Nagumo with 7 carriers at Midway

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alecsandros
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Re: Nagumo with 7 carriers at Midway

Postby alecsandros » 12 Oct 2017 06:19

glenn239 wrote:I think Isom exaggerates the point. 205nm was not a guarantee there would not be a fighter escort as the carriers could follow the strike to recover them closer, and the demonstrated performance of the CAP against the Midway strikes could not have assured Nagumo's staff that the CAP could prevent the majority of a 36-72 dive bomber group from reaching drop position.

That is true, but we know it with hindsight. THe problems then and there were based on more precarious information.
Also, Nagumo's turn towards the enemy at 0930 would assist enemy fighters so is not consistent with the calculation Isom describes, (If worried about escorts, Nagumo should turn away from the contact).

I agree, but Ngumo thought that his own strike was just about to get launched, and that the enemy was just entering attack range - therefore the enemy was just about to launch, then form up the strike, and then travel 1.5 hours towards him. Therefore, Nagumo probably expected the enemy carrier-based strike at 11:30 or later.


Given that US carriers could carry 80, 10 planes hardly sounds like a CV strike, let alone 3 CV's letting fly with an ambush So, under this hypothesis the reason why Nagumo was caught is because he underestimated the threat level and assumed it was a surface force, upon which he could deliver a crushing blow before turning back on Midway in the afternoon. Had Tone 4 reported at 0800-0830, "3 Yorktown Class carriers sighted" and "100+ aircraft heading towards you" I personally doubt Nagumo sails towards the enemy or tries to prepare some grand strike using even the Midway aircraft at 1030.

It's possible, but who knows for sure?

Some hints on the enemy strength were available to Nagumo - such as the size of the escort (5 cruisers and 5 destroyers, which was an incorrect assessment, could actualy hint that the enemy was stronger then in appearance). Another hint came in the form of Chikuma5 seaplane, which reported zero enemy ships in the area, just 1.5hours before. IF another seaplane passed by and reported nothing, who knew if the enemy was comprised of just that force, or there were others as well, lurking underneath the cloud base ?
Other informed guessings came in the form of immediate history - Doollittle Raid, battle of Coral Sea, raids on Lae and Salamua, were examples in which USN carriers worked in pairs. If there was 1, almost always there was another nearby, if not in the same task force.

If 36 dive bombers counterattack with an escort then they may disable 0-2 carriers. But if 1st Division also participates then maybe 18 or so Kates will attack, armed with a mix of bombs and torpedoes. Level bombers will not achieve much, but they will draw CAP defenses and allow more dive bombers to get through, and give Hiryu more aircraft for later that day. Also important, fewer aircraft aboard the IJN carriers to burn at 1030.

Indeed, but it's a bigger stretch to include CarDiv1 in the launch.
If that were to happen, Japanese air losses would be heavy (Yorktown HOrnet and Enterprise had over 50 available F4F4s on board, of which 50% can be expected to make interceptions, while IJN airstrike had very few, if any , A6M2 Zeroes as escort). Japanese carriers could escape immediate destruction, but the historical hits would still happen, as the ~79 SBDs would already be flying at 9:30. OF those, only 50 would attack, crippling Kaga and Soryu, and jamming the rudder of Akagi. If they wouldn't be sunk or nearly sunk by raging fires, the carriers would still be out of comission.

Later, if all 3 USN carriers are disabled , more strikes would come from Midway (were all USN surviving aircraft would go anyway), and the IJN damaged carriers , with reduced speed and little defensive force left, would go down. If not all 3 USN carriers would be disabled, then a combined Midway+carrier attack would still sink the damaged carriers.

My personal impression is that Nagumo's "window of opportunity" closed at about 7:00AM, when Chikuma5 seaplane exited the area occupied by TF17 and TF16 and not seeing anything. IF that seaplane would have sent a sighting report of enemy carrier(s) at 6:30, Nagumo could have a complete strike wave on it's way by 7:15-7:30 at the latest, making first torpedo runs on the enemy at around 9:00. Such a early wave had a good chance of tangling with the SBD inbound strike waves (as happened almost every time during the Pacific carrier wars of 1942), and thus had a good chance of stopping some SBDs before actualy attacking. They would also report to Nagumo the large force of dive bombers inbound, which would trigger a certain alertedness of IJN combat air patrol and better discipline.

The net (probable) result IMHO would be the a reduction in number of SBD bombs dropped from 48 to 36-40, and consequently a reduction of hits from 9-10 to 6-7, and thus potentialy "saving" AKAGI.

At the end of the day, Nagumo would have 2 operaitonal heavy carriers, with a mix array of aircraft of board (from all carriers). Kaga and Soryu could still be sunk.

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Re: Nagumo with 7 carriers at Midway

Postby glenn239 » 12 Oct 2017 18:20

alecsandros wrote:That is true, but we know it with hindsight. THe problems then and there were based on more precarious information.


Everything I listed Nagumo's staff already knew at 0830 the morning of the battle.

I agree, but Ngumo thought that his own strike was just about to get launched, and that the enemy was just entering attack range - therefore the enemy was just about to launch, then form up the strike, and then travel 1.5 hours towards him. Therefore, Nagumo probably expected the enemy carrier-based strike at 11:30 or later.


Nagumo knew two things. First, that the enemy carriers knew his position from about 530, or 3 hours before he became aware of theirs. Second, that the enemy carriers were currently about 200nm away. Everything else was an assumption - the number and type of enemy carriers, if, when and what they had launched.

Other informed guessings came in the form of immediate history - Doollittle Raid, battle of Coral Sea, raids on Lae and Salamua, were examples in which USN carriers worked in pairs. If there was 1, almost always there was another nearby, if not in the same task force.


Those were all instances where the USN was on the attack, not the defense.

Indeed, but it's a bigger stretch to include CarDiv1 in the launch.


Once in hypothetical land everything is a stretch from what actually happened. What is certain is that 36 dive bombers are much more likely to cripple 2 carriers if 18 Kates with 800kg bombs are sucking in the bulk of the CAP. What Yamaguchi needed to do was get at least 12 dive bombers over two carriers, then he could anticipate 4-6 hits on each, which should be enough to shut down air operations. If he gets lucky and gets 18 over a carrier, that's as many as 9 hits, which would be very lucky.

If that were to happen, Japanese air losses would be heavy (Yorktown HOrnet and Enterprise had over 50 available F4F4s on board, of which 50% can be expected to make interceptions, while IJN airstrike had very few, if any, A6M2 Zeroes as escort).


Yamaguchi recommended, “Deem advisable we launch strike immediately with ordnance as is. "Launch" is not "attack". Getting the strike aloft was the hard part. Cobbling an escort was easier. Worst case scenario, Egusa would have to orbit for 45-60 minutes while an escort was assembled.

Japanese carriers could escape immediate destruction, but the historical hits would still happen, as the ~79 SBDs would already be flying at 9:30. OF those, only 50 would attack, crippling Kaga and Soryu, and jamming the rudder of Akagi. If they wouldn't be sunk or nearly sunk by raging fires, the carriers would still be out of commission.


So, Nagumo committed two big mistakes. First was the decision to rearm the reserve wave. If Yamamoto orders it launched immediately at 0910, then that mistake is avoided. The second large mistake was the decision to rearm the Midway strike. These would land, go to the hanger, get refuelled and rearmed, get hit, have munitions cook off, burn. So Nagumo is having 3 carriers knocked out either way. The only course of action that would leave Akagi potentially operational (but not the other two) was to not rearm the Midway strike when it landed, which would allow the carriers to 'clean up' their hangers for dive bomb attack.

Later, if all 3 USN carriers are disabled , more strikes would come from Midway (were all USN surviving aircraft would go anyway), and the IJN damaged carriers , with reduced speed and little defensive force left, would go down. If not all 3 USN carriers would be disabled, then a combined Midway+carrier attack would still sink the damaged carriers.


If IJN carriers could retreat then Midway is soon out of range, whatever air forces there survived the bombardment by 4,000-8,000 5"-8" shells of the 8th CRU DIV. If the IJN carriers are drifting and one or more US carriers were intact they would be scuttled. If the IJN carriers could move and the USN had been knows to have suffered heavy air losses, then Kondo could charge them and drive them off.

My personal impression is that Nagumo's "window of opportunity" closed at about 7:00AM, when Chikuma5 seaplane exited the area occupied by TF17 and TF16 and not seeing anything. IF that seaplane would have sent a sighting report of enemy carrier(s) at 6:30, Nagumo could have a complete strike wave on it's way by 7:15-7:30 at the latest, making first torpedo runs on the enemy at around 9:00. Such a early wave had a good chance of tangling with the SBD inbound strike waves (as happened almost every time during the Pacific carrier wars of 1942), and thus had a good chance of stopping some SBDs before actualy attacking. They would also report to Nagumo the large force of dive bombers inbound, which would trigger a certain alertedness of IJN combat air patrol and better discipline.


So, for Yamaguchi's recommendations basically Genda was not interested because it was Yamaguchi sending it. Yamaguchi, in turn, appears not convinced the situation was drastic enough to kick the request up the chain of command. The options Nagumo actually considered at0830, having rejected Yamaguchi's advice out of hand, were their historical choice versus the option of holding the Midway strike in orbit until the entire reserve wave was rearmed for naval combat and launched. Under that scenario the Midway group orbits for another 1-2 hours, losing dozens of planes to fuel exhaustion. The fighters land, and maybe around 0930 Nagumo launches the reserve wave in something like its original organisation. Genda called not doing this - in hindsight - a "big mistake". But, what makes it noteworthy is that it was actively considered at the time.

The net (probable) result IMHO would be the a reduction in number of SBD bombs dropped from 48 to 36-40, and consequently a reduction of hits from 9-10 to 6-7, and thus potentialy "saving" AKAGI.


Tough to say. Kaga and Akagi were not particularily vulnerable to being sunk by dive bombers alone. They required either fires or torpedo hits. Soryu was weaker, but in all cases the amount of fuelled aircraft and high explosives sitting on deck and in the hangers was key. And no SBD brought that with them.

At the end of the day, Nagumo would have 2 operaitonal heavy carriers, with a mix array of aircraft of board (from all carriers). Kaga and Soryu could still be sunk.
[/quote]

So long as a carrier had power it could do what Shokaku did at Coral Sea - head west out of the battle at flank speed.

alecsandros
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Re: Nagumo with 7 carriers at Midway

Postby alecsandros » 12 Oct 2017 18:59

glenn239 wrote:Everything I listed Nagumo's staff already knew at 0830 the morning of the battle.

... Except the true range of the F4F4...

Once in hypothetical land everything is a stretch from what actually happened. What is certain is that 36 dive bombers are much more likely to cripple 2 carriers if 18 Kates with 800kg bombs are sucking in the bulk of the CAP. What Yamaguchi needed to do was get at least 12 dive bombers over two carriers, then he could anticipate 4-6 hits on each, which should be enough to shut down air operations. If he gets lucky and gets 18 over a carrier, that's as many as 9 hits, which would be very lucky.

Glenn, at 9:00 Nagumo didn't know about TF16. Only Yorktown had been spotted.
Therefore the probable receiver of the attack would be TF17.

Getting the strike aloft was the hard part. Cobbling an escort was easier. Worst case scenario, Egusa would have to orbit for 45-60 minutes while an escort was assembled.

Agreed, but remember Nagumo had a given number of A6M2s available. 36 had been sent to the Midway strike, over 30 had already been committed to the combat air patrol thus far (It think Isom mentions 34 or 33 committed up to 9:00), and all were down on fuel and ammo. A landing+refuel+rearm of , say, 12 Zeroes can be imagined, but that means Nagumo's combat air patrol will be 12 Zeroes smaller at the time the SBDs come.

If Yamamoto orders it launched immediately at 0910, then that mistake is avoided.

Partialy avoided I'd say, as 800kg-bomb armed Kates would be highly unlikely to hit anything (at Santa Cruz, 9 Kates obtained 1 direct hit with 1 x 800kg bomb against the near-motionless Hornet). THe mistake would be avoided if the Kates were armed with torps and a full escort were available.

Mostly agree with the other comments :thumbsup:

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Re: Nagumo with 7 carriers at Midway

Postby glenn239 » 12 Oct 2017 22:01

alecsandros wrote: Glenn, at 9:00 Nagumo didn't know about TF16. Only Yorktown had been spotted.
Therefore the probable receiver of the attack would be TF17.


TF-16 was spotted by Tone 4, not TF-17. Given that the two were operating nearby to one another, any force finding one stood a good chance of finding both.

Agreed, but remember Nagumo had a given number of A6M2s available. 36 had been sent to the Midway strike, over 30 had already been committed to the combat air patrol thus far (It think Isom mentions 34 or 33 committed up to 9:00), and all were down on fuel and ammo. A landing+refuel+rearm of , say, 12 Zeroes can be imagined, but that means Nagumo's combat air patrol will be 12 Zeroes smaller at the time the SBDs come.


For example, Akagi landed it's Zeros from Midway and re-launched those reinforcing the CAP within 30-45 minutes.


Partialy avoided I'd say, as 800kg-bomb armed Kates would be highly unlikely to hit anything (at Santa Cruz, 9 Kates obtained 1 direct hit with 1 x 800kg bomb against the near-motionless Hornet). THe mistake would be avoided if the Kates were armed with torps and a full escort were available.


The impact of 800kg armed Kates is not in what they hit, it's the number of Wildcats they divert from the torpedo bombers and dive bombers, and the number that survive to return to the Hiryu for rearmament.

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Re: Nagumo with 7 carriers at Midway

Postby alecsandros » 13 Oct 2017 05:51


The impact of 800kg armed Kates is not in what they hit, it's the number of Wildcats they divert from the torpedo bombers and dive bombers, and the number that survive to return to the Hiryu for rearmament.


CarDiv1 had 36 Kates, of which say 2/3 had torps, and 1/3 still bombs at 9:00. Transmitting to Yamamoto and receiving the order back would take at least 30 minutes, therefore spotting would start at 9:30 at the earliest. Working with numbers from Santa Cruz (which is the fastest war case that I know of for Japanese re-spotting their hangared planes) , they would need 40 minutes to spot all 36 machines on Akagi and Kaga. But that wouldn't be possible if A6M2s would be required to land for replenishment (they can't spot AND receive incoming aircraft as they don't have 2 runways on each carrier).
Therefore, best case is a full launch starting at 10:10, disregarding USN TBD Devastators (if that were remotely possible). Launch time would be approx 5 minutes.

So best case for Kates in the air is 10:15. 5 minutes before the SBD dive bombers commence destroying Akagi, Kaga and Soryu. Any small delays and... it all turns to rubble.

In any case, the trouble is that there wouldn't be any possible mid-air interceptions by A6M2s escorting the strike , tangling with the incoing SBDs. All defense woudl be done on the spot, and that favored the attackers, as the low cloud ceiling helped the SBDs conceal themselves up to the opportune moment...

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In this scenario, Kaga, Soryu, Akagi all get hit, but don't have fires raging on board. HIryu is the only one left to produce some sort of Zero escort for the strike wave. Maybe they manage to get 3 more fighters (presuming they had already launched 1 or 2 with the 18 D3As in orbit). Maybe the other carriers also launched 1-2 fighters each with the Kates and Vals. Therefore at 10:45, maybe Nagumo has 72 bombers and 10 fighters on their way. Strike time would be 12:00. Historically , IJN attacked Yorktown at 13:00.

What task force would be attacked now ? Let's see the options:
a) If it's Yorktown , he gets destroyed, but the entire force gets spent on just 1 carrier. Later, the other 2 carriers counterattack and destroy Hiryu.
b) If it's Hornet/Enterprise, we have a rematch of Coral Sea, with a few exceptions. In any case, both carriers would probably be badly damaged, while IJN wave gets badly mauled (probably 30 machines lost and 20 damaged of 82 used). Later, Yorktown counterattacks and destroys Hiryu.
c) if it's a combination of both, then there is a probability that all 3 carriers get damaged, but none sunk. There is also the probability of at least 1 USN carrier remaining fully operational and counterattacking later on. As the wave would have a best-case of 4 x 9 Kate squadrons, of which 24 with torps, that statistically yields a probable number of 2 to 3 torp hits. That's enough to incapacitate 1 carrier (possibly sinking it). Or damage 2 carriers. Extremely unlikely to damage all 3 of them.

Best case for IJN would be a very exact distribution of hits - say 1 torp on Yorktown, 1 on Hornet, and 6 bomb hits on Enterprise.

But as the war shows, this perfect distribution for the attackers hardly ever happened. Hiryu attacked, historically, with 40 planes spaced over 3 hours, all of which hit Yorktown (3 bombs and 2 torps). At Coral Sea, of 51 bombers used, 5 hits were obtained - 1 bomb on Yorktown and 2 torps and 2 bombs on Lexington. At Eastern SOlomons, 27 bombers obtained hits on only 1 of the 2 carriers. At Santa Cruz, over 80 bombers obtained 5 hits on Hornet (including 2 torps), but only 2 bomb hits on Enterprise.

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Re: Nagumo with 7 carriers at Midway

Postby glenn239 » 13 Oct 2017 18:28

alecsandros wrote: CarDiv1 had 36 Kates, of which say 2/3 had torps, and 1/3 still bombs at 9:00. Transmitting to Yamamoto and receiving the order back would take at least 30 minutes, therefore spotting would start at 9:30 at the earliest.


1st Division had 43 Kates aboard, of which probably 9 (Kaga) were not effected by the rearmament order. Of the rest, who knows. In terms of length of time for an order to arrive, 30 minutes would be a high side estimate. 5 minutes would also be possible.

Working with numbers from Santa Cruz (which is the fastest war case that I know of for Japanese re-spotting their hangared planes) , they would need 40 minutes to spot all 36 machines on Akagi and Kaga. But that wouldn't be possible if A6M2s would be required to land for replenishment they can't spot AND receive incoming aircraft as they don't have 2 runways on each carrier. Therefore, best case is a full launch starting at 10:10, disregarding USN TBD Devastators (if that were remotely possible). Launch time would be approx 5 minutes.


The time to launch depended on the size of the strike and the number of elevators. Since the Midway force was aloft, the number of elevators in use would be 2 per carrier. Given that 1st Division was unready, the number of Kates provided would probably be less than 18 each. 2nd Division could spot and commence launch in 30 minutes. Turn-around from Combined Fleet would probably be v. quick either way, to reprimand Yamaguchi, or to order the launch. Re - underlined part. The crash barriers on IJN carriers were there to allow for deck parks while recovering aircraft. That was literally their sole purpose, to provide a place on the flight deck where planes could be on the deck and other planes could land at the same time.

So best case for Kates in the air is 10:15. 5 minutes before the SBD dive bombers commence destroying Akagi, Kaga and Soryu. Any small delays and... it all turns to rubble.


Best case scenario would be about 0940 for launch. Fuchida covers the "orbit and cobble" option in his book, but basically each carrier would need to provide 3 fighters, some of which might have to recover from Midway. Akagi actually launched rearmed Midway fighters around 0930, and Yamaguchi may have had more held back, (incomplete records so unknown).

As the wave would have a best-case of 4 x 9 Kate squadrons, of which 24 with torps, that statistically yields a probable number of 2 to 3 torp hits. Best case for IJN would be a very exact distribution of hits - say 1 torp on Yorktown, 1 on Hornet, and 6 bomb hits on Enterprise.


10 Hiryu torpedo bombers scored 2 torpedo hits on one carrier. So no, 24 of them are not scoring 1 torpedo hit on 2 carriers. On average, maybe 2 hits on 2 carriers.

But as the war shows, this perfect distribution for the attackers hardly ever happened. Hiryu attacked, historically, with 40 planes spaced over 3 hours, all of which hit Yorktown (3 bombs and 2 torps). At Coral Sea, of 51 bombers used, 5 hits were obtained - 1 bomb on Yorktown and 2 torps and 2 bombs on Lexington. At Eastern SOlomons, 27 bombers obtained hits on only 1 of the 2 carriers. At Santa Cruz, over 80 bombers obtained 5 hits on Hornet (including 2 torps), but only 2 bomb hits on Enterprise.


At Midway (which is the battle we're talking about) 28 bombers scored 5 hits, for an exact hit ratio of 3 for 7 (dive) and 2 for 10 (torpedo). So if Nagumo sends 36 dive bombers and let's say 24 torpedo bombers half armed with torpedoes, then he's getting 2 torpedo hits, 6 x 250kg bomb hits and 1/2 an 800kg bomb hit for a total of 8.5 hits. But - and here's the key - if the CAP happens to go after the 800kg level bombers, then he's getting as many as 3 torpedo hits and 12 x 250kg bomb hits for a best-case total of 15 hits.

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Re: Nagumo with 7 carriers at Midway

Postby alecsandros » 13 Oct 2017 19:09

glenn239 wrote:
Best case scenario would be about 0940 for launch. Fuchida covers the "orbit and cobble" option in his book, but basically each carrier would need to provide 3 fighters, some of which might have to recover from Midway. Akagi actually launched rearmed Midway fighters around 0930, and Yamaguchi may have had more held back, (incomplete records so unknown).

Isom gives 51 A6M2s assigned for combat air patrol up until 10:22 (and 33 by 9:00), of which approx 18 rearmed and refueled from the Midway strike. Those included at least 3 x A6M2 from Akagi, assigned to 6th Kokutai (land group). It appears there weren't many carrier qualified pilots on 6th Kokutai then and there. Some sources give 5 or 6 in total, but nothing definitive.
Nagumo had a total existing number of 72 A6M2s (4 carriers x 18 per carrier) , plus 21 in 6th Kokutai. If 6 of those 21 had carrier-qualified pilots, then he could rely on 78 fighters (72 + 6). With Midway strike composed of 36 machines, he was left with 42 for combat air patrol and possible escort of own anti-shipping strike. As a large number of fighters were drawn to local defense by 9:30, it is probable that he would have a small or very small number of available fighters for escorting the anti-shippoing strike.
According to Isom, by 10:00, he lost 7 A6M2 Zeroes in combat air patrol , battling enemy bombers. He also lost 2 Zeroes in the Midway strike, and 2 others were badly damaged beyond repair. Therefore, at 10:00, not including Zeroes damaged in combat air patrol (of which we do not know), he was down to 78 - (7 + 4) = 67 operational Zeroes with carrier-qualified pilots, of which ~30 down on fuel and ammo, and 20 landed and doing refueling/rearming.

It's essential to note that the refueling of the Zeroes was done on the flight decks, and thus no spotting of Kates or Vals was possible until it was completed.



10 Hiryu torpedo bombers scored 2 torpedo hits on one carrier. So no, 24 of them are not scoring 1 torpedo hit on 2 carriers. On average, maybe 2 hits on 2 carriers.

Yes, against 12 F4Fs and ~ 150 AAA guns. Hornet+Enterprise had 30 F4Fs on patrol at the time Yorktown was hit by bombs, and ~ 250AAA guns.
Therefore, a reduction of hit rates would be expected against the more heavily defended target (see the same difference at Santa Cruz: Hornet suffered far more hits the Enterprise did, and the big part of the explanation relies on the available defenses. Hornet was down to 14 F4Fs while Enterprise vectored 23 + 6 SBDs. Also, Enterprise had a battleship to cover her with extreme AAA gunfire).

There would be no "revenge factor" associated with the Hiryu strike, as this attack will depart before the SBDs wreck havoc on the 3 other carriers, and thus the pilots would probably not know what was going on.

" In terms of length of time for an order to arrive, 30 minutes would be a high side estimate. 5 minutes would also be possible.
"

Not that fast - the request, formulated either by Yamaguchi or Nagumo, to Yamamoto, needed to be firstly written on paper. Then enciphered using the proper code. Then the radio operator of Hiryu or Akagi would send it by morse code , and the radio operator on Yamato would receive the morse code and write it. Then it would decipher it and take it to one of the members of Yamamoto's staff. The staff member would deliver the paper to Yamamoto, who would pause to make a decision. If the decision was affirmative , he would dictate an answer to the staff member, who would then go to the radio room for enciphering it and giving it to the radio operator to transmit it back, letter by letter, in morse code. Etc.

It is impossible to do all the operations, including moving between radio rooms and war room/bridge, in 5 minutes. 30 minutes is a very reasonable - and fast - estimate.

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Re: Nagumo with 7 carriers at Midway

Postby alecsandros » 14 Oct 2017 13:11

Alternatively to this scenario,
a complete identification message transmitted by Chikuma5 seaplane at 6:30, mentioning both task forces with 3 carriers,
would probably produce the following:
= attack wave of 36 torp-armed B5N2s, 36 SAP and HE bomb-armed D3As, 12 A6M2s.
Spotting: 6:40 - 7:20. Launching: 7:20 - 7:50 (interrupted and re-started again by the first waves of US Army bombers attacking from Midway, and forcing the 4 carriers into evasive manouvres, outside of the wind direction).

Form up: 7:50 - 8:00. Travel time: 8:00 - 9:20. Attack time: 9:20 - 9:40 (both task forces attacked).
results: A6M2 would face ~ 40 F4F4s, of which 25 would manage interceptions. 12 A6M2s would block 12 F4F4s, the rst of 13 F4F4s would disable 20 bombers before making their attacks on teh carriers.

AAA gunfire would disable a further 4 bombers before making the attacks.

Total number of bombers left to perform attacks: 48 (36 + 36) - (20 + 4). Let's say even numbers, 24 Kates (4 squadrons of 6 each) and 24 Vals (again 4 squadrons of 6). The total of 8 squadrons would probably attack in even numbers each task force.
So Yorktown would be attacked by 4 squadrons (12 Vals 12 Kates) , while Enterprise/Hornet by 2 squadrons each.

Yorktown would probably receive 3 torp hits and 4 bomb hits, starting to sink. Her combat air patrol and surviving bombers aloft would be heading to USS Enterprise (8 F4F4s and 15 SBDs)

Hornet would probably receive 1 torp hit and 1-2 bomb hits, losing power for 4 hours and stopping all air ops for the day.

Enterprise would receive 2 bomb hits, stopping air ops temporarily (1.5hours).

6 more IJN bombers would be disabled on the way out.

At 9:40, the reformed strike waves would depart to return to their carriers. Only 42 bombers would return, and 5 Zeroes. Of those, 50% would be damaged , of which 20% non-repairable on board (5 machines)

Return would be around 11:00

===

The American strike wave would attack as historically, disabling Kaga/Soryu/Akagi. No ship would be left in flames, but all would suffer serious damage. Maybe Akagi could be patched up, but it's a long shot.

The returning SBDs (about 60), F4F4s (8) and TBDs (6) would land on Midway and on USS Enterprise.

===

The returning IJN planes would have to que up to land on Hiryu. But also would be the 15 combat air patrol Zeroes still in operations above the fleet.

Hiryu did not have the capacity to land 62 planes (42 + 5 + 15), because she already had 12 planes on board (8 Kates, 4 Zeroes). Therefore the damaged planes would be pushed overboard.

Remaining aircraft on Hiryu as of 12:00: 22 A6M2 Zero (of which 3 from 6th Kokutai without carrier qualified pilots, but usable as spares for the Zeroes that were badly shot up). 20 B5N2 Kate. 21 D3A Val.

Of those, immediately usable were 18 Zeroes, 15 Kates and 18 Vals.

Therefore, a follow-up strike with 6 Zeroes, 15 Kates (torps) and 6 Vals would be rapidly prepared for 13:30.

The follow-up strike would find USS Enterprise, with 15 F4F4s aloft, of which 10 intercepting the enemy. The Zeroes block 6, the remaining 4 savage 8 bombers. Only 13 bombers remain, 2 are shot down by AAA gunfire. Of the 11 left, 8 are Kates and 3 are Vals.
The Kates obtain a pincer on Enterprise, and 2 torps hit the carrier.

3 more planes are lost on the way out (including 2 Zeroes).

Only 15 machines get back to Hiryu at 15:00, of which 5 non-usable.

In the mean time, Hiryu prepared and launched 12 Vals with 6 Zeroes at 14:30, that find Hornet and hit her with 2 x SAP bombs, flooding 1 machinery space and wrecking the flight deck.

3 machines are lost to all causes.
15 get back to Hiryu, of which 3 damaged.

At 16:00, Hiryu has on board maybe 25 operational machines of all types.

With 3 heavily damaged carriers (Soryu sinking), Nagumo decides a withdrawal to the North, waiting reinforcements (Yamato, Zuiho, Ryujo, Junyo, Hosho, Chitose, Nishin, Kamikawa Maru).
===

Spruance withdraws Hornet during the night to make junction with USS Saratoga. Enterprise is under tow at 3kts, but is torpedoed by I-168 the next day and sunk.

Midway planes harass the retreating enemy, but to no other effect then to increase withdrawal speed of Nagumo.

===

On June 6th, Spruance makes junction with USS Saratoga. Pilots from Yorktown, Enterprise, Hornet, are transferred to Saratoga and man all available planes on board (36 own airgroup planes + 68 crated planes previously without pilots).

Saratoga refuels from Spruance's tanker, and retains a powerfull screen of 5 cruisers and 15 destroyers, and proceeds west to reinforce Midway. Hornet proceeds slowly to US mainland under escort

===

On June 7th, Hiryu is joined by Zuiho. Together, and with 4 BBs, 8 CAs, 15 DDs, they proceed to attack Midway again.
The 3 damaged carriers, with 12 destroyers, are sent back to Japan.

On June 8th, Hiryu + Zuiho (totaling 54 operational machines, 27 A6M2, 17 B5N2, 10 D3A) launch an attack on Midway, with 12 fighters, 12 level bombers, 10 dive bombers, while keeping 15 fighters for fleet defense.

No Midway planes are found on the ground, but the IJN fleet is attacked by 9 B17s, 12 SBDs and 6 SB2Us, but suffering no hits.

In the night, the cruiser and battleship force bombards the islands, causing some damage.

On June 8th, Saratoga arives 100nm SE of Midway and launches 3 VS squadrons out to 300nm - finding Zuiho and Hiryu.
At the same time, 1 floatplane from Tone finds Saratoga.


At 10:00, a powerfull 10 F4F, 20 SBD, 10 TBD strike is launched.
At 10:10, 10 A6M2, 15 B5N2 and 8 D3A are launched by IJN carriers.

The strikes tangle in mid-air, and 5 machines are lost for either side. The Saratoga strike proceeds and battles the 12 Zeroes on CAP. 14 SBDs still attack, all diving on Hiryu - which suffers 3 x 454kg bomb hits, being badly damaged and unable to continue ops.
A total of 11 USN machines are disabled in the strike, the remaining 29 going to Midway (8 F4F, 16 SBD, 5 TBD)

The IJN strike attacks through the 25-strong F4F4 on CAP (15 intercepting), losing 4 Zeroes, 5 Kates and 3 Vals. The remaining machines plant 1 torp hit and 2 bomb hits on Saratoga, temporarily knocking her out.

The returning 21 machines go to Zuiho.

A follow up strike from Zuiho starts taking off at 13:30, with 5 Zeroes, 8 Kates and 4 Vals. They arive over Saratoga at 15:00, and battle 12 F4F4s. 4 Kates and 3 Vals manage to close on the enemy, scoring 1 torp hit that knocks out all power, and 1 bomb hit that explodes in one of the 127mm ammo magazines, causing a large explosion.

The Zuiho airgroup is decimated, but Saratoga withdraws at 16kts, out of the battle, unable ot conduct air ops.

2 days later, Ryujo and Junyo, and 3 seaplane carriers join in the battle, and Midway airgroup is destroyed.


===

glenn239
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Re: Nagumo with 7 carriers at Midway

Postby glenn239 » 14 Oct 2017 15:21

alecsandros wrote: Nagumo had a total existing number of 72 A6M2s (4 carriers x 18 per carrier) , plus 21 in 6th Kokutai. If 6 of those 21 had carrier-qualified pilots, then he could rely on 78 fighters (72 + 6). With Midway strike composed of 36 machines, he was left with 42 for combat air patrol and possible escort of own anti-shipping strike. As a large number of fighters were drawn to local defense by 9:30, it is probable that he would have a small or very small number of available fighters for escorting the anti-shipping strike.


Nagumo had 72 carrier fighter pilots and 93 carrier fighters, all of these operational. So the bottleneck was not the number of fighter planes, it was the number of carrier squadron fighter pilots. If Nagumo had decided to strike around 0900, he could have ordered reserve Zeros armed for Midway fighter pilots even before these had landed. They hop out of one plane, hop into another. That was possible. Whether he would have done so is another question entirely. Also, the number of 6th Ku pilots is not clear. Kaga was apparently intending to use a 6th trio for strike escort, because none of her own carrier fighter pilots were aboard at 1022. Akagi intended to use Midway fighter pilots, because that's what Kusaka said right after the battle and Shattered Sword's own fighter pilot CAP records confirm that 3 (and only 3) Midway fighter pilots were aboard Akagi. (Take a wild guess who one of those was). Hiryu's 1st strike record in Shattered Sword indicates either an error in their tables, or that more fighter pilots were in the squadrons than listed in the tables, or that one of the escorts for the Yorktown strike was a 6th Ku pilot, because he isn't listed in the Hiryu squadron roster.

It's essential to note that the refueling of the Zeroes was done on the flight decks, and thus no spotting of Kates or Vals was possible until it was completed.


The 'hard' requirements caused by the physical nature of carriers and their aircraft was that if launching planes there could not be a bow deck park, and if landing aircraft there could not be a stern deck park. That's it. All other statements as to what could or could not be done are opinions about IJN behaviour, not facts based on the properties of the carriers and aircraft themselves. So yes, the Japanese certainly could have rearmed fighters in the hanger or on the flight deck while spotting a strike at the stern, and could spot armed aircraft, or rearm aircraft, in a park forward of the crash barrier even while recovering small numbers of planes, or could have spotted aircraft at the stern even while launching fighters at the bow.


Therefore, a reduction of hit rates would be expected...


The expectation that 24 Kates will score no more hits than 10 actually did is a counterfactual I'm not too interested in.

Not that fast....


Yes that fast.

alecsandros
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Re: Nagumo with 7 carriers at Midway

Postby alecsandros » 14 Oct 2017 15:51

glenn239 wrote: They hop out of one plane, hop into another. That was possible.

Anything was possible, that doesn't mean it was realizable then and there.

So yes, the Japanese certainly could have rearmed fighters in the hanger or on the flight deck while spotting a strike at the stern,

No, launching the Kates or Vals requires the entire length of the deck, therefore the deck has to be clear when they take off.
Rearming the Zeroes requires them to be lowered down to the hangars, which means them being transported down with the elevators. That means the elevators are in use, and can not be used for transporting the Kates or Vals "upstairs".


The expectation that 24 Kates will score no more hits than 10 actually did is a counterfactual I'm not too interested in.

You should - at Coral Sea 18 Kates obtained 2 torp hits, at Santa Cruz 36 Kates obtained 2 torp hits.
Both times the existing AAA guns and combat air patrol were stronger then what Yorktown had at Midway.
Also, Yorktown was doing 20kts and working up to 24kts at the time of the torp attacks (barely recovering from the bomb attacks), whereas at Coral Sea and Santa Cruz the carriers were doing 28 to 31kts (faster targets - harder to hit).


Yes that fast.

No, the message that you proposed to be sent by Yamaguchi translates into 1446 morse-code characters (including spaces). A very skilled operator could type 5 characters per second, which means that simply transmitting the message required 6 minutes.

You need time to write it, encipher it , and at the opposite end - decypher it, and transport the piece of paper on Yamato's bridge.
then wait for Yamamoto's reply , then go downstairs to the radio room with Yamamoto's reply, encode it, then type it in morse code, etc.

glenn239
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Re: Nagumo with 7 carriers at Midway

Postby glenn239 » 14 Oct 2017 17:02

alecsandros wrote:Anything was possible, that doesn't mean it was realizable then and there.


That 6th Ku pilots were not used much in the battle is known. Whether 6th Ku planes were used is not known.

Rearming the Zeroes requires them to be lowered down to the hangars, which means them being transported down with the elevators. That means the elevators are in use, and can not be used for transporting the Kates or Vals "upstairs".


Your saying the rear and central elevator could not be used because the forward elevator was in use? No, that was not the case.

You should - at Coral Sea 18 Kates obtained 2 torp hits, at Santa Cruz 36 Kates obtained 2 torp hits.


Santa Cruz is not applicable due to massive increases in USN AA lethality. Coral Sea was 5th Division, which was not as good as 1st or 2nd. The applicable example is Midway itself, where 10 Hiryu Kates (actually 9 due to a hang up on one plane) scored 2 hits. To say that 24 torpedo bombers get the same number of hits as 10 isn't viable.

Both times the existing AAA guns and combat air patrol were stronger then what Yorktown had at Midway.


Yorktown's biggest advantage at Midway was that the first Hiryu strike was initially engaged without Zero escort.


No, the message that you proposed to be sent by Yamaguchi translates into 1446 morse-code characters (including spaces). A very skilled operator could type 5 characters per second, which means that simply transmitting the message required 6 minutes.


Noted. As stated, I think the answer could be much faster than 30 minutes.

You need time to write it, encipher it , and at the opposite end - decypher it, and transport the piece of paper on Yamato's bridge.
then wait for Yamamoto's reply , then go downstairs to the radio room with Yamamoto's reply, encode it, then type it in morse code, etc.


No, that's all just padding to get a longer timeframe.

paulrward
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Re: Nagumo with 7 carriers at Midway

Postby paulrward » 14 Oct 2017 19:14

Hello All ;

You need time to write it, encipher it , and at the opposite end - decypher it, and transport the piece of paper on Yamato's bridge.
then wait for Yamamoto's reply , then go downstairs to the radio room with Yamamoto's reply, encode it, then type it in morse code, etc.


No, that's all just padding to get a longer timeframe.



Perhaps, but lets look at a good example: At Leyte, Adm. Kinkaid sent a message to Halsey asking if he was still guarding the San Bernardino Strait. The message was dispatched at 04:12. It was received, decrypted, and given to Halsey at 06:48. Halsey did not get off a reply until 07:45. From this we can see that it took 2 1/2 hours to get a message from one admiral to another, and then another hour to send the message back.



'You can ask me for anything you like, except time' Napoleon Bonaparte

Respectfully ;

Paul R. Ward

alecsandros
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Re: Nagumo with 7 carriers at Midway

Postby alecsandros » 14 Oct 2017 19:40

glenn239 wrote:That 6th Ku pilots were not used much in the battle is known. Whether 6th Ku planes were used is not known.

Precisely.
And therefore I think it's more prudent to not consider them in the discussion.

Your saying the rear and central elevator could not be used because the forward elevator was in use? No, that was not the case.

It wouldn't be in use, as all available personel, including pilots, was scrammbling to prepare the bombers. There weren't technicians available to move the Zeroes downstairs or to rearm and refuel them.

What you are proposing - prepare some returning-Midway Zeroes for escort - takes time and manpower, and that was not existing at the given hours.

Santa Cruz is not applicable due to massive increases in USN AA lethality.

That is a myth. Hornet's task force was under attack by ~ 50 warplanes, of which 38 bombers and 12 fighters. The combined effect of Hornet's AAA gunfire (aprox 200 AAA guns) and combat air patrol obtaining interceptions (14 F4F4s from Hornet and a few - 4 or 5 - from Enterprise defending Hornet) was 25 Japanese machines destroyed for 6 Wildcats lost.

Hornet damage: 2 torp hits (10%) and 3 bomb hits (19%).
Escort situation: intercepting Wildcats outnumbered Zeroes by 6 or 7.
AAA situation: about 200 AAA guns.

4 months earlier, Yorktown's task force was under attack by 37 warplanes, of which 28 bombers. The combined effect of Yorktown's AAA gunfire and CAP obtaining interceptions (8 F4F4s for the initial wave and 6 more for the second wave for a total of 14 fighters obtaining interceptinos) was 23 Japanese machines destroyed for 2 Wildcats destroyed and 2 damaged.

Yorktown damage: 2 torp hits (20%) and 3 bomb hits (17%).
Escort situation: intercepting Wildcats outnumbered Zeroes by 4 or 5.
AAA situation: about 150 AAA guns.

The applicable example is Midway itself, where 10 Hiryu Kates (actually 9 due to a hang up on one plane) scored 2 hits. To say that 24 torpedo bombers get the same number of hits as 10 isn't viable.

The Midway Kates attacked a 20kts target defended by 6 Wildcats, while themselves had a 6 Zero escort (equaling the number of Wildcats).

Lexington was doing 28kts at Coral Sea; Hornet 31kts at Santa Cruz.

There was also the "revenge factor" at Midway, etc.

Yorktown's biggest advantage at Midway was that the first Hiryu strike was initially engaged without Zero escort.

Which resulted in the loss of 13 out of 18 bombers employed.


As stated, I think the answer could be much faster than 30 minutes.

You are optimistic.
remember it happened in real life on June 4th - Nagumo's staff asked Tone4 seaplane if there was an enemy carrier in the task force. The message was transmitted to the plane at 7:15, and the answer came to Nagumo's bridge at 8:00 (relayed from TOne were it was received at 7:45).

Rob Stuart
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Re: Nagumo with 7 carriers at Midway

Postby Rob Stuart » 14 Oct 2017 23:02

alecsandros wrote:No, the message that you proposed to be sent by Yamaguchi translates into 1446 morse-code characters (including spaces).

This is not how a code (as opposed to a cipher) works. The five-figure code groups represent words or phrases, not characters. For a message such as:

1st Air Fleet Headquarters ordered the rearming of the naval reserve for land combat at 0715. 1st Division torpedo bombers will not be rearmed for launch with torpedoes until 1030. The Striking Force was spotted after 0500 and could be attacked by carrier dive bombers at any moment. 2nd Division can launch a counterattack on the enemy immediately with 36 dive bombers and X fighters if Combined Fleet transmits the order.

… there would a code group for “1st Air Fleet Headquarters”, something such as 48765, so transmitting “1st Air Fleet Headquarters” would take five Morse characters rather than 23. Similarly, there would certainly be code groups for 1st Division, torpedo bombers, torpedoes, Striking Force, attacked, carrier dive bombers, 2nd Division, counterattack, enemy, immediately, dive bombers, fighters, Combined Fleet, order, and probably others. So, a lot fewer than 1,446 Morse letters would be required to transmit a message such as this.

I’d also observe that this hypothetical message is way too long. Officers are trained to be concise, and Yamaguchi would never compose as verbose a message as this. It would have to be cut down to something like this:

KdB has ordered full attack at 1030. Consider it advisable you order immediate CarDiv2 attack with carrier bombers without CarDiv1 carrier attack aircraft.

This could perhaps be encoded using as few as 20 five-figure groups, but even if it took 30 that would amount to only 150 Morse letters.

alecsandros wrote:You need time to write it, encipher it, and at the opposite end - decypher it, and transport the piece of paper on Yamato's bridge. then wait for Yamamoto's reply , then go downstairs to the radio room with Yamamoto's reply, encode it, then type it in morse code, etc.

You’re forgetting that JN-25 was an enciphered code, meaning that each message is also enciphered after it’s encoded. The process would thus be:

You need time to write it, encode it, encipher it, and at the opposite end - decipher it, decode it, and transport the piece of paper on Yamato's bridge, then wait for Yamamoto's reply , then go downstairs to the radio room with Yamamoto's reply, encode it, encipher it, then key it in morse code, etc.

alecsandros wrote:
glenn239 wrote: As stated, I think the answer could be much faster than 30 minutes.

You are optimistic.
remember it happened in real life on June 4th - Nagumo's staff asked Tone4 seaplane if there was an enemy carrier in the task force. The message was transmitted to the plane at 7:15, and the answer came to Nagumo's bridge at 8:00 (relayed from TOne were it was received at 7:45).

I believe that Nagumo's message was "Ascertain ship types" (a commendably brief message). Also, Nagumo's order and Tone 4's reply were in plain language. It seems likely that most, or at least much, of the 45 minute interval between Nagumo's message and the arrival in his hands of the response was taken up by the time it took Tone 4 to actually ascertain the ships types, so this example does not really tell us very much about how long it might take for Yamaguchi to radio Yamamoto and get a response.

paulrward
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Re: Nagumo with 7 carriers at Midway

Postby paulrward » 15 Oct 2017 03:16

Hello All ;

I am going to butt in again. I do NOT believe that the messages that were sent to aircraft in the air were enciphered, especially those sent to single engine aircraft with small crews. The labor of receiving the message, writing out the message, getting out that humungous JN 25 codebook, deciphering the message, and then writing it out for the pilot would be overwhelming in a small floatplane.

I believe that all the messages sent from the Kido Butai to their scoutplanes were sent in ' clear ' . I may be wrong, but in the USN during the war, all the ship to air and aircraft to ship radio messages were in straight Morse.

Respectfully ;

Paul R. Ward


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