Pearl Harbor Alerted

[Barb]

Well, as pointed out previously: The japanese spy will surely hear crew recals, see the ships sailing out of the harbor as fast as they can. Nagumo gets the message. "WTF?!", turn his back and run back for Japan. No PH. [:)]

[stuman]

ORIGINAL: Barb

Well, as pointed out previously: The japanese spy will surely hear crew recals, see the ships sailing out of the harbor as fast as they can. Nagumo gets the message. "WTF?!", turn his back and run back for Japan. No PH. [:)]

WTF?! ... does that stand for " Westerly Task Force " ?

[HMAS Sydney]

ORIGINAL: witpqs

I suspect the best action (this is with all hindsight) would have been staying in PH fully alert and ready. Torpedo nets? Yeah! Why the heck didn't they already do that anyway? Serious question, BTW, I've never heard why.

It was believed the harbour was too shallow to allow torpedoes. It was believed they would hit the bottom when dropped. The Japanese also believed this at first but they designed a way to enable torpedoes to not hit the bottom.

[witpqs]

ORIGINAL: Barb

Well, as pointed out previously: The japanese spy will surely hear crew recals, see the ships sailing out of the harbor as fast as they can. Nagumo gets the message. "WTF?!", turn his back and run back for Japan. No PH. [:)]

I doubt that any spy in Hawaii could have contacted Nagumo's task force, even indirectly. I think any alert would have taken too long to get to him.

[AW1Steve]

ORIGINAL: stuman

ORIGINAL: Barb

Well, as pointed out previously: The japanese spy will surely hear crew recals, see the ships sailing out of the harbor as fast as they can. Nagumo gets the message. "WTF?!", turn his back and run back for Japan. No PH. [:)]

WTF?! ... does that stand for " Westerly Task Force " ?

A common USN radio call , used when someone is doing something extremely stupid. As in "what the fudge? Over". [:D]

[Anthropoid]

ORIGINAL: witpqs

ORIGINAL: Barb

Well, as pointed out previously: The japanese spy will surely hear crew recals, see the ships sailing out of the harbor as fast as they can. Nagumo gets the message. "WTF?!", turn his back and run back for Japan. No PH. [:)]

I doubt that any spy in Hawaii could have contacted Nagumo's task force, even indirectly. I think any alert would have taken too long to get to him.

Given the radio silence under which KB operated, I tend to agree: even if battle fleet had pulled out the day before, 12 or 18 hours before the attack, I don't see how Kido Butai could have gotten word of it.

Add to this that their sub screen had not deployed as intended: properly warned, US might well have slipped most of the fleet out to a safe area, and then when the Japanese strike force arrived they would have been dropping those fancy torpedoes on empty berths, and getting shot down in substantially higher numbers. In sum, the outcome might well have been a disaster for Japan, instead of a disaster for U.S.

[Hornblower]

what if nagomo saw a PBY or B-17 suddenly loom out of the clouds over head, would he still attack?

[Nikademus]

I believe they had a surprise failed option....but the approach route was chosen deliberately to avoid detection

[witpqs]

ORIGINAL: Anthropoid

Add to this that their sub screen had not deployed as intended...

This I didn't know about. What happened?

[witpqs]

ORIGINAL: Nikademus

I believe they had a surprise failed option....but the approach route was chosen deliberately to avoid detection

I just remembered the big chance for alert (because there was early detection) was if Joe Stalin had decided to pass that merchant ship sighting along to the US.

[borner]

you also have to figure it was a weekend, with a lot of crew on shore leave. If you give the US commanders 24 hours notice, how long would it take to get the fleet ready to get underway and out to sea?

[Nikademus]

I believe the ship's were crewed enough to put to sea relatively quickly. 24 hours notice would be more than enough time. Some might not make it back in time but not enough to prevent the ship from being sortied.

[DivePac88]

Depends on their fuel status, if they were in a ready condition, or on something like 24-36-48hrs notice (remember it was peace time). I think the Home Fleet during WW2 at Scapa Flow, was on something like 9hrs notice when not on operations.

[Barb]

radio silence equals not transmitting while receiving is possible. Of course the spy must have phone to Tokio and than the message has to be transmitted through half of the world and received properly. It will take some time surely. Depends on time of the warning for the PH.

On the other hand there is possibility that USN sortied out, and as Japanese attacking waves are met with fierce fighter/Ack-Ack opposition they will find anchorages empty. At the time Second wave will be already in the air, so no real possibility to send them to search for US Fleet. If so, 800kg AP bombs carried by Kates will be mostly ineffectual agains maneuvring ships at sea -dropped from height.
So this will require 3rd wave. And lurking in range of LBAs isnt a clever idea as air force would surely send all their bombers out of the fields ASAP.
Add surprise in form of Lexington + Enterprise striking from good position and with little luck you could have half of the KB in Davy Jones Locker (Lex and Big E + some old battlewagons too).

[herwin]

ORIGINAL: Barb

radio silence equals not transmitting while receiving is possible. Of course the spy must have phone to Tokio and than the message has to be transmitted through half of the world and received properly. It will take some time surely. Depends on time of the warning for the PH.

It was all set up beforehand. The spy at the Japanese consulate had a routine that would have provided adequate notice of the fleet deploying--remember, to get steam up and recall the crews would have taken several very public hours in peacetime.

[spence]

It was all set up beforehand. The spy at the Japanese consulate had a routine that would have provided adequate notice of the fleet deploying--

"Tora, Tora, Tora" showed just how "efficiently" and "securely" the Japanese diplomatic service handled communications. Practically instantaneous.

[John Lansford]

The KB strike force had two attack plans, one if surprise was achieved and one if they didn't.  IIRC the "no surprise" plan was for the DB's and fighters to hit the airfields first, and the ship attack planes follow them in.  The surprise option reversed that order.  Fuchida saw that he had surprise, so he fired one flare as that was the signal, but when a flight of planes didn't respond he fired another to get their attention.
 
Two flares, though, was the signal for "no surprise", and the DB's took off for the airfields simultaneously with the ship attack planes, creating a bit of confusion but ultimately making little difference in the outcome.

[Anthropoid]

ORIGINAL: witpqs

ORIGINAL: Anthropoid

Add to this that their sub screen had not deployed as intended...

This I didn't know about. What happened?

Maybe I'm confusing with Midway? Somebody check me on this . . . I remembered that they had intended to have a sub 'cordon' around the PH area to monitor ship traffic, but that it had not got into position. I do seem to recall now that this was the case with Midway, and maybe the sub screen was in position for PH??

[Anthropoid]

ORIGINAL: herwin

ORIGINAL: Barb

radio silence equals not transmitting while receiving is possible. Of course the spy must have phone to Tokio and than the message has to be transmitted through half of the world and received properly. It will take some time surely. Depends on time of the warning for the PH.

It was all set up beforehand. The spy at the Japanese consulate had a routine that would have provided adequate notice of the fleet deploying--remember, to get steam up and recall the crews would have taken several very public hours in peacetime.

Okay, I didn't realize "silence" only meant no transmissions. So what you guys are saying: If the USN had sortied the fleet during the night of Dec 6, the spy would have been out there at night, observing the port? I find that hard to believe.

Had the fleet sortied during business hours on Dec 6, then yes perhaps word would have made it back to Tokyo and to the Fleet before they launched their planes in the wee hours of Dec 7.

Interestingly, this suggests a curvilinear relationship between the impact of an "alert." Had PH been elerted 20 or 24 hours before KB launched her planes, and sortied during daylight/business hours of Dec 6, the whole thing might never have happened, else the Japanese might have adjusted their plan to cope with the fact that their primary target (the BBs) would not be in its waiting, vulnerable location. But as you get to more like 8 or 12 hours before the KB launched her planes (end of day Dec 6, or evening Dec 6) the chance that the spy would have been watching to notice the Battle Fleet sortying would arguably been lower (he had a Dentist office that overlooked the port right?), and therefore that the KB attack would have been launched anyway might have increased?

[anarchyintheuk]

ORIGINAL: Anthropoid

ORIGINAL: witpqs

ORIGINAL: Anthropoid

Add to this that their sub screen had not deployed as intended...

This I didn't know about. What happened?

Maybe I'm confusing with Midway? Somebody check me on this . . . I remembered that they had intended to have a sub 'cordon' around the PH area to monitor ship traffic, but that it had not got into position. I do seem to recall now that this was the case with Midway, and maybe the sub screen was in position for PH??

Pretty sure you're thinking of Midway. The sub cordon was late setting up. TFs 16 & 17 had already cleared the area on the way to Point Luck.