Requirements for a successful Midway Invasion Force

[ChristopherPerrien]

If the spotting teams with the assault, the man on the radio, is very well trained & experienced he can save this delay problem, and a number of others I've not touched. The staff afloat executing the fires must be nearly as well trained as well, and their procedures be as friction less as possible. The NGF spotting team must survive long enough as well. There are more than a few examples of assaults failing because the spotters for the fire support were casualties. The earlier in the assault this occurs the worse the effects.

I think it has been mentioned the Japanese had no NGF doctrine and no NGF spotting teams, and one guy with a smoke grenade doesn't cut it either, neither does a wet 1/2 of a two ton radio. How the Japnese of 1941 are automatically and during this one tiny assault are going to suddenly acquire and use doctrines and have equal equipment and support that took years of combat for the USMC to develope and refine and the resources of the USA is beyond me.

[glenn239]

I think it has been mentioned the Japanese had no NGF doctrine and no NGF spotting teams

The number of spotting teams embarked is unknown.

The IJN did employ NGF support in China, so must have had some sort of a doctrine. Jinstu (Invasion fleet HQ) had spent one month preparing for the Midway invasion after April 23rd,

http://www.combinedfleet.com/jintsu_t.htm

Which included specialist training in engaging shore targets with gunfire, (Prange).

[Carl Schwamberger]

I think it has been mentioned the Japanese had no NGF doctrine and no NGF spotting teams, and one guy with a smoke grenade doesn't cut it either, neither does a wet 1/2 of a two ton radio. How the Japnese of 1941 are automatically and during this one tiny assault are going to suddenly acquire and use doctrines and have equal equipment and support that took years of combat for the USMC to develope and refine and the resources of the USA is beyond me.

It has been mentioned. I'm skeptical there was no 'doctrine' on the books. We do have the mater of Japanese landing operations in China. The few details I've had on those are not encouraging for the existance of good doctrine or procedures at that moment. However that does not preclude improvement from the experience. The development of the Daihatsu landing craft and the Shinshu Maru shows someone was thinking about the problems of amphibious warfare, tho it does not automaticaly mean they also developed suitable fire support techniques.

The number of spotting teams embarked is unknown.

A average of one per battalion size assault group became common for well prepared beach assaults. With a landing group for each island two teams minimum would have been necessary, unless there is time for the team to move to the second attack before it launches. Digressing into battlefield reality NGF spotting teams were vulnerable and often (usually) took heavy casualties. One of the 'doctrines' US amphib forces in the Pacific developed was that during the assault all radios became defacto property of the NGF spotting teams, every man trained in any sort of artillery or mortar observation/control was a replacement for a NGF team member, and every frequency channel was a potential NGF control channel. If a NGF spotter came up on the command channel, S4 logistics coordination frequency, or the mess kit repair platoons admin channel the radio operators and supervisors had to be able to recognize it and forward the messages correctly to the fire control. Forty years later this was still at the core of our fire support training. The fire support network remained open no matter what, if every other radio station and channel had to be sacrificed. This gave the NGF spotting teams some depth & returned them to action after key members/equipment became casualties.

Jinstu (Invasion fleet HQ) had spent one month preparing for the Midway invasion after April 23rd,

http://www.combinedfleet.com/jintsu_t.htm

Which included specialist training in engaging shore targets with gunfire, (Prange).

If this training was derived from a strong skill set in place it would be useful. Otherwise it has a low probability of getting to the skill level needed. To put it another way, taking a low skill set & getting it to adaquate requires a extremely perceptive leader with a deep understanding of the technical problems to reach solutions.

To digress again. The term doctrine has been used in this thread as a blanket term. My experience doctrine is a general guidance or statement of intent for coordinating a set of actions. It is usually a few paragraphs or sometimes several pages. The technical side, the skills and procedures were led to by the doctrine statements, but seperate from it. In this case we are discussing I've not yet seen a actual statement of the Japanese NGF doctrines, nor any sort of description of the procedures/skills this would include.

[glenn239]

The few details I've had on those are not encouraging for the existance of good doctrine or procedures at that moment

The TROM’s of the warships suggest Jinstu was doing specialist training in Japan, but in the handful of other TROM’s I checked, it does not appear that the other warships were doing so, at least to the same degree. There was the final layover in Saipan in which final preparations were made. Whatever specific arrangements on fire planning (if any), may have presumably been done there.

In terms of carrier air support, 2nd CAR DIV had participated in the 2nd assault on Wake, and there seems to have been a simple system for air control that probably would have been repeated for Midway. Basically, the infantry displayed numbers of large flags, and the aircraft attacked positions or movements lacking them. This wouldn’t work against concealed positions, but it would work against movements, (especially between islands) or counterattacks. Therefore, in terms of direct engagement of Marine positions, the warships would be the key, while airpower would have little effect, more of a factor in knocking out coastal batteries or interdicting the movement of defending reserves.

If this training was derived from a strong skill set in place it would be useful. Otherwise it has a low probability of getting to the skill level needed

But comparing IJN 1942 doctrine to USMC 1944 doctrine might not be particularly useful, in that by 1944 it was never a question of whether any given amphibious assault would fail, only a question of whether improving USMC doctrine could hold friendly casualties to the absolute minimum level possible to secure the objective. In fact, the quality of USN fire support was not instrumental to the question of whether any particular invasion succeeded or failed, because no American amphibious assault during WW2 ever failed regardless of how good or bad the NGF support was.


The question about Midway is how close the attacking warships intended to come to the beach, whether they could or could not pick out Marine positions, and whether they could hit the positions they were firing at. Realistically, given the level of firepower possessed by the attacking fleet, unless this firepower was not applied for some reason, (defending coastal batteries or timid/incompetent ship handling) , then it might have been possible for the defenders to contain an invasion to the beachhead, perhaps forcing a withdrawal, but that’s about it. We don't know the answers to these questions.

Compounding the problem is that the defenders have to win two battles, not one. Basic probability says that if you have a 90% chance of succeeding, you’re odds of doing it twice drop to 81%. Assuming that the defenders had a 90% chance of winning each battle, but that concentrating the reserves allowed the attackers a 30% chance of success on one island, then the chances for the defenders to hold both islands would be 63%.

[Carl Schwamberger]

In terms of carrier air support, 2nd CAR DIV had participated in the 2nd assault on Wake, and there seems to have been a simple system for air control that probably would have been repeated for Midway. Basically, the infantry displayed numbers of large flags, and the aircraft attacked positions or movements lacking them.

That system & a more sophisticated version was available to the US forces, or at least the Marines. We still had it on the books & the equipment in 1985. It did require a well trained pilot, to read the ground & understand what he was seeing. On Betio Island USN pilots flew the CAS & they had some training in the thirty days to the attack. They failed consistently to recognize the difference between the Japanese positions despite flags & other cloth pannels, the use of smoke, and radio guidance. After repeatedly attacking the US positions the landing force air controllers waved off the aircraft on station and requested no further air attacks. Cant remember if any more were flown in the remaining 50 hours of the battle. For reasons of perspective, speed, altitude (distance), and distractors pilots have a lot of trouble picking out one side from another and orienting on landmarks in the few second of their attack. I've watched them drop thousands of meters from the target due to misidentification of the ground & the targets on the ground.

This wouldn’t work against concealed positions, but it would work against movements, (especially between islands) or counterattacks. Therefore, in terms of direct engagement of Marine positions, the warships would be the key, while airpower would have little effect, more of a factor in knocking out coastal batteries or interdicting the movement of defending reserves.

One of the reasons we tried so hard to make it work was it can be devastating against the close on targets, more so than those further back like reserves. As with any other fire support there has to be precision in space and time. But I digress.

If this training was derived from a strong skill set in place it would be useful. Otherwise it has a low probability of getting to the skill level needed

But comparing IJN 1942 doctrine to USMC 1944 doctrine might not be particularly useful, in that by 1944 it was never a question of whether any given amphibious assault would fail, only a question of whether improving USMC doctrine could hold friendly casualties to the absolute minimum level possible to secure the objective. In fact, the quality of USN fire support was not instrumental to the question of whether any particular invasion succeeded or failed, because no American amphibious assault during WW2 ever failed regardless of how good or bad the NGF support was.

To address the first sentence, I was not comparing doctrines, that is a bit impractical since I dont have the Japanese doctrine in hand. My point was the question of accumulated or long term skill available to build on in a thirty day preparation.

The question about Midway is how close the attacking warships intended to come to the beach, whether they could or could not pick out Marine positions, and whether they could hit the positions they were firing at.

The last there is no doubt, the second is the critical question & connects directly to one of timing, the first relates to the experince of the ships gunnery officers at this situation and their understanding of the situation ashore. In this last case the question of radio communications is important. As with radio communication visual signals require a high level of skill and experience to prevent firing on ones own side. Without any signals the problem of coordinating fires is insurmountable. Undirected supporting fires tend to lose a large degree of efficiency.

Realistically, given the level of firepower possessed by the attacking fleet, unless this firepower was not applied for some reason, (defending coastal batteries or timid/incompetent ship handling) ,

From experience I know that piling on large amounts of cannon fires tends to obscure the target. There is a point of marginal returns in this and where the targets require precision fires it comes fairly quickly. Dust & smoke build quickly and disapate slowly. Brush, fuel, and buildings afire aggravate this. Simply piling a lot of projectile on the island without precise spotting leads back to the level of effectiveness or ineffectiveness typical of preparatory fires.

We do have a idea of what the assigned fire support ships were. It is possible to direct the entire fleet, or more likely part of it, to reinforce the fire support group. This leads to the question of how fast the need could be perceived, the plan generated, orders transmitted, and the ships moved to the necessary positions. How fast is fast enough depends entirely on the situation ashore, or perhaps on the reef. The critical moment may or may not pass before the necessary saving effect from reinforcing fires occurs. This question of renforcing the NGF group brings us back to this:

The TROM’s of the warships suggest Jinstu was doing specialist training in Japan, but in the handful of other TROM’s I checked, it does not appear that the other warships were doing so, at least to the same degree.

Compounding the problem is that the defenders have to win two battles, not one. Basic probability says that if you have a 90% chance of succeeding, you’re odds of doing it twice drop to 81%. Assuming that the defenders had a 90% chance of winning each battle, but that concentrating the reserves allowed the attackers a 30% chance of success on one island, then the chances for the defenders to hold both islands would be 63%.

This can be extended to items like the percentage of sucessfull attacks across the reef, or sucessfull attacks up the choke point of the channel, percentage of attacks that have their radios all lost reaching the beach, ect... ect...

So much speculation here. Without accquiring more solid data we are liable to drift into a circular conversation.

[glenn239]

There is tons of speculation, yes, but broadly speaking I think it's safe to assume that the defenders would be very likely to defeat an invasion if the invasion were repulsed within 24 hours of landing. But after 24 hours, it gets less and less likely the defenders could prevail.

From experience I know that piling on large amounts of cannon fires tends to obscure the target. There is a point of marginal returns in this and where the targets require precision fires it comes fairly quickly.

True, but a heavy volume of fire is better than no fire at all. Defenders being forced to keep down and unable to see well in front of their position are defenders that are less able to prevent infiltration or clear a beach, and more likely to get rattled and spend their irreplaceable ammunition missing as opposed to hitting.

We do have a idea of what the assigned fire support ships were. It is possible to direct the entire fleet, or more likely part of it, to reinforce the fire support group. This leads to the question of how fast the need could be perceived, the plan generated, orders transmitted, and the ships moved to the necessary positions.

Immediately available warships were 4 heavy, 1 light cruiser, 12 destroyers. That’s corps-level firepower employed for a regimental-level assault. In terms of other warships, there is Kondo’s force, but this would presumably only become available on the 2nd day of the assault. Given that Kondo’s AP to HE loadout would probably have been heavily weighted to AP, the support from Kondo would probably be more in the secondary than main batteries, as well as in the potential formation of additional infantry shore parties from warship companies. After that, the closest source for more infantry would be Wake Island, at least 4+ days away. (If a beachhead was secured, IJN prestige would demand that reinforcements be sent in to capture the islands, even if this took weeks).

This can be extended to items like the percentage of sucessfull attacks across the reef, or sucessfull attacks up the choke point of the channel, percentage of attacks that have their radios all lost reaching the beach, ect... ect...

Sure, but none of that changes the fundamental fact remains that it is harder to win 2 battles than it is to win 1 battle, especially when the attacker can shift reserves between battles while the defender cannot.

[Carl Schwamberger]

There is tons of speculation, yes, but broadly speaking I think it's safe to assume that the defenders would be very likely to defeat an invasion if the invasion were repulsed within 24 hours of landing. But after 24 hours, it gets less and less likely the defenders could prevail.

I was thinking the first four hours or less. Looking at the difficulties in trying to boat up the narrow channel, or wading across the reef the initial assault is liable to fail right there without continuous suppression of the defense. As I've pointed out before where infantry came ashore against unsuppressed defenses things went very badly. The reinforcing battalions that crossed Betio islands reef without the LVT are a close analogue.

What happens after that depends to a large degree on how well the land forces radio communications hold up. If they can get the radios for both the NGF channel and the command channel ashore and operating in the first hour they have a chance. If not then the landing force is liable to be defeated before anyone on the ships figures it out.

Given time I could take the total ammo count & sort the tea leaves on just how far along the suppresion-nuetralization-destruction scale that gets the Japanese.

[Rob Stuart]

At http://www.j-aircraft.org/smf/index.php?topic=11673.0 there is a thread entitled How long could a victorious KdB have remained off Midway? The consensus was that the number of bombs carried by KdB's carriers would have permitted its B5Ns and D3As to fly only 8-10 sorties against Midway during the period 4-6 June, so about three per day. Of course, if KdB attacked both TF16 and TF17 on 4 June it would have lost a lot of B5Ns and D3As even if it won, and one or more of its four carriers may have been disabled and be on its way to Japan on 5 June. KdB started MI with 70 D3As. If half were lost or made unserviceable on 4 June and a few of the survivors were on a disabled carrier, then they'd be down to 30 serviceable D3As, the only aircraft capable of the pinpoint bombing required in CAS missions. The bomb stocks might permit this smaller force to make 16-20 sorties each, but 30 aircraft is not very many and the defenders' AA guns might well destroy or disable one or two of them per strike.

The landing was planned for 6 June, wasn't it? Were the four heavy cruisers going to bombard Midway on 5 June? If they were, then at least some of the defending AA guns could have been identified and shelled when they opened fire on attacking aircraft. If their bombardment was not going to start until first light on X Day, then most likely dawn that day would find virtually all of the defenders' AA and coastal guns intact. If the latter held their fire until the landing craft came into range, then it's unlikely that a couple of hours bombardment and bombing would knock many of them out.

[ChristopherPerrien]

On a side note, I've always wondered why they did not launch 2 carriers full deck strikes on the morning of June 4 instead of 4 1/2 deck strikes off all 4 carriers. This ensured all decks would be tied up for landing ops instead of having 2 carriers ready to launch against an enemy fleet. There does not seem any good reason for what they did. Even if it took a little longer to launch 2 full from 2 CV's it wasn't like Midway was going to move so 15 mins seems like nothing compared to having all 4 carriers tied up waiting on Midway ops(a secondary objective actually) while also being ready for enemy fleet action(primary objective), which obviously didn't work.

[Carl Schwamberger]

On a side note, I've always wondered why they did not launch 2 carriers full deck strikes on the morning of June 4 instead of 4 1/2 deck strikes off all 4 carriers. ...

Looking at this from their PoV I see two thoughts at work. One was that of strike a massive blow vs a partial. There may have been a desire to ensure the air field and other defense on Midway was as incapacitated as possilbe. 'Smack them, not pat them' as the German slogan went. The other half of this was the complete lack of knowledge of where the USN was, and the lack of evidence suprise was lost. The submarine screen was properly deployed and reported nothing. The signals intel units detected no pattern indicating the US fleet was seeking battle, or even warned. The air reconissance launched that morning reported nothing. The only negative contact had been a couple long ranged air recon contacts the previous day, including the torpedo attack by the PBY flight. So, the logic went: why degrade a strike at a know and important target to retain a capability for attacking a enemy for which there is no evidence of its existance?

To turn slightly back towards the topic, where can we find a accurate report of the damage done to Midway by the air strike? things like damage to the artillery, ammo storage, communications, personel killed, morale? Getting to some decent information on that will tell us how far the Japanese still had to go to suppress or destroy the defense.

[ChristopherPerrien]

On a side note, I've always wondered why they did not launch 2 carriers full deck strikes on the morning of June 4 instead of 4 1/2 deck strikes off all 4 carriers. ...

So, the logic went: Why degrade a strike at a know and important target to retain a capability for attacking a enemy for which there is no evidence of its existance?

Except , that is EXACTLY what they did. They retained 4 carrier 1/2 deck loads armed with "anti-ship" weapons, solely for that- "no evidence of existence" thingy. It was listed in the op orders( be ready for ship action) and followed to the letter. The orders(4 cv attack Midway,4cv be ready for fleet action, at the same time) as they did it, were mutually contradictory. No one saw that? Let us not even get into "the second strike needed " thing, because it gets even uglier.
I.E.- OTL and is proof of my case.

And how does launching against Midway get degraded by using 2 full decks, instead of 4 1/2's. How are 4 1/2's better than 2 full's?

Do you see?

They could have used and occupied 2 carriers with bombing Midway, and have 2 carrier ready for fleet action.

Instead they sent 4 1/2's . effectively tying up(wasting) the other 4 1/2's and all four carrier decks , till the first 4 1/2's were done , the whole time presenting 4 big vulnerable targets unable to react, or attack.

Maybe the Japanese in the their ideas of "foolish glory" and "consensus" thought all 4 carriers should be a part of "attacking" Midway. To have used two, would have meant a dis-respect and caused a "loss of face" to two awaiting carriers' crews if the op had been done Non-japanese style, so to speak. Also the Japanese seem to consistiently expect their enemies to follow the Japanese time-table too.

I can see why Midway looked like a disaster in prior Japanese Naval staff war-games. IIRC, Yamamoto finally forbade them, or someone high-up.

[Carl Schwamberger]

Ok, I see what you are aiming at. I dont know the nuances of how and why they organized their missions and deck operations. There are a lot of details with deck ops, aircraft types, and the desireability of spread loading groups vs concentration on few decks. I can see some potiential paralles in decisions surrounding how to move a artillery unit when executing and expecting fire missions. Simple logic is not quite adaquate where a nuber of critical technical considerations lie under the surface.

Anyway this diverges from the subject. We have quite a few questions relating directly to the OP still pending.

[ChristopherPerrien]

I know , but their passing game turned into such a failure, and with this topic their ground game looks to have been no better. I am trying figure out why the Japanese couldn't play "football".

[glenn239]

The consensus was that the number of bombs carried by KdB's carriers would have permitted its B5Ns and D3As to fly only 8-10 sorties against Midway during the period 4-6 June, so about three per day. Of course, if KdB attacked both TF16 and TF17 on 4 June it would have lost a lot of B5Ns and D3As even if it won, and one or more of its four carriers may have been disabled and be on its way to Japan on 5 June. KdB started MI with 70 D3As.

Any type of carrier battle would almost certainly have - more or less - neutralized significant IJN carrier support for the invasion.

The landing was planned for 6 June, wasn't it? Were the four heavy cruisers going to bombard Midway on 5 June? If they were, then at least some of the defending AA guns could have been identified and shelled when they opened fire on attacking aircraft. If their bombardment was not going to start until first light on X Day, then most likely dawn that day would find virtually all of the defenders' AA and coastal guns intact. If the latter held their fire until the landing craft came into range, then it's unlikely that a couple of hours bombardment and bombing would knock many of them out.

The invasion forces consisted of 5 cruisers and 12 destroyers. Assuming a carrier battle, it seems highly unlikely that much of the coastal defences would be knocked out.

[glenn239]

I know , but their passing game turned into such a failure, and with this topic their ground game looks to have been no better. I am trying figure out why the Japanese couldn't play "football".

Nagumo had the option to hit Midway with either 4 half decks or 2 full decks - most of the time he'd done the half-deck tactic, but at Darwin he did the full-deck unified strike. The full-deck option had the advantage of leaving two carriers in reserve for naval operations. But the half-deck option gave him more flexibility - if an enemy were spotted he could launch a unified full-strength strike quickly and then rearm the Midway strike. If an enemy was not spotted, then he could concentrate on Midway. Where he fell down was in the details - that the enemy was spotted after the decision was taken to concentrate on Midway.