 36 Val and 24 Kate, vs. about 15-17 F4F and 10 SBD available to Fletcher for defence (less than in OTL 8th of May battle, crucially also very unlikely Hara's flyers meet returning US fighters from the strike on Shoho as they were going in different directions, so less japanese losses in the strike, not to mention they have avoided the OTL disastrous dusk attack that cost them 9 attack planes and very experienced flyers)

All things being equal i am guessing at least one, maybe both (if Lexington is still unlucky) american CVs are sunk, but quite likely they have one sunk and one severly damaged. The japanese lose about 25 planes to all causes, with more damaged, their force is still depleted but not nearly as bad as OTL. After repairs next day they could still have available 30 Zeros, over 20 Vals and over 20 Kates (plus some more that will be too damaged to be repaired on the spot, they were not jettisoned as in OTL because none of the CVs were damaged).

Ironically, after this clear victory the best and "safest" scenario (imo anyway) for the japanese is still retreat as in OTL, because if they get into trying a landing, no matter what happens Shokaku and Zuikaku will be exposed to some extent to the US heavy and medium bombers from PM and Australia (but they were relatively few and inaccurate), but much more dangerously, they might be sucked into a fight with Halsey's Enterprise and Hornet coming at maximum speed and at full strength from the South. Given the still depleted state of CarDiv 5s airgroups, this is not a good situation for them.

So best case for them is Hara smashes the US force, the invasion convoy enters the Coral Sea but in the face of increasing air attacks from US bombers (B-17, B-26 and B-25s) which might hit some transports Inoue still loses his head and orders a retreat next day or the 9th (maybe they even bump into Crace).

What happens next, particularly at Midway, well, it's up to one's imagination, either no CV fight (with the invasion having a fair chance to succeed), or 2 vs. 4 (very risky for US), or 2 vs. 5 (worse scenario for US- assuming at least Shokaku or Zuikaku participate) or 3 vs. 4 or 5 (risky to very risky for IJN) if somehow the americans manage to get Saratoga there. Either still an overwhelming US victory, draw, or another japanese victory, take your pick.

 

[mack8]

I can even think of one scenario where a decisive Japanese win at Coral Sea could shorten the war...the Japanese, determined to draw out the remaining US carriers, goes ahead with the Midway attack, and the weaker USN simply lets them have the place after evacuating everything they could, and destroying everything they can't. The USN submarine force then has a field day picking off supply ships trying to support the Midway garrison. If they lose enough shipping, the Japanese navy's performance will be degraded badly, leading to a shorter war.

They will not commit nowhere near enough shipping that if lost it will have a big impact. This is not like say Guadalcanal, the Midway garrison is small and not fighting (at least not until the US tries to retake the atoll sometime in second half of 1942 imo- in the meantime there will be of course steady air raids from Pearl with PBYs and B-24s) so it's supply needs are comparatively small. They will send a convoy every once in a while, they might lose a few ships but given the US submarine's performance at this point of the war, their showing might not be too good. Having a dozen or more US subs around Midway at all times though of course limits by that much the number of US subs available for more profitable attacks against japanese sea lines closer to the mainland.

 

[TFSmith121]

That's a good possibility, but it also speaks to the reality that

One of the most clear opportunities for Hara to destroy the US force is on the morning on the 7th (another chance was couple of days earlier when Fletcher was fueling i think, have to recheck again). As known the scout from Shokaku mistakenly signalled "one CV and one cruiser" to the south (Sims and Neosho), prompting Hara to send everything he got. The real sighting of Fletcher came after the strike was launched, about half hour or so (again, have to re-check).

That's a good possibility, but it also speaks to the reality that both navies were still feeling their way in terms of fast carrier operations; "first battles" are a real phenomenon for every military, even one that is NOT the first time ever, as Coral Sea was...

The realities of warfare is that chance tends to work out (for good or for ill) for all sides; Sims and Neosho are balanced by Shoho getting plastered, and Zuikaku being covered by the weather when Shokaku got hit (IIRC).

Nobody ever catches all the breaks.

Best,

 

[mack8]

That's a good possibility, but it also speaks to the reality that both navies were still feeling their way in terms of fast carrier operations; "first battles" are a real phenomenon for every military, even one that is NOT the first time ever, as Coral Sea was...

The realities of warfare is that chance tends to work out (for good or for ill) for all sides; Sims and Neosho are balanced by Shoho getting plastered, and Zuikaku being covered by the weather when Shokaku got hit (IIRC).

Nobody ever catches all the breaks.

Best,

I remember this argument being made some time ago, and also the counter-argument that chance is just a lottery, there's no "entity" sort of thing to even things out for both sides. The lopsided US victory at Midway shows that imo. The dices of fate could have fallen in so many other ways...

 

[nbcman]

They will not commit nowhere near enough shipping that if lost it will have a big impact. This is not like say Guadalcanal, the Midway garrison is small and not fighting (at least not until the US tries to retake the atoll sometime in second half of 1942 imo- in the meantime there will be of course steady air raids from Pearl with PBYs and B-24s) so it's supply needs are comparatively small. They will send a convoy every once in a while, they might lose a few ships but given the US submarine's performance at this point of the war, their showing might not be too good. Having a dozen or more US subs around Midway at all times though of course limits by that much the number of US subs available for more profitable attacks againt japanese sea lines closer to the mainland.

The US could have used the shorter range S-Class boats to interdict Midway-and those subs used the Mark 10 torpedo which had less faults than the Mark 14 torpedo used in the longer range subs. But even without the USN there to contest the invasion, it would be difficult for the 5000 Japanese to take Midway assuming the US built up the garrison to approximately 3600 defenders including light tanks, guns up to 7" and other defensive preparations as OTL.

 

[TFSmith121]

Midway was not lopsided, in the scheme of things...

I remember this argument being made some time ago, and also the counter-argument that chance is just a lottery, there's no "entity" sort of thing to even things out for both sides. The lopsided US victory at Midway shows that imo. The dices of fate could have fallen in so many other ways...

Except Midway was not lopsided, in the scheme of things...

The USN had excellent intelligence, about the best imaginable, and although one less fast carrier than the IJN, the number of aircraft in action, including those based on Midway, was actually to the US advantage. Odds were more than even, really, including the intelligence advantage, at the strategic level.

At the operational level, the failures of the IJN's air search plan at Midway (sense a pattern?) was balanced in terms of chance by the loss of Hornet's air group...

It's worth noting that when the US went on the offensive in the Central Pacific, the numbers of operational aircraft for GALVANIC and FORAGER etc was always significantly to the US advantage; the USN never tried a major amphibious operation with fewer aircraft than the Japanese had available, which is what the IJN tried at Midway.

Midway was not quite to the "never give a sucker an even break" levels of Philippine Sea or Surigao Strait, but the correlation of forces was certainly to the US advantage.

Best,

 

[mack8]

The US could have used the shorter range S-Class boats to interdict Midway-and those subs used the Mark 10 torpedo which had less faults than the Mark 14 torpedo used in the longer range subs. But even without the USN there to contest the invasion, it would be difficult for the 5000 Japanese to take Midway assuming the US built up the garrison to approximately 3600 defenders including light tanks, guns up to 7" and other defensive preparations as OTL.

There is of course the issue that, as the USN won't fight, is Nimitz still beefing up the garrison, knowing the extent of japanese forces arrayed against it? It might look like sending the men to sure death. Maybe he will evacuate rather than beef it up, or just not reinforcing it to the OTL extent (thinking it will be a needless waste of men and resources).

Midway was not lopsided, in the scheme of things...

As these things go i guess it's a matter of personal perspective, as i see it losing 4 CVs vs. 1 and 3000 men vs 300 is pretty darn lopsided. Even with all the causes of the historical result you listed, could have easily been a more "even" battle if the dice would have fallen differently.

 

[TFSmith121]

My point is the results, although certainly strongly in the

As these things go i guess it's a matter of personal perspective, as i see it losing 4 CVs vs. 1 and 3000 men vs 300 is pretty darn lopsided. Even with all the causes of the historical result you listed, could have easily been a more "even" battle if the dice would have fallen differently.

My point is the results of Midway, although certainly strongly in the favor of the US, were well within the range one would expect, given the initial intelligence advantage and the reality the balance between the Americans and Japanese in terms of the decisive arm, air power, was essentially to the US advantage... in terms of carrier combat in 1942, all it takes is getting four dive bomber squadrons (maybe just three) over the IJN fast carriers at the right time to end the battle in the space of a half-hour; the US carriers had six dive bomber squadrons aboard...

If anything, given the reality the US was reading the Japanese play book beforehand AND had the ships, aircraft, and trained aircrew in theater to take advantage of it, it would have been surprising if the results didn't break in the US favor.

Basically, the codebreakers made the battle; without the intelligence advantage, the US never would have engaged anyway, and the Japanese essentially would have been swinging at the air, and Midway is regarded like Attu or Kiska or Wake.

Best,

 

[Brother Stormhammer]

They will not commit nowhere near enough shipping that if lost it will have a big impact. This is not like say Guadalcanal, the Midway garrison is small and not fighting (at least not until the US tries to retake the atoll sometime in second half of 1942 imo- in the meantime there will be of course steady air raids from Pearl with PBYs and B-24s) so it's supply needs are comparatively small. They will send a convoy every once in a while, they might lose a few ships but given the US submarine's performance at this point of the war, their showing might not be too good. Having a dozen or more US subs around Midway at all times though of course limits by that much the number of US subs available for more profitable attacks against japanese sea lines closer to the mainland.

They wouldn't *have* to commit very much shipping (or troops, or anything else) to a Midway Garrison for it to have a disproportionate impact. The Japanese were waging war on a shoestring budget everywhere they went, and that's assuming a very thin shoestring. They don't have any margin at all for troops or logistical support. I wasn't assuming that the Japanese suddenly developed a fondness for lead-paint sushi with Thalidomide sauce and tried to turn Midway into Okinawa East .

 

[EnglishCanuck]

A decisive Japanese Coral sea victory means the Japanese carriers are intact with a decent amount of remaining places and both USA carries are sunk, Japanese proceed to Port Moresby and are drawn into a nasty fight with land based error and the Australian garrison which could get messy and drawn out which might preclude Midway from happening.

Regardless Japanese might end up in July 42 with more fleet carriers not sunk which probably precludes a Guadacanal counterattack but a New Guinea counter attack is still likely.

Essentially what I'm wondering about. What would happen if the US lost both carriers while still retaining a more robust air arm in the aftermath of the battle and how this could upset US operations in the coming months.

 

[mack8]

They wouldn't *have* to commit very much shipping (or troops, or anything else) to a Midway Garrison for it to have a disproportionate impact. The Japanese were waging war on a shoestring budget everywhere they went, and that's assuming a very thin shoestring. They don't have any margin at all for troops or logistical support. I wasn't assuming that the Japanese suddenly developed a fondness for lead-paint sushi with Thalidomide sauce and tried to turn Midway into Okinawa East .

To get at least some idea of what taking Midway and holding for a while at least (surely the americans will come back trying to take it a soon as they are in a position to) would mean for IJN and Japan, one has to study relatively similar situations, like ressuplying Wake or or the Aleutians, i would love to see any statistics on the issue. I am convinced though that whatever losses the japanese had trying to supply those places in 1942 surely pale in comparison to the crippling losses at Guadalcanal. This is why i cannot see any losses trying to supply Midway have more impact than at Wake or Aleutians, which like i said certainly were not anywhere near as crippling and wasteful in men, ships, fuel and aircraft as the hell at Guadalcanal, it was just a pinprick in comparison.