WI: Combined Fleet spotted days before Pearl Harbor attack?

The Kra landing operation was at sea on the 5th - US time & spotted by Commonwealth reconissance on the 6th. The Brits knew they were coming.[

In regard to the British I was wondering if would they be secure in the knowledge that the US was going to be in the war such that they would launch Matador and also launch air strikes when they discovered them
 
Considering how Dugout Doug dithered after an actual attack, hard to see the PI going much different from OTL: maybe worse, as he would have even more times to rush even more troops and supplies to undefendable beaches

I am not a Mac fan but am curious with a more concrete warning of war would he have actually met them on the beaches. Originally wasn't really on the beaches in force. For the Vigan and Aparri landings might have done some damage.
 
I'd say everything else goes as planned. But with Pearl not attacked maybe an earlier offensive? Would the battleships actually be sent into combat? Be interesting to have one or more of the old BB's early in the Guadalcanal fight...

I think they would have just added to the collection in "Iron Bottom Sound". Unless they were equipped with Radar they most likely would have been torpedoed with long lance's.
 
I'd say everything else goes as planned. But with Pearl not attacked maybe an earlier offensive? Would the battleships actually be sent into combat? Be interesting to have one or more of the old BB's early in the Guadalcanal fight...

The available BB we're not sent until October. A careful study of War Plan Orange & Nimitzs background in war planning suggests only if there were a large advantage visible. OTL the use of the Washington & S Dakota was made after the cruiser squadrons we're shot up in previous battles. Two of the old Standards we're present in S Pac then, but we're used for convoy escort to Australia.
 
But would the Japanese abandon the attack if spotted?
They were under direct orders to abandon the attack if spotted.
it was supposed to be a hit and run surprise attack . If the element of surprise was lost it would become a real battle. The Japanese were at the end of their logistical train, fighting a real battle was something they were not capable of doing and the Imperial Japanese Navy knew it*.

Yamato knew it, I'm not sure about the other officers in the room.
 
So lets say the PH attack force turns around. What about the operations against Wake, Gaum and the Kra peninsula. Those operations were on a time table so what would happen there?

This is an interesting question.

Guam goes as scheduled. No reinforcements could reach Guam in time. I don't think the defenders could be any more prepared than they were historically.

With the Wake operation, the Japanese now have to consider that the Pacific Fleet may intervene, may even already have ships headed in Wake's direction. The initial air raids will still go on. Would Kido Butai be sent to support the Wake operation? It would make sense. They could wait for the possible American reinforcements to show up.
 
... Would Kido Butai be sent to support the Wake operation? It would make sense. They could wait for the possible American reinforcements to show up.

OTL the KB was scheduled to imeadiately support operations in the S PAC. Two carriers were eventually sent to bomb Wake, after the first landing attempt was defeated.
 
OTL the KB was scheduled to imeadiately support operations in the S PAC. Two carriers were eventually sent to bomb Wake, after the first landing attempt was defeated.
OTL track of KB
640px-PearlHarborCarrierChart.jpg
 
ITYM "WI the Striking Force was sighted a few days before the Pearl Harbor attack?" The "Combined Fleet" was the term for all the seagoing vessels of the IJN: the destroyers, cruisers, battleships, and carriers. It excluded minesweepers, patrol craft, escorts, submarines, tenders, and training vessels. If the entire Combined Fleet was somewhere to be spotted, that's weird.

The Japanese expected to have operational surprise (they achieved tactical surprise, which was a bonus). That is, they expected to be spotted a few hours to a day before the attack, which would not allow the US forces to get fully ready for battle. (Consider what the US forces would need to do: get the report to all the relevant commanders, get everyone out of bed, get the command staffs up to speed, get all personnel out on liberty back to their posts, get steam up in all warships, get all planes armed and fueled for takeoff, get the fleet out to sea... All from a "standing start", i.e. peacetime conditions. Thus even with several hours warning, the US forces would be at a disadvantage.)

It has been written in this thread that Nagumo's orders were to turn back if sighted more than 24 hours before H-Hour, because that much warning would lose operational surprise. Otherwise, press on.

If per tbhe OP Nagumo turns back on say 4 December 1941... ISTM that Japan is already committed to war with the US and Britain. So the "Southern Operation" continues. Lots of issues to discuss but I have no time now.

Here's one:

The Japanese landed in Thai territory at the start of the Malaya operation. Thai forces opposed the landings, and inflicted hundreds of casualties before their government ordered them to stand down. If the British have two days warning, what do they say to Thailand, what does Thailand do? Do the British execute Operation MATADOR (move forces across the border to the landing sites)?
 
I am not a Mac fan but am curious with a more concrete warning of war would he have actually met them on the beaches. Originally wasn't really on the beaches in force. For the Vigan and Aparri landings might have done some damage.
MacArthur actually had his forces massed and ready to annihilate the main Japanese landing at Lingayan Gulf. But then he lost his nerve, froze in place for 24 critical hours, and then told everyone to run for Bataan. He could not have won in the long run, but he could have done WAY better than he did.
 
ITYM "WI the Striking Force was sighted a few days before the Pearl Harbor attack?" The "Combined Fleet" was the term for all the seagoing vessels of the IJN: the destroyers, cruisers, battleships, and carriers. It excluded minesweepers, patrol craft, escorts, submarines, tenders, and training vessels. If the entire Combined Fleet was somewhere to be spotted, that's weird.

The Japanese expected to have operational surprise (they achieved tactical surprise, which was a bonus). That is, they expected to be spotted a few hours to a day before the attack, which would not allow the US forces to get fully ready for battle. (Consider what the US forces would need to do: get the report to all the relevant commanders, get everyone out of bed, get the command staffs up to speed, get all personnel out on liberty back to their posts, get steam up in all warships, get all planes armed and fueled for takeoff, get the fleet out to sea... All from a "standing start", i.e. peacetime conditions. Thus even with several hours warning, the US forces would be at a disadvantage.)

It has been written in this thread that Nagumo's orders were to turn back if sighted more than 24 hours before H-Hour, because that much warning would lose operational surprise. Otherwise, press on.

If per tbhe OP Nagumo turns back on say 4 December 1941... ISTM that Japan is already committed to war with the US and Britain. So the "Southern Operation" continues. Lots of issues to discuss but I have no time now.

Actually imagine if the fleet would have sortied without proper air cover. All the battleships would have probably been sunk anyways and not recoverable like they were in harbor. The US was not prepared for this battle in any way shape or form. In the end it probably worked out for the best (the best worst option).
 
Actually imagine if the fleet would have sortied without proper air cover. All the battleships would have probably been sunk anyways and not recoverable like they were in harbor. The US was not prepared for this battle in any way shape or form. In the end it probably worked out for the best (the best worst option).

Battleships underway move, ships in harbor do not, the Americans will lose ships yet the ships that survive will have taken far less damage than their historical counterparts. Also, there is no way the IJN somehow sinks all 7 between triple-A, smoke, and the mass of ships it is likely a good portion of the IJNs strike package will go after other targets
 
The plan was to send the fleet over the horizon to the SE. The worst possible direction for Nagumos air recon. If a air strike is suspected then it can side step out of bomber range. Nagumo cant run straight off to hunt as that leaves 300+ modern combat aircraft on his flank. & two enemy carriers location unlnown.
 
Actually imagine if the fleet would have sortied without proper air cover. All the battleships would have probably been sunk anyways and not recoverable like they were in harbor. The US was not prepared for this battle in any way shape or form. In the end it probably worked out for the best (the best worst option).
Why would they have gone out without aircover?
Enterprise: On 28 November 1941, Admiral Husband E. Kimmel sent TF-8, consisting of Enterprise, the heavy cruisers Northampton(CA-26), Chester (CA-27), and Salt Lake City (CA-24) and nine destroyers under Vice Admiral William F. Halsey, Jr., to ferry 12 Grumman F4F-3 Wildcats of Marine Fighting Squadron (VMF) 211 to Wake Island. Upon completion of the mission on 4 December, TF-8 set course to return to Pearl Harbor. Dawn on 7 December 1941 found TF-8 about 215 miles west of Oahu.


Lexington: On 5 December 1941, TF-12, formed around Lexington, under the command of Rear Admiral John H. Newton, sailed from Pearl to ferry 18 Vought SB2U-3 Vindicators of Marine Scout Bombing Squadron 231 to Midway Island. Dawn on 7 December 1941 found Lexington, heavy cruisers Chicago (CA-29), Portland (CA-33), and Astoria (CA-34), and five destroyers about 500 miles southeast of Midway. The outbreak of hostilities resulted in cancellation of the mission and VMSB-231 was retained on board [they would ultimately fly to Midway from Hickam Field on 21 December].


Saratoga: The Saratoga, having recently completed an overhaul at the Puget Sound Navy Yard, Bremerton, Washington, reached NAS San Diego [North Island] late in the forenoon watch on 7 December. She was to embark her air group, as well as Marine Fighting Squadron (VMF) 221 and a cargo of miscellaneous airplanes to ferry to Pearl Harbor.


BBs, and USS BBs in particular, were well built and protected.

Six Kates from Soyru dropped tops on thi immobile Gunneryship Utah.
Two hit.

Moving and maneuvering targets are much more difficult, esp. when all possible AAA is operating. Level bombing with the big AP bombs that doomed Arizona is right out.

Vals carried a 550 pound bomb, they didn't have smaller AP bombs, they started at 1600+ pounds, too heavy for the Val. The Type 99 N.25 that was an almost SAP that had a high dud rate when used even on lightly armored ships

So it will be up to Kates with torpedoes.

The Tennessee and Colorado classes had very good Torpedo Protection, then the New Mexicos, Nevada and then Pennsylvanias.
Having watertight doors closed and engineering spaces not open for inspection makes a big difference.
 
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