Could the Japanese have captured Hawaii if they had won the battle of Midway?

[Schweik]

In another thread, someone posted:

"By the middle of 1942, invading Hawaii is simply a fanciful notion. From where would the invasion forces sail? How combat ready would an invading force be after several days at sea? 'Fraid that's not a viable outcome. "

I am not so sure this is true. I'm sure logistics would be a challenge, but so was capturing the Philippines and Malaysia, or invading the Aleutians. If you start with the assumption that Midway had really gone the other way - say 4 US carriers sunk and only 1 IJN, could they have invaded and captured Hawaii in late 1942 or 1943?

Midway Atoll as a staging ground? It's not much of an island but there are ample facilities for seaplanes and some capacity for troops and land based planes. The US put ~3,000 men on the atoll and had NAS Midway there, plus a second airfield on "Sand Island". During the battle of Midway the US had a squadron of TBF Avengers, one of (4 x ) B-26 Marauders and one of (17 x B-17s) based on the island, plus 62 more fighters and dive bombers (7 x Wildcats, 21 x F2A, 17 x Vindicators, and 24 x SBD). So there was some capacity for aircraft, supplies and billets there. Presumably the Japanese could have put 20 or 30 G4M, ~ 30 Zeros and 30 D3A or B5N / B6N. In addition it's a good spot for seaplanes, like A6M2-N and F1M "Pete" etc.

Midway is still 1,500 miles from Hawaii - too far to conduct strikes or for a "single step". But in a sustained campaign against Hawaii, Midway could be a shelter for the Japanese fleet, protected by a pretty substantial force of land based fighters and augmented by whatever seaplane assets they could muster.

But the other islands of the Leeward chain could serve as seaplane bases etc., for quite capable planes like the A6M2-N in addition to whatever land based capacity the bases could hold to protect any build up in the Leeward Isles.

The US put a 3,500 foot runway on French Frigate Shoals (761 miles from Midway, 530 miles of Pearl Harbor) had a 3,000 ft runway on it, and was in striking distance of Hawaii. capacity for troops or aircraft was no doubt limited but I'm sure you could have fit some there, or make it a refueling spot. It seems pretty marginal to me from photos (very little land area) though there is a fairly large protected bay where subs or transport / supply ships could shelter, and from which search / scout assets such as the H8K flying boat could range far out to sea. Protection could be augmented with some A6M2-N floatplane fighters.

Any Hawaii invasion would certainly have had to have been primarily a carrier supported operation, but those islands could have provided some support. Overall it doesn't seem inconceivable to me.

 

[buffnut453]

My primary question is what size of invasion force (IJA) would be required and where would that force be established prior to sailing? Midway could accommodate a few thousand personnel but surely not enough for a successful invasion of Hawaii. Also, Midway is 1,500 miles away from Hawaii so I suspect we're talking about soldiers spending a couple of weeks at least aboard the vessels...so how combat fit would they be?

The other question is resupply. Even if an assault on Hawaii was successful, how on earth would the garrison be resupplied? Yes, they could repurpose machinery locally for some needs but simply getting ammunition would be a massive logistical effort.

 

[Schweik]

I agree these are all challenges, I'm not sure Hawaii can even feed itself as of 1943, but are they insurmountable?

 

[Schweik]

French frigate shoals seems like it could be a place for an invasion fleet to pause and get over being seasick before the remaining 2 or 3 day trip to Hawaii.

 

[pinsog]

Japan didn't have the sealift capacity to invade Pearl Harbor. The runway at French Frigate Shoals would have been wonderful bombing practice for B17's flying from Hawaii. Midway would have been constantly bombed from Hawaii as well. I would probably have bombed both at night so any Zeros based on either island would have been irrelevant. Japanese AA fire was notoriously poor, so if a few B17's could simply bomb at dark when Zeroes couldn't effectively engage them it would have simply been good navigation and target practice. I would have loaded a lot of rather small bombs, mostly wanting to destroy aircraft on the ground. Saratoga, Ranger and Wasp could have been held back and simply used as aircraft ferries between Hawaii and the mainland. Hawaii had more aircraft by I think January 1st then they had the day of the attack on Pearl. Hawaii has Radar as well. In addition to P40's, Wildcats and P39's all P38's could have been diverted to Hawaii if Midway was lost as well. I personally believe if Pearl Harbor would have had 24 hours notice before the December 7 attack, the 1st Japanese strike would have been decimated. We had almost as many fighters available as the entire 1st strike had aircraft.

 

[pinsog]

December 7,1941

USAAF on hand
P-36A - 39
P-40B - 87
P-40C - 12
The USN/USMC had, on hand:
F2A - 8
F4F-3 - 21

Total 167 fighters
From the Getting the P40 into the air quickly thread

 

[Schweik]

Well the Japanese managed to move 130,000 troops and 90 tanks at least 200 miles to invade the Philippines with so I'm not sure I buy the lack of sealift capacity.

The vulnerability of Midway and French Frigate Shoals is a somewhat more plausible point, though given their track record I'm fairly confident B-17s could not have hit them at night. Maybe during the day time, but then they'd need to contend with 30 + land based zeros plus whatever carrier fighters might be on hand. I agree Hawaii could have been made into a formidable base for land based fighters (though here, as relates to the other thread, I see assets being stripped away from the MTO etc.) but does that mean it's invulnerable?

Lets say they go a little bigger than what they had on Dec 7, say 250 modern fighters (mostly P-40s, P-39s, F4Fs, plus a few early mark P-38s) and half again as many bombers (SBDs, TBFs, B-26s, B-25s, B-17s and maybe some B-24s). At Midway there were 250 carrier aircraft on each side, probably 1/3 of them fighters, plus the US had 120 land based aircraft and some seaplanes. And that wasn't quite enough for a Japanese win though it was pretty close. So the Japanese would have to up the ante a bit more than that.

For the invasion of the Philippines the Japanese mustered 541 aircraft, to face a US force of 277 aircraft on the ground. They certainly handled up in that situation. Of course, many of these US planes were caught on the ground due to surprise and mistakes on the part of the American leadership.

So Hawaii looks like a hard fight. Still it doesn't seem completely beyond the scope of possibility. In theory Japan had quite a few carriers. Some were in dry dock at the time of Midway, others being held in reserve, and some (their escort carriers) were maybe too slow for an operation like that.

But lets assume you had 3 of the 4 Midway carriers: Akagi, Kaga, and Soryu. Zuikaku though damaged at Santa Cruz would be available, as should the light carrier Zuiho, possibly also Hiyo and Jun'yo. Shokaku is in drydock after being damaged by aircraft from the Hornet in the Eastern Solomons, and would not be back until Spring of 1943, so maybe that's it. Say 4 heavy and 3 light carriers.

Would that be enough? If we could assume full compliments that would be roughly 120 aircraft total for the light carriers (with a capacity of roughly 40 planes each) plus another 260 aircraft for the four fleet carriers at roughly 65 aircraft each (averaging since they varied by ship). So a total of 380 aircraft, say 250 fighters and 130 bombers. That's a good start.

Lets say you put some long range bombers on Midway. Ki-21 is supposed to have a range of 1,680 miles - is that a sortie range? The G4M had a range of 1,772 miles. Maybe you could launch some of these all the way from Midway and have them land at French Frigate Shoals after the raid. I know that is a bit of a stretch, I'm not sure if they could make it.

But if not those you could use some G3M "Nell" bombers for sure, they had a range of 2,700 miles. So lets say you put 50 of those on Midway for extra raids against Hawaii airfields. These were used in raids against Darwin from Indonesia, admittedly not quite as long of a distance but still pretty impressive. Use about 30 or 40 H8K and H6K flying boats from out of Midway to drop mines in the US sea lanes to help block reinforcements.

What if you put ashore say 20 Zeros on French Frigate shoals the night before the attack for some extra combat support.

Then add say, 150 A6M2-N float plane Zeroes, staged to attack from the same spot (brought by seaplane tenders). These are not quite as deadly as the regular ones but no slouch either.

That would make roughly 270 Zeros, 150 float plane zeros, 50 land based bombers, and 130 carrier based bombers. I don't know, even with all that, it would be tough to quickly establish air superiority and soften up defenses. However if you add a big bombardment fleet with 5 or 6 Battleships and a dozen heavy cruisers to blast Pearl Harbor and the other Hawaiian airfields from the sea in a pre-raid night bombardment, maybe that is enough right there.

 

[Schweik]

I think it would make for a great wargame regardless!

 

[Schweik]

I guess victory might depend on what the remaining three US CVs did. If they were used to attack at just the right moment they might tip the balance.

 

[pinsog]

Carriers have no staying power, they run short of fuel, no way to bring in replacements. The US had several airfields around Pearl to disperse aircraft, each one could, I'm sure, been quickly expanded (parking at least, leave pavement for use as runways. Hawaii can't be sunk. Fuel reserves can be widely dispersed around the island. Saratoga, Ranger and Wasp could probably remain 300 miles off the opposite side of the island with an additional maybe 300 fighters, if they are used solely as aircraft ferries. I read/saw Ranger carrying around 70 P40's, no telling how many Saratoga could carry. Hawaii could hold as many fighters as we had pilots to fly them. Don't even worry about bombers for counter strikes, several B17's for scouts everything else is a fighter. If you put 300-400 fighters on Hawaii and shoot down all or most of Japan's carrier qualified pilots then the carriers aren't really worth much.

 

[Schweik]

I would think you would want bombers for counter-strikes though, to sink surface ships and threaten carriers. Otherwise the battleships can come in and bombard and blow the crap out of the military facilities on the island.

You have a good point about staying power but the carriers would only have to win air superiority long enough to land those 150,000 troops or however many they bring. Then they can start capturing airfields. Oahu isn't that big.

 

[Schweik]

Maybe once some of the US defenses were broken down you could move some of your carriers back toward Midway and their air umbrella for refueling and taking on more reinforcement fighters and bombers flown in on ferry flights. From where I don't know. Maybe Adak?

 

[pinsog]

Ranger alone carried 75 P40's, another time carrying 76 P38's (I wonder if the P38's were disassembled?) P40's were assembled and flown off.

If the Japanese showed up with 380 total fighters and bombers and Hawaii had 400 P36's, P40's, Wildcats, P39's and a few P38's, all of them warned by radar, in the air ready to fight, I don't see it ending well for the Japanese. What could a handful of Japanese twin engine bombers do flying from French frigate shoals or Midway besides make wonderful target practice for P38's?

 

[pinsog]

Your right, 0 bombers would be bad because of the shore bombardment threat, if in fact they knew we didn't have any bombers. But on the other hand, if all your carrier aircraft are depleted, would you take the chance that there were no bombers on the island and send battleships in close? But it's irrelevant, there was plenty of room to park them and fly them from somewhere even if they used roads.

The Japanese didn't have unlimited supplies of carrier pilots or aircraft. They were actually under strength at Midway because they couldn't replace the attrition from the first 6 months. They couldn't even deploy the undamaged carrier from Coral sea to Midway because the air group had been pummeled and they couldn't replace them

 

[pinsog]

Also consider how badly the Japanese airgroups got mauled at Coral Sea and Midway. At Coral sea they faced what, 18 Wildcats per carrier, 36 total give or take. First strike on Midway caused the Japanese strike force 20% of their aircraft. They were opposed by 21 Buffaloes and 6 Wildcats flown by inexperienced marine pilots. Imagine if it had been 50 or 75 Wildcats with well trained navy pilots?

 

[michael rauls]

I don't think it was likely or if they did try it that it was likely to succeed but that doesn't mean it was impossible. The IJA/IJN pulled off some pretty unthinkable feats early on. It seems unthinkable now because we know how things turned out but if The US looses Midway and maybe one more pivotal engagement I don't think ot was out of the realm of posibiity. The possibility certainly would have weighed heavy on the minds of military planners had that happened.

 

[Shortround6]

The Japanese could certainly attack Hawaii if Midway had gone the other way.
Having even a successful attack is another story let alone an invasion.

I believe there are other threads on this.

It seems some people are making assumptions as to Hawaii's defences that may not stand up to scrutiny. Hawaii's defences did not depend entirely on the Navy or even the Navy and AAC combined. Hawaii is a lousy place to try to do an amphibious landing on.
The suitable beaches are few and well known (invasion scenarios had been war-gamed many times by local forces from the 1920s on.) There had been a frenzy of fortification construction from the date of Pearl Harbor. Ground forces had been much increased (and Hawaii was a staging area for the upcoming Allied offences, The US did not win at Midway and then decide to attack Guadalcanal and send everything for the Guadalcanal operation from the west coast.

Within weeks of Pearl Harbor two convoys of troops and equipment had left west coast ports with their arrival in Hawaii army ground forces were over 58,000 men.

"the unit reinforcements included two regiments of infantry, one regiment each of field artillery and coast artillery, and light tank, signal, and railway artillery battalions"

Further reinforcements were sent later and the outer Hawaiian Islands got garrisons and light support weapons.

However " With small additions during March, the authorized strength of the department became at the beginning of April 106,000 ground and 16,000 air troops, including replacements for all soldiers of Japanese descent; and the department reached these strengths before the end of June 1942. The Army air units to be retained in the islands for local defense were to contain 96 heavy and 24 medium and light bombers and 225 pursuit planes, and the Navy was obligated to keep 67 patrol planes on hand for long-range and local reconnaissance. "

Number of Army planes fluctuated and sometimes did not reach the totals in the passage quoted. Just before Midway there were 56 B-17s in Hawaii and 12 of them were sent to Midway on May 30th, however by June 10th 60 more B-17s had reached Hawaii. With the Midway victory some of them were sent on to other places in the south Pacific.

The American troops may have been green and perhaps not well trained but it is the Japanese who are trying to attack prepare positions over narrow beaches and into very challenging terrain.

There are often not a lot of flanking options for an attacker. Oahu is small 44 miles long and 30 miles wide. Modern map.

Like I said earlier. Beaches suitable for landing were well known and pre zeroed by defensive guns, avenues of attack once on the beaches were also well known and limited.
the two modern highways up through the center of the Island are only possible by tunnels through the ridge.

The Philippines were large, many places had to be defended and while the terrain could be rugged the distances allowed flanking maneuvers.

resupply for the Japanese would take weeks if not well over a month for a round trip by a ship.

Despite allied fears the Japanese had about reached the end of their logistical rope with areas they had already taken. They had neither the transport capacity nor the fuel oil to support far flung invasion schemes.

 

[pinsog]

That is 225 army fighters, not including however many Wildcats the navy had there for training, completed major overhauls, or just replacements waiting on a carrier to come through. 225 P40's and P39's plus another 50 or so Wildcats would be quite a force to deal with for a carrier born attack. Also, Saratoga arrived with 98 aircraft from the west coast just as the Midway battle ended. Those could have immediately been off loaded, keeping a few SBD's or TBM's onboard for anti sub patrol and the Saratoga could have immediately returned to the west coast for another load. How many trips could she alone have made by the time the Japanese had reconstituted their aircraft and aircrew losses from the Midway battle? Shōkaku wasn't repaired until mid July, not sure how long it took Shōkaku and Zuikaku to work up their airgroups. Also with the loss of Midway, US aircraft and aircrews would be focused at Pearl Harbor instead of being distributed among various carriers and Pacific islands. It wouldn't surprise me if their were 400-500 fighters at Pearl by the time the Japanese were able to attack, both army and navy combined.

 

[Admiral Beez]

Well the Japanese managed to move 130,000 troops and 90 tanks at least 200 miles to invade the Philippines with so I'm not sure I buy the lack of sealift capacity.

That had me questioning as well. Surely before the USMC's great moves across the Pacific in 1943-45 there was no other power capable of a Pacific Ocean sealift of this size. The Brits have but a few ships creaping back and forth to Singapore and the French and Dutch nothing.

Mind you, to take Hawaii, I'd say every transport used in the above sealifts will need to instead be diverted to taking the Hawaii. So Japanese strategy needs to change to taking Hawaii first, and then going for DEI and Malaya. The don't have the ships or the men to do both.

 

[pinsog]

I think the only thing an attempted Japanese invasion of Hawaii in 1942 would do is substantially shorten the war