Battle of the Philippine Sea Dates: 19-20 JUN 1944
Note: This is another in the my series discussing Imperial Japan in the Great Pacific War. Up to this point I have largely concentrated on the relative incompetence of the Imperial Japanese Army of WW2 as an industrial armed force. How the Japanese military government came to launch a war that they should have known was hopeless, given the primitive abilities of their industrial base and their army has always intrigued me; it seems like such a fundamentally avoidable error.
The Imperial Navy seems to have been more technically competent than their army counterpart; indeed, until about mid-1943 the IJN was ahead of the USN in some critical tactical and technical elements such as torpedo and naval aircraft design. The IJN's failings seem to have been largely strategic, or mental, or perhaps even emotional. The Japanese admirals seemed to have an odd sort of defeatist outlook. Even when they won, when the USN took the harder pounding and the heavier losses, many of the IJN commanders seem to have hugged a lurking fear that their victories were mirages, their enemies hiding some dreadful power untouched by defeat.
The admirals had logistical and organizational problems, as well. As with the Imperial Army, logisticians were not particularly esteemed in a warrior culture and the IJN suffered from the sorts of logistical problems you'd expect. The 軍令部 (Gunreibu), the IJN General Staff, had issues as well. Fixated on the Mahanian notion of the "decisive battle" that (in the minds of the WW2 generation of senior officers, at least) had been vindicated by Tsushima they desperately wanted the USN to shove its collective head into that meatgrinder. That fixation was one of the driving forces behind what happened in the central Pacific in the early summer of 1944 and its part in Imperial Japan's remorseless slog towards destruction.
I've noted this in the earlier posts; the idea of a Japanese defeat as a "decisive battle" in WW2 is almost an oxymoron. Yamamoto was right from the beginning; Imperial Japan had no business making war on the United States. The empire was doomed from the moment the first anchor rose dripping from the greasy waters of Yokosuka harbor in 1941. If the counterfactual...perhaps; had the USN obliged and sortied into Philippine waters in March of 1942 they would very likely have been sent to the bottom and the war might have gone very differently.
The Battle of the Philippine Sea is of interest to me principally because it does such a good job of highlighting what the USN did right and the IJN did wrong that contributed to Japan's shattering defeat. It is a tale, written in steel and blood, in the sky and on the sea, of two organizations; one the learned and changed and succeeded...another that didn't.
Forces Engaged: United States Navy - The Philippine Sea was another of the Pacific War "over-the-horizon" engagements in which the only human eyes that saw an enemy warship were either in the air or beneath the sea. So regardless of the total numbers of warships engaged the important combatants for the USN were aircraft carriers of Task Force 58 of the Fifth Fleet and the submarines of the Fifth and Seventh Fleets.
TF 58 was the so-called "Fast Carrier Force" of Chester Nimitz's Pacific Fleet. As organized for the Marianas Campaign it consisted of four carrier task groups, TF58.1, TF58.2, TF 58.3, and TF58.4 and the "fast battleship" escorts of TF 58.7.
The carriers in each group are listed below with the number of aircraft embarked: F6F "Hellcat" fighters, SB2C "Helldiver" or SBD "Dauntless" dive bombers and TBF "Avenger" torpedo bombers.
TF 58.1 - 2 fleet carriers (CV12 USS Hornet [41 F6F, 33 SB2C, 18 TBF], CV10 USS Yorktown [46 F6F, 40 SB2C, 17 TBF, 4 SBD]) 2 light carriers (CVL24 USS Belleau Wood [26 F6F, 9 TBF], CVL29 USS Bataan [24 F6F, 9 TBF]), 3 heavy cruisers, 1 light cruiser, 9 destroyers under RADM Clark in Yorktown
Note: The USN in 1944 had three types of aircraft carriers, although two were very similar to another.
A "CV" was a "fleet" or full-size carrier. The two TF 58.1 CVs were typical of the Essex-class fleet carriers of 1944; about 870 feet long, 27,000 tons burden, capable of 33 knots and embarking 90 to 100 aircraft. Typically these consisted of a fighter squadron or squadrons (USS Yorktown had one in June 1944, VF-1's "High Hatters"), a dive-bombing squadron (Yorktown's was VB-1) and a torpedo-bombing squadron (VT-1 for Yorktown). Some fleet carries had a scouting detachment (identified as a "VS" unit) that at the time would still have flown the TBD Douglas Dauntless, the fleet dive bomber from 1942.
A "CVL" was a "small aircraft carrier"; an 11,000-ton, 600-foot-long, 31-knot flattop based on a light cruiser hull. Typically these smaller carriers embarked only fighters and torpedo bombers and only about 30 of these. The idea was originally to arm the CVLs with a miniature fleet carrier air wing of 9 aircraft of each type, but experience quickly showed that the fighter-torpecker mix worked better. The CVLs were an expedient, initially ordered because the fleet carriers were slow to build, but they did decent work as sidekicks to the big flattops. The Wiki entry points out that
"...(t)hese were limited-capability ships, whose principal virtue was near-term availability. Their limited size made for seakeeping difficulties in the many typhoons of the Pacific, and their small flight decks led to a relatively high aircraft accident rate. However, being based on a light cruiser, they were fast ships...(with) the speed necessary to operate with the main fleet carrier task groups."
The last carrier type didn't take a direct role in the naval engagements of the Marianas Campaign. A "CVE" was an "escort" carrier, a dinky 500-foot long, 7,800-ton, 21-odd-knot vessel often known as a "jeep" carrier or even worse names; "Kaiser coffin" or "torpedo junction" for their supposed fragility. The jeep carriers embarked about 25 aircraft that were typically divided into F4F fighters and TBF bombers (that were used as bombers - CVE Avengers typically carried either depth charges for antisubmarine work or iron bombs for ground attack).
Anyway, that was the brown-shoe Navy of '44.
TF 58.2 - 2 fleet carriers (CV17 USS Bunker Hill [42 F6F, 33 SB2C, 18 TBF], CV18 USS Wasp [39 F6F, 32 SB2C, 18 TBF]), 2 light carriers (CVL28 USS Cabot [26 F6F, 9 TBF], CVL26 USS Monterey [21 F6F, 8 TBF]), 4 light cruisers, 9 destroyers under RADM Montgomery in Bunker Hill
TF 58.3 2 fleet carriers (CV6 USS Enterprise [31 F6F, 3 F4U, 21 SBD, 14 TBF], CV16 USS Lexington [41 F6F, 34 SBD, 18 TBF]), 2 light carriers (CVL30 USS San Jacinto [24 F6F, 8 TBF], CVL23 USS Princeton [24 F6F, 9 TBF]), 1 heavy cruiser, 4 light cruisers, 13 destroyers under RADM Reeves in Enterprise
Note: the flagship of TF 58.3 is the old lady of the fast carrier force, the 1934 USS Enterprise, one of the victors of Midway and the sole survivor of her Yorktown-class. Note also that the Big E had embarked three F4U Corsairs. This fighter had some fairly significant deck-landing issues and by early 1943 was largely a) assigned to Marine fighter units that were b) operating from land bases. I'm not sure why the Enterprise still had these Corsairs aboard and would be very interested to find out.
TF 58.4 1 fleet carrier (CV9 USS Essex [42 F6F, 36 SB2C, 20 TBF]), 2 light carriers (CVL27 USS Langley [23 F6F, 9 TBF], CVL25 USS Cowpens [23 F6F, 9 TBF]), 4 light cruisers, 13 destroyers
TF 17 (5th Fleet submarine pickets) 20 fleet submarines, including 7 each of the Balao and Gato classes, two Sargo class subs, and one sub each from the Tambor, Porpoise, and Salmon classes.
7th Fleet submarines: 9 fleet submarines
It's worth noting that the 5th Fleet had an entire task group that included seven battleships (TF 58.7) including USS Iowa and USS New Jersey, the newest of the USN's big-gun capital ships and what less than five years earlier would have been the pride of the battleline. Their work for the next two days would be that of huge destroyers, guarding the carriers, their 16-inch cannons silent, their only prey the fleeting aircraft.
So 4 fleet carriers, 7 light carriers, embarking a total of approximately 470 F6F fighters, 190 SB2C divebombers, 180 TBF torpedo bombers, and about 60 SBD scout bombers with their escorting cannon-armed warshipe under the command of VADM Mitscher embarked in USS Lexington. In overall command of 5th Fleet was ADM Spruance in the heavy cruiser USS Indianapolis sailing with TF 58.3.
Imperial Japan - The 1st Mobile Fleet 第一機動艦隊 (Dai-Ichi Kidō Kantai) was also divided into task groups, in this case three main carrier squadrons. In June 1944 two of these (A and B Force) operated more-or-less together, while the third - C Force - worked as a forward or screening unit.
The Japanese naval air arm's fast carrier force, the 機動部隊 (Kido Butai) had been hammered hard at Midway and in the battles for the Solomons. The surviving carriers had been reorganized into the 1st Mobile Fleet and had begun to field some newer aircraft by 1944.
Although the Zero fighter (A6M and variants) still hung on the D3A "Val" dive bomber was being phased out in favor of the D4Y "Judy" and the B5N "Kate" torpedo bomber replaced by the B6N "Jill".
As we'll see, however, the problems that affected Japanese manufacture and design made this process slow and incomplete, and many air groups still flew the older aircraft. We'll also see that obsolete aircraft were often the least of the IJN's air arm problem...
C Force, 3rd Carrier Squadron - 3 light carriers (CVL HIJMS Chitose [21 A6M5b, 3 B6N, 6 B5N], CVL HIJMS Chiyoda [21 A6M5b, 3 B6N, 6 B5N], CVL HIJMS Zuiho [21 A6M5b, 3 B6N, 6 B5N]), 4 battleships, 8 heavy cruisers, 1 light cruiser, 14 destroyers under VADM Kurita in the heavy cruiser Atago
A Force, 1st Carrier Squadron - 3 fleet carriers (CV HIJMS Taiho [26 A6M5, 23 D4Y, 17 B6N, 2 D3A], CV HIJMS Shokaku [26 A6M5, 24 D4Y, 17 B6N, 2 D3A], CV HIJMS Zuikaku [27 A6M5, 23 D4Y, 17 B6N, 3 D3A]), 2 heavy cruisers, 1 light cruiser, 7 destroyers under VADM Ozawa in Taiho
B Force, 2nd Carrier Squadron - 2 fleet carriers (CV HIJMS Junyo [27 A6M5, 6 B6N, 9 D4Y, 9 D3A], CV HIJMS Hiyo [26 A6M5, 6 B6N, 18 D3A]), 1 light carrier (CVL HIJMS Ryuho [27 A6M5, 6 B6N]), 1 battleship, 1 heavy cruiser, 7 destroyers under RADM Joshima in Hiyo
24 mixed fleet (I-class) and small (RO-class) submarines (more about which later)
Okay...now the real pain in the ass...
Base Air Force, Marianas (1st Air Fleet; 第一航空艦隊 Daiichi Kōkū Kantai) - Originally supposed to be more than approximately 1,000 aircraft distributed across 17 airfields on 12 land-base locations, but in fact heavily attrited and close to ineffective as a force by 18 JUN 44.
In assessing the actual condition of the land-based naval aviation in 19 JUN 44 the big problem is that the number and type of aircraft at these land bases is not included in most general references for this engagement and what we do have is often confusing, contradictory, flat out wrong, or a mix of all three.
The most commonly used figures are contained in Morison (1947) and he just throws out numbers and locations without telling us what type of aircraft or the units assigned; 35 aircraft at Saipan, 67 on Tinian, 70 at Guam, and so on.
This is problematic.
For example, what were the aircraft on Saipan; fighters? Bombers? Both? Were they a single unit with some experience flying and fighting together, or a hotch-potch of odds and sods, a Zero here, a Judy there, a bunch of random guys who'd barely had tea in the mess once?
The problem with Morison's numbers isn't just the lack of information in the raw numbers alone. His relative numbers seem odd, too. He suggests that there were only 67 kites under the 1st Air Fleet flagpole on Tinian but 134 on Palau (presumably Pelilieu), a smaller post? Why 50 in Iwo Jima, far northwest of the fighting? Does the 35 aircraft on Saipan reflect that the airfields there had been hit harder than Palau, or that they had left Saipan to go elsewhere? And why; were they fleeing the USN or (as one of the commentors at Nihon Kaigun's aviation page tells us) because of an IJN tactical shift?
The pieces are all over the place, and I had to dig like hell to find anything. I found several sources; one that looks superficially promising is The campaigns of the Pacific war, a study published in 1946 by the United States Strategic Bombing Survey (USSBS, 1946). It's available online here and has a list of the unit postings, assigned aircraft number and types for the 1st Air Fleet in 1 JUN 44.
But the neat organization from this source looks more misleading the harder you look at it.
As we'll see, the USSBS (1946) order of battle appears to be the plan. The field intel suggests that the actual strengths of these units were far less and the actual locations are often far different from that plan and that makes it much more difficult for us to figure out who in the IJN Air Service (大日本帝國海軍航空隊, Dai-Nippon Teikoku Kaigun Kōkū-tai) land-based units was attacking from where with what on 19 JUN...but is a pretty good reflection of the degree to which those plans had gone sideways.
It's really unfortunate that this information is so difficult to obtain because it is fairly important to understanding this engagement. The original Plan A-Go relied heavily on land-based air attacks to supplement (and replace) the carrier airpower lost in the Japanese defeats of 1942 and 1943.
For what it's worth, here's some idea of what the IJN Naval air arm wanted to have in place in June 1944...with some comments about what we think really was there.
I've listed the units grouped by location then the USSBS (1946) roster of unit and aircraft type.
Note: The primary unit designation here is an "Air Group" (航空隊, or Kōkūtai). For the IJN this was roughly the equivalent of a USN carrier air wing, typically two or more squadrons (Hikōtai) that could be similar or identical type aircraft; all fighters, for example, or all A6M Rei-sen fighters ("Zekes" or "Zeros" as the Allies called them) or (when embarked) all the aircraft in a carrier task group, so several fighter, dive or scout bomber, and torpedo squadrons.
The Kōkūtai was, like its Allied equivalent, the primary administrative and tactical organization of the Navy air arm and at least in the Marianas in 1944 most of the Kōkūtai appear to have been single-type or, at most, two-aircraft-type organizations.
Chichi Jima (northwest of the engagement area) - a small seaplane force, probably no more than 8-10 "Rufe" seaplanes? This area was not included in the 1st Air Fleet area so I don't really have a good sense of what the IJN might have had there.
Iwo Jima (northwest of the engagement area) - Morison (1947) reports 50 aircraft posted here, also outside the 1st Air Fleet AO. This may represent something he got from CAPT Ohmae as a locally based unit there, or it may be the remnants of an outfit he identifies as the "Hachiman Group" or "Hachiman Unit" that is supposed to have been formed from the naval aviation base at Yokosuka, attempted to shift over to Iwo, and was badly shot up in the process.
Saipan (in the Marianas chain) - originally approximately 80 A6M fighters from 261th Air Group (航空隊, Kōkūtai) A detachment of this unit is also reported from Guam, however, where a USN radio intercept dated 1 JUN 44 notes that the Guam detachment has a total of 12 A6M fighters, of which 11 were operational and 12 pilots - 6 with over 1,000 hours, 5 with more than 400, and a cherry with less than 10 weeks of stick time.
Tinian (in the Marianas chain) - originally approximately 125 aircraft, divided between five air groups over two airfields: 121st (10 x probably D4Y "Judy" scout bombers or possibly C6N "Myrt" reconnaissance aircraft)
(Note: the USSBS (1946) lists these aircraft as only as "Suisei (reconnaissance)" without giving the alphanumeric. Suisei is presumably a direct translation of 彗星, or Comet. This was the name the Japanese used for the D4Y that the USN called a "Judy" carrier dive bomber. Since this aircraft was also used for reconnaissance, and given the relative scarcity of the C6N, I suspect these were "Judys")
, 321st (15 x J1N "Irving" heavy fighter), 523rd (40 x D4Y dive bombers), 761st (40 x G4M "Betty" medium bombers), and the 1021st (20 x L2D "Tabby" transport aircraft).
Guam (in the Marianas chain) - originally approximately 215 aircraft from four air groups over two airfields: 263rd (80 x A6M "Zeke" fighters), 321st (15 x J1N "Irving" heavy fighters), 521st (80 x P1Y "Frances" medium bombers), and 755th (40 x G4M "Betty" medium bombers).
This is very clearly a massive overstatement and, as the radio intercept information shows, these units and aircraft were widely scattered by 18 JUN 44.
Truk (in the Caroline chain) - originally approximately 280 aircraft from seven air groups over three airfields: 151st (20 x D4Y "Judy" scout bombers), 202nd (40 x A6M "Zeke" fighters), 251st (20 x J1N "Irving" heavy fighters), 253rd (80 x A6M "Zeke" fighters), 503rd (40 x D4Y "Judy" dive bombers), 551st (40 x B6N "Jill" torpedo bombers), and 755th (40 x G4M "Betty" medium bombers).
Keep in mind that this is the assigned strength for the 22nd air Flotilla (航空戦隊 or Kōkū Sentai); the USN air attacks in February destroyed some 300-odd aircraft, many of which would not have been replaced by June, and many of the survivors were shifted about the engagement area.
Yap (in the Caroline chain) - approximately 40 A6M "Zeke" fighters from 265th Kōkūtai
However, a radio intercept dated 5 JUN reports the following units and aircraft at Yap: 202th from Truk (4 x A6M fighters), 261th from Saipan (1 x A6M), 321st from Guam (5 x J1N "Irving" heavy fighters), 503rd from Truk (6 x D4Y "Judy" scout bombers), 521st from Guam (2 x P1Y "Frances" light bombers), 523rd from Tinian (1 x D4Y scout bomber), 1021st from Tinian (3 x L2D "Tabby" transports).
Pelieliu (in the Palau chain southwest of the engagement area) - originally approximately 90 aircraft in three air groups: 121st (10 x D4Y "Judy" scout bombers), 265th (40 x A6M "Zeke" fighters), and 761st (60 x G4M "Betty" medium bombers)
Here, again, the IJN's intercepted radio transmissions tell the story of the chaos that reigned in the 1st Air Fleet in the summer of 1944. On 18 JUN a group of aircraft arrived on Pelilieu: 9 x G4M "Betty" bombers from 732nd Kōkūtai supposedly based on Halmhera, 4 more G4Ms assigned to the 753rd Kōkūtai from Manado, and 10 A6M fighters assigned to the 153rd Kōkūtai out of Sorong
Mereyon (reported to have been an "island fortress" in the Marshall chain) - originally approximately 40 x D4Y "Judy" dive bombers of the 202nd Kōkūtai. Given the pounding the Marshalls had already taken by June it is difficult to believe that many, or any, of these aircraft remained serviceable.
Halmhera (in the Indonesian archipelago) - reported to be approximately 40 x G4m "Betty" medium bombers of 732nd Kōkūtai at Wasile airfield. An intercept from 10 JUN 44 reports the follwing aircraft at Wasile; 17 x D4Y "Judy dive bombers of 523th Kōkūtai (of which 12 were operational and all of which were supposed to be on Tinian...), 18 x P1Y "Frances" light bombers of 521st Kōkūtai (supposedly posted to Guam), a total of 59 A6M fighters, including 10 that were non-mission-capable 25 from 261 Kōkūtai (assigned to Saipan), and 34 from 265 Kōkūtai (officially supposed to be on Yap).
Menado (or probably Manado, in the Celebes) - assigned 40 x G4M "Betty" medium bombers of 753rd Kōkūtai.
Davao (in the Philippine archipelago) - the problem at this location is that Morison (1947) only reports 25 aircraft based here . But the IJN records suggest two and possibly four Kōkūtai if the units reported at Lasong and Sorong are also Philippine air fields and his identification of the 201st Kōkūtai as at Cebu is wrong. The list of assigned Philippine-based aviation units includes the 153rd (20 D4Y "Judy" scout bombers and 40 x A6M "Zeke" fighters" at Sorong), 201st (20 x A6M "Zeke" fighters), 501st (40 x A6M fighter-bombers at Lasong), and the 751st (40 x G4M "Betty" medium bombers); however you'll note that
Adding up all the "assigned" strengths you get something like 1,240 aircraft; this is not supported by any of the published sources as close to the existing strength of the 1st Air Fleet on 19 JUN. The raids of late winter and spring had destroyed a very large number of the naval aviation strength at the Marshalls, Carolines, and Marianas bases.
There is some useful discussion here about the displacement of many of these aircraft to southwestern locations to support the defense of Biak. Commentor Rick Dunn remarks (about the aircraft list in the USSBS, 1946):
"The aircraft strengths are totally inaccurate and the bases are misleading. On June 1st much of the strength of the 1st Air Fleet was deployed to or en route to Wasile and other bases away from the Marianas in order to support the Japanese response to the invasion of Biak (May 27th). Just as the KON operation diverted part of the Combined Fleet so also was the Central Pacific's base air force diverted to the south. This was a major strategic blunder that went a long way toward making the base air force ineffective during the Marianas operations."
Later the same commentor includes the information from radio intercepts noted in the airbase paragraphs above.
So we can't be sure of the location, number and type of the land-based naval air units other than that they were considerably smaller, weaker, and more battered that they were supposed to be - or, more importantly, thought to be by VADM Ozawa - by 18 JUN 1944. My best guess is that the 1st Air Fleet probably had about 200-250 aircraft of all types spread out across the Marianas as well as all the way from the Philippines to the Volcano Islands, all at least notionally under VADM Kakuta on Tinian.
Altogether 5 fleet carriers, 4 light carriers and escorts embarking 220 A6M fighters, 97 D4Y divebombers, 16 D3A divebombers, 81 B6N torpedo bombers, and 17 B5N torpedo bombers supported by about 200-250 land-based aircraft of various types under the overall command of VADM Ozawa.
The Sources: The events of June 1944 are well-documented as is nearly always the case when two industrial societies fight. As always for the Great Pacific War, however, the caveat is that for an English-only speaker one side is much less accessible than the other.
The United States National Archives notes that:
"The major collection of Japanese World War II records accessible to those who do not read Japanese is in the National Archives in Washington. There are several series of intercepted Japanese diplomatic, military attache‚ naval attache‚ army and navy...with some of them running to tens and even hundreds of thousands, which are included in the Record Group 457 of the National Security Agency, the inheritor of the American wartime decoding records. These materials are of immense importance because they reflect not only affairs internal to the Japanese diplomatic and military services but because they report on the countries where Japanese diplomats were stationed. Furthermore, for the Japanese as for the German records, the destruction of war has in many cases left the translated intercepts the only surviving copies of documents of which no German or Japanese originals exist."
You'll note the important statement there - "for those who do not read Japanese".
For those who do there is a Japanese National Archives, that is reported to include a relatively full record of the Showa Period, the reign of the Emperor Hirohito that lasted until 1989.
This includes both Imperial Army and Navy records. Although some destruction took place (both by American bombing and Japanese incineration) in 1945 the Japanese war records are said to include
"Official records of the...Navy General Staff Office...(t)he military organs’ important records, which are crucial for understanding the Showa history, had been hidden away for years from the eyes of the public. Senshi Sosho (War History Series), which totals 102 volumes, was compiled by the then Military History Office (now Department) of the National Institute for Defense Studies, on the basis of records of the Imperial Army and Navy which survived in Japan, as well as ones seized and later returned by the GHQ. Most of the documents used for Senshi Sosho are now kept at the Military Archives of the NIDS (National Institue for Defense Studies)."
The problems inherent in this otherwise magnificent source are many. The materials do not circulate, so those unable to make the five-minute walk from Exit 5 of Ebisu Station by Tokyo Metro Hibiya Subway Line to the NIDS at 2-2-1 Nakameguro, Meguro-ku, Tokyo cannot access the records. And, unfortunately for the non-Japanese speaker many, perhaps most, of these records have still not been translated.
So for the casual researcher the Japanese sources are incomprehensible and the information that has migrated into English language sources is not always completely reliable.
Perhaps the biggest single open question is, as noted above, the condition and number of the land-based naval aviation units engaged in the battle. The commonly cited list of airbases and aircraft and the source for the order of battle listed above is from S.E. Morison's monumental History of United States Naval Operations in World War 2 (Volume 8: New Guinea and the Marianas, March 1944 – August 1944).
Morison's footnote on page 219 of that volume reads "Capt. Ohmae's list furnished 3 November 1951, compiled 'from every available document and interrogation of the officers concerned'"
This gentleman was CAPT Toshikazu Ohmae who was extensively questioned after the war (HyperWar has several of his interrogations here). CAPT Ohmae is described in his interrogation as Chief of Operations for the IJN's Third Fleet in June of 1944 and as VADM Ozawa's G-3 would, or should, have known the dispositions of the 1st Air Fleet, so we may assume that his information was not a complete fabrication, but, still...we're dealing with a recollection of a relatively minor statistic more than a year after the event. No matter how good a staff officer Ohmae may have been it's hard to believe he was that good.
So far as I know there has never been a Japanese-language account of the engagement translated into English, either first-hand or as a work of secondary-source history.
Other than Morison - whose history is more for the general reader than the true military historian - the other significant secondary English-language source is William Y'blood's 1981 Red Sun Setting, described as a very good source as well as a very readable account.
Internet resources appear to be taken largely from either Y'blood or Morison. The Wiki entry appears fairly well researched and written, though it appears to rely heavily on two other published sources: E.B Potters' 1990 Admiral Arliegh Burke and H.P. Wilmott's 1984 June, 1944.
The salty blogger-samas at Nihon Kaigun - "Combined Fleet" - have a relatively brief account but one that is profusely illustrated and well worth the visit.
The World War II Database has a page covering the Marianas campaign but the actual section on the naval engagement we're discussing is fairly sparse, the bulk of the information being from the ground actions on Saipan, Tinian, and Guam.
The NavWeaps site has a relatively complete order of battle, though with the same problem with the IJN's land-based air assets I have.
The U.S. Army's official history of the Marianas Campaign is available in PDF form; obviously the focus is on the island defenses, but there's a useful discussion of Japanese preparations for the defense of the Marianas in Chapter IV and a brief summary of the naval engagement as well.
The Campaign: To discuss the place of the Battle of the Philippine Sea in the overall course of the Pacific War we have to back up a bit, to late 1943 and early 1944.
Actually, we could go as far back as early 1943, as we did back in December of 2013 when we talked about Bataan or even earlier, when we talked about the strange little action on the Clatsop Plain near Astoria, Oregon in 2012.
In both we discussed the original objectives and factors that led, or drove, Imperial Japan to war with the United States. But once the war was on, the Empire really had only one strategic plan; to defend as fiercely as possible and hope that the Yankees would get sick of slaughter.
Well, that wasn't the entirety of the plan, but that was the gist. The idea was to push the Imperial perimeter as far out as possible and then make the Allies pay in blood for every kilometer, sea mile, fortification and island they took. It wasn't pretty, but given Japan's economic and logistical limitations it was really the best the Imperial General Headquarters (大本営 or Daihon'ei) could come up with.
The Imperial Navy, though...they had another idea, an old, bad (thought they didn't recognize it as bad) idea that had been kicking around the IJN for forty-odd years.
This was the so-called "Decisive Battle Doctrine" (艦隊決戦, or Kantai Kessen).
The idea was that the naval part of the Pacific War would be decided - in Japan's favor, of course - by one great decisive battle. The IJN had been designed around this monster gunbattle because of a book and a battle.
The book was Mahan's The Influence of Seapower Upon History and the Japanese were just one of the many groups of squids who got all misty-eyed and semi-erect reading Mahan.
His was a seductive tale of naval power, a sort of Fifty Shades of Battleship Gray naval strategy porn for the wannabe admiral, a stirring ode to battleships and their command of the sea that would lead to total victory.
This sort of military arm-waving wasn't unusual for the late 19th and early- to mid-20th Century, by the way. Some joker named Douhet scribbled a similar paean to wing-wiping called The Command of the Air, and a Russian named Seversky cranked out something similar called Victory Through Air Power that was made into a Walt Friggin' Disney cartoon, fercryinoutloud. Compared to the zoomies the sailors were so restrained as to be positively Stoic...
The battle was the one-sided 1905 slaughter of the Imperial Russian Navy at the Tsushima Strait that appeared to have written the epilogue to Mahan in blood and steel.
The problem with this is that the lesson was wrong. Completely, utterly wrong. Tsushima was not the Mahanian decisive victory of one better-prepared, better-commanded battlefleet over another but a back-alley beatdown of a ramshackle shitshow of a floating goat rodeo by a Japanese fleet that was at least capable of pointing its cannon in the right direction.
Most "decisive battles" at sea - Trafalgar in 1805, Manila Bay and Santiago in 1898, Coronel and the Falkland Islands in 1914 - all had one thing in common; one side was completely, utterly fucking hopeless. Hopeless physically, numerically, technically, tactically, morally...or some combination of all of them. The winning side would practically have to have turned their cannon on themselves to have lost.
So the IJN had based their overall strategy on a couple of total goofs, and not surprisingly, that didn't go well.
Of course, the IJN had other issues. COMSEC, for one; most of us know about the breaking of the Imperial diplomatic PURPLE cypher but the Imperial Navy's codes, particularly the primary command and control cypher the Allies termed JN-25, were being read as early as 1942 and the Japanese both refused to believe that or significantly change their codes.
Logistics, always Japan's weak point, was particularly difficult for a Navy dependent on fuel oil. The Indonesian oilfields produced a relatively light "sweet" crude that could be used for bunker fuel at a very rough level of refining...but impurities in the fuel were hard on the boilers.
The Navy also used a tremendous amount of fuel (as always, the guys as Nihon Kaigun are great on this, providing a good discussion of the fuel problem as it affected the Solomons Campaign here...) and given the small number of tanker marus and the aggressive US submarine war against them the Mobile Fleet was largely tied to its bases and those bases both dispersed widely and perforce pushed southwest - closer to the fuel source but further from the outer defenses.
And those defenses had to be reconsidered. The U.S. Army's official history discusses the revisions in Japanese strategic planning that had been forced by the losses of 1942 and 1943;
"The defeat at Midway in June 1942 followed by the loss of Guadalcanal and Papua early in 1943 had been serious but not fatal blows. More serious had been the loss of ships and pilots, and these, it was hoped, would ultimately be replaced. But MacArthur's and Halsey's victories in the Solomons and New Guinea during the summer of 1943 cast a more serious light on the situation. Obviously the Allies were making a determined assault on the Solomons, eastern New Guinea, and the Bismarck Archipelago, which the Japanese called the Southeast Area. Failure to hold the outposts in New Guinea and the Solomons, they recognized, could have disastrous consequences and might well be the prelude to an Allied advance toward Truk and the Philippines." (Chapter XXVII)
The Imperial defenses of the Southeast Area in 1943 and early 1944 looked like this:
The Daihon'ei planned that the 8th Area Army and the Southeast Area Fleet would slow MacArthur's SOWESPAC offensive towards the Philippines by defending north-central New Guinea and the Bismarcks. In the South and Central Pacific the concentration of forces around Truk in the Carolines and around Rabaul and Bougainville in the northern Solomons aided by the Mobile Fleet would slow Nimitz's advance. This would attrit the Yankees and - at least the IJN hoped - would set up the Kantai Kessen somewhere in the central Pacific.
Supposedly the Japanese war councils considered the Marianas too isolated and too far from any large-enough landmass to be militarily vulnerable. They also didn't anticipate the speed with which the US had learned to plan, stage, and launch amphibious attacks, so CENPAC's attacks on Tarawa and Makin in the Gilbert Island chain in late 1943 and Eniwetok in early 1944 unhinged the planned defensive schemes.
Following on the loss of the Marshall and Gilbert line the Fast Carrier Task Force raids hammered Truk and the eastern Carolines as well as the 1st Air Fleet bases in the Marianas and pounded them flat;
"During the operations against Eniwetok, United States carrier task groups struck Truk on 16 and 17 February, Jaluit on the 20th, and the Marianas on the 22d. At Truk the sustained two-day attack by carrier aircraft destroyed 26 merchant vessels, 6 combatant ships, and 270 aircraft, damaged 6 more naval vessels, and inflicted severe damage on fuel and provision storage. It had been planned to strike Ponape and Jaluit next but in view of the success of the Truk operation a carrier strike on the Marianas was substituted. Although detected by reconnaissance aircraft 420 miles east of Saipan, the task force fought its way through a night-long series of attacks (and hit the Marianas bases) the next morning. One hundred twenty aircraft were destroyed. The destruction of the advanced echelon of the First Air Fleet was a severe blow to the air organization upon which Japan was depending heavily for the defense of the Marianas and Western Carolines."
In theory the Japanese should have been able to use "interior lines" to shift forces from the southwest to the central Pacific to counter MacArthur's and Nimitz's moves; in practice both the Allied organizations got "inside the Japanese OODA loop" to put it in modern terms.
Part of this success included outthinking the Daihon'ei on the vulnerability of the Marianas.
The Japanese had counted on bleeding CENPAC through the Carolines, assuming as we've noted that the logistical difficulties precluded a jump to the northwest into the Marianas. And given the methodical way the U.S. had worked up the Solomons and New Guinea that wasn't exactly a stupid assumption.
But the Daihon'ei didn't recognize what a huge strategic advantage the Fast Carrier Force was. The success of the Gilberts/Marshalls operation and the late winter raids were so shocking that even the American commanders missed the implications for half a year; now the U.S. didn't need island bases to rule the skies and, ruling the skies, rule land and sea.
And that, in turn, meant that the U.S. didn't have to grind slowly island-by-island through the Japanese defenses. With USN airpower crushing Japanese air and surface ship movements the island garrisons were reduced to the force projection metric of 1890 - the maximum effective range of their shore batteries. The "island fortresses" were so many military prisons for their garrisons. They couldn't run, they couldn't reach out to fight, all they could do was sit and slowly starve.
So after battering the hell out of Truk, for example, the USN didn't need the Carolines or the Palaus; they could go right through the outer defenses and punch a hole in the inner ring of the Marianas.
This was a knife at the throat of the Home Islands. Aircraft and USN warships sailing from the Marianas could control the air and sea right up to the southeastern coast of Honshu. Worse, the new B-29 bomber could range almost all of Japan from Marianas bases and without the logistic and tactical problems inherent in flying from China bases.
At this point the Imperial Naval General Staff had to make some kind of countermove, and VADM Ozawa's "Operation A-Go" was it.
The idea behind A-Go was your basic Kantai Kessen; the Mobile Fleet would sortie from its ports in the the Philippines and hit the USN as it supported the Marianas landings. The Wiki entry notes that the critical part of the plan was that the Mobile Fleet wouldn't have just carrier airpower but the "unsinkable carriers" of their land bases along with some material and tactical edges:
"In addition, the Japanese aircraft had superior range, which could allow them to engage the American carriers beyond the range of American aircraft. Furthermore, with island bases in the area, the Japanese hoped to launch at distance, have their aircraft attack the U.S. fleet and then land on island airfields. They then could shuttle back and attack again on the return flight. Thus the U.S. fleet would be in the position of receiving punishment without being able to deliver it. Lastly, the area was dominated by the easterly trade winds. Naval aircraft of the era needed a head wind blowing across the flight deck to enable the aircraft to launch. The easterly trade winds that dominated the Central Pacific seas meant that aircraft carriers would necessarily have to be steaming eastward to launch and recover aircraft. This meant that a fleet located to the west of the Marianas would be in position to initiate and break off the battle, placing the initiative in the hands of the Japanese."
But this meant that the success of the plan largely depended on;
1. Fending off the USN airpower from the airbases; unable to run and hide they had to be defended and their runways and aircraft ready to attack,
2. Finding the US carriers first, and
3. Seeing the attacks through; not just striking but sinking American carriers to clear the way to attack the amphibious forces.
The opportunity came sooner than expected; on 12 JUN 44 USN aircraft appeared over the main Marianas bastions of Tinian, Saipan, and Guam and began striking the airbases and what fortifications, weapons systems, and troops they could catch.
Over the next three days the air and naval bombardment pounded Saipan and on 15 JUN the first Marine infantry from the 2nd and 4th divisions crossed the strandline. The U.S. Army's 27th Division landed the following day.
The warning order to the Mobile Fleet to execute Operation A-Go had been issued in early May. Now the execute order went out on 13 JUN. The main body of the Mobile Fleet sortied from Tawi Tawi that day heading north through the Philippine archipelago, while several more heavy cruisers and destroyers were pulled from the actions around Biak and headed northeast around the east side of the islands.
These two main portions of the fleet met east of Leyte on 16 JUN and refueled over the night and into the following day in preparation for what the commanders and their crews hoped, and many, probably believed, would be the victorious decisive battle.
The Engagement: You probably know what happens next; I mean, this thing is called the Great Marianas Turkey Shoot, right?
So what I want to do from here on is to use the events of the next three days to point out why the IJN - for all that it seemed to be more grounded in reality than the Imperial Army - had by 1944 put itself in a position where it could only lose and should have known that. The rational option at that point should have been surrender. A hell of a lot of people on both sides had yet to die in June of 1944, and an Imperial General Staff that recognized how utterly fucked they were might have helped a lot of them, well...not.
But they didn't, and one of the reasons is that the leaders of the IJN - hell, the leaders of Japan - were as blind to their hopelessness as they were to their technical and tactical and logistical failings.
The story of the battle is really pretty simple, and goes like this:
17 JUN 1944 - The IJN attack forces - the main body of the Mobile Fleet from Tawi Tawi and the southern force pulled from the fighting around Biak rendezvous in the western Philippine Sea off Samar. USN Task Force 58 is still close to the fighting on Saipan, although two task groups have been diverted northwest of the island to intercept air attacks from the Volcano and Home islands.
18 JUN 1944 - IJN forces continue north and east, with search aircraft ranging out front to locate the American carriers. At this point the USN deployment looks like this: TF58.7 (the fast battleship escort unit) was spread out in front - west- of the carriers as an antiaircraft screen. TF58.4 was close and north, since it was the smallest and weakest of the carrier units. East of the the three main carrier groups were in a rough line, with TF58.1 north, 58.2 in the center, and 58.3 to the south.
Around midnight on the 18/19 JUN the USN intercepted an IJN transmission it located about 350 miles west-southwest of the TF58 location. This was two problems; one, that if the two forces continued on convergent courses they chanced a night surface engagement (that the IJN had long been great enthusiasts of) and, two, that the IJN had a long tradition of using decoy forces, and especially sending out single vessels to transmit to spoof radio direction-finding into fooling enemies into mislocating their forces.
Mitscher wanted to move west, risking the night fight, so as to be in position to strike the Japanese carriers at dawn. Spruance, concerned about uncovering the amphibious force, refused permission, and held TF58 eastward during the night.
19 JUN 1944 - Both sides searched for each other. The IJN had the weather gauge - meaning that they didn't have to reverse course to get the wind over the carriers' bows to launch aircraft - and the longer-range aircraft, so an A6M fighter out of Guam spotted the USN first at about 0550hrs and the Japanese launched two strikes from both the Mobile Fleet's carriers and with what land-based aircraft they could.
IJN Raid 1: The first raid was a land-based strike and was spotted on radar about 1000 hours. Fighters of the US carriers were vectored to intercept, and some USN aircraft were sent to attack the airstrips on Guam.
The interception and retaliatory strikes were crucial, and we'll talk about that in depth in just a bit.
IJN Raid 2: Also at about 1000hrs more Japanese aircraft showed up on US radar to the west - this was the first IJN carrier strike. US aircraft over Guam were recalled and, along with the fighters orbiting over the US carriers - the "Combat Air Patrol" or CAP, intercepted this raid at about 70 miles out at 1030hrs.
Of the 68 aircraft in the IJN strike force 41 were shot down before sighting an American warship and the attack formation was badly scattered. Small groups and individual aircraft did manage to reach the advanced US gunline group and attacked TF58.7. A bomb damaged USS South Dakota and killed or injured 50 of her crew, the only significant damage or losses suffered by a US ship that day.
Most of the attackers were shot down. The US antiaircraft batteries had recently begun using a new fuze, the variable time or "VT", that used radar emissions to burst when near a target. Combined with radar fire control and the CIC (which we'll discuss in a bit) the Japanese aircraft were pretty roughly handled.
IJN Raid 3a: At about 1100hrs US radar picked up the largest strike of the day thus far, about 100 carrier aircraft. These were intercepted 60 miles west of TF58's positions and at least 70 were destroyed over the horizon from the US fleet. This time small groups of survivors got through to the US carrier groups.
The Wiki entry notes that:
"Six attacked Rear Admiral Montgomery’s group (TF58.2), nearly hitting two of the carriers and causing casualties on each. Four of the six were shot down. A small group of torpedo aircraft attacked Enterprise, one torpedo exploding in the wake of the ship. Three other torpedo-aircraft attacked the light carrier Princeton but were shot down. In all, 97 of the 107 attacking aircraft were destroyed."
IJN Raid 3b: Concurrent with Raid 3a - 47 aircraft spotted inbound from the north, intercepted 50 miles out and broken up; seven A/C shot down but the majority don't press through and return to the IJN carriers.
IJN Raid 4: - carrier strike launched between 1100 and 1130hrs but given bad target location. The flight leaders searched in two loose gaggles for some time before abandoning the mission and heading for Guam and Rota for fuel. En route one of the groups encounters TF58.2 and attacks; half the Zero fighter escorts are shot down by the CAP but a group of 9 D4Y "Jill" divebombers attack USS Wasp and USS Bunker Hill; no hits and 8 of the 9 are shot down.
The larger group is intercepted by USN F6F fighters over Orote Field on Guam; of the 49 IJN aircraft all are either shot down or damaged so badly on landing that they are unflyable.
The aircraft engagements of the first day are entirely defensive for the USN (aside from the strikes on the land bases on Guam) but are also entirely one-sided; about 350 IJN aircraft are destroyed and the majority of their pilots and crews killed. The USN loses roughly 30 aircraft but probably less than half of the aircrews. No US warships are more than slightly damaged.
What Happened and why? IJN aircraft versus USN aircraft and surface forces
Contrast the events of June 1944 with June 1942, the Battle of Midway. In the engagement two years earlier the two opposing air groups had pretty much traded blow for blow. The USN TBD "Devastator" torpedo bombers were annihilated but the SBD "Dauntless" dive-bombers hammered the Kito Budai, sinking four fleet carriers.
In return IJN D3A "Val" dive bombers and B5N "Kate" torpedo bombers put three bombs and two torpedoes into USS Yorktown, crippling her. Both air groups were pretty badly torn up, although the loss of all her flight decks meant that the IJN effectively lost all her carrier aircraft, as well. The radio intercepts had enabled the USN to achieve strategic surprise, VADM Nagumo's mistake to strike Midway twice helped sink his own carriers...but the USN still came away knowing they'd been in a scrap.
By 1944 the Teikoku Kaigun Kōkū-tai was flat-out butchered, the USN - both on the sea and in the sky - barely nicked.
What the hell had happened?
First, technically the Japanese carrier warplane design and production teams had fallen behind.
Let's look just at the fighters. In 1942 the A6M Zero was a decent carrier fighter; long-ranged, maneuverable, and reliable if lightly armored.
Its opponent, the F4F Wildcat, was sturdy but slower, relatively lightly armed, and with a fairly short range.
By 1944 the IJN fighter pilots were still flying the Zero but their American opponents now had the F6F Hellcat.
Heavier, better armed and armored, faster, and longer-ranged the F6F was a significantly better aircraft than the F4F. It was still less agile than the Zero but much more robust; the A6M paid for its agility by lacking armor and self-sealing fuel tanks, making it both flammable and fragile. And the USN had learned not to try and dogfight with the Zero, at least the Zero with a good pilot. US tactics negated most of the low-speed turning advantage that the Zero still maintained when flown by an experienced pilot.<br