Modeling of Carrier Battles

[Nikademus]

ORIGINAL: spence

While I would agree that the IJN Cardiv launch doctrine posed no impediment to launching an integrated strike; the construction of the IJN carriers themselves did.
They could and did clear their decks in 10 minutes but after the decks were clear they needed another 35-45 minutes to spot and warmup the other half of their strike aircraft. Unlike US carriers which had wide doors ventilating the hangar deck the Japanese hangars were completely enclosed and starting engines therein would asphixiate the servicing crews.

In any case the 35-45 minute delay in readying the 2nd half of the strike would seriously effect the range to which the 1st half could proceed if they waited around.
Besides, a delay of only 35-45 minutes would have been completely predicated on a flight deck closed to any recovery operations (CAP and or search a/c).

Yes, I can see that point. (roughly 30min window to launch a 2nd deckload) which is probably why the Japanese never attempted "deferred" departure type launches. It wasn't worth the wait. Better to from a 2nd or even third strike. As mentioned a page or so back....a future product should limit the strike package size to reduce PULSE effects. The Japanese are easier to model because they preferred deckload strikes. The USN is tougher because their launch scheme was more complicated but if we are "abstracting" for the sake of a wargame, my vote would be for a blanket rule limiting both sides in the absence of a more specific system.

[spence]

The capabilities of the IJN in carrier battles are best shown by their performance at the Battle of the Santa Cruz Islands. In that battle, the mission tasking was simply "get the American carriers". The battle is really the only one of the four 1942 carrier battles that the Japanese clearly won (at least tactically).

The Japanese were divided into two uneven carrier TFs:

1) Shokaku (Sh), Zuikaku (Zk), and Zuiho (Zh)
2) Junyo (J)

The Japanese launched their first strike group from Force 1 at 0740 composed of:
21 A6Ms - 6 Sh, 6 Zk, 9 Zh
20 B5Ns - Sh (+2 unarmed B5Ns for strike coordination) ( contribution fm Zh?)
21 D3As - Zk
Arrived over Hornet and attacked at 0852

The 2nd wave followed 1 hour later at 0840 composed of:
8 A6M (unknown but likely 4 Sh and 4 Zk)
19 D3A - Sh
16 B5N - Zk
D3As arrived over Enterprise and attacked at 1008, B5Ns began attack after divebombers at approx 1028

Junyo launched its 1st strike at 0914
12 A6M
17 D3A
this group attacked Hornet at 1121

meanwhile Shokaku and Zuiho were put out of action and retired

Junyo and Zuikaku launched a subsequent attack group at 1306
8 A6M - J
6 B5N (torpedos) plus 1 command B5N (unarmed) - J
5 A6M - Zk
7 B5N - Zk (probably with bombs)
2 D3A - Zk
these groups attacked Hornet at 1520 scoring 1 bomb (Zk planes) and 1 torpedo (J) hit on Hornet which was DIW

Junyo launched a third wave at 1535
6 A6M
4 B5N (with bombs)
these attacked Hornet at 1720

A couple of observations and questions for those with access to more resources than myself:
1) I have read somewhere that Junyo was incapable of spotting and launching more than 6 B5Ns with torpedos in a single launch cycle. Its strike package here would seem to support that statement. True?
2) IIRC "Shattered Sword" mentions the development the idea of a "CAP carrier" to prevent the sort of problems that so delayed the IJN anti-ship strike at Midway after that battle. Was this the first implementation of that idea?
3) Did Zuiho's B5Ns participate as torpedo carrying strike a/c in the battle or were they used for search and ASW only?
4) It appears that the only IJN carrier that launched any particular bomber a/c more than once on the day of the Battle was Zuikaku. Junyo's (surviving) divebombers were recovered in plenty of time to join its 3rd strike wave but none did. Was Junyo handicapped in some way with regards to repair of minor battle damage?
5) The interval of time between Shokaku's and Zuikaku's first strike package and their second one was 1 hour. That'd come pretty close to reducing the range of the first wave by 2 hexes if they'd waited around for the 2nd wave.

[el cid again]

ORIGINAL: okami

Could not strike coordination be linked to experience? First the carriers experience(planning the strike) end result modifier. The strikeleaders rating(leading the strike) end result modifier. Finally squadrons experience(executing the strike) end result modifier. Would this approach better model the strike coordination abilities of both sides. It would also differentiate between carriers on the same side. So that while the KB of 1941 may have a better coordination than it's opponents, war loses in pilots and the gaining of experience by the allies will eventually even the playing field.

This may be a good idea. It might also give players an incentive not to be gamey - and to value their experienced units rather than always throw them into combat. Pick your battles as it were.

[okami]

ORIGINAL: el cid again

ORIGINAL: okami

Could not strike coordination be linked to experience? First the carriers experience(planning the strike) end result modifier. The strikeleaders rating(leading the strike) end result modifier. Finally squadrons experience(executing the strike) end result modifier. Would this approach better model the strike coordination abilities of both sides. It would also differentiate between carriers on the same side. So that while the KB of 1941 may have a better coordination than it's opponents, war loses in pilots and the gaining of experience by the allies will eventually even the playing field.

This may be a good idea. It might also give players an incentive not to be gamey - and to value their experienced units rather than always throw them into combat. Pick your battles as it were.

It also forces you to use your carriers to learn the lessons to get better. All this talk about limiting strike ranges of Japanese for coordinated attacks would also limit the range of allied strikes by about the distance and thus be meaningless.

[el cid again]

ORIGINAL: Ron Saueracker

ORIGINAL: TheElf

ORIGINAL: el cid again




The "most desireable angle" is on the bow - navy talk for about 45 degrees ahead of the beam.

The ideal torpedo attack is an "anvil" - two different attacks 45 degrees off the bow in both directions. If the ship turns one way - to "comb the wakes" of one attack - it is turning broadside to the other set - and vice versa if it turns the other way. A torpedo launched from ahead of the ship tends not to have to "catch" the target and gains some time/speed from the target's own speed. If the ship wants to comb such an attack (if from just one side) - it must turn TOWARD the torpedo - and actually close the range faster - making the pattern more likely to hit. If it tried to turn stern to the attack and comb the other way - it needs much more time - and must turn broadside to at the most likely time to be hit. Not nice choices.

Yes, the Anvil. Even though I spent much time designing this attack type it will not make AE unfortunately.

A long time ago during development I mentioned anvils and simultaneous TB/DB attacks. These could simply be achieved abstractly by having those aircraft which make it through the CAP pass a series of checks (leadership, skill, percentage loss to CAP per group etc) then give them an accuracy bonus. Given, in my view anyway, that ordinance is far too accurate (vs ships at least) perhaps an overall reduction in ordinance accuracy is paramount before adding any more accuracy bonuses.

On that note...is anything being done to reduce the accuracy in AE. JWilkerson even noted recently in his flak tests that the accuracy is somewhat over the top while noting however that because near misses are not modelled perhaps this is acceptable.

On that note...[;)]any chance you guys will include near misses in AE?

Don't let the anvil confuse the main point:

the best angle for torpedo attack is not on the beam - but on the bow - that is half way between bow and beam - so the torpedo speed partially aided by ship speed - and if the ship wants to comb the wakes it must actually turn toward the attack - closing the range faster (the faster the range closes, the more likely the torpedo's won't run out of fuel, the more likely the pattern - if a multiple launch - will have a hit).

[el cid again]

Spence: See Hara on this battle in Japanese Destroyer Captain. He thinks there were command errors in the senior force - and he says the force was a "snake" - a carrier TF as "head" and "tail" with a SAG as body. He thinks only the smaller carrier force was aggressive enough closing the enemy in the context of what was known - and that the bigger carriers could have launched again.

[spence]

Spence: See Hara on this battle in Japanese Destroyer Captain. He thinks there were command errors in the senior force - and he says the force was a "snake" - a carrier TF as "head" and "tail" with a SAG as body. He thinks only the smaller carrier force was aggressive enough closing the enemy in the context of what was known - and that the bigger carriers could have launched again

I read Hara quite some time ago, and enjoyed the book and his commentary on some of the battles he participated in but I question his ability to comment first hand and with any authority on the readiness of the Japanese air wings on the afternoon of Oct 26, 1942 since he was at the time pre-occupied commanding the DD Amatsukaze. Rogers Clemens' commentary on pass coverage in Superbowl would likewise be interesting but nothing to take too seriously.

50 odd IJN a/c were shot down by American CAP and AAA. Damage to a/c that returned to their carriers probably grounded a lot of planes after the initial strikes.
Zuikaku's small afternoon strike, was, considering that it had landed all the surviving strike aircraft of its own, Shokaku and Zuiho from the morning strikes is pretty indicative that battle damage must have been severe amongst those planes. The smaller carrier force, Junyo, only got one strike out of each of its attack aircraft that day.

[TheElf]

ORIGINAL: el cid again

ORIGINAL: Ron Saueracker

ORIGINAL: TheElf



Yes, the Anvil. Even though I spent much time designing this attack type it will not make AE unfortunately.

A long time ago during development I mentioned anvils and simultaneous TB/DB attacks. These could simply be achieved abstractly by having those aircraft which make it through the CAP pass a series of checks (leadership, skill, percentage loss to CAP per group etc) then give them an accuracy bonus. Given, in my view anyway, that ordinance is far too accurate (vs ships at least) perhaps an overall reduction in ordinance accuracy is paramount before adding any more accuracy bonuses.

On that note...is anything being done to reduce the accuracy in AE. JWilkerson even noted recently in his flak tests that the accuracy is somewhat over the top while noting however that because near misses are not modelled perhaps this is acceptable.

On that note...[;)]any chance you guys will include near misses in AE?

Don't let the anvil confuse the main point:

the best angle for torpedo attack is not on the beam - but on the bow - that is half way between bow and beam - so the torpedo speed partially aided by ship speed - and if the ship wants to comb the wakes it must actually turn toward the attack - closing the range faster (the faster the range closes, the more likely the torpedo's won't run out of fuel, the more likely the pattern - if a multiple launch - will have a hit).

I know. And it doesn't really matter.

[Local Yokel]

ORIGINAL: spence

A couple of observations and questions for those with access to more resources than myself:
1) I have read somewhere that Junyo was incapable of spotting and launching more than 6 B5Ns with torpedos in a single launch cycle. Its strike package here would seem to support that statement. True?

True. 7 B5N2's launched from Junyo at 1306 on 26 Oct 42. Of these, only 6 were lugging torpedoes, the 7th was for recce/shadowing.

ORIGINAL: spence

3) Did Zuiho's B5Ns participate as torpedo carrying strike a/c in the battle or were they used for search and ASW only?

Not as torpedo strikers. Even after Midway Zuiho's attack planes operated with ordnance loads less then the maximum possible.

[Nikademus]

Zuiho contributed 1 B5N as a "tracker" aircraft for the 1st wave. She was then knocked out by an SBD on an intruder mission before she could do more (losing three Zeros parked on deck astern from fire)

Zuikaku for the 2nd wave took over providing the B5N "tracker" for the 2nd wave (unarmed). Using B5N's as contact/tracker aircraft to assist navigation and search was standard practice. They filled a role similar to the SBD in the search role.

[el cid again]

ORIGINAL: TheElf

ORIGINAL: Mike Scholl

ORIGINAL: TheElf
The flip side to that is that the IJN CARDIVs still have their other component left to arm, warm up, spot and launch. The alternate units that was not launched in the first wave. If we were to do the IJN doctrine right we'd only see HALF the total Strike A/C available in the AM phase and the other half in the PM.

Actually, both strikes would fly in the AM, and might possibly fly again in the PM. They certainly did at PH. But no more than half of KB's planes should ever be in the SAME strike. Japanese doctrine should never produce a full strike, but two half strikes.

PH was a set piece. Launching vs. a stationary object with suprise on your side is fairly easy. Spot, Arm, Warm up, launch - rinse - repeat.

And I agree. If every CV action was as simple as this I'd say sure, but in reality CV vs. CV combat embodies a lot of misinformation that needs sorting, descisions have to be made and long distances are flown while searching out targets.

Also consider depending on the time of the year these large scale strikes occur mostly during the day, so while the Air phases may absolutely occur on a 12 hour scale you are really talking about 6 hours of day light in each phase, less in the winter depending on lattitude, but man are we in the weeds now!

So to remain within the confines of our current box, the WitP Code, the CV combat day begins before first light. In some cases strikes could be launched before sunrise (Targeting land) but CV vs. CV requires a day search phase so the kick off is later. Depending on the length of the day the second one may be prepped, but who would launch before hearing the assessment of his 1st Hikotaicho? These things take time.

It isn't ALWAYS a matter of Spot, Arm, Warm up, launch - rinse - repeat. If that were the case then all KB strikes would look like PH. So realistically each CARDIV would be launching an early strike, post dawn best case for CV vs. CV. The strike has to find, fix, and target the enemy, execute and then report. Comms were problematic, it may be that report has to be face to face. So your reserve gets airborne at 1300 for the sake of arguement. That is the PM phase. It still has to return update the sitrep and need for continued ops. Could a third launch occur? sure, but it would be subject to limitations from a myriad of factors. State of the Airgroup, state of the CVs (are they afloat?), fatigue, daylight, misinformation, a reatreating enemy etc.

The 90% solution is 1 AM raid, 1 PM raid. With a random chance for an ad hoc last ditch effort.

As it was the Midway example is a combination of Land Primary, CV secondary. So it benefited from an early kickoff. The main attack against Midway was airborne before dawn and after all the hulabaloo the second wave was still not spotted at 1020-1030. That is an hour and a half prior to our game's PM phase beginning, and with the "headstart" afforded by the early Midway strike.

I like this - but have a somewhat different take:

I agree we need no more phases -

maybe we redefine phases as 8 hours each - instead of two of 6 hours and one of 12 hours - but three is enough

I agree that a CV vs CV battle normally has only one strike in the AM phase -

BUT that "one" strike might be 2 strikes in immediate succession - if coordinated - and more than that if uncoordinated squadrons come in

AND I think the PM phase is inherantly different

because you have AM recon to work with it is LIKELY you get two PM strikes

There should be a chance of a night strike - better if radar equipped planes are involved and if the target was tracked in the PM phase

And LAND combat is not the same -

it is inherantly two strikes AM and two PM - if the range permits it.

Also Land bombat in Philippines was very iffy - confused - and die rolls are very appropriate - no guarantees.

[wdolson]

ORIGINAL: TheElf
Can this be confirmed? Can it be an exclsuive statement? CVEs NEVER carried torpedoes in their magazines?

Let me know.

I read a book on Leyte last year, can't remember the name now, and it was borrowed, so I don't have it handy. The book talked about the weapons load on the CVEs before Leyte. According to that book, CVEs usually carried a small load of torpedoes, but before Leyte, the decision was made to remove the torpedoes from the CVEs because it was asumed that the IJN was not going to make an appearance and the CVEs could use the extra magazine space for more bombs to attack ground targets.

Bill

[wdolson]

ORIGINAL: spence
OK I take back what I said about US CVEs having no torpedos. According to the following link each CVE in Taffy 3 at the Battle Off Samar carried 12 torpedos in its magazines. Use of the single catapult on the CVE to launch a TBM with one was undoubtably required due to deck length and max speed of only 19 kts.

http://www.bosamar.com/book/bosc2.html

The planes that loaded torpedos at Tacloban airstrip went there because the wind was from the NE and to be recovered meant the CVEs would have had to steam towards the IJN fleet.

Maybe they did? I tracked down the book I talked about in the previous post, it is "The Battle of Leyte Gulf: 23-26 October 1944" by Thomas Cutler. Cutler said the torpedoes had been removed from the CVEs just prior to the battle, but that was a pre-battle decision and not standard doctrine.

Bill

[wdolson]

ORIGINAL: el cid again
A principle taught in USN is that "no carrier escorted by a battleship was ever lost." This applies to Japanese carriers and others, not just our own. The heavy AA guns of an escort should apply to the defense - even if not the light ones - and it is very likely you will get MORE THAN ONE escort firing if the number of escorts is large enough - in any navy.

ORIGINAL: Mike Scholl
You sure Cid? I thought KB had a couple of battleships along for Midway... Of course, comparing the AAA of a Kirishima to a South Dakota is a pretty one-sided contest.

At Leyte, Ozawa's decoy force (with the carriers) had the Hyuga and Ise in his force and the IJN lost what was left of their carrier fleet that day.

Bill

[wdolson]

ORIGINAL: el cid again

OK - look - Midway "prooves USN CAP was incapable of defending and inflicting even small scale losses on the enemy" - else we would not have lost Yorktown. And that WITH radar on the ships and radios in the fighters.

CAP should fatigue - I thought it did - and it should be weather dependent - even if there is radar. You cannot shoot a target you cannot see. Radar should give a better CHANCE of getting on the right vector. And it should always only be a chance - you can play games with enemy radar - sucking his CAP in the wrong direction. That is too tactical for us - but it does mean there is a chance of failure to intercept.

I think Shattered Sword shows how effective American CAP was at Midway. The Yorktown didn't have many fighters in position to engage the Hiryu's dive bombers, but the unit was ripped apart by the F4Fs. The fact that the unit was extremely high experience allowed them to complete the strike.

Direction of fighters from the surface was still in its infancy, but the embryo of what would become uberCAP can be seen in US fighter direction at Midway. The USN lacked training of operators, had more primitive radar equipment, and was overall fairly green and they still put up a modestly decent CAP effort, IMO.

Bill

[wdolson]

ORIGINAL: jwilkerson
Ok, here is a summary table of the data Nik posted earlier in this thread related to the Flak and CAP losses during the 1942 Carrier Battles.

Of course, as always, the devil is in the details, some could argue that this plane should be included and this plane not included, but I tried to be fairly strict and count only enemy planes shot down over enemy ships (for example). This means that losses to "escort fighters" are not included (among other things). Also, I did not include "possible"(s) which Nik had on his list.


A next step would be to take stock and try to run the historical battles a few times and see what the results are. Let's take a "base line" before we decide how "broke" it is!

Richard Frank's account of Santa Cruz in his book on Guadalcanal is probably the best account I've read. From a doctrine point of view, Santa Cruz was a big shift for the US. Most ships had new AA suites and had worked out many of the bugs with the earlier carrier defense techniques. Putting a fast battleship with the Enterprise provided uber flak for that TF. When a gaggle of Vals slipped past the CAP, the Enterprise and South Dakota shot down most of the attacking force. The initial claims were for more than the attacking force, but that was lowered after the war when Japanese records were examined. They still shot down something like 90% of the attacking force in that one encounter.

As far as uberCAP goes, I think it is fairly realistic for late war vs. the US. The only time in the real world the US was had to defend Pacific bases from any major attacks late in the war (1944 and later), were in carrier battles. That's why the Hellcat guys ran up such a staggering kill to loss ratio and such a high total.

The Japanese were wise enough to avoid attacking Allied bases except with harassment forces late in the war. If the Japanese tried to launch a massive air strike on any Allied base with any kind of air defense set up in 1944, they would have had their heads handed to them.

The only reason they put the effort into attacking US carriers was that it was deemed worth the risk.

I forget, is there anything in the code that has effects on interception based on the size of the attacking force? One or a few planes are more likely to slip past CAP than a large force. The Princeton was sunk by a single plane that got past the CAP when the CAP had caught and destroyed most of the rest of what had been thrown at it.

Bill

[spence]

quote:

ORIGINAL: el cid again
A principle taught in USN is that "no carrier escorted by a battleship was ever lost." This applies to Japanese carriers and others, not just our own. The heavy AA guns of an escort should apply to the defense - even if not the light ones - and it is very likely you will get MORE THAN ONE escort firing if the number of escorts is large enough - in any navy.


quote:

ORIGINAL: Mike Scholl
You sure Cid? I thought KB had a couple of battleships along for Midway... Of course, comparing the AAA of a Kirishima to a South Dakota is a pretty one-sided contest.


At Leyte, Ozawa's decoy force (with the carriers) had the Hyuga and Ise in his force and the IJN lost what was left of their carrier fleet that day.

And then I checked on USS Princeton's screen at Leyte Gulf and lo and behold there was the USS South Dakota and another BB. It would seem the principle cited is not entirely supported by the facts.

Bill

Just for the record, BB Nagato was in the screen of CV Hiyo when she was torpedoed and sunk by aircraft at the Battle of the Philippine Sea.

[Local Yokel]

ORIGINAL: wdolson

I think Shattered Sword shows how effective American CAP was at Midway. The Yorktown didn't have many fighters in position to engage the Hiryu's dive bombers, but the unit was ripped apart by the F4Fs. The fact that the unit was extremely high experience allowed them to complete the strike.

Bill

To put this in context it should be borne in mind that perhaps as many as 8 of Kobayashi's 18 carrier bombers were brought down in the course of the CAP's initial passes, at a time when the 4 surviving Zero escorts were still lagging some distance behind the bombers. Had the escort stuck to its primary task and not engaged retiring US aircraft whilst it was en route to the target, Hiryu's 1st strike might well have proved even more destructive than it actually was.

[spence]

To put this in context it should be borne in mind that perhaps as many as 8 of Kobayashi's 18 carrier bombers were brought down in the course of the CAP's initial passes, at a time when the 4 surviving Zero escorts were still lagging some distance behind the bombers. Had the escort stuck to its primary task and not engaged retiring US aircraft whilst it was en route to the target, Hiryu's 1st strike might well have proved even more destructive than it actually was.

Hiryu's dive bombers ended up losing 2/3rds of the squadron in this attack. The fighter escorts tangling with the retiring American strike planes also cost the escort 2 Zeros damaged and forced to return to Hiryu. All in all the escorts' decision to engage the American bombers seems ill-advised considering the circumstances facing the IJN at the time. Particularly so in that the fighter pilots themselves could not help but be aware of what those circumstances were (that the other 3 IJN carriers were burning wrecks) and that the bombers engaged by the escorts were clearly no immediate threat to the Japanese.

Some of Zuiho's fighters acted in a similar manner at Santa Cruz but in that instance they attacked American bombers which had not as yet expended their ordinance and were heading towards the IJN CVs.

[spence]

Question

Ordinarily in a carrier battle the Japanese would launch a combined hi-lo attack from their carriers. At the Battle of the Eastern Solomons the Japanese didn't launch their torpedo bombers at all after locating the Enterprise at 1425. The two carriers (Shokaku and Zuikaku) appear to have launched their dive bombers separately approx an hour apart (1450 and 1600). Very peculiar. Anybody know why?