Pearl Harbor vs. open seas

I'd think though with that declaration already out there the Japanese would have been attacking a fully entrenched US force at that point. I'm not sure how the US carriers would have been in the mix at that point but for sure anti-aircraft and then the all those planes at each of the different airfields that were targeted would likely have been fully mobilized to defend Pearl.

 

Maybe I'm assuming too much when I say that a dec. removes sabotage from being the main concern from the Japanese, at that point I would think a full military attack has to be expected. Still having those ships active instead of destroyed or out of commission just adds to the speed and efficiency that the US could move through the Pacific.

 

In the future please refrain from using the term "Japs" in here. We here try to stay away from such derogatory terms

Welcom aboard Skontos1.

 

Thanks, I apologize for that I wasn't sure when I posted it I've changed it already

 

Really? thanks for that I can probably guess the rest but I probably would have missed that one

 

Marcus,

Your thinking in terms of attacking Pearl Harbor, not in attacking the US Fleet at sea.

The normal torpedo drop technique of a B5N Kate was much less complicated than the ones used during Pearl Harbor. A "normal" drop was flown at speeds up to 200 knots and at 100-300 feet in altitude, whereas, at Pearl Harbor, the drop was about 140-150 knots and about 50-60 feet in altitude. Further, the Kates attacking "Battleship Row" had to fly a fairly complicated flight path to their targets. Thus, only skilled aviators were chosen for the torpedo attacks.

However, by attacking the US Fleet at sea, Japan can use all of it B5N Kates as torpedo bombers. The attack will likely take place at a later date, allowing more training for the pilots aboard the Shokaku and Zuikaku. As such, the 90 B5N Kates that attacked Pearl Harbor, given a generous hit rate of 33%, would yield 27 hits. A more realistic rate of 15 to 20 percent should yield 13-18 hits. Yet, this would be from one strike, and there likely would be further strikes before the US battleships can close with the Japanese.

The US Fleet maneuvering at sea cuts both ways. It will make it harder for the Japanese to attack the US warships, but it will also hinder the AA fire from those warships. Also, the Kates will likely be flying faster than they were at Pearl.


The unknown variable remains the US carriers, are they within the US Fleet or are they operating on the fringes of the Fleet, thus forcing the Japanese to divide there effort between battleship and carrier task forces. If the carriers are with the Fleet, then their CAP could be very effective, it they are operating on the fringes, than their CAP will likely have trouble covering both effectively. And, if the Americans decide to launch a "strike" of their own, further fighters will be needed to escort that.

All in all, I believe that the Japanese stand a decent chance of striking a crippling blow on the US Fleet at sea. It will be all the more decisive if the Japanese battle fleet can follow up by engaging the surviving forces.

 

Yes, all Kates could be armed with torps but many would be flown by pilots with little operational experience and only theoretical knowledge about torpedo attacks because:

I don’t think a mass attack by Kido Butai on the US battle line could happen at a later date. Kimmel was aggressive but not suicidal. He would not have raised anchor and steamed towards the Philippines. That idea was long dead by 1941 and even if not, the fleet train for such an operation didn’t exist until 1943.

IMO the confrontation either happens around Dec.7th or so much later, that the USN is vastly stronger(Leyte).

We need to consider the fate of Force Z, don’t we?

The only ship with a modern AA-battery was PoW and she was out of the fight almost immediately. Repulse had a poor AA, eight hand operated 4” guns and two pom-poms, the four destroyers had so little AA that they could not eve defend themselves.

The attackers were planes from the Genzan Ku. The pilots were rather more experienced than the average Kido Butai pilot and they had been training torpedo attacks for some time.

In spite of the very poor opposition they faced, they still only managed a 12-16% hit rate.


Now let’s take a look at Kimmel’s fleet:

-eight battleships
-six modern cruisers
-twenty six modern destroyers

Every single ship had modern, heavy, power operated and director controlled AA-guns. A cruiser had as many heavy AA-guns as a battleship, a destroyer at least half as many.

This fleet would have fought back many times harder than Force Z ever could.

 

I believe US doctrine at the time was that the ships stayed in formation and manuevered as a unit. Part of the idea was to aid the AA defences. Note that the US also had specific formations for AA defence which would have involved the torpedo planes flying past the destroyer and cruiser screens to get to the big ships.

 

If the Japanese Navy had decided on an "open seas" battle instead of an attack on Pearl Harbor, those pilots would have received the training necessary to conduct the attack, since the pilots of the Akagi, Kaga, Hiryu, and Soryu were already trained in "normal" torpedo attacks, and would not need the "specialized" training to attack Pearl Harbor, focus could be easily shifted to a more intense course for the Kate pilots of the Shokaku and Zuikaku. As I stated earlier, this would not require the intricate flying that was necessary for the attack on Pearl Harbor. Although, they would need to be trained in estimating the proper "lead" for targets steaming at some 20 knots.

Nowhere did I state the Kimmel would steam blindly to the Philippines. Kimmel's intention was to bring about a major fleet battle somewhere in the vicinity of Wake Island or the Marshall Islands, this would likely occur within the first few months of the opening of hostilities.

"Almost immediately" is a matter of perspective, since the attack on Force Z took so long to develop. The torpedo bombers did not begin their strike until a good half-hour after the attack began.

The Genzan Kokutai was only "more experienced than the average Kido Butai pilot", in level bombing, which they had been doing in China since late-1940. If by "some time", you mean a few months, then you are correct. The Genzan Kokutai was withdrawn from China during September-October, 1941, to train in torpedo bombing. I believe you have mistaken the Genzan Kokutai for the another of the Force Z attackers, the Kanoya Kokutai - which was Japan's premier land-based torpedo force(and would score the bulk of the torpedo hits against force Z).

Now, if Kido Butai were to follow the attack premise that was the basis for the attack on Force Z, the bombers would attack first in an attempt to suppress the warships AA fire by wrecking the AA guns, their associated fire control, and other lightly armored upper works. Then, the torpedo bombers would commence their attack on the warships - against hopefully diminished AA fire. Since, without radar guidance and proximity fuses, they 5-inch/25s and /38s were not all that effective against dive bombers in dives, the bombers should stand a fair chance(in the absence of or negligible presence of CAP) of disabling some or several of the warship guns(this would depend on the temperamental 250 Kg bombs used by the Vals).

I would point out that the effective number of AA guns aboard battleships and cruisers is the same as a destroyer. You know, being divided between port and starboard, whereas, a destroyer can bring all of it's heavy guns to bear against an incoming torpedo bomber.

Or do you plan on having the battleship/cruiser AA guns on the un-engaged side fire through the superstructure? Thus, you don't have near the number of effective AA guns as you suppose.

And, as I said earlier, the dive bombers will have their shot at lessening the return fire against the dive bombers.

Finally, the US Fleet would be attacked by a far greater number of planes than Force Z faced, and with a type more suited to attacking ships, the Val dive bomber, as opposed to Nell level bomber.

 

Thank you for this comment OP.

I had read that Admiral Richardson had place his carrier/s at the center of a fleet formation, but was not sure if Kimmel had continued or modified this practice or how the carriers would operate if a fleet engagement was likely.

 

IIRC, during the early Pacific War, US warships followed a general fleet course, but the warships would maneuver individually so as to avoid attacks and to bring the most weapons to bear on an attacker.

I would think, that if the dive bombers go in first, against a large American formation, they might stand a good chance of breaking it up or at least "stringing" it out, as the larger warships maneuvered to avoid their bombs. Of course, if the Fleet is in smaller task groups, then the risk would be lessened.

 

Except I believe both the IJN and the USN practiced "hammer and anvil" type attacks which would come from opposite sides of the ships so if you tried to comb one set of torpedos you turned broadside to the other.

But that also strings out the attacks and allows CAP a chance to interfere with both. Note that the POW and company didn't have any CAP nor was there any during the first wave at PH.

 

Small point, Repulse had six 4" Mark V, a weapon dating from WWI (with two High Angle Control System directors) and three 8-barreled 2pdr pompoms; also eight Oerlikons. The basic point is still valid. She had briefly carried eight 4" in the 1930s as trials ships for the twin Between Decks mounting, two of which were mounted aft, but these had been removed and replaced by Mark Vs, partly because the trials were complete and partly to free up interior space when Repulse was being considered to carry the King and Queen on a visit to the Far East. The BD is more familiar mounting 4.5" guns in wartime aircraft carriers and modernized capital ships including Repulse's sister Renown.

Modern US destroyers and cruisers carried the Mark 33 and 37 tachymetric gunfire control systems, among the best of the period; Mark 37 was probably the best dual-purpose system of the war.

Automatic weapons is one area in which the US fleet of December 1941 was lacking even by comparison with the 1942 carrier battles. Battleships and large cruisers were supposed to have four quad 1.1s (not a great weapon to begin with) but deliveries were slow and most ships were either lacking them or had hand-worked 3"50s, without directors, as a temporary installation. We had few if any 20mm Oerlikons; big ships other than carriers made do with just eight water-cooled .50-calibers.

 

Now I understand. We talk past each other. I was thinking in terms of: "While Kido Butai closes in on PH they are spotted and the Pacific Fleet sorties to intercept."

I did not mean to imply you did.

In a Wake/Marshalls battle the PacFlt would have the support of its carriers and from recon-PBY based at Wake. How that plays out depends on what the Japanese bring to the show. W/o PH some of their carriers would have been send to support the attack on the DEI.

The main point was and still stands that the PacFlt had a vastly better triple-A than Force Z.

 

I actually think there are too many variables to "accurately" speculate the outcome. As the British found out in the Med, trying to BRING A RELUCTANT FLEET TO BATTLE is a difficult proposition, even in the "restricted" waters of the Med. Out in the open ocean...? My study of the Japanese "battle" philosophy is that the battleship was still "king", BUT...they had probably THE most potentially destructive carrier force, and had the doctrine of concentration of carriers. The US did not even operate PAIRS of carriers until Midway. So I think the CONCENTRATION of carriers of the Japanese would give them an attack advantage, but the radar on board US carriers giving advanced warning of attack would be a TREMENDOUS advantage (as it was at Midway, when we could shut down and secure fueling operations to lessen fire danger).

Remember, too, that carrier Yorktown, her cruisers, and several battleships were taken FROM Pearl in mid-1941 and shunted to the Atlantic. Part of "our" scenario would depend on our own and the Japanese makeup of the fleets opposing each other, and the month/year of its meeting.

If we JUST include the historical forces extant at the PH attack on Dec. 7th, the MUCH FASTER Japanese fleet would NEVER get caught in a stand-up gunnery duel, and the six carriers would most likely have damaged the American fleet more than the historical outcome at Pearl.

But an "at sea" battle of our respective combined fleet units is just too complicated to predict, methinks.