The invasion of Oahu, December 1941.

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glenn239
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Post by glenn239 » 28 May 2007 23:48

So Japanese mini-subs never torpedoed an underway ship during the war. Here, not only do they have to do something that never occured, but they need to do it just as the blockship makes its run.

The reason I didn't include much on submarines is because they tended to exert a statistical pattern of attrition, predictable over the course of time but completely random on a per-engagement basis. So, the 'hoops' to jump through here are:

1) Mini subs must first accomplish a feat never performed during in war.
2) They must do it in a very narrow timeframe, and not soon enough to alert the base prior to the attack.
3) Only one warship can be on guard in the restricted zone.
4) The coastal defenses have to be mostly unmanned.
5) The blockship has to move quickly to the channel, but not too quickly that it grounds.
6) The blockship (no doubt now being shredded) has to make soundings as it goes, to discover the point to sink.
7) It has to sink itself in a way to block the channel.

Any comments on the thread other than commando attacks/blockships?

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Blockship responses ...

Post by robdab » 29 May 2007 08:33

Glenn,
in the order that you posted ...

"I didn't include much on submarines is because they tended to exert a statistical pattern of attrition, predictable over the course of time but completely random on a per-engagement basis. " > I'll bet that the captains of the Royal Oak, the Tirpitz, the Barham, those British battleships at Alexandria and the Japanese heavy cruiser Takao would hasten to disagree with you. Submarines often succeeded at special missions for all sides in WW2.

"1) Mini subs must first accomplish a feat never performed during in war." >I've already demonstrated a very close PH "almost" in my just previous posting.

"2) They must do it in a very narrow timeframe, and not soon enough to alert the base prior to the attack."> Historically the Ward attacked (and sunk as finally proven in 2002) a minisub at about 0645 but no effective warning went out to the other US defenders of Oahu prior to the surprise Japanese air attack at 0755, some 70 minutes later. She was only able to do so because the USS Antares spotted that minisub trying to follow her into the PH ship channel. Had the 5 minisubs been ordered to stalk the Ward instead so as to aid a blockship attempt instead, then those 5 minisubs would have been nowhere near Antares to be spotted at all. My scenario suggests the sinking of the Ward at about 0730 resulting in 45 minutes LESS possible warning time and the silencing of the naval unit most likely to report the Japanese minisub presence, the USS Ward. How does this increase the risk of loss of surprise to the Japanese ?

"3) Only one warship can be on guard in the restricted zone."> Historically there was ONLY one US warship, a DD, on watchdog patrol, which on that morning happened to be the USS Ward. The Japanese consulate staff in Honolulu would have easily known it too. Although with 5 minisubs AND 5 more submarine motherships available, further US 'gatekeepers' could easily have been dealt with anyway.

"4) The coastal defenses have to be mostly unmanned."> Just as they WERE historically. Except for two examination batteries, most of the CA battery positions were only manned by anti-sabotage sentries, NOT by full gun crews ready to instantly open fire. General Short admitted under oath that NOT A SINGLE ONE of the 100+ CA fire control, range finding or observation bunkers scattered around the high ground of Oahu were manned that morning so on what basis do you dispute the inability of the majority of US CA batteries to speedily open fire on an approaching blockship ? I have yet to see you provide even a single reference in support of your 'opinions' while I have provided several in support of mine.

"5) The blockship has to move quickly to the channel, but not too quickly that it grounds.">Yes, and so what ? My just previous post answers these concerns quite well, I believe. Provided that the helmsman can steer a straight course, more speed will reduce the amount of time under the fire of the examination batteries. In fact, a prepared alternate steering position down below would have been a good idea just in case an examination battery got lucky and hit the bridge/wheelhouse directly. Other than that possibility, more speed might be needed to help the blockship crash the anti-submarine net which historically remained OPEN until almost 0900, long after my blockship would have passed thru/over. That rusted old salt water soaked net was btw of 1918 vintage, was composed only of thin anti-torpedo mesh, had NO conrtact mines attached to destroy ships or submarines attempting to crash thru/over/under it and was only held closed by two small tender vessels rather than a strong cable slung from shore to shore across the full 100 yard dredged channel width. The bridge wing AA guns of a fake 'Jagersfontein' blockship could easily have taken care of those two tenders had they tried to close the nets earlier than happened historically.

"6) The blockship (no doubt now being shredded) has to make soundings as it goes, to discover the point to sink."> Glenn, my "throwing the leadline" comment was a JOKE, a JOKE man ! The Japanese consulate officials could have easily determined the "best" blockship location by talking directly with the small army of native Japanese construction labourers who worked annually for the civilian firms hired to dredge both Pearl Harbor AND the ship channel leading from the ocean, into it. In any case. a blockship of some 60' from keel to main deck level IS going to block that channel whether she settles in 75" of water or 40' of water. It matters little.
>In fact your "being shredded" comment is the only one that goes to the heart of this matter. Can either of the 2x3" or the 2x6' examination batteries sink or shift from her course, a blockship BEFORE it enteres the PH ship channel, or not ? I have posted three sourses in supprt of my position, while you haven't posted anything yet but your unsourced opinions.

"7) It has to sink itself in a way to block the channel."> But that IS what blockship crews are trained to DO ! A ship the size of 'Jagersfontein' is 265' in length. If turned sideways across the 100 yard wide dredged ship channel and sunk while at anchor, I think that a vessel of her size (or larger) would have made a fine "cork in the bottle" and would have completely blocked that ship channel for the few days/weeks necessary for the IJA/IJN to completely pulverize the US Pacific Fleet thereby trapped inside of Pearl Harbor. Its not my fault that you still refuse to include this tactic as a part of your "Invasion Oahu" plans.

And finally:"Any comments on the thread other than commando attacks/blockships ?">Hundreds. As you know, I've already sent you dozens of corrections which you have been editing into your original 20 postings (thanks for the credits wrt ammunition information supply btw) which started this thread. So far I have only been supplying factual corrections with the occassional target suggestion, but NOT yet beginning the debate on whether or not your theories make any logical sense at all.

It is apparent that you do NOT agree with my blockship proposal, and will NEVER be convinced as is evidensed by your earlier April 29th posting to Chris wherein you stated," "Totally gay", as in, "blocking the entrance to the harbor is a totally gay strategy" means that the plotters of such a move would have to conduct themselves with a disconnected sense of joyous levity in order to arrive at the conclusion such a move was a feasible method by which to barr the US Pacific Fleet from obtaining access to the Pacific Ocean." > It is apparent that your mind was made up from before the start of this blockship discussion and that you do NOT intend to be swayed by the facts that anyone else presents. You have consistantly engaged in debate all the while refusing to provide sources in support of your 'opinions'. Could it be that there are NO sources to backup your opinions because they are totally wrong ?


Please correct me if I am mistaken but I thought that your stated objective (in that April 29th posting) was to solicite ONLY "final fact-checking" corrections here on this discussion board BEFORE taking this entire thread to another discussion forum to begin the real debate ? I have been "keeping the poisoned daggers sheathed" in the spirit of that statement. Please let me know if that was a mistake on my part, won't you ?

I certainly hope that when the real debate begins, you are better able to defend your opinions, with sources, rather than with just vague recollections that may or may not be relavent.

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Post by ChristopherPerrien » 29 May 2007 12:07

In any case. a blockship of some 60' from keel to main deck level IS going to block that channel whether she settles in 75" of water or 40' of water. It matters little.
About the only ships that had such dimensions are aircraft carriers and some battleships.

Herein lies a problem with a blockship, only the hull and some parts of the superstructure provide the obstacle . Cruisers draw 20' of water and battleships draw 30' so sinking a ship of moderate size (cruiser) with a hull height of 40' (keel to deck) in 75' ft of water will probably not block anything but battleships. And with a 100 yard channel even that is highly problematic as the beam(width) of most ships, even BB's, was at most 115' feet( the width of the Panama canal, IIRC). So they can go around it.

Hard to sink a ship perfectly, lengthways, and dead center across a channel especially if you,approach at night, don't know the channel, can't anchor it properly at all, are being raked by MG and probably cannon fire, and are on suicide mission to begin with.

The block ship will have to be a good size ship and get to the 40' depth channel to have a possible chance of working And even if it works , there is nothing to stop US divers from blowing the thing apart to clear the channel. Which they would quickly do in such an emergency, so it better be a tough ship. I would use an old cruiser.

Also, when you use this ship, along with the rest of the Japanese navy and about 1/5 of their merchant fleet, to launch this attack, don't forget for the last few(2-3) days you are within the aircraft search range of Hawaii and probably a few other islands , and/as many/most of these ships are alot slower than the 1st Airfleet task force. So even if the US doesn't hear this white elephant approaching ,which I severly doubt, They will probably see it a few days away, and all takes is a couple hours warning to end up with a very very dead pachyderm. And underneath it, a prostrate Japan.

Chris

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Pearl Harbor Ship Channel ...

Post by robdab » 29 May 2007 14:27

Chris,
thanks for re-joining the debate but I believe that I can rebutt most of your points.

If you'd be kind enough to try http://www.derbysulzers.com/shipasamamaru.html you'd see info about the Tatsuta Maru, a Japanese cargoliner of draft 28.5' and speed of 17.5 kts. The photo isn't scaled but I don't think that 60' keel to main deck is an unreasonable estimate for this puppy, at all. In fact, I think that it's too low of an estimate. And as you can also see, her superstructure runs for most of her length of 564 feet. Even if only turned to 45 degrees in the 300' wide PH ship channel she IS going to plug it. There ain't nothing US much bigger than a PT boat thats going to get around/over her. No need to use a slow, old cruiser at all.

And her 17.5 kt speed combined with an overnight run in of some 210 miles (12 hours of darkness at that time of year for Oahu) for dawn PH arrival ensures that she will only be within effective US airsearch range after the sun comes up. Not that the US defenders were flying any effective long ranged air searches in the weeks proceeding Dec.7'41 anyway. Even IF spotted outside of 210 miles from Oahu, why would she arouse suspision at all ? Just a lone civilian cargoliner on her way across the Pacific on her usual scheduled commercial run. In peacetime.


And to top it off she, her captain & crew had just been to Oahu on a repatriation run in late October 1941, on top of her years of experience of passing thru Honolulu as a regular part of her Yokohama to San Francisco trans-Pacific run. So, she and her crew well knew the waters and had many opportunities to have toured at least one side of that ship channel AS WELL AS rented a private sight-seeing plane to overfly it, at least obliquely. Surely "good enough" recon for proper and thorough mission planning, don't you think ? Hardly "strangers in a strange land" when trying to position a blockship.

The run up the ship channel would NOT be at night at all. Since Ward would be torpedoed 0715-0745 or so I would envision Tatsuta'a high speed rush at 0745-0815. Far too late (indeed an 0755 air attack might already be underway) for an effective warning to be sounded throughout the numerous non-unified Oahu defense commands, early on a peacetime Sunday morning. I do agree that proper scuttling positioning would be very critical which is why I suggested the use of anchors to aid in that goal. Yes, she would be shot up by the 2x3" and/or 2x6" examination batteries but do you really see those size of guns sinking this 17,000 ton monster in time for her to NOT block the shipping channel, especially after she gets to the 40' depth portion of that channel ?

Sure, given weeks or months, US divers could blow/cut her up and clear the wreckage from the shipping channel. Afterall they DID clear most of the wrecked USN warships from PH eventually but assuming that a Japanese invasion landing is fairly close behind the block attempt, there WON'T be anywhere near enough time to even get started on that task. Glenn seems to be suggesting a battleship bombardment of the USN ships in Pearl Harbor rather than the initial historical air strikes but whichever way they are attacked, a US Pacific Fleet trapped inside of Pearl Harbor won't last long enough for divers to clear the Tatsuta. With or without igniting the oil tank farms. Even if US divers notice the numerous additional seacocks installed thru her bottoms, it would still take days/weeks to pump her dry and refloat her. And with other more urgent tasks like rescuing US sailors trapped inside of overturned hulls in PH, I think it unlikely that the few hardhat divers available (no SCUBA yet, I believe) would get to work on Tatsuta right away.

No stampedeing white elephants in sight, at all.

I see that you are back to your ponderous assertion that the US absolutely MUST spot/decode/radio-intercept any Japanese invasion fleet headed for Oahu. I must say that I have yet to see the proof of your theory. Just endlessly repeating it, won't "prove it" to be the most likely outcome. Historically, the US missed the Kido Butai completely AND the majority of the Phillipines invasion force, as well. Why would a hypothetical Hawaii invasion force, comprised of most of the same Japanese military units, produce a markedly different result ?

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LWD
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Post by LWD » 29 May 2007 14:38

Weren't there defencive mine fields around the entrance to Pearl?

robdab
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PH Minefields ?

Post by robdab » 29 May 2007 14:55

Not since 1929 when the WW1 vintage electrically fired minefields (then called torpedoes ?) off of PH and Honolulu were removed because of maintenance and explosives stability issues. Its not good for business or security if you accidentaly blow up your own shipping as it is headed into port !

The USN did indeed stockpile several hundred newer mines at its Oahu West Loch and Lualualie ammunition depots but NONE had been deployed by mineplanter vessels before Dec.7'41. I believe that there were 6 converted ex-destroyer fast minelayers posted to the US Pacific Fleet at that time but I would have to check to be sure. Yet another good reason to cork that PH ship channel asap, isn't it ?

It seems that Short/Kimmel/Washington assumed that there would be more than enough time to deploy mines AFTER hostilites started because no nation would be foolish enough to attack Fortress Oahu ?

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Post by ChristopherPerrien » 29 May 2007 17:17

robdab wrote:Chris,

I see that you are back to your ponderous assertion that the US absolutely MUST spot/decode/radio-intercept any Japanese invasion fleet headed for Oahu. I must say that I have yet to see the proof of your theory. Just endlessly repeating it, won't "prove it" to be the most likely outcome. Historically, the US missed the Kido Butai completely AND the majority of the Phillipines invasion force, as well. Why would a hypothetical Hawaii invasion force, comprised of most of the same Japanese military units, produce a markedly different result ?
Jee? Please read "Days of Infamy". past that.

Do you even give thought to the scale of the operation being talked about here, or the fact that the distances involved make the PI invasion look like a hop across a puddle. This operation is similar to scale of the US invading Saipan in 1944 , and Saipan had no huge navy base or airforces on it. If you think the Japanese could mount such such an invasion IN 1941, it flies in the face of logic.

Had they ever remotely attempted any invasion on that scale? no , Did they have any idea how to do it? no, Moved that amount of equipment?, no, Landed in the face of opposition? no, Coorordinated a massive aerial assault with a massive amphibious invasion ? no.

Using the excuse that the 1st airfleet(10 major warships) 'historically" managed to get close enough to launch ONE air attack, to say that the US would not eventually know of this elephant when it was being assembled, or when it left , or when it got over ON THIS SIDE OF THE GLOBE is beyond reason. As it was the Japanese were worried as hell that the 1st Airfleet would be discovered, Do you think they would even remotely consider thinking they could sneak 200? ships, in god knows how many groups, to within sight of Hawaii , to achieve suprise? And they are going to perfectly coordinate the movements of these ships for the entire voyage(2 weeks) and the attack approach using total radio silence?

I see no need to prove the obvious. Prove it ain't true. Find(source) me some discussion by the Japanese on the feasibility/planning of/for this attack, even if it was quickly dismissed.

On the subject of intelligence , here we are talking about an invasion/operation using perfect 2007 information about the targets and tides and military forces and their dispositons and etc., for the entire Hawaiian island chain and I guess the entire US military presence in the Pacific. Do you think the japanese had 1/100 of this info to plan this operation? Need I bring up that they thought there were 4 US carriers in the Hawaiian area just for the "air-raid" to show how imperfect their intelligence was on something so vital and, you would think ,much easier to ascertain than all the intelligence required for this operation.

I have said it alot, in many topics and in many ways, you cannot exclude the effects of intelligence in the study of the Pacific War. The US had an advantage even before the war started and it got better as it went. In comparision I would rate Japanese intelligence for the war as "non-existant", even worse a "non-existant detriment", becuase they seemingly and consistently used "wishful thinking" as a substitute. Yet even the Japanese never considered invading Hawaii.

This is why wargaming or theorizing "what-if's" about the Pacific War is usually so unrealistic , as the intelligence side of the war is left out. Because with that lop-sided, and historic, advantage the US will always win.

Unless you do a second phase consolidation :wink:

Chris

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Post by LWD » 29 May 2007 17:40

There was also the fact that a lot of attention was centered on the Japanese BBs. One of the reasons the US wasn't particularly worried is that they had a pretty good idea where the Japanese BBs were and also knew where a bunch of Japanese transports were. If the Japanese battle fleet "disappeared" at the same the carriers there would have been much more concern. Even if the Japanese fleet were not sighted the odds are the US miliary would have been at a much higher level of readiness across the Pacific and at Hawai in particular. If the word was out to expect an air attack as a prelude to naval bombardment there is a very good chance that for instance the radar report would have been percieved for what it was and the initial Japanese attack met by US fighters before it could bomb PH. Torepedo nets may also have been deployed rendering the torpedo attacks uselsess while AA fire would have made life much tougher on them.

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Post by glenn239 » 29 May 2007 19:23

CA fire control, range finding or observation bunkers scattered around the high ground of Oahu were <un>manned that morning so on what basis do you dispute the inability of the majority of US CA batteries to speedily open fire on an approaching blockship ? I have yet to see you provide even a single reference in support of your 'opinions' while I have provided several in support of mine.
The references I used for the chart on coastal defenses, including which were manned, are listed in the “Coastal Artillery” post – they are from Congressional Hearings, pg 3172 of vol 30, and Vol 15, 1447 and 1448.
Sure, given weeks or months, US divers could blow/cut her up and clear the wreckage from the shipping channel.
The USN would have to weaken the structure of the ship sufficiently to allow a ship to plow through the shattered remnants and out to sea. If I had to hazard a guess, I should imagine that in an emergency they’d take 500lbs and 1000lbs HE bombs from Hickham and start pummeling the wreck as quickly as possible.
This operation is similar to scale of the US invading Saipan in 1944 , and Saipan had no huge navy base or airforces on it. If you think the Japanese could mount such such an invasion IN 1941, it flies in the face of logic.
When the IJA cut orders for the invasion of Oahu in 1942, they earmarked 3 divisions for the assault – the same number as here.

The number of men defending Kauai, Maui, Molokai and Hawaii is listed in the “Bases of Hawaii” post on page 1. The sum total of these garrisons was only a tiny fraction of the Japanese units on Saipan and the rest of the Marianas islands. As such, the operations are not comparable, since the United States had neglected the basic rule of defense on these islands – to make sure you have one. As noted, had Rainbow Five been a better war plan, the weaknesses which left the other islands open to occupation would have been addressed, which then would have made an invasion practically impossible. (Note: had the Japanese forgotten or neglected to garrison all but one of the islands of the Marianas group, the analogy would be on more solid ground, save for the fact that Japanese support bases were much closer to Saipan than the 2,000 miles from San Francisco to Oahu.)

With respect to the anticipated nature of an IJA landing on Oahu, see the IJA doctrine post.
Using the excuse that the 1st airfleet(10 major warships) 'historically" managed to get close enough to launch ONE air attack, to say that the US would not eventually know of this elephant when it was being assembled, or when it left , or when it got over ON THIS SIDE OF THE GLOBE is beyond reason.
If you could provide a more detailed analysis to support your contention, that might be helpful. For example, LWD writes,

There was also the fact that a lot of attention was centered on the Japanese BBs. One of the reasons the US wasn't particularly worried is that they had a pretty good idea where the Japanese BBs were and also knew where a bunch of Japanese transports were.

(Note also that the Pearl Harbor strike force and the Midway Destruction Unit totalled about 31 ships).
Please correct me if I am mistaken but I thought that your stated objective (in that April 29th posting) was to solicite ONLY "final fact-checking" corrections here on this discussion board BEFORE taking this entire thread to another discussion forum to begin the real debate ? I have been "keeping the poisoned daggers sheathed" in the spirit of that statement. Please let me know if that was a mistake on my part, won't you?
“Poisoned daggers” is an odd statement.
Historically there was ONLY one US warship, a DD, on watchdog patrol, which on that morning happened to be the USS Ward
Two warships were on patrol – USS Ward and the minesweeper USS Condor.

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Now this is finally beginning to be a healthy debate ...

Post by robdab » 29 May 2007 20:58

Glenn,
basically our two different CA sources disagree on two basic points: 1.) the number of 240mm howitzers (and their pre-built firing bases) ready to go to war on Oahu and 2.) was Battery Williston (2x16") at Fort Weaver manned and ready to fire instantly at dawn on Dec.7'41 ? Apparently further research/sources are needed before one of us can convince the other of "the truth" wrt these two points.

I just don't see any USN commander being happy with the prospects of his delicate rudder(s) and props chewing their way thru the "shattered remnants" of a 17,000 ton blockship. Even the slightest damages there would make the ship a sitting duck against any form of Japanese attack. More likely would be the use of several rotary suction dredges in an attempt to dig around whichever end of the blockship showed the best positioning for such an effort. I know that there were at least 2 and maybe 3 shallow-water barge mounted dredges within PH that day. My blockship was never intended to be a permanent obstacle, rather to just cork up that ship channel for about a week while the burning fuel oil, the IJN battleline and/or the Kido Butai's aircraft chewed almost the entire US Pacific Fleet out of existance. And if bombing an already sunken wreck then the USAAF and/or USN aircraft still surviving are NOT out air searching for the invasion fleet, the bombardment fleet nor the Kido Butai, are they ? What an excellent distraction for the benefit of the Japanese attackers. I wish that I had thought of it first !

"Poisoned daggers"s NOT an odd statement at all if you consider the debating style of Brad Smith III and others to be found on other discussion boards, as you well know.

IIRC the Condor and another small US coastal minesweeper, the Crossbill, completed their daily minesweep of offshore USN exercise areas and returned thru the open nets and up the PH ship channel as per their usual routine at about 0458, some 2.5 hours BEFORE my suggested ambush of the Ward at about 0730+/-. You are however correct in your statement of their being two US patrol vessels out there at that time because a US Coast Guard 26' launch equipped with a .50 machine gun (but no radio) callsign CG#8 had been dispatched from Honolulu Harbor (HH) to escort a fishing sampan caught in the exclusion zone by Ward, back to HH. I'm not too worried about her raising an alarm however, for the obvious reason, no radio. Flares maybe but in daylight, not that visible from a distance of 5-6 miles out. Smoke from possibly burning Ward wreckage would attract attention BUT there is no guarantee that she would burn rather than just sliding under, after one or more 18" torpedo hits.

LWD,
I agree with you that taking almost ALL of Japan's battleline (9 IIRC) to Oahu would increase the risk of US detection but as I've posted before, perhaps Glenn could find a way to leave a few of them well back from Oahu as a reserve/distraction ?

Chris,
Still locked into Costello's conspiracy theories are we ?

It is precisely BECAUSE the Japanese had NEVER before tried a long distance invasion on this scale that the US would (as they DID historically) likely overlook or discount any evidence discovered to that effect. Almost no one in the US command structure BELIEVED that a mass Japanese airstrike could be called down on Pearl Harbor (after all it had NEVER been done by them before had it ?) either. But it happened. Same with the Phillipines landings, the NEI ever so swift takeover and same with the historical Japanese invasion of Malaya. They kept the Allies SO off balance that none could stand before them, at least initially.

If you'd re-read Glenn's 20 post plan you'd see that he does NOT envision all 75-200 odd Japanese ships arriving together in Hawaii, by surprise and without any radio use. The initial attack vessels yes, but NOT the entire invasion, all at once. Please, have another read.

You posted "I see no need to prove the obvious. Prove it ain't true. Find(source) me some discussion by the Japanese on the feasibility/planning of/for this attack, even if it was quickly dismissed" - try starting at page #26 of Prange's "At Dawn We Slept"and read on from there if you have yet decided to acquire more reference books other than just Costello's single tome ?

Were Japan intent on a Hawaii invasion then additional Honolulu consular staff (in the form of disguised Japanese military experts) could have been sent to Honolulu to gather more of the required information as DID happen historically. And Japan actually suspected 5 (not only 4) US carriers to be operating out of PH and San Francisco at the time. That is why they expected to loose at least two carriers in order to successfully complete the historical Pearl Harbor air raids.

There has NEVER been any doubt raised that US strategic production capability will eventualy bury Japan. Yes, the US will always win, eventually, if her people/leaders can just find the will to go on fighting ?.

Glenn,
A suggestion if I might ? I think that your 20 part posting is just TOO massive for most to "wrap their heads around". You know it's contents in detail because you wrote it but I certainly find it hard to follow when I have to scroll down thru so many pages/posts to find the information that I wish to refer to. Perhaps when you post your final version in its new thread location, you might consider first posting only the index and operational plan and then, just one part per week thereafter ? That way, others may be better able to digest your full plan and post their own counterpoints in a neat and more organized fashion ? And I'll be finished with my blockship ideas by then so there will be less distaction to the discusson of your Hawaii invasion plans.
Last edited by robdab on 29 May 2007 23:49, edited 1 time in total.

glenn239
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Post by glenn239 » 29 May 2007 23:44

Battery Williston (2x16") at Fort Weaver manned and ready to fire instantly at dawn on Dec.7'41 ? Apparently further research/sources are needed before one of us can convince the other of "the truth" wrt these two points.
The proposed operation doesn't care if the batteries in question were or were not manned. The yes/no on battery status was included for interest sake only. For your blockship, unless they had a direct LOF, then they wouldn't matter anyway.
More likely would be the use of several rotary suction dredges in an attempt to dig around whichever end of the blockship showed the best positioning for such an effort.
I'd rate this as unlikely due to time constraints. The USN would wish to clear the channel as quickly as possible. That means hauling large amounts of explosive out to the hulk and blowing it to hell.
And if bombing an already sunken wreck then the USAAF and/or USN aircraft still surviving are NOT out air searching for the invasion fleet, the bombardment fleet nor the Kido Butai, are they ? What an excellent distraction for the benefit of the Japanese attackers. I wish that I had thought of it first !
I said that they might use 500lbs and 1000lbs bombs to shatter the wreck. I didn't say they'd bomb it from the air - that would be a waste of time. Nothing subtle - float 5-10 bombs out to the ship, place them, wire them for simultaneous detonation and push the button. Repeat as necessary.
"Poisoned daggers"s NOT an odd statement at all if you consider the debating style of Brad Smith III and others to be found on other discussion boards, as you well know.
You're Brad Smith?
IIRC the Condor and another small US coastal minesweeper, the Crossbill, completed their daily minesweep of offshore USN exercise areas and returned thru the open nets and up the PH ship channel as per their usual routine at about 0458, some 2.5 hours BEFORE my suggested ambush of the Ward at about 0730+/-.
In the "Bases of Hawaii" post, under the section on Pearl Harbor you will find a link to an interactive Pearl Harbor attack map sponsored by National Geographic. Click on it and scroll to the harbor mouth and zoom in, you will see Condor on patrol with Ward as the attack began.
Smoke from possibly burning Ward wreckage would attract attention BUT there is no guarantee that she would burn rather than just sliding under.
It is poor operational planning to anticipate an unlikely result.
I agree with you that taking almost ALL of Japan's battleline (9 IIRC) to Oahu would increase the risk of US detection but as I've posted before, perhaps Glenn could find a way to leave a few of them well back from Oahu as a reserve/distraction ?
Should the British have left 1/3rd of their battle fleet 'back' from Jutland?

Tinkerbell anticipates that the IJN makes an intellectual leap in 1941 - that the proposed plan for raiding Oahu is indeed the Decisive Battle of Japanese doctrine. In Decisive Battle, the concentrated IJN Main Body would decend upon and destroy the enemy Main Body.

With respect to LWD's point, it is possible that a greater movement would be detected. But as I wrote in the conclusions, when Japanese ships went off the air (which they did for weeks at a time), the USN invariably assumed they were inactive and in port. The pattern of IJN ships going silent before major movements was well-established by December 1941. IMO, it is more likely that the inability to track major fleet elements would be interpreted as the IJN standing by in home ports to support the southern drive.
A suggestion if I might ? I think that your 20 part posting is just TOO massive for most to "wrap their heads around". You know it's contents in detail because you wrote it but I certainly find it hard to follow when I have to scroll down thru so many pages/posts to find the information that I wish to refer to. Perhaps when you post your final version in its new thread location, you might consider first posting only the index and operational plan and then, just one part per week thereafter ?
For a headache, try writing it instead of just reading it. I've done my best to lay it out so that anyone wishing to look at it or debate, or whatever, can get to where they wish to go as quickly as possible.

ChristopherPerrien
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Post by ChristopherPerrien » 30 May 2007 01:38

Hi Robdab,
Chris,
Still locked into Costello's conspiracy theories are we ?
It is alot better than being locked into outdated studies and work based on limited information about the Pacific War.

Bother to read Costello's book? , And yelling "conspiracy" is a lame excuse for totally ignoring the intelligence side of the Pacific war. Of which, most information has been released years after Prange died . Do you know when that was ? 1980. While Prange's work from the 50's to the 70's was good for making "Tora!, Tora! , Tora!, it is hardly a sound basis to slander or deny excellent scholarship work published long afterwards which includes research on mountains of post 1980 released classified information (i.e the intelligence war ) that Prange had no chance of knowing about.

If you'd re-read Glenn's 20 post plan you'd see that he does NOT envision all 200 odd Japanese ships arriving together in Hawaii, by surprise and without any radio use. The initial attack vessels yes, but NOT the entire invasion, all at once. Please, have another look.
So now you are talking about the minute sequencing of these various groups and yet this doesn't matter, as all units invovled have to be loaded and moving toward Hawaii for a period of 2 weeks , I don't care if some are 170 miles from Pearl or 500 on December 7th, they are all "at sea " and "in motion", they have to be, to make a landing on the 8th-10.
It is precisely BECAUSE the Japanese had NEVER before tried a long distance invasion on this scale that the US would (as they DID historically) likely overlook or discount any evidence discovered to that effect.
Congradulations, 2 Non-sequitars in one sentence.

As you are saying a smaller navy with no experience at doing any of the things required and an infintesimally smaller fleet train and no specialized ships, could have somehow done this 1941. And because(historically) a small force was missed appproaching near Hawaii , it is LIKELY :roll:, that the US would have missed most of the IJN and a large part of their merchant fleet attemping to do the same from several directions and in many groups.

Go tell Nagano that +200 ships has much better chance of suprise than 10(actually about 25?) ships that he grudingily allowed to perform the raid. Maybe 8-) He'll have the heart attack that killed him ,a few years earlier. Of course this happening might be the best way to get this elephant flying in the first place :?
Same with the Phillipines landings, the NEI ever so swift takeover and same with the historical Japanese invasion of Malaya.
Jumps across a puddle. The Pi invasion was done from Formosa and China, Malaya and NEI were run from Veitnam and China. Distances of 100's of miles , we are talking 1000's of miles here. Fly them and/or take a boat between them(PI -Japan, HI -Japan) you will see what I am talking about. Try it in a WWII Japanese transport if you dare. I seem to recall the Japanese acceptable to taking a fair amount of casualties from heat-stroke and sickness of transported soldiers during long voyages , especially in the "tropics". Maybe the US forces will help you unload the bodies at Hawaii.
They kept the Allies SO off balance that none could stand before them, at least initially.
Sure, the Japanese went in so many directions it caused some confusion at first, as it was like trying to figure out which way a mob of crazy people would go. But the "off balance bit" is far-fetched. By Febuary and certainly March 1941, US carrier forces were attacking Japanese possessions and military forces with relative impunity. Contrary to Yamamoto's assertion of six months of running wild , the Japanese got away with it for about a month. By the end of January, US command had formulated exactly how to kick Japan's ass , that and the rest is history.
Were Japan intent on a Hawaii invasion then additional Honolulu consular staff (in the form of disguised military men) could have been sent to Honolulu to gather more of the required information as DID happen historically.
Good idea, And when this crowd of spies start sending back some of this mountain of specific intelligence pertaining to invasion operations back through the Japanese Consul , just hope they don't use "Purple" or "Red" to do it.
There has NEVER been any doubt raised that US strategic production capability will eventualy bury Japan.
Sure, but we stopped and decisively beat them twice with our pre-war stuff in the first seven months. Even before Coral Sea, we mounted several successful carrier raids on numerous Japanese possessions and bombed Tokyo. I.E. Japan was losing the war by March, even if you include Macarthur losing an oversized regiment of US troops in PI in May.

Sorry if this does not seem to directly relate or refute how much HE a Japanese cruiser/battleship/etc. can pump at HAWAII on a Dec 7th, etc. But it does, in the big picture and the realties at the time.

Chris
Last edited by ChristopherPerrien on 30 May 2007 01:57, edited 1 time in total.

robdab
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PH Patrols

Post by robdab » 30 May 2007 01:54

Glenn,
Battery Williston (2x16") DOES have a direct line of fire on the PH ship channel.

If you direct suppresssive fire from aircraft or IJN ships then it would be very dangerous and slow for USN engineers to place explosive charges on a sunken blockship. Not that it would be a fast underwater job anyway while wearing hardhat diving gear in filthy harbor waters with very poor visibility.

Damn, you've guessed my secret identity so now I'll have to give back my secret agent X decoder ring.

That National Gepgraphic map is neat BUT the time code to the lower left shows 0342, not 0730 +/-

Lord's book "Day of Infamy" goes into great detail about the exact timing of the comings and goings thru the PH anti-submarine nets that morning, starting at page 30. It seems that destroyer USS Helm historiclly exited the nets at 0813 and thus in my scenario would have met my blockship Tatsuta Maru just a few hundred yards inside of the net gate. 17,000 tons moving at 17.5 knots WON'T be stopped by the momentum of only 1646 tons moving at 25 knots however. Even if the smaller is well equipped with guns and torpedoes. I'd expect one hell of a bang though unless Helm swerves out of Tatsuta's path. And two sunken blockships instead of just one in the PH ship channel if she cannot get out of Tatsuta's way.

I wasn't complaining about your organzational skills but rather pointing out that if you post all 20 subcategories to the other forum, at once, you are likely to be swamped with 20 different rebuttals all arriving at the same time.
Last edited by robdab on 30 May 2007 17:31, edited 1 time in total.

robdab
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Strategic Surprise ?

Post by robdab » 30 May 2007 17:06

Chris,
I see that you are still in "unpleasant reply" mode too.

Yes, I have read and indeed do own a copy of the Costello book that you put so much faith in. I didn't find much new or of interest in it.

Inexperienced you say ? Hardly. If you would devote some time to reading (other than sigint) about the China/Japan war ongoing before WW2 you would note that Japan succeeded at some 27 over-the-beach combat landings there. By 1941, Japan was THE most qualified/experienced nation on the planet wrt amphibious combat landings.

Sure, a 3,500 mile sea journey is different from a 500 mile 'puddle-jump' but the loading and combat unloading are the really difficult parts and don't change that much from case to case. And Japan had lots of long distance sea movement experience via her trans-Pacific liner fleet of vessels such as the Tatsuta Maru. Certainly a different (lower) level of service would be required for invasion troops but Japan HAD the experienced people to call on for advice/skills.

As I have typed before, the US couldn't find invasion fleets that it WASN'T even searching for. Please Chris, can you send me the source(s) that show widespread, long ranged US air/surface/submarine recon over wide swaths of the north Pacific Ocean during November/December 1941 ? I doubt it because AFAIK, these searches never happened.

And I don't see the cool wintertime North Pacific Ocean providing many overheating problems for the below decks Japanese troops being carried in DECEMBER/JANUARY, do you ?

Btw Chris, during my 26 year career as a construction civil engineer I HAVE lived/worked/travelled extensively in the countries/regions that we now discuss. While I can't say that I have (knowingly) done so in a WW2 freighter (considering the state of some of the ferries that I have travelled on it IS possible that some might have dated from WW2), I can claim 35,000 regional sea miles logged in a 48' sailing bark. Can you ?

Your statement,
"By Febuary and certainly March 1941, US carrier forces were attacking Japanese possessions and military forces with relative impunity. Contrary to Yamamoto's assertion of six months of running wild , the Japanese got away with it for about a month. By the end of January, US command had formulated exactly how to kick Japan's ass , that and the rest is history."
is historically true but I would point out that, had Japan grabbed Hawaii in December'41 a dfferent reality would have prevailed for the next 2-3 years. The USN's Pacific Fleet started the war with 17 tankers, only 4 of which could do underway re-fueling. It is not unreasonable to project the immmediate loss of 3 of these 4 since two were inside of PH on Dec.7'41 and one more was approaching PH with a full load of USN fuel. In fact, she (Neches) was sunk by a Japanese submarine about a month later while moving to refuel a US carrier group west of Hawaii.

Without access to (destroyed) PH fuel stockpiles or an effective tanker fleet, the (few) survivors of the US Pacific Fleet would have had NO other option than to return to US west coast bases such as San Francisco. As testified to by several high level USN commanders at the PH inquiry hearings. (Oh, sorry Chris, you don't recognize the validity of any of that sworn testimony do you, because its all part of the grand conspiracy, right ?) Without effective tankers, not much distant US offensive action could have been even considered, including the relief of Hawaii, until replacement US tankers eventually arrived from the Atlantic. And you can bet that a picket line of Japanese (floatplane equipped) submarines would have been awaiting any US reinforcements down nearer to Panama.

As far as the intell. gathering abilities of the Japanese Consular staff in Honolulu goes, what more need I say than, it WORKED as proven by the historical Dec.7'41 Japanese strikes. Had not a broken refueling hose wrapped around a propeller shaft, then the entire Enterprise group WOULD have been caught in that port too. Had Japan altered or expanded her goals then I am sure that her consular staff would have done their best to provide the needed information as they DID do historically, right from under the noses of the watching FBI. It was afterall, an "asleep at the wheel" US defense establishment that squandered its own huge codebreaking advantage by NOT having enough trained people to work on decoding the right Japanese messages, at the right times.
Last edited by robdab on 31 May 2007 01:23, edited 1 time in total.

glenn239
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Post by glenn239 » 30 May 2007 23:10

Go tell Nagano that +200 ships has much better chance of surprise than 10(actually about 25?) ships...
6 CV
2 BC
2 CA
1 CL
9 DD
8 Tanker
3 SS
2 DD (Midway Destruction Unit)
1 Tanker (Midway Destruction Unit)

= 34 ships.
So now you are talking about the minute sequencing of these various groups and yet this doesn't matter, as all units involved have to be loaded and moving toward Hawaii for a period of 2 weeks , I don't care if some are 170 miles from Pearl or 500 on December 7th, they are all "at sea " and "in motion", they have to be, to make a landing on the 8th-10.
Chris - can you post a link to the thread to which you are referring?
As you are saying a smaller navy with no experience at doing any of the things required and an infinitesimally smaller fleet train...
The size of the IJN fleet train is provided in post 2, with a breakdown by type. Note that what you are describing as "infinitesimal" was in actual fact a massive 1.8 million tons of shipping. Do recall that the entire Japanese economy could get by with 3 million tons.
I wasn't complaining about your organizational skills but rather pointing out that if you post all 20 subcategories to the other forum, at once, you are likely to be swamped with 20 different rebuttals all arriving at the same time.
C'est la vie. Not out to convince anyone of anything. Just looking to show what a successful invasion of Oahu might have looked like. If some wish to suppose the exercise was impossible, all the more power to them....We forgot to garrison Maui? Oops, how silly of us.
Inexperienced you say ? Hardly. If you would devote some time to reading (other than sigint) about the China/Japan war ongoing before WW2 you would note that Japan succeeded at some 27 over-the-beach combat landings there. By 1941, Japan was THE most qualified/experienced nation on the planet wrt amphibious combat landings.
Rob, enough of your bloody facts already. Sheesh. Next, I suppose that you'll claim the IJA invented the dedicated landing vessel, so important to amphibious operations today!
Sure, a 3,500 mile sea journey is different from a 500 mile 'puddle-jump' but the loading and combat unloading are the really difficult parts and don't change that much from case to case. And Japan had lots of long distance sea movement experience via her trans-Pacific liner fleet of vessels such as the Tatsuta Maru. Certainly a different (lower) level of service would be required for invasion troops but Japan HAD the experienced people to call on for advice/skills.
The major differences in shipping are in the time between waves, and how much 'stuff' one ship can contribute to a campaign. At Hawaii, a Japanese ship can do a round trip about once per month or worse, at least until Midway falls.

The initial landing (Kauai) must originate from Northern Japan (3,300 miles), since it would be dangerous to have sent this force towards Oahu from any other bearing save the one being used by Kido Butai. All other landings are conducted in two stages. Japan>Marshall Islands and then Marshall Islands>Hawaii.
It is not unreasonable to project the immediate loss of 3 of these 4 since two were inside of PH on Dec.7'41 and one more was approaching PH with a full load of USN fuel.
In addition, the Operational Order mimics early IJN planning in singling out fleet auxiliaries as high priority targets.
And you can bet that a picket line of Japanese (floatplane equipped) submarines would have been awaiting any US reinforcements down nearer to Panama.
It's mentioned in passing, but one of the purposes to building up a forward base at Maui is to allow 6th Fleet to better project its submarine force forward to the American West Coast towards the end of December.

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