How could Japan have bombarded the Fortress of the Pacific ?
Since the Combined Fleet didn't historically do much in it's distant support of the Kido Butai's effort against Oahu, I'd like to propose a "what if" discussion about what they
might have done, instead.
I know that there are a multitude of historical reasons for why such an alteration in history could not have happened but, I'd like, with your agreement, to ...
1.) ... leave aside the
entire "Japanese strategic doctrine would never have allowed that" discussion/debate and just
assume that somehow/someway, it was so ordered. Maybe Emperor Hirohito had a dream ... about conducting the Decisive Battle of the Pacific War off of Hawaii ?
2.) Likewise, I'd like to sidestep the
entire "the IJN didn't have the logistics base to support a move by the Combined Fleet to Oahu" discussion/debate. I know and accept that already but would like to have a bombardment discussion and so have
assumed that the fuel/supplies/ammo would be provided, somehow/somewhere, like manna from heaven.
Actually, my pet theory is that Japan might have used many of the high speed modern tankers
idled by the American led oil embargo against her, to re-fuel the Combined Fleet as it headed east. Historically they did so convert, to underway re-fueling status, some of those tankers otherwise anchored in the Inland Sea. In effect, creating more last minute and poorly trained fleet oilers, in great secrecy. Since they did it historically, I don't think it too much of a "mental stretch" to assume that 3.) they could have so converted more in the time that they had available. With the a similar degree of success and secrecy.
So, if you agree, the IJN's Combined Fleet, less the two battlecruisers historically sent south in support of the Southern Operation, crosses the northern Pacific just behind the Kido Butai, having also left it's usual radio operators back in Japan to transmit fake messages from there.
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Now, some map homework for you, the reader,
Pre-mission scouting on Oahu by Yoshikawa would have revealed that the map found at
http://militarymaps.org.ua/maps/ospr..._008/map9.djvu is
far too optomistic for Dec.'41. (You'll need the Djvu viewer which is available for free download at djvu.com to see that map). The map, by C.Taylor, comes from the Osprey book entitled "Defenses of Pearl harbor and Oahu 1907-50" by Williford & McGovern
First, you'll have print out a copy and then erase all of the black firing arcs because those batteries were built after Dec.7'41. Next go the browns for a similar reason. Finally the purple #6 arc gets converted to a 360 degree circle to more properly show its real 16" firing abilities on Dec.7'41. The existing purple arc shows it's casemated firing arc after it was fortified circa late 1942.
Do the same for purple arc #5 for battery Closson. In 1941 it too could fire 360 degrees, not just a forward arc.
Not nearly so impressive a defensive map of US 8" and larger coastal artillery firepower now, is it ?
I note that the map does
not show any of the 4x4x8" railway gun batteries then on Oahu because they each took at least two days to get into firing position on their pre-built strengthened sidings and were NOT so emplaced on Dec.7'41. I suspect that this action will be long over before they could so deploy to specially strengthened firing sidings capable of taking the stresses of shooting.
Also
missing are eight US Army 240mm semi-mobile howitzers, for a similar reason. They each took two full days to deploy onto pre-poured circular cement bases and they were all "in the barn" on the mornming of Dec.7'41. Their crews were not trained/equipped for anti-shipping fire in any case. Their mission was anti-invasion beach defense, firing at pre-registered likely landing points. And very nasty in that role they would have been to any invasion troops.
The map does
not show the short 360 degree firing arcs of the the 155mm towed howitzers either since the US troops did not customarily leave them out on their "panama mount" concrete bases, untended, when they returned to their barracks for the weekend. A very few 4 gun 155mm batteries were indeed deployed on their panama mounts when such were located inside of US military bases but we can deal with those on a one at a time basis as the discussion progresses.
The US Army on Hawaii was equipped with many more smaller artillery pieces also but I have ignored these as being too small to pose a significant threat to an IJN armoured battleship, battlecruiser or heavy cruiser. They too were parked in their armories buildings for the weekend and their gunners were trained (and ammo supplied) for ground combat support, not anti-shipping fire in any case.
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Having viewed the US coastal artillery defences and their range arcs, please now go to
http://militarymaps.org.ua/maps/ospr...bor/map03.djvu to view the potential IJN bombardment targets on Oahu. This map also shows the historical air attacks which would likely be
much modified in the event of my suggested IJN Combined Fleet capital ship participation.
Potential targets
missing from that map are Fort Shafter which is located just south of the "NAS" of the "Pearl Harbor NAS" label, the John Rogers International Airport located just to the right of the "d" in the Hickam Field" label and the oil tankfarms located at the "E" below the "Pearl Harbor NAS" label. Several more including the Aliamanu Crater Ammunition Depot, the Luailuai radio transmission towers and Fort Ruger located inside Diamond Head Crater could also be added to the targeting list. There is NO shortage of American targets to blow up on Dec.7'41.
Please note that there are at least two errors on this map. The first is that in 1941 there were not two highways between Kaneohe and Honolulu. There was just one, the Pali Highway, running over/thru the Pali Pass which is the more southeasterly of the two roadways shown. The second error is a road shown running around the NW tip of Oahu, Kaena Point, which was never built. A railway line did run over several narrow trestles there, but no roadway.
As soon as I learn how to modify a map I'll attempt to add these other targets/errors to it, for clarity.
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Have I overlooked anything major ? Are you interested in such a discussion ? Let me know.