H6K as a Flying Boat-Bomb.

trurle

Banned
What is that based upon?

Look again. This actual picture of battleship row shows a difficult (not impossible) approach vector. Naturally, you would want to hit the Tennessee before the Arizona, and the Navade after that. True, the vector does not allow for a 90 degree angle to the beam, but is such really needed? Based upon the first pic, the USS Nevada would be targeted third, but as it can be attacked on both beams, it is the most likely to get hit/harder. The USS Maryland is the best protected of the 7 afloat BB's, but the Nesho is right on her bow, so...

With crack aircrews, I could easily see the attack vector in blue above being tried, followed by the Arizona and Nevada attack from the north, while all the other ships in battleship row can be attacked from the south or east. Mind you, if the Arizona is sunk, then the armor piercing bombs that did her in historically can go elsewhere (USS Maryland), so flying boat-bombs first, then first wave, and all but USS Pennsylvania are out of action for a couple years or so.

That isn't even the worst part, I've been looking at other photos, and it seems that not only US aircraft were parked to close together, and we still have ~ 12 remaining flying boat-bombs left over...

I was thinking the Yamamoto`splans were convoluted, but you beat him flat. Depicting attack compromising already bad attack accuracy and requesting the precise attack vectors with pre-determined timing sequence of multiple attacks are not the features suitable for a viable plan of operation.

War is chaos. Usable military plans should be expressed vaguely, with the room for improvisation for the on-the-scene soldiers.
Usable order would be like "Proceed to Pearl Harbor base with general approach vector XXX degrees, and attack targets of opportunity using general arrangements YYY or ZZZ as ordered by your wing commander, having priority for striking largest vessels"

Making the plans convoluted (like you did) is just the recipe for missing important part as has finally happened with Yamamoto. For example, captain of "Arizona" orders in last moment to change orientation of ship, for better protection from waves for boat with sailors returning from the shore. Which by chance block your precision approach to "Tennessee".

Also, kamikaze behave very bad if held in waiting. Watching the picture how your friends dying or the friend`s recent "grave" is not very good for motivation. If left circling for 10 additional minutes, of remained 12 flying bombs 2/3 are likely to develop "mechanical problems" serious enough to prevent attack but not serious enough to prevent ditching in the safe location. I mentioned before other limitations of kamikaze pilots too - the instinctive adherence to "maximin" strategy (surest tactics gets the priority) and the principal impossibility to get precise piloting due aircraft handling changes in expendable configuration.
 
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Here is a drawing, that shows something I didn't know before...
o7frbiSl.jpg

The USN ships were anchored side by side, and if the in port big ships are hit hard first, and then the remaining Kamikaze flying boat-bombs hit the Cruisers and destroyer packs, all the KB delivered torpedoes have to find different targets. I'm assuming that 20 of 25 assigned aircraft make it to the attack, and as they are well trained and well rehearsed for this attack, all 20 make successful strikes.

I'm going to go with that to make a point, and ask for thoughts on a group by group basis.

So, battleship row has 9 ships, 7 BB and the Nesho and Vestal. Going with just the OTL hits, but taking place after the H6K strike...
1) Do the H6K's plaster the Nesho & Vestal? Not high priority targets in themselves, but they are right next to the US BB's, and their destruction might also damage the ships near them?
2) Either way, the KB first wave got 3 armor piercing bomb hits on Arizona, and IIRC, 15 torpedo hits on 4 Battleships in BB row? If the H6K strike leaves these ships sinking, where do these hits get placed in this ATL? The bombs could best be used on Maryland, as that really is the best way to get her destroyed. Hitting Nesho opens up her oil tanks, and depending on how much fuel is in them, this could make the fires caused by Oklahoma's and West Virginia's fuel bunkers being ruptured seem mild by comparison.

Next, if we go with having 20 of the 25 H6K's making good on their attacks, they use 7-9 on battleship row, leaving 11-13 to go after the lesser ships.

Tempting Target Group A:
cRPsblfl.jpg

I'm not even sure what all these ships are, but let's just assume the three big ships here get hit in their sterns, and the group in the top left gets another strike in the stern of one of the middle ships. Perhaps the group in the lower right also gets one more H6k. What kind of damage can such closely packed ship suffer at the hands of the 4,000 lbs explosives detonating in close proximity? None? All sunk? What? Call this 3-5 H6Ks.

Next up, we have
Tempting Target Group B:
OlDH0wul.jpg

Lets go with the two big guys getting an H6K each, and perhaps some spare H6K's can get up close and personal with the densely packed small craft. Call this 4-5 H6Ks.

Tempting Target Group C:
IJ2GFxWl.jpg

Of these 4 ships, I only know that the Utah is a former Battleship, but lets say the H6Ks pay these four ships a visit as well, so call this 4 H6Ks.

This would give us 11-14 H6Ks left over from battleship row, so that basically would take care of all the H6K in the attack.

We have to reassign the OTL damage against ships covered by these attacks to ships as yet untouched. Since some of these ships were also targeted by the KB first wave, we are going to have more than the 15 torpedoes used on battleship row to spread around, but far more damage could be done to the US pacific fleet, if the H6K can really "one-hit-kill" the Battleships.

Thoughts? This is meant to be a worst case, by the way...

 
I'll start with this, much of what you post makes good sense. However, there are a few things to quibble over

I was thinking the Yamamoto`splans were convoluted, but you beat him flat. Depicting attack compromising already bad attack accuracy and requesting the precise attack vectors with pre-determined timing sequence of multiple attacks are not the features suitable for a viable plan of operation.
This need not, as you have posited it to be, be anything like predetermined, from the get go. You are the one that introduced the "bad attack accuracy" with your alternative version, loaded with 10-12 tons of liquid TNT. My current version has none of those problems. Precision attack vectors are going to be determined by what the attack force finds awaiting them in PH, and will be made on the spot. Where you got that this was going to be (Or for that matter, need to be) pre-determined is not anything that I have put into this discussion, but rather something that you just threw in there for apparently no (good) reason.

War is chaos. Usable military plans should be expressed vaguely, with the room for improvisation for the on-the-scene soldiers. Usable order would be like "Proceed to Pearl Harbor base with general approach vector XXX degrees, and attack targets of opportunity using general arrangements YYY or ZZZ as ordered by your wing commander, having priority for striking largest vessels"
All that you say here is good, true, and basically correct, but...
It is not me that is claiming some sort of overly complicated, pre-determined, pre-mission plan that dictates such detailed information (which the Japanese do not, and cannot, have) need be given to the pilots, but rather you.

Making the plans convoluted (like you did) is just the recipe for missing important part as has finally happened with Yamamoto. For example, captain of "Arizona" orders in last moment to change orientation of ship, for better protection from waves for boat with sailors returning from the shore. Which by chance block your precision approach to "Tennessee".
This is where you are making your mistakes. I am giving the best case for the attack, based upon what the Japanese find when they get to PH, but not dividing up WHO is making these decisions. Obviously, the Japanese don't know even which ships they are going to be finding within PH when they arrive, nor which are which, so there isn't going to be any chance of your above example with the Arizona making any difference, as the details given by me, and wrongly assumed by you to be part of an overly detailed, convoluted plan, are in fact nothing more than an intelligent look at what might have happened in the case of this fictional attack. So, as you mentioned yourself, the on the spot orders would look more like, "You three, hit the Yankee battleships from the North, and you others, Hit them from the SE." I have to point out what you did here, so that we can see it for what it is. I posted, using historical photos and information that the Japanese couldn't possibly have had on Dec 7th, 1941, an explanation of how my posited attack could shape up, based upon the historical dispositions of the ships within PH, so that it would be clear to all that read the post and looked at the picture what I was talking about. What you then did, was to assume that the Japanese had to have been pre-planning who would do what, where, and against which target, which is not at all possible, and in no way what I was posting. Your perspective would have held much more water, had I been attempting to post from the "POV of a Japanese pilot involved in the raid", but here I am simply using an historical photograph, making the information as clear as can be, so folks don't get confused, and can see what the actual raid did, and what my posited augmented raid might be able to do, given the historical ship positions upon their arrival.

Now that that is out of the way, let us look at what you have to say about the mindset of the guys that have been training to do this for months, so that they have the chance to strike a telling blow against the enemy by delivering large explosive charges to as many of the enemies ships as they can.

Also, kamikaze behave very bad if held in waiting. Watching the picture how your friends dying or the friend`s recent "grave" is not very good for motivation.
I have to say that I am extremely dubious here. The guys overhead just saw their buddies cream one or more USN Battleships, and their going to somehow be 'less' motivated? Really? I think rather, that they are going to be relieved that the plan is working, and want to get their turn while there are still some ships left to sink. But don't start in again now with, "well, in that case, they will just throw out their professionalism, and all their extensive training, and screw up the plan for [insert whatever] reason. These pilots came here to die, and take out as much of the US fleet as they can in the process, and earn their place in Japanese history.


If left circling for 10 additional minutes, of remained 12 flying bombs 2/3 are likely to develop "mechanical problems" serious enough to prevent attack but not serious enough to prevent ditching in the safe location.
First, where is the world are you getting that little gem from? You still seem to be attempting to force an extremely unlikely persona into these aircraft flight crews, that somehow managed to get into this elite force, knowing that it is a one way trip from the start, and that nobody is going to notice that the unreliable ones are going to be showing their doubts, and that no campaign of reinforcing the propagande balderdash is going to remove this possibility. Late war, involuntary volunteers, maybe, but not the guys that are here by choice, and well trained, well drilled, and well brainwashed.

Second, why are they going to be circling for ten minutes? Battleship row is not the only target in PH, as shown in my post above, there turns out to be a great many other targets of opportunity in the place, and I don't think that skilled pilots are going to need to be loitering about, but rather making their attack runs as quickly as they can to make them count, before the enemy has a chance to mount any effective defense, and will understand which targets need to wait till other targets have been hit.

Let me just ask this of you and all reading this thread, which is more likely:

In Turtle's psycho profiling, we are to believe something like onto the Kamikaze pilots reaction to the first attacks/deaths of their fellows is going to be along the lines of,
"Oh NO, Freddie and Joe and Smoo just bit the farm, oh the humanity of it, I cannot do this, I'll just accept the huge loss of face, humiliation and shame that goes with me aborting my attack, and land in some quiet corner and hope to survive..."

While in Shadow Masters psycho profiling, we would see something more like, "BANZAI!!!"

I mentioned before other limitations of kamikaze pilots too - the instinctive adherence to "maximin" strategy (surest tactics gets the priority) and the principal impossibility to get precise piloting due aircraft handling changes in expendable configuration.
You did indeed mention that, I'll give you that. OTOH, it was you, and not I, that wanted to go in with planes of vastly different handling characteristics, and not having the pilots having any previous opportunity to fly the planes in such a configuration. In my version, the development and training regime is going to be extensive, and kept as simple as possible, and as close as possible to normal handling characteristics as possible, and one that the pilots are going to have flown many times before. So no, you don't get to just dismiss far greater accuracy because your really talking more about your version than mine.
 
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BlondieBC

Banned
@Shadow Master

Distance from Majuro to Honolulu is 3677 km. You can fuel the planes in a friendly atoll. Range is 6580 km. There is plenty of fuel to get there and to loiter and to attack. You don't even need to fuel the tanks totally full, so some of the weight can be used for explosives.

Weight Savings:

  • It could carry 2,000 pounds of bombs.
  • We go to two crew. We save 7 people at 200 pound of men plus gear. 1400 pounds. 3400 pounds of explosives.
  • 4 machine guns plus ammo. 400 pounds?? Call it 3800 pounds
  • one 20 mm cannon. hundreds of more pounds. Call it 4100 pounds.
  • There got to be another 400 pounds of stuff we can remove. Life rafts. Tools to fix the engines. Maybe cut out some steel hear and there with a welding torch. Call it 4500 pounds
  • 7764 L on the plane. We can be 25% short of fuel. Call it 2500 L of fuel, at 1.6 pound per liter. 4000 pounds. So we have 4500 to 8500 pounds of explosives
I don't get why we are getting such a complex operation. And the refueling issues. We can hand mold the TNT into the aircraft. We don't have to have a standard bomb fitted in. Some point fuse. Seems a lot simpler to just do it this way. Why is not say 6000 pounds of explosives enough?
 
There seems to be some ongoing confusion, and part of the blame for that falls on my idea undergoing multiple revisions, and part goes to Turtle, for posting his alternative version.

Distance from Majuro to Honolulu is 3677 km. You can fuel the planes in a friendly atoll. Range is 6580 km. There is plenty of fuel to get there and to loiter and to attack. You don't even need to fuel the tanks totally full, so some of the weight can be used for explosives.

Weight Savings:

  • It could carry 2,000 pounds of bombs.
  • We go to two crew. We save 7 people at 200 pound of men plus gear. 1400 pounds. 3400 pounds of explosives.
  • 4 machine guns plus ammo. 400 pounds?? Call it 3800 pounds
  • one 20 mm cannon. hundreds of more pounds. Call it 4100 pounds.
  • There got to be another 400 pounds of stuff we can remove. Life rafts. Tools to fix the engines. Maybe cut out some steel hear and there with a welding torch. Call it 4500 pounds.
  • 7764 L on the plane. We can be 25% short of fuel. Call it 2500 L of fuel, at 1.6 pound per liter. 4000 pounds. So we have 4500 to 8500 pounds of explosives
I don't get why we are getting such a complex operation. And the refueling issues. We can hand mold the TNT into the aircraft. We don't have to have a standard bomb fitted in. Some point fuse. Seems a lot simpler to just do it this way. Why is not say 6000 pounds of explosives enough?
Great information here, and thanks.

One thing, it could carry 2 800 kg torpedoes, so 1,600 kg = ~ 3,500 lbs just for the payload? So that's 6,000 lbs already. I wouldn't want to skimp on the fuel, as the planes are going to need all the range they can get if they hit rough weather/experience engine problems not severe enough to force them to scrub/ditch. Also, there is the issue of co-ordination of the H6K's and the KB first wave. If the KB first wave goes in first, by even 30 minutes, most of the targets the H6K could more effectively kill are already hit. Plus, if the first wave expends it's efforts on the battleships, then they have nothing left for the rest of the fleets ships. If the H6K's arrive with the first wave, then they get the protection of the zero's, and will get their attacks in first, leaving the carrier aircraft free to hit the lesser ships, to much greater effect. If the H6K attack early, then this doesn't break the attack, but it does cause changes, and these changes will most likely not be to Japan's benefit.

My final version, do in no small part to Turtle's input among others, is to have the specially modified H6K with an internal payload, so range and aerodynamics have minimal changes, that allow the flying boats to touchdown in pearl harbor, and then just drive straight into the anchored ships. In order to get an underwater detonation, the payload needs jettisoned far enough before actual impact, that the bomb can sink to a better/more damaging depth, prior to detonation. This attack profile give the best precision possible to the delivery of the explosives. I would go with a 3 way system, contact depth & timer detonators. So either the bomb hits the ship/harbor bottom hard enough to detonate, or it misses the ships hull by passing under it, and explodes when reaching a given depth, just like a depth charge, or it both missing the ship, and doesn't reach it's programed target depth (hung up in a net, for instance), but then it explodes anyway because of it's timer.
 
I think I owe you an apology, as the H6K doesn't look to sit as deep in the water as I was expecting. See my other thread for a better look at the latest revision, and share your thoughts...

MOECYuil.jpg


fHWNXyNl.jpg

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I think the physics is a bit off on this idea. The boat is running on the Water and hence the bomb would be at the waterline at best.
I was thinking that the bottom of the planes hull would be deeper than this underwater, but the other thread probably has the answer needed to make this work.
 
Now, if we have an ATL attack on pearl harbor, that opens with the use of the posited H6K's, each carrying and delivering the equivalent explosive content of 10 type 91 torpedoes, and flying in from bases in the Marshall Islands (With or without the need for a refueling stop at French Frigate Shoals), as outlined in the other thread, just how bad can the damage be to the US pacific fleet on that fateful sunday morning?
 
Depends on how the items already identified work out, and how the many details not yet identified play out. I'm not up to rereading the thread today, so I won't toss a couple critical questions. out now.
 
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