US fleet sail before attack on Pearl harbour.

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paul.mercer
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US fleet sail before attack on Pearl harbour.

Post by paul.mercer » Mon Jun 08, 2020 9:34 am

Gentlemen,
if the US fleet at Pearl Harbour had prior warning of the Japanese attack and had sailed out to meet them what would have been the result, assuming that the US had their 3 carriers with them, the US were far superior in battleship numbers,(8 v 2) but the Japanese had 4 carriers plus submarines, any thoughts on the outcome?
As an after thought, the Japanese torpedoes were modified for shallow attack in what would presumably be the calm waters of the harbour would they have worked as well in open sea which would likely to be much rougher?

Francis Marliere
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Re: US fleet sail before attack on Pearl harbour.

Post by Francis Marliere » Mon Jun 08, 2020 9:54 am

One can never know what would happen, but all the elements of a first class disasters would be present. The USN carriers were not battle ready at the time, as the 'early raids' have shown. They had too few fighters, and their fighter direction was not up to the task. The planes lacked self-sealing tanks, and so on. And anyway, the 3 USN carriers would face 6 IJN ones.

The US battleline, slower than the Japane fleet, would never get in contact. The US battleships, with their slow speed and anemic air defenses, would be probably seriously hit by enemy dive and torpedo bombers. It's probable that if the USN was attacked in open sea rather than in port, the looses would be more important than those at PH, for several reasons.
During the attack on PH, about half of the battleships could not be attacked by torpedo bombers, because they were protected by another BB anchored nearby. In open sea, all ships would be attacked.
At PH, Arizona was destroyed by an explosion while Oklahoma capsized, but other ships sank in shallow waters. That saved the crews and allowed to repair the ships. Ships sank in open waters would be lost forever, and looses among the crews would be more important.

Strictly my opinion of course.

Francis

Steve Crandell
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Re: US fleet sail before attack on Pearl harbour.

Post by Steve Crandell » Mon Jun 08, 2020 8:38 pm

The USA was not at war, so no they weren't ready and any ships lost at sea would not be repairable.

Having said that, ships at sea are much more difficult to hit with torpedoes and their compartments would not have all watertight doors open for inspection. The special Japanese bomber formations equipped to drop modified 16' shells from level flight at 10,000 feet would have been pretty much useless against a fleet at sea.

To Francis: What makes you think Japanese AA was better than that of the US on Dec 7, 1941? I know the Japanese were pretty impressed when their second wave ran into significantly more flak than the first wave, and the ships in the harbor weren't fully manned even then. Japanese AA has never looked very impressive to me. Of course fighters are always more important when defending against air attack, but I don't understand why you think Japanese fighter direction was better than that of the US. I doubt either was all that great, and the IJN version didn't look very good six months later at Midway, the easy slaughter of Torpedo 8 not withstanding.

OpanaPointer
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Re: US fleet sail before attack on Pearl harbour.

Post by OpanaPointer » Mon Jun 08, 2020 9:38 pm

"ships not fully manned"?

Steve Crandell
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Re: US fleet sail before attack on Pearl harbour.

Post by Steve Crandell » Mon Jun 08, 2020 10:43 pm

OpanaPointer wrote:
Mon Jun 08, 2020 9:38 pm
"ships not fully manned"?
I was assuming that if the fleet was at sea, the ships would not have a significant portion of their crews ashore like they were on Sunday morning of the attack on Pearl Harbor.

Francis Marliere
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Re: US fleet sail before attack on Pearl harbour.

Post by Francis Marliere » Tue Jun 09, 2020 8:21 am

Steve Crandell wrote:
Mon Jun 08, 2020 8:38 pm
To Francis: What makes you think Japanese AA was better than that of the US on Dec 7, 1941? I know the Japanese were pretty impressed when their second wave ran into significantly more flak than the first wave, and the ships in the harbor weren't fully manned even then. Japanese AA has never looked very impressive to me. Of course fighters are always more important when defending against air attack, but I don't understand why you think Japanese fighter direction was better than that of the US. I doubt either was all that great, and the IJN version didn't look very good six months later at Midway, the easy slaughter of Torpedo 8 not withstanding.
Steeve,

I agree that the Japanese flak was not outstanding. IJN air defence relied on 12.7 cm / 40 guns, that were not outstanding, and 25 mm guns that had too many defects (too much flash and vibration, slow rate of fire due to the inadequate supply of ammunition, crude fire control, etc.). The Japanese were aware of this limitations and did not expect much of their AA guns. Eventually, they had more faith in their ship handling than in air defence.

However, the AAA suit of most USN ships was in late 1941 even worst. Most battleships and cruisers had 8 8"/25 (which had at the beginning of the war a lot of faulty ammunitions) and the same number of 0.50" machine-guns, that proved almost useless against torpedo and dive bombers. Chicago pianos (1.1" guns) were more effective but existed in limited numbers only, and were prone to jamming. With insufficient number of inadequate guns manned by inexperienced gunners, it is not surprising that the air defense of USN ships was ineffective during the first months of the war (from memory, I think that no enemy plane was shot down by flak during the early raids).

Best,

Francis

paul.mercer
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Re: US fleet sail before attack on Pearl harbour.

Post by paul.mercer » Tue Jun 09, 2020 8:56 am

Thanks for your replies,
Would the modified Japanese torpedoes been effective in the rougher waters of the open sea as i assume they were designed for the calmer waters of PH

Francis Marliere
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Re: US fleet sail before attack on Pearl harbour.

Post by Francis Marliere » Tue Jun 09, 2020 9:00 am

My guess is that they would not use the modified torpedoes but the standard ones.

OpanaPointer
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Re: US fleet sail before attack on Pearl harbour.

Post by OpanaPointer » Tue Jun 09, 2020 12:28 pm

Steve Crandell wrote:
Mon Jun 08, 2020 10:43 pm
OpanaPointer wrote:
Mon Jun 08, 2020 9:38 pm
"ships not fully manned"?
I was assuming that if the fleet was at sea, the ships would not have a significant portion of their crews ashore like they were on Sunday morning of the attack on Pearl Harbor.
You know that sailors weren't automatically granted overnight liberty, right? "Cinderella liberty" was the norm back then. CPOs and officers could spend the night ashore, but as this wasn't the Fleet's home port a lot of them didn't have regular accommodations ashore.

OpanaPointer
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Re: US fleet sail before attack on Pearl harbour.

Post by OpanaPointer » Tue Jun 09, 2020 12:30 pm

Francis Marliere wrote:
Tue Jun 09, 2020 9:00 am
My guess is that they would not use the modified torpedoes but the standard ones.
There were a limited number of the Nagasaki-modified torpedoes, IIRC. The ones without the wooden fins were in good supply as they weren't offloaded before the fleet sailed.

Steve Crandell
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Re: US fleet sail before attack on Pearl harbour.

Post by Steve Crandell » Tue Jun 09, 2020 6:57 pm

The Japanese lost nine aircraft in the first wave and 20 in the second wave. Not a huge number, but note that they lost a lot more in the second wave. This doesn't look to me like AA that was useless, as implied earlier. Of course, it was plagued by defects and other issues and was never going to be as good as fighters.

Francis Marliere
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Re: US fleet sail before attack on Pearl harbour.

Post by Francis Marliere » Tue Jun 09, 2020 8:30 pm

Steeve, the conditions are IMHO very different. In PH the antiaircraft fire was dense because the ships were anchored in a harbor. The distance between ships was small and a plane attacking a ship could be engaged by almost every ship in the harbor. That's the reason why so many Japanese planes were lost during the attack.

Now imagine the fleet in open waters. The carriers operate in separate Task Forces, with their own screen of cruisers and destroyers. Some cruisers are scouting ahead and some destroyers make an ASW screen ahead of the battleline. The battleships are probably in column formation with at least 1.000 yards between each ships, so they cannot support each others. Only a few destroyers screen each flank of the battleline. That means that a plane attacking a battleship, instead of being engaged at point blank by two or three dozen ships at anchor, is fired by the ship under attacked plus possibly a destroyer from the screen. The grand total is less than 10 5" guns and same number of machine-guns. Moreover, the ships are now making evasive actions at high speed. Under this conditions, I do not expect the US air defence to shoot down 3 dozens of enemy planes. Once again, it's strictly my educated (well, I hope ...) guess. Alan Zimm, in his book on Pearl Harbor, thinks otherwise.

Best regards,

Francis

Steve Crandell
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Re: US fleet sail before attack on Pearl harbour.

Post by Steve Crandell » Tue Jun 09, 2020 10:06 pm

When you say "Alan Zimm, in his book on Pearl Harbor, thinks otherwise.", I'm not sure what you mean. It seems to imply that he agrees with me.

It's apparent to me that a CV operating at sea is difficult to attack if for no other reason than her fighters.

Being able to maneuver also makes them much more difficult to attack from the air, and that assumes that the enemy can even find you. Whoever attacks first tends to have a big advantage in an air battle. Of course in this case the USN hadn't yet learned the proper tactics to use against the IJN Zero fighter and in this case their torpedo planes were obsolete and carried torpedoes which didn't work a lot of the time.

If the IJN doesn't attack the harbor, that means that the large aviation component based in Hawaii probably doesn't get attacked either, and that frees up a lot of aviation assets to use against the IJN.

Francis Marliere
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Re: US fleet sail before attack on Pearl harbour.

Post by Francis Marliere » Tue Jun 09, 2020 10:19 pm

Zimm's book is -still IMHO - a mix of excelent and discutable things. Zimm thinks that the air defense of the Pacific Fleet is trong enough to repell a Japanese air atatck and shoot down lots of planes. For the reasons you know, I don't agree with him.

You're right that it's easier to hit a stationary target than an evading one. However, since the US battleships (the main targets of the attack on PH) could not steam faster than 20 knots, its probable that their evasive steering would not be very efficient.

Most of the land based aircraft were short range obsolete fighters of little use in a naval battle, and heavy bombers unable to hit a naval target.

Best regards,

Francis

Steve Crandell
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Re: US fleet sail before attack on Pearl harbour.

Post by Steve Crandell » Wed Jun 10, 2020 1:08 am

I'm pretty sure the USN would be more than happy for the IJN to attack their battleships while the US carriers were attacking the Japanese carriers.

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