Japan wins at Guadalcanal - what next?

I... I think they will find themselves too exhausted to even think about launching operation FS. ...

That often occurred to me in these discussions. If victory on Guadalcanal does not come until November Its likely to incur all the attrition & perhaps more of OTL. A victory in October is not going to be much better. September is probably the last chance assuming the losses of OTL.
 
This is pretty much the scenario i was looking for, whether there is a reasonably plausible way to have the japanese win the battle in September. This means of course a larger number of troops being send to Guadalcanal in August and September, and of course things going worse for the US during the landings (f.e. having it discovered a day early), at Savo, Eastern Solomons, the IJN managing to land the first convoy of troops in late August with their heavy gear etc. etc. But again they need to mount a massive all or nothing attack with everything they got to push the americans from the airfield.
 
Probablly deserves a separate thread, but what happens if the Japanese leaders double down, or would it be triple down (?) in December & decide to mount a new offensive instead of evacuating Guadalcanal?
 
... the IJN managing to land the first convoy of troops in late August with their heavy gear etc. etc. But again they need to mount a massive all or nothing attack with everything they got to push the americans from the airfield.

Thats one way. Another would be a less capable US commander on the spot. Vandigrift could have done a lot worse in his defense deployment & use of intelligence. Franks argues Vandigrift did not use the current US doctrine for infantry in the defense & had his battalions deployed in a tight linear pattern that did a better job of confounding the Japanese offensive tactics. I've seen a lot of examinations of the battles over Henderson field, but none deeply examined the logic behind the defense deployment or current doctrine. They usually focus on the Japanese side & their assumptions and errors or successes.
 
I think Prados touches this very subject, if the IJN effort going into the successful operation KE (the evacuation) would have been spent into actually ressuplying and adding more troops, at the very least the battle would have continued for a few more months? But that is even more attrition for IJN.

I would also add, rather than evacuate, support them with whatever possible and let the troops there fight to the last, at least this will delay the americans some more.
 
AFAIK the turning point in the Guadalcanal Campaign were the two Naval Battles of Guadalcanal in November. According to the book I read the IJA still wanted to hold the island after these battles but the IJN didn't.

If the Japanese had sunk the Enterprise as well as Hornet at Santa Cruz (preferably without the Shokaku being damaged and loosing fewer of their own aircraft and aircrew) and followed that up by inflicting heavier losses on the USN at both Naval Battles of Guadalcanal and getting the troop convoy through without loss then the IJN will want to fight on too.

After loosing Enterprise as well as Hornet at Santa Cruz and more ships at the Naval Battles of Guadalcanal will the USN be willing or even able to supply the marines on Guadalcanal? In a year all the extra American ships sunk will be replaced by new construction and then some. But in the short term the Japanese have control of the sea around Guadalcanal by day and night.
 
If the Japanese do force the Americans to evacuate Guadalcanal at the end of 1942 might there next move be a second attempt to take Port Moresby by sea? It might be more feasible on logistical grounds than Operation FS.

IOTL the Japanese had 5 aircraft carriers (Hiyo, Junyo, Shokaku, Zuikaku and Zuio) at Truk in the first half of 1943. Because of the OP they would also have Akagi and Hiryu now repaired from the damaged they received at Midway plus Ryujo which I have suggested survived the Eastern Solomons. That increases the total to 8. Meanwhile the Americans don't have the Enterprise because she was sunk at Santa Cruz ITTL.

I had also suggested that the conversions of Chitose, Chiyoda, Mizuho and Nisshin be converted to aircraft carriers 1941-42 and @mack8 said that was permissible. I deliberately kept them out of the Guadalcanal battles, but they would increase the number of aircraft carries available to the Japanese in the first half of 1943 to 12.
 
USN gets 2 Fleet carriers in 43 - Essex in May and Bon Homme Richard / Yorktown in Aug

And also from May they got "USS Robin" with Victorious's wires upgraded to handle Avengers - in this scenario where more USN carriers are lost its possible there might be a "USS Sherlock" as well!

There is also a number of baby flattops coming on line throughout 43 - possibly a couple less sent to the RN under these circumstances?
 
USN gets 2 Fleet carriers in 43 - Essex in May and Bon Homme Richard / Yorktown in Aug

And also from May they got "USS Robin" with Victorious's wires upgraded to handle Avengers - in this scenario where more USN carriers are lost its possible there might be a "USS Sherlock" as well!

There is also a number of baby flattops coming on line throughout 43 - possibly a couple less sent to the RN under these circumstances?
Yes the Japanese naval superiority won at Guadalcanal ITTL would only be temporary.
In a year all the extra American ships sunk will be replaced by new construction and then some. But in the short term the Japanese have control of the sea around Guadalcanal by day and night.
My spreadsheet has Essex herself completing on 31st December 1942 to be followed by 6 in 1943. Also the first 5 Independence class CVL were completed in the first half of 1943 and the other 4 in the second half of that year.
 
If the Japanese do force the Americans to evacuate Guadalcanal at the end of 1942 might there next move be a second attempt to take Port Moresby by sea? It might be more feasible on logistical grounds than Operation FS.

IOTL the Japanese had 5 aircraft carriers (Hiyo, Junyo, Shokaku, Zuikaku and Zuio) at Truk in the first half of 1943. Because of the OP they would also have Akagi and Hiryu now repaired from the damaged they received at Midway plus Ryujo which I have suggested survived the Eastern Solomons. That increases the total to 8. Meanwhile the Americans don't have the Enterprise because she was sunk at Santa Cruz ITTL.

I had also suggested that the conversions of Chitose, Chiyoda, Mizuho and Nisshin be converted to aircraft carriers 1941-42 and @mack8 said that was permissible. I deliberately kept them out of the Guadalcanal battles, but they would increase the number of aircraft carries available to the Japanese in the first half of 1943 to 12.

Because of the large numbers of aircraft in Australia Port Moresby (not to mention troops), i don't think the japanese would try another seaborne invasion of PM even if they have as many carriers as you say. They might try a carrier supported invasion of Milne Bay area though (which imo is vulnerable as it is the furthest airbase in NG) in addition to funneling supplies and troops to Buna-Gona area. I can also see an operation similar to I-Go, but directed exclusively at Port Moresby.
 
Yes the Japanese naval superiority won at Guadalcanal ITTL would only be temporary.My spreadsheet has Essex herself completing on 31st December 1942 to be followed by 6 in 1943. Also the first 5 Independence class CVL were completed in the first half of 1943 and the other 4 in the second half of that year.

Yeah sorry should have explained myself better - the dates I was quoting are when they are available to do the job - for example Essex was commissioned on 31st Dec 42 but was not ready for combat (trials / working up / fixing issues / training crew etc / actually reaching Pearl Harbour etc) till May 43. The only other Fleet CV to commission and reach actual service that year was Yorktown CV 10 which commissioned on 15th April 43 but did not reach the combat area until 24th July - undertaking further training for a month out of Pearl and starting actual combat ops in late Aug - Edit: due to a tragic google fu failure I Missed Bunker Hill CV 17- Combat ops in Nov 43 and Lexington CV16 Combat Ops in Sept 43 - so that's 4 Fleet CVs in late 43 - :eek: - they were joined by the Light Carrier Independence (who arrived in pearl in late July 43) for the same combat op. Her sister Princetown arrived at Pearl in early Aug 43 and started combat ops late that month. Belleau Wood arrived Late July and again was conducting ops in late Aug. Cowpens arrived late Sept 43 - combat ops in Oct 43. Monterey - started combat ops in Nov 43. Langley is next but she does not enter combat until early 44.



The Essex and Independence Pez dispenser does not actually start to tip the balance much before the 2nd half of 43 and in this scenario effectively until early 44.

In the face of the POD I suspect that some time could be shaved off these times but they were already very very impressively short - Hull laid down - commissioning times OTL.

Still that is 4 Essex class by Xmas 43 and a similar number of Light carriers - but that's still a year - 18 months where KB holds the advantage in this scenario.
 
Yeah sorry should have explained myself better - the dates I was quoting are when they are available to do the job - for example Essex was commissioned on 31st Dec 42 but was not ready for combat (trials / working up / fixing issues / training crew etc / actually reaching Pearl Harbour etc) till May 43. The only other Fleet CV to commission and reach actual service that year was Yorktown CV 10 which commissioned on 15th April 43 but did not reach the combat area until 24th July - undertaking further training for a month out of Pearl and starting actual combat ops in late Aug - Edit: due to a tragic google fu failure I Missed Bunker Hill CV 17- Combat ops in Nov 43 and Lexington CV16 Combat Ops in Sept 43 - so that's 4 Fleet CVs in late 43 - :eek: - they were joined by the Light Carrier Independence (who arrived in pearl in late July 43) for the same combat op. Her sister Princetown arrived at Pearl in early Aug 43 and started combat ops late that month. Belleau Wood arrived Late July and again was conducting ops in late Aug. Cowpens arrived late Sept 43 - combat ops in Oct 43. Monterey - started combat ops in Nov 43. Langley is next but she does not enter combat until early 44.

The Essex and Independence Pez dispenser does not actually start to tip the balance much before the 2nd half of 43 and in this scenario effectively until early 44.

In the face of the POD I suspect that some time could be shaved off these times but they were already very very impressively short - Hull laid down - commissioning times OTL.

Still that is 4 Essex class by Xmas 43 and a similar number of Light carriers - but that's still a year - 18 months where KB holds the advantage in this scenario.
No problem. I suspected that you were allowing for working up.

The Japanese will also have the problem of their fuel supply drying up over the course of 1943-44. How far into 1943 will it be before it effects the ability of the KB to train and its use operationally?

Also the KB had 5 aircraft carriers at the start of 1943 would the training schools be able to produce enough aircrew for the 2 extra ships in the OP (Akagi and Hiryu) plus Ryujo if she is not sunk at the Eastern Solomons and the Chitose, Chiyoda, Mizuho and Nisshin if they are converted to aircraft carriers 1941-42? While more aircrew survive Midway in the OP I think many of them will be killed in the TTL version of Santa Cruz. IOTL Yamamoto took the carriers air groups away twice IIRC for operations in which they suffered heavy losses and I suspect that he will do the same ITTL.

So the IJN might have as many as 5 extra aircraft carriers (Akagi, Hiryu, Ryujo, Mizuho and Nisshin) in the TTL Battle of the Philippine Sea or its TTL equivalent, but they won't have the aircraft or aircrew for them or at best if they have more obsolete aircraft flown by inadequately trained aircrew. So the result is likely to be an "Even Greater Marinas Turkey Shoot" for the fighter pilots and anti-aircraft gunners of Task Force 58. Also as the Japanese have the same number of destroyers to screen more aircraft carriers it might be that the American submarines sink more than 2 Japanese aircraft carriers ITTL.
 
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After loosing Enterprise as well as Hornet at Santa Cruz and more ships at the Naval Battles of Guadalcanal will the USN be willing or even able to supply the marines on Guadalcanal? In a year all the extra American ships sunk will be replaced by new construction and then some. But in the short term the Japanese have control of the sea around Guadalcanal by day and night.

The Enterprise was of marginal use after Santa Cruz & no decision to evacuate was taken. The withdrawal of the IJN carriers was not clear for several weeks & less clear that their air wings were crippled. Halsey could not dismiss that they were refitting at Truk & could return to support the surface ship attacks. So, OTL it was very close to the situation you describe in the US PoV. One of the influences on the decision to continue the battle was the Saratoga was preparing to return to battle, it departed PH 12 November for the S Pac.
 
The Enterprise was of marginal use after Santa Cruz & no decision to evacuate was taken. The withdrawal of the IJN carriers was not clear for several weeks & less clear that their air wings were crippled. Halsey could not dismiss that they were refitting at Truk & could return to support the surface ship attacks. So, OTL it was very close to the situation you describe in the US PoV. One of the influences on the decision to continue the battle was the Saratoga was preparing to return to battle, it departed PH 12 November for the S Pac.
That's fair enough regarding the Enterprise and Saratoga.

However, I'm also suggesting that the Americans have heavier losses in both Naval Battles of Guadalcanal. That's partially because they receive more hits from Long Lance torpedoes due to worse luck and partially because the Japanese send in the Kongo and Haruna (and possibly Mogami and Mikuma if they survive Midway ITTL) to support the Hiei and Kirishima.

Plus I suggested that the troop convoy that lost 7 out of 11 ships got through with lighter losses or even unscathed ITTL due to no Enterprise to support the aircraft from Henderson Field and the Japanese providing more fighter cover.

Do you think that would be enough to make the Americans decide to evacuate?
 
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Do you think that would be enough to make the Americans decide to evacuate?

Vandigrift judged evacuation impractical & had his staff work up a plan for moving into the central highlands & possibly establishing a emergency airfield and beachhead on the south side. I don't know how practical the latter two items were, but the point is Vandigrift wrote off evacuation were the airfield lost. I have not yet found a opinion from the commander of the amphhib fleet. He was the one who'd have to actually do the task. Since Vandigrift was in near daily communication with the gator fleet I'm guessing his judgment was influenced by the fleet commander & staff.
 
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