No surprise at Pearl Harbour- likely outcome?

Nagumo could, theoretically, retreat a little then reverse to catch the fleet at sea but he is not going to do that - a major fleet engagement was what he was supposed to avoid.

IIRC, this would also result in him having to abandon 100% of his destroyer escort while returning to Japan, due to lack of fuel
 
A number of P-36's had their 0.50-cal MG removed to be installed in P-40's heading for the Philippines.

You must remember these aircraft were parked with empty tanks and empty guns. Unless you have several hours notice getting a large number of fighters airborne is going to be difficult. And it's Sunday morning, many pilots were partying the night before and are hung over and scattered all over Oahu. You should be able to get AA ammo and crews to guns however, at least enough to operate the battery. And you should be able to get more fighters airborne, not a large number but still more than the dozen or so that did so historically.

Getting the ships moving will also take time as boilers are down. At least you can get watertight integrity operational (assuming the gaskets aren't deteriorated) and get crews and AA ammo to the guns.

But even this will throw off the IJN attack...
 
The P-36 wasn't as bad as they say, but I don't think it was as good as you say.

Also did well with the Finns, who thought it almost as good as the B 239

ME-109 663 kills
Buffalo 447
Hawk 75 190

It was very good for a 1939 plane against 1941 Japanese planes, which is what you need to blunt a sneak carrier attack. It wouldn't be a good choice as a level bomber interceptor, it was a dogfighter, like the Zero or I-16

And as far as French overclaiming, sure, that happens. But do you think the Hawk pilots were just better at lying? Their loss rate was lower than other fighters in 1940: can't fudge KIA numbers
 
No, the provision was for the capital ships to refuel the destroyers if necessary.

No, they were already at the very limit of their fuel reserves, one of the reasons why there was no third strike. Any attempt to do so, or any attempt to have the destroyers maneuver at combat speeds (As could reasonably be expected in any sort of defense against a series of Air Strikes or for a mass naval action) would have used up whatever safety margin was left and forced the majority of the destroyer escorts to be abandoned on the way home. Which in turns means 9 less destroyers to use in the war.
 
What would be really interesting to speculate on, is what would really happen, given the stregths and weaknesses of both sides, if KB was dicovered before the attacks? What is the most likely scenario for them to be discovered, any missed opportunities from the US side that would be interesting to ponder on?

The attack planning was a rushed affair, with surprise being more or less a planning. IIRC, it was realised by 1st Air Fleet staff late in the day that they needed some contingencies for non-surprise scenarios.

The short answer is that if surprise were lost Nagumo probably turns around and sails home. If within 24 hours of his target he was to attack, but given that he could have attacked with 240 aircraft on the afternoon of the 7th and decided not to, it seems unlikely to me he'd have sailed straight in for an assault against an alerted base.

That being said, I believe Genda's contingency plan for an assault was to send the fighter units (80 Zeros) in the first attack to shoot down the defending fighters, then send the bombers only later.

(i'm refering to searches and targets, presumably if they find any warships at sea they will attack those first and not the harbour).
Apparently Nagumo knew from signal intercepts that Enterprise was nearby by the afternoon of the battle, and he did nothing to find it. So, assuming the fleet were at sea I'd guess he'd turn around and go home rather than look for it.

...given a few hours warning the US is likely to still loose 3 or 4 BBs but i think at sea as they were just trying to clear harbour (but please correct me on that if it's not the case), while the KB lost 75 aircraft. Don't recall much about any US counterstrikes though.
What is the key is what the Army planned for air patrols in the event the navy was at sea and the base was also threatened, and what capacity the air defence network had to intercept incoming raids. 75 IJN aircraft shot down sounds to me like the best controllers in the Battle of Britain are wisked around the globe to Hawaii and expertly direct fighters well handled for fuel consumption and well trained in radar guided intercepts onto the target.

Conversely, either Yoshikawa (if discovered the day before) or a lumbering PBY (if discovered at dawn on the 7th) could prompt KB that they have been discovered.
The radio net at Hawaii would light off, prompting 1st Communications Unit in Tokyo to warn Nagumo.
 
Some very interesting assessments posted here, thank you all. A few more issues if i may.

I seem to remember reading that after the fleet was permanently stationed at PH in 1940 the plan was to have at least one BB group at sea at any time, but obviously this was not the case at the attack. Any more details on the subject, was this practice maintained for any length of time? Again from memory, funds for fuel might have been the reason why this was not the case in December and indeed before that, is that correct?

Secondly, where was the usual exercise area for the BBs (to the north or south of PH), and any rough details as to their activities in December in that respect?

Lastly, as known Nevada got underway during the attack. Any details as to the boiler status of the other BBs before the attack, i.e., with say couple of hours warning, could most of them just be clearing harbour?

Now i take note of what Glenn said about Nagumo, indeed, possibly he might have turned for home if he was discovered before the attack (with all kinds of consequences)! But anyway suppose this does not happen, one last query is i read that in case the US fleet sortied before the attack, KB's plan was to search on a radial 300 miles from PH and attack if contact made. Does this should be interpreted as in they would have searched 300 miles from PH, from KB's expected northern attack position (about 250 miles give or take from PH), which means they would have only searched north of PH, OR they would actually get to a position close to PH and search SOUTH of it as well?

Thanks again.
 

jahenders

Banned
It all depends on the timing and specificity of the warning.

So, a few options based on timing:
An hour: The US gets a few more small ships to sea, gets men to their ships, and crews to battle positions, gets far more planes aloft. Effect, Japan suffers considerably higher losses and does slightly less damage to battleship row. However, the more ships at sea, or moving to sea, are sunk in deeper water or in Pearl's channels -- less crew/ships recoverable and possibly more blockage of Pearl.

6 hours: US gets several cruisers and a few battleships to sea, etc and heads toward best estimate position. Everything that gets to sea is sunk or badly mauled and the sunk ships are totally irrecoverable. Japan takes heavier losses and can only spare a few flights for attacking Pearl directly.
 
mack8 said:
Some as known Nevada got underway during the attack. Any details as to the boiler status of the other BBs before the attack, i.e., with say couple of hours warning, could most of them just be clearing harbour?
I'll defer to CalBear on this one, but as I recall, Nevada (reason I don't recall:eek:) had more boilers lit. The others were all cold, & that (IIRC) meant a minimum 4hr cold start. (My recollection is 8h, but that's not solid.)
 
But do you think the Hawk pilots were just better at lying?

Fighter pilots in multiple a/c engagements often don't get time to check results. The pilots themselves don't record material in archives, and the French destroyed many more aircraft than were destroyed, according to records. The oft-quoted records of H75 units are a part of the overall false statistical record, and there's not much cause to presume that they too are false. The record of the Curtiss H75 in French service was outstanding. The British and American forces dropped it as obsolete. In combat against the humble Wildcat, it fulfilled expectations. Those statistics too are oft-quoted.
 
What effect would have torpedo nets played if they were deployed as precaution after the first midget submarine is sighted and the attack of the first wave of Japanese planes. How many torpedoes would not hit their targets if nets and other ASW defenses for anchored ships were properly deployed?
 
What effect would have torpedo nets played if they were deployed as precaution after the first midget submarine is sighted and the attack of the first wave of Japanese planes. How many torpedoes would not hit their targets if nets and other ASW defenses for anchored ships were properly deployed?

I think it would have made a large difference, the reason Kido Butai had so many Kate's carrying 800 kg bombs was to get around those. One of the specific questions to the naval attache in Hawaii was about torpedo nets. Once it was determined none were deployed (due to the harbor being shallow it was felt torpedoes would end up burying themselves in the mud) a torpedo attack was planned...
 
Now i take note of what Glenn said about Nagumo, indeed, possibly he might have turned for home if he was discovered before the attack (with all kinds of consequences)! But anyway suppose this does not happen, one last query is i read that in case the US fleet sortied before the attack, KB's plan was to search on a radial 300 miles from PH and attack if contact made. Does this should be interpreted as in they would have searched 300 miles from PH, from KB's expected northern attack position (about 250 miles give or take from PH), which means they would have only searched north of PH, OR they would actually get to a position close to PH and search SOUTH of it as well?

Thanks again.

The plan might have been along those lines, but I'd have to wonder whether Nagumo goes through with it rather than seize the opportunity to retreat.

In terms of precise planning, I've not read from where 1st Air Fleet intended to search from if hunting for the US fleet at sea. Genda's account suggests the TF might move south of Oahu during the hunt by passing to the west of Oahu.
 
No, they were already at the very limit of their fuel reserves, one of the reasons why there was no third strike.

Fuel reserves were not an issue for a third wave - the destroyers had been topped up just before the attack and the weather had been unexpectedly good on the way over, allowing even the ships with the range to make the attack unrefuelled to do some refuelling. The tanker train itself had ample fuel reserves, the limitation being the possibility of bad weather. Aircraft availability was also not an issue - Nagumo had 60 dive bombers, 100 Kates and 80 fighters operational for a third wave, (Osamu Tagaya provides these stats in Aichi 99 Kanbaku units, 1937-1942). The issue appears to be that Nagumo had already decided to withdraw before the attack. Not even intercepts of the Enterprise nearby could alter the decision. Small wonder Fuchida was furious at Nagumo and his staff!

On the return trip KB did hit the nasty weather it feared for the way out, disrupting refuelling for (I think) six days. Had that happened inbound fuel could have been an issue.

Any attempt to do so, or any attempt to have the destroyers maneuver at combat speeds.
The destroyers were topped up before the attack (to about 600 tons each) at 0630 December 6th. The next refuelling was done from tanker 44 hours later, with Akigumo taking 250 tons to refill. That's hard data - it means the destroyers were burning 6 tons per hour for the high speed operations, or about 144 tons per day.

Had Nagumo remained for a third wave, then that would have been another 6 hours near the target, or about 35 tons of fuel on a destroyer with a capacity of 600 tons. Akigumo had about 350 tons aboard when she refuelled, so in that instance she would have had about 315 tons. There would have been no difference.

But Nagumo's other option was, as I just mentioned, to refuel the destroyers from the capital ships at night. This was not done during the attack because there was no need. But if it had been done, then the destroyers would have stayed topped up and the limiting factor would have become the fuel load of the capital ships. If Nagumo was returning to Japan I would not think he'd stay more than a couple days in case bad weather was encountered on the way home - he had plenty of fuel in the tanker train, but couldn't access it in bad weather. Instead, his best bet would be to pass west of Hawaii with his tanker train to get south of Oahu. In these waters the stormy North Pacific would not be an issue and he could refuel and come back, similar to what he did in the Indian Ocean Raid.
 
I'll defer to CalBear on this one, but as I recall, Nevada (reason I don't recall:eek:) had more boilers lit. The others were all cold, & that (IIRC) meant a minimum 4hr cold start. (My recollection is 8h, but that's not solid.)

IIRC, the main reason the USS Nevada was able to get underway was because the officer of the watch, an Ensign Joe Taussig, had ordered a second boiler lit that morning with the intent of switching the ships power load to that boiler at around 8 AM or so. The Nevada was also not moored alongside another battleship, and thus more able to maneuver freely.
 
Alanith said:
IIRC, the main reason the USS Nevada was able to get underway was because the officer of the watch, an Ensign Joe Taussig, had ordered a second boiler lit that morning with the intent of switching the ships power load to that boiler at around 8 AM or so. The Nevada was also not moored alongside another battleship, and thus more able to maneuver freely.
That sounds right.
 
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