A different Pearl Harbor scenario to consider

[steel_captain]

Could Japan have been able to deal a more decisive blow to the US if Kido Butai had remained in the vicinity of Hawaii after the 2 waves which it sent? To wait for the arrival of the LEXINGTON and ENTERPRISE to arrive back and engage them at sea? Obviously the IJN ships would have to be refueled at sea and restocked with planes and ammo, but the USN carriers would have not been able to fight at full strength and would have been in a disadvantageous position being low on fuel and planes.

What could the USAAC have done with land based aircraft after Hickham Field had been hit so hard on Dec. 7? What kind of search could have been mounted? How about the carriers? What kind of search could they have mounted? Would Kimmel gave ordered the US carriers to not engage their IJN counterparts? Did our carries have enough fuel to make it to the West Coast if they knew the IJN carriers were still in the area and didn't want to risk a fight?

If our carriers bailed out and fled the scene, what would a refuelled Kido Butai do to take advantage of their unchallenged position? Keep striking PH? Attack and then neutralize Midway simultaneous to PH so their fleet could use it as an advance base?

Single biggest question is what capabilities did the IJN possess in Dec. '41 to replenish its fleet at sea? If they didn't have any, what else could be done or what could they have done pre PH to be able to?

 

[Garrison]

Could Japan have been able to deal a more decisive blow to the US if Kido Butai had remained in the vicinity of Hawaii after the 2 waves which it sent?

Well not unless the IJN is planning to row home, because it was short on fuel and had no ability to replenish, fuel, aircraft or munitions. They also have no clue where the US carriers are or when US submarines might show up.

 

[naraic]

Single biggest question is what capabilities did the IJN possess in Dec. '41 to replenish its fleet at sea?

Next to none.

If they didn't have any, what else could be done or what could they have done pre PH to be able to?

I'm sure they could have managed something basic easily enough. Top up fuel from an oiler or something.

If they make a big change in doctorine everyone will know. Pearl Harbour will not be assumed safe. Leading to greater American readiness.

Could Japan have been able to deal a more decisive blow to the US if Kido Butai had remained in the vicinity of Hawaii after the 2 waves which it sent?

I'm sure they could get a 3rd wave in and run up the score a little by staying a couple of extra hours but nothing significant.

To wait for the arrival of the LEXINGTON and ENTERPRISE to arrive back and engage them at sea? Obviously the IJN ships would have to be refueled at sea and restocked with planes and ammo, but the USN carriers would have not been able to fight at full strength and would have been in a disadvantageous position being low on fuel and planes.

Of course not. This would require a major change in Japanese doctorine about replenishment at sea. Everyone would know that it had occurred and Pearl Harbour's increased readiness would see that the initial attacks bounce.

 

[mtpalmer1]

Obviously the IJN ships would have to be refueled at sea and restocked with planes and ammo

The non-trivial is strong with this one! Developing such a capability would take years. Not to mention be rather conspicuous in it's intent.

I have a feeling that Nagumo's comparative timidity is going to feature strongly.

 

[Garrison]

The non-trivial is strong with this one! Developing such a capability would take years. Not to mention be rather conspicuous in it's intent.

I have a feeling that Nagumo's comparative timidity is going to feature strongly.

Probably could be refueled by all the Milchkuh Type XIVs the Germans have doubtless built to supply all those extra U-Boats from the OPs other thread.

 

[jlckansas]

They had to deck load fuel in drums to accomplish what they did and have, as part of orders for the mission, the orders to scuttle the Destroyers if they didn't have the fuel or were slowing the rest of Kido Butai down and to make it back to the fuel rendezvous with the limited tanker support.

 

[CV12Hornet]

For the record, the Japanese could refuel at sea and brought eight oilers for the task, but that was all they could spare from their Southern Operation.

They had zero capacity to replenish munitions, planes, and avgas.

 

[steel_captain]

So how about splitting off SORYU and HIRYU to neutralize Midway while the remainder bomb PH on the 7th. Afterwards, all the Kito Butai rendezvous at the atoll, replenish and wait for the Americans to show up. If the US carriers don't show up and refuse battle then the IJN wins in a far bigger way than just taking out old battleships and capturing Midway. If the US carriers do replenish in PH and quickly head to Midway then Kido Butai's experienced pilots would have wiped the floor with them leaving the LADY LEX and BIG E burning wrecks giving the IJN a victory nearly as satisfying as the dreamed of Kantai Kessen. If the USN waits for SARATOGA to arrive from San Diego it is still three against six and none of our pilots have experience and our planes (the SBD Dauntless excluded) are no where near as good as those in the IJN so game, set and match to Japan

Eventually the usn would have tried again with the other fleet carriers but could they have done any better on a second go and how long would they have needed to wait? Certainly long enough for HORNET to be worked up and arrive from the Atlantic.

 

[Nik]

Not catching the USN carriers in port meant they were out there, some-where, and very, very riled....

( Cue meme of mime's invisible dog getting off leash... )

Hence IJN aborting third wave attack --I'd thought second, but was mistaken-- and departing at best speed initially, slowing to fuel-economy when clear of plausible pursuit...

Having USN carrier aircraft run them down and 'destroy in detail' would have 'turned the tables' on the mission. Losing those IJN carriers, aircraft, skilled pilots and 'spanners' would be ruinous...

 

[Glenn239]

Single biggest question is what capabilities did the IJN possess in Dec. '41 to replenish its fleet at sea? If they didn't have any, what else could be done or what could they have done pre PH to be able to?

Here is the TROM (tabular record of movement) of the Japanese oilers Kyokuto and Kenyo Marus. These show in the Oct-Dec 1941 entries that once the raid was approved, the IJN rapidly equipped their ships to do at sea refuelling, and did all the training necessary to make the supply unit functional in its task in all but heavy weather,

Japanese Auxiliary Oilers

30 October 1941: The Chief of Staff 1st Air Fleet, Rear Admiral (later Vice Admiral) Kusaka Ryunosuke (41)(former CO of AKAGI) signals KYOKUTO and SHINKOKU MARUs that when installation of gear for refueling undertow and preparations for action have been completed, KYOKUTO and SHINKOKU MARUs will depart Sasebo and Kure, respectively, on the 13 November and proceed to Kagoshima Bay, conducting exercises with carriers en route. Kusaka further requests their COs load fuel oil for refueling purposes before departure.

10 November 1941: Kure. The Chief of Staff of the Kure Naval District advises Rear Admiral Kusaka that arrangements have been made to reequip oilers KYOKUTO, SHINKOKU, KENYO, KOKUYO MARUs for simultaneous port and starboard refueling by 13 November.

13-14 November 1941: Oilers KYOKUTO, KENYO, SHINKOKU and KOKUYO MARUs conduct fueling at sea exercises with CarDiv 1's AKAGI, DesRon 1, CruDiv 8, CarDiv 2's SORYU and HIRYU and CarDiv 5's SHOKAKU and ZUIKAKU.

18 November 1941: The Hawaii Operation: Departs Saiki. Seven oilers are assigned to the Hawaii Operation, but the IJN’s practical experience in refueling at sea is almost nil. Earlier in the month, three refueling exercises were held in Sukumo Bay and the Ariake Sea. Now, while enroute to the Kuriles, all units in the carrier formation are refueled ten times.

Japanese Auxiliary Oilers

Kenyo Maru's trom confirms that this oiler refuelled the Akagi three times during the voyage, once on November 28th for 435 tons, once on Dec 2nd for 607 tons, once on Dec 5th-6th for an unknown amount, but probably over a thousand tons because weather had prevented refueling in the previous days. Call it maybe 2,000 tons all-in.

To put that into perspective, Akagi carried something like 6,000 tons of fuel for a cruise range of maybe 8,000nm at 16kt, (wiki credits 10,000, but this seems too high). Roughly, at the transit speeds of 12-14kt, she's burning maybe 250 tons a day and it takes 10 days to transit to the point where the oilers drop away. She's spent not less than about 2,500 tons to get there, and recieved maybe 2,000 tons from the refuelling force. She had about 1,000 extra tons loaded aboard, so at the point that the Akagi orders 24kt for the final run, she's got near to a full fuel load.

At the point of the final run in, the oiler forces had kept the carriers, cruisers and destroyers fully fuelled. This meant they were capable of about 3 days operations off Oahu, with the destroyers being the most vulerable. (These carried about 550 tons of fuel and burned about 125 tons a day during very high speed operations).

 

[Glenn239]

They had to deck load fuel in drums to accomplish what they did and have, as part of orders for the mission, the orders to scuttle the Destroyers if they didn't have the fuel or were slowing the rest of Kido Butai down and to make it back to the fuel rendezvous with the limited tanker support.

Wrong. The orders as per the Kenyo Trom were,

Nagumo's orders from Admiral (Fleet Admiral, posthumously) Yamamoto Isoroku (32), CINC, Combined Fleet, are that if refueling proves impossible in the stormy winter waters of the Northern Pacific, Nagumo is to detach AGAKI, SORYU and HIRYU and his destroyers and make the attack with only KAGA, SHOKAKU and ZUIKAKU.

So the destroyers would NOT have been sacrificed. On the overloaded fuel drums, this was not done because the fleet lacked underway refuelling capability, it was done as insurance against very heavy weather preventing refuelling. The striking force was provided with 8 (actually 7) oilers with 70,000 tons of supply. The force had about 50,000 tons aboard for a cruising radius of about 7,500nm, for a total of about 120,000 tons of oil available. That gave the force a total cruising range of about 18,000nm, on a mission that was actually about 8,000nm. Combat operations were much more expensive - maybe 6,000 tons a day vs. 2,200 a day at cruise speed. Still, with a 70,000 ton fleet train, Nagumo has the resources for an extended attack.

 

[steamboy]

The Pearl op was a real bum squeaker in terms of fuel loads and logistics for the Japanese, there was an Admiral who suggested that if it became necessary that the Soryu and Hiryu be abandoned and scuttled to keep the fleet operating longer if needed, or left out of the operation entirely. But when the Admiral in charge of that Division basically tried to physically assault the idiot who suggested scuttling his ships, the idea was quickly withdrawn.
Basically the IJN can't just sit around off the coast waiting for the USN to show up. The US would be sending reinforcements by air and then attacking the IJN, forcing them to move at high speed and air ops itself means you've got to go at high speed to get the wind across the deck needed.

Another issue was that the IJN had a weird high tempo for operating their CAP. They didn't really have a designated CAP but instead would send up aircraft as the air group commander of a specific carrier felt necessary, this meant lots of high speed steaming for short intervals whilst you're rotating your CAP. This wasn't needed on the way in but if you're now lingering off Pearl waiting for the US carriers to show up, then you're going to be running a lot of air ops as well as probably dodging a lot of bombs from B-17's or anything else the US can surge out as fast as they can.

And this is also for recon aircraft as well, and then you've no clue if the USN would show up to fight 2 against 6 even with Pearl's support.

And before you suggest it.

No

They can't invade.

 

[steel_captain]

I still believe the best scenario for Japan would have been a simultaneous taking of Midway on December 7th and then using it as a forward base to replenish the Kido Butai and then wait for the USN to try to get revenge. Then it is a question of how long our Navy would want to take before doing that? They could go pretty fast if it was just LEXINGTON and ENTERPRISE or longer if they waited for SARATOGA but that would have given the Japanese additional time to prepare their fleet for the next operation which in no way is advantageous for the Americans.

 

[Sekhmet_D]

Hence IJN aborting third wave attack --I'd thought second, but was mistaken-- and departing at best speed initially, slowing to fuel-economy when clear of plausible pursuit...

Given that the second wave achieved nothing significant, the idea of aborting it is actually rather interesting.

 

[CV12Hornet]

I still believe the best scenario for Japan would have been a simultaneous taking of Midway on December 7th and then using it as a forward base to replenish the Kido Butai and then wait for the USN to try to get revenge. Then it is a question of how long our Navy would want to take before doing that? They could go pretty fast if it was just LEXINGTON and ENTERPRISE or longer if they waited for SARATOGA but that would have given the Japanese additional time to prepare their fleet for the next operation which in no way is advantageous for the Americans.

Where do the Japanese get the sealift to try and take Midway, which was after all not an easy nut to crack? Their oiler capacity is a debateable topic, one I'm not going to wade into at the moment; transport capacity is not. Parshall and Tully's excellent article on invading Hawaii goes into some detail on this, but the tl;dr was that the Japanese were already straining their shipping pool to move all the troops they needed to move for the Southern Operation that Pearl Harbor is in service of and it's nearly impossible to move more troops without having to give up some sort of Southern Operation, which has been Glenn's move in the past. Glenn, though, has always been trying to invade Oahu, not Midway, and regardless of my opinions on that it's a far more defensible op than taking Midway.

Furthermore, even if they do take Midway it has several major problems as an advanced fleet base. For one, it's too small. The entire atoll is 40 kilometers square, which sounds like a lot of space until you have to cram it full of warships and auxiliaries with enough clearance to not swing into each other at anchor. Worse, most of the atoll is not usable; only a fraction was dredged to be deep enough to house oceangoing warships:

Apologies for the poor resolution, but the light blue area in the center is the deep part of the atoll. There's a reason it was mainly used for seaplanes and submarines.

On top of all that, remember what I said about shipping? That applies to ammunition and aircraft replenishment. Checking the TROMs, all of Japan's aircraft transports and light carriers were busy supporting their leapfrog advances in Southeast Asia, which depended on the air cover those ships could provide. Ammunition ships, I admit, were mostly idle and could be spared. Aircraft, too, are a problem. A while back I did a survey of what was on hand in Japan and it's pretty grim reading. No Zeroes, only a handful of Vals.

So to pull off this plan you need to pull aircraft and troop transports off the Southern Operation that's the entire point of running the Pearl Harbor Op in the first place, and you're weakening the opening strike to grab Midway. All to bait the carriers that, quite frankly, matter less for Japan's aims than the battleships.

Like, this is still when carriers are considered secondary attrition assets, not decisive battle forces. Philosophically, the Japanese wouldn't put this much energy into bagging two carriers, and given the strategic rationales of the Pearl Harbor op they're not wrong to think that. The USN, as we emphatically saw IOTL, was not going to steam west in force to try and bring the Japanese to battle with or without Enterprise and Lexington. They might have been pressured into it politically if they'd still had all their battleships, and that was what the Japanese were worried about.

In summary: not a good plan.

 

[steel_captain]

Where do the Japanese get the sealift to try and take Midway, which was after all not an easy nut to crack?

Two fleet carriers air groups launching a complete surprise attach on such a small facility should pretty much flatten everything there. Land a naval detachment to capture survivors and then use the lagoon just like we used Ulithi, Manaus, etc. A forward fleet anchorage. Japan needing the war to be short doesn't invest in occupying it with troops or to build facilities there except as a seaplane base until after the US carriers are dealt with.

I mean everything I put forth here is simply re the period of Dec. 41 to Dec. 42. Once the ESSEX class carriers start arriving in the Pacific, the IJN begins its long road back to the Home Islands. Japan never wins but starts the war in a much more painful way for the US.

And as far as SE Asian ops go, the IJN postpones what they must but can the USN allow Midway to be a base for the IJN after all they did at PH? Surely there would be tremendous pressure on the USN to get revenge and what the IJN wants is to humiliate the Navy who looked up on them as inferior because they are Asians.

 

[sparky42]

I’m not sure of the logic of dispersing the striking power before the Japanese know what they have hit in Pearl, I mean they could have got luckier and found at least a carrier there for all they knew at the time. Now on the counter point this is the Japanese military planning we are talking about and all the gambles/risks/insane dispersing they got up to in OTL.

 

[CV12Hornet]

Two fleet carriers air groups launching a complete surprise attach on such a small facility should pretty much flatten everything there. Land a naval detachment to capture survivors and then use the lagoon just like we used Ulithi, Manaus, etc. A forward fleet anchorage. Japan needing the war to be short doesn't invest in occupying it with troops or to build facilities there except as a seaplane base until after the US carriers are dealt with.

It didn’t flatten Wake, which had less of everything than Midway does even in December 1941. It still required a regimental assault and 600 casualties. You’re overestimating the effects of air attack in an era before smart bombs.

Also, reminder that Midway is much, much smaller than Ulithi and Manaus.

 

[mack8]

Actually taking Midway in December 1941 would have been far easier that it became later on. There were hardly any aircraft there, and how many ground troops? I'm sure a number much smaller that it became later on. I'm very interested to find out the number as of December 1941 though.

And with the benefit of hindsight, the japanese troops could come from the Guam invasion force. OTL the japanese prepared a large force for invading Guam expecting heavy resistance, it reality the Guam invasion was a walk in the park. So half or even 2/3 of that force could have been redirected to Midway. With Nagumo in the area, air support would have been plenty.

 

[steel_captain]

Also, reminder that Midway is much, much smaller than Ulithi and Manaus

But the ijn doesn't have anywhere near the number of ships that we had when we are at ulithi and manaus plus they would only need to use the lagoon for those ships that were being refueled and rearmed.

I can see the downside of this idea being that if the US does not take the bait and try to get revenge right away then Kido Butai can't just sit there waiting because there is violence to be done elsewhere. They certainly would taunt the US to send the best they could but if the USN just sits in PH, the Japan would get to call them too afraid to take on the masters of carrier aviation and win a big propaganda victory and then use their carriers and subs to effectively blockade the Hawaiian Islands using Midway to sortie from. Keep a couple carriers always lurking right offshore waiting for the moment the US carriers emerge from hiding? How could have Hawaii been used with IJN carriers a constant threat?

In other words, no Kido Butai running wild like they did in the 5months after PH but let the remainder of the navy capture the Dutch East Indies and blockade the Philippines. I know the KB was very active but how much so in capturing those island groups? Could they have been taken without the fleet carriers being present?