The Gun Counter

Not being either an aviator or a navalist, how hard would it have been for the various Japanese strike waves to change their targeting, and what were the limitations of the ordnance they carried?

With the benefit of 75 years of hindsight, if I was Commander Genda, my target priority would be:

1) Airfields and the aircraft on them, to establish air superiority over the target and reduce or eliminate the chance of the land-based counter strike on my carriers.
2) American carriers, if any were in the harbor
3) Drydocks and repair facilities
4) Fuel farm(s)
5) Submarines and tenders for same
6) Fleet oilers and other underway replenishment ships

That said, I would probably assign the fuel tankage to the last wave, for the simple reason that once it starts to burn, it's going to create a huge amount of smoke, making flying around over the target hazardous and making ID of other targets much more challenging.

Now, the question is, how hard is it to re-assign targets? The first wave would have arrived over the harbor without the benefit of any sort of scouting or reconnaissance. So, could they have diverted torpedo bombers to attack the dry dock gates (assuming the gates were closed; if they were open, I don't see any easy way to attack them)? Could the level bombers, with their armor piercing bombs used to attack battleships have instead be sent to attack the concrete of the dry docks (I assume they would do considerable damage, by penetrating the concrete before exploding)? In any case, the dry docks would be easy targets; they can't move, and they probably didn't even have guns to shoot back.

Short answer, very hard if you don't want a complete Charlie Foxtrot. Especially given the technology of the time (communications particularly). That operation was planned down to the last detail and rehearsed extensively. And while the Japanese practiced tactical flexibility (i.e. no one had to tell the pilots to switch to attacking the Nevada as she made her run rather than striking her assigned berth as, say a Tomahawk would).

Massive re-assignment while en-route or over the target area is pretty much a recent development, being made possible in the last 20 or so years only with the development of SATCOM, digital communications in the cockpits and "smart" weapons. We wouldn't have tried it during DESERT STORM .

It as actually a bomb (whether from a dive or horizontal attack I don't recall) that took out Arizona by hitting her magazines.

For the dry docks you go after their gates (but I don't think torpedo would have much effect) their control mechanisms and the structures (cranes etc) that support them.

Punching holes in concrete is pretty much a waste of time for any long term effects.

Which leads to attacking airfields, if by that you mean hitting runways, 10x that. Not to slam you (and you did say you weren't trained on this) but this is one of my pet peeves as it is the sure sign of an amateur to look at hitting runways even today. The only reason to attack runways (for which there are NO good munitions) should only be done with a limited (in time frame, hours at most) tactical objective such as keeping those aircraft on that field interfering with a particular strike package. [/Standard Rant #3]

As it was the IJN counter-air was extremely effective (helped by the grouping of US aircraft to protect against sabotage). The Zeroes were more than enough to handle anything that did get off the ground. That, and there really was nothing on the island that would have effectively threatened the Japanese strike group if they had survived. Certainly the Army had nothing and the majority of dive and torpedo bombers the Navy had were at sea on the carriers (where they belonged). Once the air strike was over, the real threat from land based air was in scouting for and locating the strike group, and again the strike as it was effectively ended that threat by destroying the aircraft.

One thing about attacking the dry docks, is it seems if you switch from attacking ships to the repair facilities instead, if you destroy fewer ships you also reduce the immediate need for the facilities. Now moving ahead as the war progresses, that does mean that any US ships that the IJN damages bad enough to require drydock repair will STAY damaged for longer due to having to sail all the way to west coast for repair, but in the immediate future it also means you will be facing more ships since you shifted targeting priority away from them. And while it may have been a carrier war for the most part, early on in the war there were some engagements where having a few more large surface combatants available could have really tipped the scales in favor of the USN.

Really what they needed to have done differently was launch the aborted final wave of attacks and take out the facilities in addition to the ships, not instead of.

+1

There's a interesting, if minor, question worthy of historical research: how many ships were repaired in the Pearl Harbor dry docks, either due to battle damage, refit/upgrade, or routine maintenance that required a dry dock?

I know one instance where the services of the Pearl Harbor dry dock was quite significant: repairing the damage suffered by the Yorktown in the Battle of the Coral Sea in time for her to take part in the fun at Midway. If the Yorktown had had to sail to San Diego or Bremerton, she probably would not have been available for the battle, giving the U.S. only two carriers.

As far as big ships go, Saratoga went to Bremerton to repair battle damage from the Guadalcanal campaign; North Dakota was repaired at Pearl (torpedo damage, Guadalcanal*), South Dakota went to New York for battle damage repair (naval gunfire, Guadalcanal) and stayed in the Atlantic; Franklin went to the Brooklyn Navy yard for battle damage repair (dive bombs off Honshu); Bunker Hill went to Bremerton after being hit by kamikazes.

As the war moved westward, the dry docks at Pearl probably became less important for regular, non-battle damage repair and maintenance, as the floating dry docks (which were one of the USN's greatest innovations of WWII) went into service in captured anchorages.

*The torpedo salvo by I-19 that damaged the North Dakota was probably the most effective torpedo salvo by a single submarine in the entire war. In addition to damaging the North Dakota, it sank the carrier Wasp and an escorting destroyer.

I thought it was Harry Dexter White who caused Japan to pursue its "Southern" Strategy instead of advancing north from its puppet state in Manchuria.

Netpackrat wrote: ↑Mon Jun 25, 2018 12:50 am Really what they needed to have done differently was launch the aborted final wave of attacks and take out the facilities in addition to the ships, not instead of.

The most important thing that they missed was the fuel oil store.

That's 4000 fuel loads for a Pennsylvania class battleship. The dry docks were useful, but, they weren't necessarily critically important.

In my opinion, the most important target - of anything - at Pearl Harbor was the fuel supply. The US could get more oil to Pearl, but, it would take a long time. If the US navy had no fuel for its battleships, then they're as crippled as if they're sitting in the mud.

Jered wrote: ↑Tue Jun 26, 2018 4:05 am

Netpackrat wrote: ↑Mon Jun 25, 2018 12:50 am Really what they needed to have done differently was launch the aborted final wave of attacks and take out the facilities in addition to the ships, not instead of.

The most important thing that they missed was the fuel oil store.

That's 4000 fuel loads for a Pennsylvania class battleship. The dry docks were useful, but, they weren't necessarily critically important.

In my opinion, the most important target - of anything - at Pearl Harbor was the fuel supply. The US could get more oil to Pearl, but, it would take a long time. If the US navy had no fuel for its battleships, then they're as crippled as if they're sitting in the mud.

Yeah, I was kind of lumping both the tank farm and the dry docks in under facilities. And as Langenator mentioned, without the Pearl dry docks, Yorktown probably doesn't fight at Midway, which might have changed the whole course of that battle for the worse, and prolonged the war.

The Japanese doctrine leading up to WW2 was almost entirely battle centric with almost no room for anything else. They did not attack fuel depots, repair facilities or other non battle related items because they did not put a great deal of importance on those things. It was a very weird outlook.

This fact colors almost all of the Japanese strategy and operational level planning, but most clearly impacted their submarine doctrine. For most of the war they more or less forbid their submarine captains from attacking non-combatants and when Dönitz tried to send U-boats into the Pacific they refused to support it (although the Germans did operate in the IO a bit.)

I think it might have stemmed from the version of Bushido practiced by the militarists that effectively took over the government starting in the 20's. As with all movements based on nostalgia for a period in their "great" past, they exaggerated aspects of the old Samurai culture and became a parody of what they supposedly wanted to emulate (CF Italian Fascist party and German National Socialists).

The yearned to prove themselves in battle against worthy warrior opponents, disdained those that could nor or would not fight back, and fetishized their weapons (pot meet kettle ) to the point that it was beneath them to attack anything other than enemy warships, or to degrade their weapons by soiling them on the unworthy.