Earlier possible date for an six-carrier attack on Pearl HArbor?

You need to stop using Hearts of Iron as your standard for what can/can't be done.

It took something like 80-90 ships to move two Japanese divisions to the Phillipines for the invasion.

You're proposing an invasion of Hawaii with the same or greater number of troops in a scenario where the Japanese had barely enough fuel/tankerage to get a small sized task force into Hawaiian waters for 48 hours...
 
I don't want to get too worked up about it, but it might be worth noting that what is possible in wargames isn't always practical in anything resembling reality. Axis & Allies has probably caused more irate AH responses than any other single subject (Unmentionable Marine Pinnipeds included), and Hearts of Iron isn't far behind.

For a bit more analysis and information on the subject you could take a look here - the option you're discussing is right down the bottom, and labelled "The Really Gutsy Scenario". Spoiler alert: the author doesn't think it's practical, basically because of the lack of troops and sealift capacity.
 
You need to stop using Hearts of Iron as your standard for what can/can't be done.
I'm not using Heart of Iron, it isn't my standard for what can or can't be done, & your condescending tone has been noted. I clearly said that I haven't thoroughly researched the issue.

It took something like 80-90 ships to move two Japanese divisions to the Phillipines for the invasion.
That is-- to put it mildly-- ridiculous. James Dunnigan in "Victory in the Pacific" says that it took about 20 Liberty ships to move a US division-- combat-loaded. About 6 ships to send the same division "boxed". Since a Japanese division is smaller than a US division, with not nearly the heavy equipment & much leaner logistical requirements... I trust my point is made.

On the tankerage issue I concede that it's possible you're correct.
Thegn.
 
...what is possible in wargames isn't always practical in anything resembling reality.
Thank you for that observation. I'm aware of that. Not to get testy about it, I already said that my suggestion-- & it was just that, a suggestion-- was based upon first-glance appearances & hadn't been thoroughly researched.

So OK-- maybe it isn't a great idea.
Thegn.
 
I'm not using Heart of Iron, it isn't my standard for what can or can't be done, & your condescending tone has been noted. I clearly said that I haven't thoroughly researched the issue.

You said you were using wargames. HoI was an assumption, I play a lot of it myself and so know it's limitations.


That is-- to put it mildly-- ridiculous. James Dunnigan in "Victory in the Pacific" says that it took about 20 Liberty ships to move a US division-- combat-loaded. About 6 ships to send the same division "boxed". Since a Japanese division is smaller than a US division, with not nearly the heavy equipment & much leaner logistical requirements... I trust my point is made.
On the tankerage issue I concede that it's possible you're correct.

Japanese divisions were very large (18-24,000 for the divisions used in the Phillipines) and (I'd suggest) their ships were smaller than the US equivelent. Even 40 ships is a lot of shipping to move accross the Pacific, especially when there are other much more important targets than Hawaii - The Phillipines, DEI, Malaya - that all require shipping and troops.

EDIT: Here's a quote from the invasion of the Phillipines:

To the north, 24 transports with 7,000 Japanese troops aboard departed from the Ryukyu Islands, heading for Lamon Bay at eastern Luzon island.
. 24 ships for 7,000 troops.
 
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In regards to the troops needed, I would, as an off-the-cuff estimate, say 5 divisions, if you can ensure everything goes right. Mind, this really is nothing more than a wild stab, but as the US had 2 divisions in Hawaii, I'd say that 5-2 is probably a reasonably good ratio for numerical superiority if they could ensure that the Japanese had air superiority.
 
EDIT: Here's a quote from the invasion of the Phillipines:

. 24 ships for 7,000 troops.

I did some quick calculations based upon the numbers given in Willmotts "Last Century of Seapower" and it would seem that Japanese merchant ships at the beginning of the war averaged about 5000-7000 tons (with half of their merchant marine under 1000 tons). Liberty ships were two to three times this size so numbers given for US shipping requirements are not reliable applied to the Japanese.
 
...I would, as an off-the-cuff estimate, say 5 divisions...as the US had 2 divisions in Hawaii, I'd say that 5-2 is probably a reasonably good ratio for numerical superiority...
That isn't a bad ratio for orthodox military planning, but this is a shoestring operation. We've established that tanker capacity is at a premium. (Although why is a mystery to me, since cargo ships ply their way across the entire Pacific all the time without refueling. Tankers are needed for hi-speed warships, but a troop transport is essentially just a big cargo ship, so they wouldn't even require any additional tankerage-- but let it go.)

It's also a surprise attack. Given the chaos that prevailed at Pearl during the air raids, if you land even a single division at dawn & rush the bases then you can catch those 2 American divisions before they even issue their small arms. Their artillery will be in their motor parks, which you'll capture relatively intact, along with an entire strategic reserve of desperately needed fuel & all sorts of other lavish American supplies.

As George C. Scott said in the role of Patton, misquoting Georges Danton--"l'audace, l'audace, toujours l'audace".
Thegn.
 
And where do you think the air support for this invasion is going to come from? The very same carriers that couldn't hang around.

There was also a crap-tonne (metric) of coastal artillery all around Hawaii, and a great many ships that survived the attack that could and would slaughter your invading forces troop ships while the PH attack force sailed back over the horizon.
 

nbcman

Donor
That isn't a bad ratio for orthodox military planning, but this is a shoestring operation. We've established that tanker capacity is at a premium. (Although why is a mystery to me, since cargo ships ply their way across the entire Pacific all the time without refueling. Tankers are needed for hi-speed warships, but a troop transport is essentially just a big cargo ship, so they wouldn't even require any additional tankerage-- but let it go.)

It's also a surprise attack. Given the chaos that prevailed at Pearl during the air raids, if you land even a single division at dawn & rush the bases then you can catch those 2 American divisions before they even issue their small arms. Their artillery will be in their motor parks, which you'll capture relatively intact, along with an entire strategic reserve of desperately needed fuel & all sorts of other lavish American supplies.

As George C. Scott said in the role of Patton, misquoting Georges Danton--"l'audace, l'audace, toujours l'audace".
Thegn.

The IJA wasn't set for a rush. They were a foot infantry force with horse & mule transport. There were, at a minimum 3 Army Air Fields, 3 Naval Air Stations, multiple Coastal defense batteries, and multiple Army bases. The IJA division couldn't neutralize them all - plus the IJN had to leave immediately or they were going to have some ships stranded at sea without fuel.

You should read the Combined Ops article:

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

for a cogent discussion of the limitation of the Japanese and the impossibility of a Hawaiian invasion while conducting the OTL operations (such as the Philippines, Malaya and other ops).
 
I entirely agree that it was a tight time-window & that going significantly earlier or very much later weren't very realistic options.

...however, the thing that bugs me about the Pearl Harbor attack was Japan's failure to follow up by landing troops. I understand that transports would have had trouble keeping up with carrier task forces, so send 'em earlier. Don't break radio silence for position reports-- use scout planes. After a devastating surprise attack, it seems to me a necessity to land troops.
Thegn.

It cant be done. They can't supply any invasion force across the Pacific, the Carriers were already on the edge of their range and to launch an invasion afterwards is impossible. They would run out of fuel and supplies and the last thing Japan wanted was to risk almost all of it's Naval power in an extremely risky engagement.

How would you supply the invasion force after they have landed? The logistics are impossible. It relies completely on capturing all the American supplies depots and completely overwhelming the garrisoned divisions. If that fails then what? You have lost four or five divisions of men who will bleed out from lack of supplies. Supplies aren't going to come from across from Japan or her home islands, it's way to far for a round trip.

No sane military would do this, and don't try and argue the Japanese were insane or anything, because they weren't. Made some false assumptions about American war willingness, but this was not some suicidal, poorly thought out plan. Also, the Americans would be on high alert after this, and to think they will crumble just like that is stupid. You don't base an invasion plan on hope, you plan an invasion with the worst case scenario in mind. Look at D-Day, the allies had almost ten to one numerical advantage and it took weeks to break out. The Americans can also bring reinforcements across a much shorter distance and you can guarantee that reinforcements would be screaming from California and the Pacific chain.

This is basically the Bible on the subject http://www.combinedfleet.com/pearlops.htm
 
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Flubber

Banned
Don't know how IRL it is, but in a wargame...


Good sweet Christ... If I had a dollar for every fantasist I've come across a gaming conventions over the decades who truly believe war games are anything but a distant reflection of reality I'd be retired on my own South Seas island by now...

"Well, I could most certainly beat Rommel because I win at Afrika Corps all the time..." Sure you could, sure you could... :rolleyes:

I see that a few others have already given you the Combined Fleet site's URL so I'll limit myself to the thinking and planning behind the Pearl raid.

Because Pearl was so wrenching to the US too many believe that Pearl was the centerpiece of Japan's plans in December 1941. Pearl was nothing of the sort actually. It was a last minute addition, an addition suggested by Taranto and an addition which Yamamoto had to threaten his resignation in order to get adopted. Every asset used at Pearl was already slotted into other operations which had been planned for over a decade and, in Japan's eyes, those operations were more important than Pearl.

The IJN barely had the fuel capacity to get the Kido Butai and it's escorts to Hawaii, let alone the transports necessary for an invasion. The IJA released so few divisions for the "Lunge to the South" that many had to perform double and even triple duty so none would have been available for Hawaii.

Pearl was a gamble added late in the game and Pearl wasn't the most important part of the game.
 
Its not so much a question of whether it was possible to invade Hawaii but whether the Japanese were willing to accept the probability of losing these troops (who presumably would have had to be elite), their transports, the tankers and possibly the carriers, because the logistics of it all would interconnect.

Best Regards
Grey Wolf
 
Its not so much a question of whether it was possible to invade Hawaii but whether the Japanese were willing to accept the probability of losing these troops (who presumably would have had to be elite), their transports, the tankers and possibly the carriers, because the logistics of it all would interconnect.

Best Regards
Grey Wolf

Exactly, it was not a sane move, you were risking a lot, against the odds, for what is guaranteed to be a bloodbath. If you fail, you lose all your carriers, those troops and god knows how much supplies.
 
(Although why is a mystery to me, since cargo ships ply their way across the entire Pacific all the time without refueling. Tankers are needed for hi-speed warships, but a troop transport is essentially just a big cargo ship, so they wouldn't even require any additional tankerage-- but let it go.)

Long-haul freighters moved at 9-10 knots for maximum fuel economy. Invasion transports have to move at 16-20 knots to get to the target in a reasonable amount of time - and fuel consumption is roughly the square of speed. Also, long-haul freighters get to refuel at the destination

This particular troop convoy has to move especially fast, because it has to avoid detection in an ocean basin that is not controlled by its side. The movement is in peacetime, and there are thousands of non-Japanese ships and hundreds of non-Japanese planes roaming around the Pacific. Yes, the northern Pacific is relatively untravelled - but a convoy of a hundred or more ships stooging around for weeks is very likely to be seen by somebody.


It's also a surprise attack. Given the chaos that prevailed at Pearl during the air raids, if you land even a single division at dawn & rush the bases then you can catch those 2 American divisions before they even issue their small arms. Their artillery will be in their motor parks, which you'll capture relatively intact, along with an entire strategic reserve of desperately needed fuel & all sorts of other lavish American supplies.

I'm extremely tempted to ask a very rude question here. Instead, I'll just note that this is very close to the platonic ideal of a wank. I suggest you look at the Japanese landings in Malaya and Thailand, which were made with surprise against very weak forces, and stillmet substantial resistance. (Thai forces, which had no reason whatever to expect Japanese attack, and amounted to at most a couple of battalions, fought for several hours, inflicting hundreds of casualties, before surrendering on orders from their government.)

And I'll add two points.

The south coast of Oahu was fortified against attack, with numerous strong points and several batteries of coast artillery (up to 14" caliber, IIRC). A landing there would require massive naval gunfire support, air cover, and overwhelming numbers - none of which the Japanese could have had.

The north coast of Oahu was not fortified. It's where they hold the world surfing championships. Troops in full kit, trying to come ashore in small boats or rubber rafts amid 20 and 30 foot breakers? Giggle.
 

CalBear

Moderator
Donor
Monthly Donor
That isn't a bad ratio for orthodox military planning, but this is a shoestring operation. We've established that tanker capacity is at a premium. (Although why is a mystery to me, since cargo ships ply their way across the entire Pacific all the time without refueling. Tankers are needed for hi-speed warships, but a troop transport is essentially just a big cargo ship, so they wouldn't even require any additional tankerage-- but let it go.)

It's also a surprise attack. Given the chaos that prevailed at Pearl during the air raids, if you land even a single division at dawn & rush the bases then you can catch those 2 American divisions before they even issue their small arms. Their artillery will be in their motor parks, which you'll capture relatively intact, along with an entire strategic reserve of desperately needed fuel & all sorts of other lavish American supplies.

As George C. Scott said in the role of Patton, misquoting Georges Danton--"l'audace, l'audace, toujours l'audace".
Thegn.

The Japanese COULDN'T logistically support a strike on Pearl. It isn't possible, given their available shipping, the needs for what shipping they had to supply the Army in China and, perhaps in one of the most ignored facts of WW II, the need to import enough food to FEED THE COUNTRY. Japan lacked sufficient merchant bottoms, pre-war, to supply the needs of the Home Islands. The need of the Home Islands for imported food is best illustrated by the starvation conditions that the U.S. submarine offensive (and the less well known, but spectacularly successful, USAAF mining campaign) imposed on the Japanese population.

Something like 90% of the world's merchant ships in 1940 were U.S., UK or Western European registry. None of those were available to the Japanese once the U.S. Trade Embargo was emplaced and the UK engaged in the Battle of the Atlantic (the shipping from the occupied European states that were not taken in port by the Heer fled to the UK or U.S. where they were used to send supplies to Britain). This reality put the Japanese at a massive, more or less unsustainable disadvantage whenever logistics came into play. This is demonstrated quite nicely by the fact that the Japanese had to DECK-LOAD fuel drums on several of the Kido Butai carriers to allow the force the range to strike at Pearl. The Pearl attack force also had just enough fuel to get home after the raid, it had zero loiter time available. There is a significant difference between supplying a lightning raid and supporting a long term invasion effort.

Next you have the reality that the Oahu was quite well defended. There were multiple divisions on the Island, and substantial shore defenses. Japanese tactical doctrine took as an axiom that gunfights between ships and forts would always result in defeat for the ships (see some of Yamamoto's comment regarding the chances of taking Midway after the Kido Butai was lost). Japanese Navy doctrine was much more than advice, it was Holy Writ. In the case of Oahu it was also correct.

Japan also simply lacked the available troops. The lightning advance across the Pacific used, in aggregate, less than five divisions, with units both doing double and triple duty, going from one invasion straight into another without any refit time, and in virtually every case traveling only a few hundred miles from base to launch their assaults (the Philippine force was embarked in large part at Formosa, the Malaya force in Thailand and Vietnam, Guam from Saipan, etc.). Many of the IJA units were also only on short term loan from the main effort against China.

Lastly, and perhaps most critically, Hawaii was not important to the Japanese plans. They could not hold the Islands, again a logistical impossibility, and every soldier used their took away from the real goal of the Pacific War, gaining access to the Southern Resource Area and securing a defensible perimeter. Starting a war with the United States at the cost allowing the British to massively reinforce Malaya with regular Indian Army units and allowing the troops there to actually be prepared for an assault would have been utterly insane. The same can be said for the Philippines. Even MacArthur could have held the Islands for a year if he had actually had a couple months to get his act together (the SOB could plan, and he had a decent staff, as long as they didn't have to think on their feet). Recall that the IJA had less than 6 month of oil reserves in December of 1941, they had to have the DEI oil, and they had to have it immediately.

Audacity is a good trait, assuming it is tinted with a touch of common sense. Invading Oahu would have been an epic example of a lack of common sense.
 

CalBear

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...

The north coast of Oahu was not fortified. It's where they hold the world surfing championships. Troops in full kit, trying to come ashore in small boats or rubber rafts amid 20 and 30 foot breakers? Giggle.


November to February is also the peak season for the big breakers. They are generated by the winter storm coming out of the Gulf of Alaska.
 
Thegn said:
the thing that bugs me about the Pearl Harbor attack was Japan's failure to follow up by landing troops.

Thegn said:
To the Japanese militarists who planned Pearl Harbor, this kind of defensive set-up would have looked eminently reasonable.
Leave off it was completely impossible, since Japan had neither the sealift nor the troops, nor would IJA agree to it.:rolleyes:

Actually, it wouldn't have looked reasonable at all. They could read a chart, & they weren't complete morons. (Not complete...:rolleyes:) They knew how long the LOCs were. And they knew how committed they were in China. It would have been a mostly IJN show, so for that reason alone, IJA would never go along. Plus they needed all the troops they were pulling out of China & Manchuria (where they'd been waiting for a chance to attack the SU again since 1939...:rolleyes:) for ops in SEA. Plus Japan didn't have enough shipping to sustain her economy as it was, after the IJA/IJN requisitions.

You're treating it with hindsight. Japan never intended to actually occupy Hawaii. That was never, never ever, an objective. The idea wasn't to piss off the U.S. so much she'd come over & stomp Japan flat.:eek::eek: The idea was, smack the Pacific Fleet hard enough it wouldn't be able to interfere while Japan took over the Dutch East Indies & built an "impregnable" barrier defense. (It never would be, since IJN ASW doctrine was a joke, but that's another thread.:rolleyes:)

In short, beside impossible, it was simply never considered.

BTW, "set the war back a year"? Not if the Pacific Fleet Sub Force is concentrated in San Francisco. Hawaii is closer to SF than Japan is to Hawaii, & with all the boats, staff, maintenance personnel, & repair in one place, you've maximized the transfer of information, & made upgrading all the boats much easier & quicker.

If Japan has to supply Hawaii, the Sub Force can stage into Midway (which should rapidly be upgraded as it was OTL) & shoot Japanese transports with abandon.

Plus, you've avoided splitting the command, which makes hiding the Mk 14's problems harder.:cool: Plus you've opened the Luzon Strait, which is hell on Japanese shipping later on.:cool::cool::cool:

You end up actually shortening the war compared to OTL.:cool:
 
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