Japan wins at Guadalcanal - what next?

[mack8]

So yeah, let's assume they somehow manage to win at Guadalcanal, i'm welcoming realitisc PODs and ideas on when and how this japanese victory could happen. Of course, as some of you know me, i always want to start with a POD at Midway! Say Hiryu or Akagi or both survive, even if the battle is still quite calamitous for Japan, couple of carriers and many planes lost as well as about 100 aircrew.

Anyway, ok so IJN wins at Guadalcanal. What is happening next, for instance in New Guinea, would the freed up japanese forced commited there alter the outcome of the Kokoda campaign? Can the japanese take Port Moresby? Any rough idea how many US and australian troops were in NG after August 1942? I know about that time there were about 500 USAAF plane in Australia and NG of which 250 fighters.

Oh and what about USN and USMC, given the threater splitting between army and navy, what are they doing if they lost at Guadalcanal, do the USN and USMC end up taking part in the NG campaign as well, or just mostly stay back in the New Hebrides, New Caledonia, Fiji and Samoa areas? No F4Us in serious combat until late 1943 then, except to intercept japanese raids from Guadalcanal presumably?

Let's run things up to before the atomic bomb.

 

[The Wizard]

POD - Vice Admiral Gunichi Mikawa goes after the transports after the Battle of Savo Island.

 

[Catspoke]

Taking Port Moresby by land doesn't seem likely. Avoiding the attritional losses the Japanese suffered is a good thing for them. However I see a prolonged Buna/Gona campaign in NG. Maybe the Japanese try harder at Milne bay. So maybe the attrition is just somewhere else.

Any "victory" at Midway or Guadalcanal allows the Japanese to be in the game until late 43 when the Essex class carriers, the Hellcat and newer radars win regardless any sea battle.

 

[Carl Schwamberger]

Let's assume for a moment Mac does not hand over control of the WATCHTOWER Op. To the Navy & atempts to run it as a all Army op. His staff manages to bungle the planning & coordination with the Navy & the NG/Army units ashore are even worse off than the Marines were.

The Greek. Tragedy of the Ichiki Det would play out as per OTL, but in mid Sept the Kawaguchi Brigade attack makes the Army position untenable. So in Oct Japans Army controls the airfield & critical coast areas. Since there is a lot less attrition of Japanese forces they will still have the overconfidence to reach further east in the next step of the FIji-Samoa op.

The distances are even harsher on the Japanese than in the Solomon's & the US is fighting closer to its bases. The result in losses as bad or worse than surrounding Guadalcanal.

 

[Some new guy]

can the japanese take Port Moresby?

In my honest opinion no the Japanese are simply too far from thier supply lines while the allies are practically next door to thiers. And if they do mange to take New Guinea it would probably turn out like OTL Guadalcanal did slowly bleeding the Japanese on the edge of thier supply lines.

 

[Geon]

Here's my best guess.

The Japanese win at the Battle of Savo Island and then go after the transports as indicated above. The USN is forced to withdraw as they did in our TL. Meantime the Japanese send in troops to re-take the airfield. With no supplies and little support after a long bloody battle-good guess maybe 2 weeks-the Japanese retake the air field. Surviving USMC head into the jungle and now the shoe is on the other foot. The Japanese are the ones facing guerilla attacks as the U.S. Marines live off of what they can forage. After about a month the U.S. sends in more Marines to retake the airfield. Caught between fighters in the jungle and the new troops the Japanese are defeated and the air field is taken again. End result in my humble opinion is that the Battle if Guadalcanal has an extra month added onto it and becomes more if a meat grinder then it was for both sides.

 

[Pempelune]

Really, the answer is easy.

 

[Glenn239]

So yeah, let's assume they somehow manage to win at Guadalcanal, i'm welcoming realitisc PODs and ideas on when and how this japanese victory could happen. Of course, as some of you know me, i always want to start with a POD at Midway! Say Hiryu or Akagi or both survive, even if the battle is still quite calamitous for Japan, couple of carriers and many planes lost as well as about 100 aircrew.

Even if these CV's survive they'll be out for the rest of 1942 to severe fire damage in their superstructure would be my guess. After Midway Yamamoto committed the reconstituted carrier forces prematurely, sending in Zuikaku, Shokaku and Ryujo in August with Hiyo, Junyo and Zuiho still working up in Japan. The new air groups were only slightly different than the old air groups, but let's say they'd have done this instead, (not sure if there were enough B5N1/N2 to do this) -

Zuikaku, Shokaku - 36 x A6M2, 36 x B5N
Zuiho, Ryujo - 21 x A6M2, 9 x B5N
Hiyo, Junyo - 21 x A6M2, 27 x B5N
Hosho - 12 x A6M2

Shore based (in reserve) - 90 D3A1

And let's say it's late September (or whatever) before the IJN is ready. This totals 168 fighter and 144 torpedo bombers. In other words, by giving up the dive bombers the ship killing power of the Hawaii strike force is fully restored. The idea is to cripple the US carriers with torpedo attack then finish them off with a surface group. Once the US carriers are eliminated, the reserve DB's come aboard for reducing Henderson. The counterattack would not be the "bungle in the jungle" crap of the historical campaign, but an all-out 2 division amphibious assault straight over the beach right at Henderson Field.

Anyway, ok so IJN wins at Guadalcanal. What is happening next, for instance in New Guinea, would the freed up japanese forced commited there alter the outcome of the Kokoda campaign? Can the japanese take Port Moresby?

I doubt it. Taking Guadalcanal back will have shot their bolt and left the carrier forces exhausted. At best, they might see the Solomons put a bit on the backburner and the USN return its attention to the Central Pacific. Nimitz will not fall, (almost bulletproof after Midway), but even more heads than historical will roll.

Let's run things up to before the atomic bomb.

The USN 1944 counteroffensive would kick off in the Marshalls and roll west at about the same pace. Without the Solomons draining resources the IJN air forces might be in a better position to resist and cause losses, but the overall trend can't be in question.

 

[mack8]

Hi Glenn,

Thanks for your insightful contribution like usual. There are of course many permutations to obtain this ATL japanese victory at Guadalcanal, in regards to Midway what i had in mind was a scenario in which Akagi is not hit, both it and Hiryu launch and kill Yorktown, second wave hits TF16 (haven't decided if to sink or just damage one of TF16 carriers), Spruance clears the area etc. Perhaps, in order to have the japanese not underestimate the US troops on Guadalcanal as they did in OTL, we could have a failed attempt to invade Midway, they loose many troops and some beached transports, while the americans grow overconfident that their ground troops can dig in against the japanese, so Midway is still seen as a victory, with 3 carriers still available they still decide to execute Watchtower etc.

So my ATL carrier line-up is Akagi, Hiryu, Shokakau, Zuikaku, each with 18 plane D3A and B5N squadrons, and while Shokaku and Zuikaku have 27 plane Zero squadrons, Akagi and Hiryu only have 18 Zeros each. As OTL for Ryujo, Junyo, Hiyo etc.

So when Watchtower happens the japanese are more concerned and uneasy about dealing with the threat, they mobilize a significant landing force covered by a large scale fleet sortie, preferably including CA and BB bombardment of the airfield, with 3 (or even 4) fleet carriers (Shokaku, Zuikaku, Hiryu and even Akagi, plus Ryujo), somewhat keeping to the OTL doctrinal changes Nagumo sends 54 D3As (18 from each ship as i assume they have 18 plane squadrons because there is also Hiryu, and even Akagi -which btw i suspect it would still be in refit at this time, in OTL it was planned to have one after Midway- to fill up with planes and pilots, which are in relatively short supply) in the first wave and 36 B5Ns (some of the 54 total are on search) the second wave which let's say are sinking one and damaging another american CV at Eastern Solomons, subs sink or disable the third and last operational american CV not long after, so September is very bleak for Ghormley. IJN controls the adjacent sea, as you suggest Nagumo can launch a few strikes against the airfield as the US carrier threat is eliminated, meanwhile japanese troops pour in on Guadalcanal, the offensive pushes the americans away from the airfield (that is all the japanese need to do, as long as they take the airfield the island will eventually be theirs) japanese planes quickly take station there and with it finally controlling the air over Cactus, IJN warships can take station at Tulagi etc. The americans are trapped, Ghormley doesn't know what to do, they may decide to evacuate the remaining US troops, or they are eventually captured, but either way they lost the island.

Anyway, this is my scenario for this japanese victory at Guadalcanal.

 

[mack8]

Here's my best guess.

The Japanese win at the Battle of Savo Island and then go after the transports as indicated above. The USN is forced to withdraw as they did in our TL. Meantime the Japanese send in troops to re-take the airfield. With no supplies and little support after a long bloody battle-good guess maybe 2 weeks-the Japanese retake the air field. Surviving USMC head into the jungle and now the shoe is on the other foot. The Japanese are the ones facing guerilla attacks as the U.S. Marines live off of what they can forage. After about a month the U.S. sends in more Marines to retake the airfield. Caught between fighters in the jungle and the new troops the Japanese are defeated and the air field is taken again. End result in my humble opinion is that the Battle if Guadalcanal has an extra month added onto it and becomes more if a meat grinder then it was for both sides.

Except if the japanese retake the airfield for any length of time, the first thing they will do (OTL plan btw) is immediately bring planes there to control the air, and probably IJN warships right at Tulagi, so now THEY control the air and the americans can't get a convoy in without being spotted, attacked from the air and met by IJN surface forces. The only way to push through is with carrier support, but in August-September the US carrier force was gutted, so they can't do it, and even if they try with what they had left (just Hornet?), they have to get not only past japanese aircraft at Cactus but critically, Nagumo's carriers. They will walk right into a trap.

So all else being equal, if the japanese manage at any point to retake the airfield, they pretty much won the battle from then on imo.

 

[Carl Schwamberger]

A few minor points.

...

So when Watchtower happens the japanese are more concerned and uneasy about dealing with the threat, they mobilize a significant landing force covered by a large scale fleet sortie, preferably including CA and BB bombardment of the airfield,

Using BB or heavy cruisers for shore bombardment was against IJN doctrine. It took near two months of ineffective bombardment of Henderson Field before they broke with doctrine & committed two BB to the task. Given their love for their 'perfect' doctrines its unlikely they would give a BB a third hand mission like shore bombardment this early in the campaign.

{quote], so September is very bleak for Ghormley.[/quote]

Who was on the verge of being replaced in September.

... meanwhile Japanese troops pour in on Guadalcanal, the offensive pushes the americans away from the airfield (that is all the japanese need to do, as long as they take the airfield the island will eventually be theirs) japanese planes quickly take station there..

"Quickly" is problematic as even without US interferance the Japanese had difficulty concentrating a suffcient cargo fleet anywhere at this time.

...IJN warships can take station at Tulagi etc. ...

Tulagi lacked fuel storage. Thats one of several reasons the US did not station more than a few ships there. The IJN would have to risk a tanker/s that far forward.

The americans are trapped, ...

Certainly would be.

 

[mack8]

Thanks for your comments.

In regards to BB and CAs, this whole "doctrine" thing has been repeatedly discussed before, i can only quote the example of Midway where apart from all 4 Mogamis specifically earmarked to bombard the island, Kondo's 2 BB and another 4 CA were apparently earmarked to participate too, if the situation required (this according to the much quoted Shattered Sword).

In the scenario i made they sort-of won the carrier battle and tried a landing at Midway (and failed), so they got that experience earlier, hence committing heavy ships to bombarding the airfield earlier in this ATL Guadalcanal campaign.

As for planes, probably after quickly filling the craters they'll deploy Zeros and D3As, as well as seaplanes (later on they will deploy G4Ms - OTL pre-invasion plans called for up to 100 planes to be stationed on Guadalcanal later in the year in September or October). Fuel and bombs can be initially delivered quickly by destroyer. As for convoys, now with Cactus Air Force gone, it will be relatively safe to land the supplies by day, under the cover of the IJN planes at Henderson as well as cruisers and DDs etc., so most of the earmarked supplies and troops will be landed. Oilers can shuttle from Rabaul etc. into the waters north of Guadalcanal to refuel IJN ships there, and Nagumo's carriers can sweep into the lower Solomons helped by long range searches from Tulagi against potential american reinforecement efforts, and the list goes on and on.

So basically, if the japanese retake the airfield somehow, pretty much all the crucial advantages the americans had because of Henderson Field will pass on to IJN.

 

[NOMISYRRUC]

Would it have helped if the aircraft carrier Hiyo had been present at the Battle of Santa Cruz?

 

[mack8]

Hi NOMI,

http://www.combinedfleet.com/hiyo.htm

Well according to it's TROM above, the engine breakdown of Hiyo and it's subsequent retirement took 16 A6M and 17 D3A out of the battle (a few more planes from Hiyo were transfered on Junyo). So with Hiyo at Santa Cruz, it may well be that Enterprise is mortally crippled by the 35 D3As Kakuta could have launched (or alternatively the 17 D3A from Hiyo plus 7 B5N and say 9 D3A from Junyo in the first wave, with 8 more D3As in second wave), so it too may be caught and sunk by Kondo.

What effect would this have on the November battles would be interesting to ponder, though to me it seems November is much too late to turn the battle around, though certainly it could be prolonged.

 

[NOMISYRRUC]

This is a quote from An Illustrated History of the Navies of World War II by Anthony Preston.

On August 31 the Saratoga was torpedoed by the Japanese submarine I.26; although she survived, this valuable ship was out of action at a crucial time. Two weeks later Wasp was hit by three torpedoes. This time the results were disastrous, for the Wasp caught fire and had to be abandoned. The battelship North Carolina was hit by a torpedo on the same day, September 15, leaving only one battleship, her sister Washington, and one carrier to cover the landings. This was the greatest hour for the Japanese submarine arm, but unfortunately it only demonstrated the Japanese talent for wasting their submarines. There were only two submarines in the Solomons, and had there been more the Japanese Navy might have been able to avenge Midway. But the large submarine force was scattered around the Indian and Pacific Oceans in unimportant areas.

Was he right?

 

[mack8]

I'm not very familiar with IJN subs and their operations, but according to this, f.e. there were at least 10 subs (and possibly more) in the Solomons by Eastern Solomons battle:
https://books.google.co.uk/books?id...nepage&q=japan submarines guadalcanal&f=false

Perhaps they could indeed have obtained even better results (imagine if Hornet is sunk or just damaged by torpedoes as well, will be out of action for months) if the picket lines were better positioned?

 

[Obergruppenführer Smith]

Let's just say that Japan really squandered their submarines with bad tactics. They had such nice submarines.

 

[Athelstane]

Even if these CV's survive they'll be out for the rest of 1942 to severe fire damage in their superstructure would be my guess...

It doesn't happen often, but this is a Glenn post I agree with 100%.

The Japanese don't have any attractive options here. I think they have to count themselves lucky they beat off the initial American thrust into the Solomons.

 

[Carl Schwamberger]

Thanks for your comments.

In regards to BB and CAs, this whole "doctrine" thing has been repeatedly discussed before, i can only quote the example of Midway where apart from all 4 Mogamis specifically earmarked to bombard the island, Kondo's 2 BB and another 4 CA were apparently earmarked to participate too, if the situation required (this according to the much quoted Shattered Sword). ...

Yet the situation called for a heavy bombardment of the airfield, 'required it' as it were & the Japanese neglected this option for many weeks.

 

[Glenn239]

, in regards to Midway what i had in mind was a scenario in which Akagi is not hit, both it and Hiryu launch and kill Yorktown, second wave hits TF16 (haven't decided if to sink or just damage one of TF16 carriers), Spruance clears the area etc. Perhaps, in order to have the japanese not underestimate the US troops on Guadalcanal as they did in OTL, we could have a failed attempt to invade Midway, they loose many troops and some beached transports, while the americans grow overconfident that their ground troops can dig in against the japanese, so Midway is still seen as a victory, with 3 carriers still available they still decide to execute Watchtower etc.

If Hiryu and Akagi exit Midway operational, it gets harder to see how Watchtower can happen at all, as the USN will be on the defensive against the next phase of Yamamoto's planned offensive, in the direction of Fiji and Samoa in July or August 1942.