"Pearl Harbor Forewarned?" Topic

I was watching Tora! Tora! Tora! on TMC on Dec. 7th and as usual was shaking my head at all the warning signs that were being ignored by the US. But honestly, I have to wonder just how much good warnings from the USS Ward and the radar site would really have done? Would an hour's warning made any real difference? So I started making a sort of list of different warning lengths and what might have happened. I'm not saying there was much chance of the US actually getting these warnings, but what might they have done with the time if they'd had it?

1 Hour Warning:
Ships start getting up steam, but few, if any are out of the harbor when the Japanese attack arrives. But crews are at their stations, AA guns manned, and watertight doors closed. Army AA guns are mostly manned and a few planes are up and waiting. End result: Slightly less damage to ships and airfields, Heavier losses to the Japanese. Not that much difference.

2-3 Hours Warning:
This could be a mixed blessing for the navy. A lot of ships could have made it out of the harbor but none could have gotten out of sight of the attackers. The ships would have been a lot harder to hit since they could maneuver, but any ship sunk would have been lost for good in deep water. OTOH, the Army could have gotten a lot more planes in the air. End result: fewer ships lost, fewer planes lost, much heavier Japanese losses in aircraft. Still a heavy blow to the US.

4+ Hours Warning:

Okay, this is major. With that much warning, the bulk of the Pacific Fleet could have been out of the harbor and over the horizon and beyond any chance of the Japanese finding them with their first two waves of attack planes. The Army airfields are empty and lots of fighters and flak are waiting. End result: quite a bit of damage to ground installation (there would be no other targets--except poor Pennsylvania in a drydock and a few other support ships) and much heavier losses to the Japanese attackers. Given Nagumo's caution, I doubt he would have hung around trying to locate the US Fleet. The operation is a failure.

1 Day's Warning:
Okay, let's assume everything goes wrong for Nagumo and his fleet is spotted by a US submarine or something and he doesn't realize that. The US Fleet sorties, swings around to the north of Oahu and catches the Japanese fleet just as its planes are all off bombing an empty Pearl Harbor. Oops! War over on Day 1 :) Even if the slow US BBs couldn't catch the faster Japanese ships, the US had enough cruisers and destroyers to run down and sink all the carriers. Bad day for Japan.

So that's my take. What do you think?

Just based on the difference between the first wave and second, I think an hourīs notice would have made a huge difference in the result of the attack.

Of course, there would still have been the qualitative difference in aircraft, but the P-40s were the home team, and as such would have had quite an advantage over the visiting Zeros.

My Uncle Curtiss was there (joined the Marines in July, arrived at Pearl in November), and he told me that when the second wave arrived the defenders were all burning for revenge. He also said they were disappointed there was no third wave, nor an invasion attempt. Gotta love the USMC!

I watched Tora Tora Tora as well. It is my Pearl Harbor Day tradition (despite what my wife says about it!).

I think an hour would have made quite a bit of
in the air defence of the area.

True, the P-40 was not as maneauverable as the Zero,
but there were a number of them and combined with
a heightened AA presence, might have caused a lot
more damage to the IJN's aircraft and aircrews,
especially among the more vulnerable Kates and Vals.

An earlier warning resulting in loss in deep water of
USN vessels probably true.

A day's warning – don't know. Maybe there would be
paralysis of indecision for several vital hours, but
there might also have been a pre-planned sortie
scheme in anticipation of an attack.

I think the 1 hour warning would have been more useful then you think. Just getting everyone to battle stations, getting the guns armed and prepped, and getting some birds into the air would have made a lot of difference. Japanese causalities would have been quite heavy, maybe as high as they feared, and the Americans would have been in better shape to "fight" their ships. Also having even a few dozen fighters in the air could have been very disruptive. Even the few that made it into the air disrupted parts of the attack. Having 20+ fighters in the air might have made a real difference.

One thing to be aware of though is that the Japanese forces were a lot better than ours. Their fighters were better, their ship crews were better, their torpedos were better. Having our fleet meet theirs could have been really bad, for us! The Japanese cruisers were way better than ours and their torpedos were a nightmare. Check out the Guadalcanal Campaign for details.

Honestly, Pearl Harbor was a blessing in disguise. The only terrible loss for us was in personnel. The warships, planes, and materials lost were obsolete or outclassed and easily replaced by our industry. And by attacking and crippling the US fleet the Japanese ensured that the US Navy would be forced to fight a different battle than it planned- a Jutland style battle that Japan probably would have won! Instead the Japanese ensured that the US would only seek battle later when it had a better tactical doctrine, better planes and ships, and more experience!

I really think that the Japanese would have been better off leaving Pearl alone, attacking our other territories, and letting the US get its wish: a decisive battle in the Central Pacific. Odds are that Japan would have won that fight!

Tgunner, I agree for the most part with what you say (especially about torpedoes, the Japīs actually worked!), but donīt discount the USN in a surface fight in daylight. After all, the great Japanese advantage at Guadalcanal was in night fighting.

I also agree with you and Ed, the P-40s would have caused considerable damage to the first wave attackers, and I believe the second wave would have had great difficulty in even getting to their targets. If only!

I have a book that documents many, many more warning signs that were ignored (for example, the bonfire in the yard of the Japanese consulate in Honolulu where they were burning secret communications, coding devices, etc – the smoke cloud could be seen for miles). IIRC, it stops short of saying we knew definitively. Unfortunately, it's at home and I'm here so I can't post the title. It was well documented from what I recall and certainly made a case that even if we didn't know, we should have done a better job of guessing.

As for a surface fight, keep in mind the numbers. The Nagumo's Japanese task force consisted of 6 carriers (presumably empty), 2 BBs, 2 CAs, 1 CL and 9DDs. The Americans at Pearl Harbor had 7BBs (Pennsylvania was stuck in dry dock) 8 CAs and 30 DDs. A rather huge numerical advantage for the US.

4 hours warning and the Imp fleet meets a flight of B-17s, flying boats, and half of the fighters based in the islands and maybe 20 subs. End of Imp fleet before it can recover the attacking planes.

"4 hours warning and the Imp fleet meets a flight of B-17s, flying boats, and half of the fighters based in the islands and maybe 20 subs. End of Imp fleet before it can recover the attacking planes."

Unlikely, since the performance of aircraft of these types against manoeuvring warships was somewhat less than stellar. But throw in the US carriers, which were at sea….

But as Sundance noted there were so many other signs that went unnoticed that its given conspiracy theorists more than enough material…..

When did B-17s ever accomplish anything against surface ships?
Well, occasionally they made the ships zig-zag…

The Americans at Pearl Harbor had 7BBs (Pennsylvania was stuck in dry dock) 8 CAs and 30 DDs. A rather huge numerical advantage for the US.

Very true, but the BBs just didn't have the speed to catch such a swift force. That leaves the cruisers and destroyers who might have a chance to catch up. Then they would have to press through wave after wave of Japanese torpedo bombers and dive bombers with limited air support. And then they would face a very powerful screen of BCs, CAs, CLs, and DDs. While most of the US cruisers (except some CLs) were pretty modern the same wasn't true for the destroyers. Many of them were old four stackers who would have been of limited use in a clash with the Japanese. The Japanese CAs and DDs were tactically superior to their US counterparts… heck, some of the DDs were almost CLs! Toss in the Long Lance and things get really ugly for the squids.

Now the Big E was nearby and she could have supported an attack and I want to say that there was another carrier group or two not too far away… but that would have taken a LOT of coordination to carry off and there's a good chance that each group risked being defeated in detail because the Japanese were in one powerful group.

It would be a fun one to game out, that's for sure!

When did B-17s ever accomplish anything against surface ships?
Well, occasionally they made the ships zig-zag…

There's at least one Japanese captain who would grumble about that. IIRC, during Guadalcanal at least one Japanese destroyer was sunk in a B-17 strike and her captain was captured. That VERY irritated officer grumped, "I know that the B-17s had to hit SOMETHING sooner or later. Why did it have to be MY SHIP!"

Even with some advanced warning I don't think it would have made a lot of difference. The Army Air Corps wasn't that good at the time, considering their poor performance in the Philippines the indication is they would not have done any better over Pearl Harbor or meeting the Japs out at sea. Neither would have the Navy done a whole lot better either The night actions of of the Canal later in the war proved to be a nightmare for the Navy. I think that all the US Armed Forces needed to cut away the dead weight of horrible peace time Officers and SNCOs.

Taylor and Welsh shot down what? Six Japanese planes all by themselves? Not too shabby. Keep in mind, despite some action against the Chinese, the Japanese were just as inexperienced as the Americans in this sort of combat.

In fact that's another interesting issue: the Japanese are portrayed as so experienced vs the Americans early in the war, but they really weren't. At Midway, the Americans (especially the Yorktown task force) were actually far more experienced in a carrier-vs-carrier action than the Japanese.

4+ Hours Warning:

…The operation is a failure.

If the fleet had been gone, the Japanese strike force might have gone for the oil storage facilities – and if those had been lost, Pearl Harbor would have been useless.

Could have been a major strategic victory for the Japanese.

"At Midway, the Americans (especially the Yorktown task force) were actually far more experienced in a carrier-vs-carrier action than the Japanese."

They also outnumbered the Japanese in aircraft, had far more efficient aircraft handling techniques and had a massive intelligence advantage.

At the time of the attack:
Lexington with 4CA and 5 DD were 500 miles SE of midway on its way back to Pearl.
Enterprise with 3CA and 9DD were 215 miles W of Oahu.

Ranger, Yorktown and Long Island were in Norfolk VA or the Atlantic on their way there.
Saratoga would be entering San Diego that afternoon.
Wasp was in Bermuda
Hornet was still completing fitting out in dry dock at Newport News VA.

A couple of the BB's at pearl were not in a state to sail for more than 4 hrs. One had its access openings to the keel/bilges opened for inspections/repair. Many would need 4-6 hrs to raise steam, get crews aboard and especially those on the inside of the side by side docking arrangement. Only a couple had steam enough to sail immediately (Nevada).

Lex joined up with Enterprise to search SW of Pearl after the attack. Even with a 1-4 hr notice, the fleet cant fight what it cant find…tho some of it might get outside the harbor running the risk of being torped by the subs waiting near the entrances.

And even if the US managed to find the Japanese, then what? With 6 carrier air groups available to the Japanese, the US battleline would be hard pressed to survive. If anything, the results might have been worse with the BBs resting on the bottom of the Pacific instead on the bottom of Pearl Harbor.

And about those supposed 'warnings': Yes, there were lots of evidence that the Japanese were up to SOMETHING. But very little solid operational evidence of specific objectives. That the PI was high on the list is obvious, but Pearl Harbor? Not so much. Most (if not all) of the conspiracy theories are fevered ravings that properly belong in 'tinfoilhat.com' file….

The US called war warnings several times before December 7. Everyone in the intelligence field knew the Japanese were up to something but were not exactly sure where they would strike or when. MacArthur did not believe they would attack the Philippines until March or April. Other commanders believed the attacks would hit only colonial possessions of Dutch, UK and France since they were too busy in Europe.

Part of the reason to form the Central Intelligence Agency was to coordinate this type of information so that all the data could be collected in one place for analysis. Pearl Harbor clues were everywhere, but no one person or group had all the signs together in one place.

Mike Bunkermeister Creek
Bunker Talk

The US Navy had to be on a war footing. They thought they were, but not really. They had contempt for the "little yellow monkeys", and thought that just by being Americans, the would beat the Japs.
The US fleet was NOT ready for war. Just look at the torpedoes.

Had the BBs sortied, they would have all been sunk, with a much greater loss of life than at Pearl Harbor.
Making do and learning the hard way was the best thing that happened to the US Navy.

John, you act as if the whole Japanese navy was lying in wait off Hawaii. Only a small fraction of it was. The US would have had about a 4-to-1 advantage in ships and adding in the airpower based on Hawaii and the two carrier groups that were not that far off, the odds were heavily in the US favor. Plus, at this stage in the war the Japanese were no more experienced in this sort of combat than the Americans were. If Nagumo failed to catch the Pacific Fleet at anchor he would have had to retreat or face annihilation.

Scott, the Japanese were already at war.
The USN did not know what it did not know. The airpower could not hit anything at this stage.
My money is on the Japanese.

Already at war but against who? The Chinese? Aside from strafing junks and a US gunboat in the Yangtse River, how many Japanese pilots had actually tried to bomb or torpedo a maneuvering warship against heavy flak? How many Japanese AA gunners had actually shot at a plane trying to bomb them? How many Japanese damage control parties had ever had any actual damage to control? I think the answer to all those questions is: "none". :) The Japanese were superbly trained but still green, just as the Americans were. And when the Americans and Japanese met on equal terms the Americans generally did pretty well.

Scott, if you want to see what 'green' IJN pilots could do at this stage of the war, I suggest you look at what happened to Repulse and Prince of Wales. Not bad work for 'green' pilots. As to the US battleline catching the IJN carriers: With a substantial speed disadvantage and the normal scouting that all carrier navies did, the only thing the US BBs will catch are bombs and torpedoes from a IJN airstrike. There is no way the battleline could catch the IJN carriers. And as for airstrikes from Pearl Harbor, IIRC, there were no aircraft on the island that were capable of that (other than the limited number of B17s. And we already know how effective that would've been…).

Of course Prince of Wales and Repulse were sunk by land-based bombers :)

But you are correct about the chances of the Pacific Fleet at Pearl Harbor actually catching Nagumo's strike force. My Option 4 from my original post was sheer fantasy.

On the other hand, I do believe that Japanese prowess has been exaggerated. After all, any time US and Japanese carrier forces engaged the Americans usually won decisively and never did worse than a draw.

"Of course Prince of Wales and Repulse were sunk by land-based bombers :)"

Yes, IJNAF torpedo bombers specifically trained for anti-ship missions.

Even today, it takes a good 4 hours to get steam plants up to battle/full power temperatures and pressures.

If you're not completely cold iron, you might make it out in less than 2 hours; but if you have to get the entire steam plant up to temp, forget it.

Modern steam plants are 600 or 1200 lb, WW2 were 400 or 600. My BT's told me they could bring the plant up in about an hour if they fudged the rules a bit (not from cold iron). The 1200 lb plants were extremely touchy, we usually lit off two days before underway just so we could shut the plant down, fix whatever was broken and light off again without missing movement. The earlier plants were far more robust. My second ship had a 600 lb plant and the reliability difference was noticeable.

I think in the US Navy all the steam plants that aren't nuclear are in mothballs or gone.

The argument I have heard many times is what would have happened to the battleship fleet had it been caught even 10 miles outside the harbor?

In any case Opana point identified the Japanese formations when they were, by my estimates 40 minutes from the target. 40 minutes is a lot of time to get aircraft in the air, IF they had been ready. The question I have is why more interceptors were not ready. Even parking them in a central location, they could still be made ready. They weren't.

Just having enough time to shut all of the watertight doors on the ships would have greatly reduced American casualties. The P-40 was not equal to the Zero but was more than a match for the Dive Bombers and Torpedo Bombers in the Japanese air forces. With our fighters in the air the Zeros would not have been free to strafe the ground targets, which would have reduced damage even further. What is more, 4 hours of warning to Pearl would have been 4 hours of additional warning to Wake and the Philippines.

Well, the Philippines had plenty of warning they just made a mess of what they did with it. The Japanese attack was delayed by bad weather over their bases on Formosa. The Americans, getting the war warning, got their planes up at first light and were waiting. But the Japanese were late. Their attack came just as the Americans had to land and refuel.

Read Gordon Prange, Pearl Harbor, The Verdict of History. Big,huge book in which Prange pretyt much demolishes every conspiracy and revisionist history (Rossevelt did it! Churchill Did it! It was Bush's fault!) whatever argument you want to blame, and along the path you can find also the mangled bodies of all the "Kuda,Shuda,Woulda, Mighta, " contingencies and arguments.

If anything what one learns from Prange's book is that Countries and Navies are no different from any other large bureaucratic human institution. They don't stop on a dime and can't make bootlegger turns easily, and in fact are designed to precisely do that (have commanders go off half cocked on their own.

Indeed through all of Prangs book he deals with all the various contingencies and caveats most of you have made, and shows that while in the aftermath "all the evidence was there and plain to see" he also shows that for the Japanese "all the evidence was there and plain to see" as to the eventual outcome of the war as well. The Japanese were no different- being members of a large bureaucratic human institution.