December 28th - The Day of Infamy, Part XVIII

The Marshalls Campaign, Part I

Nimitz had long and carefully planned for the US offensive launched towards Kwajalein in May of 1944. Most of his staff had suggested a more cautious approach, hitting several of the outer islands first. Nimitz overruled them, sure that was what the Japanese would expect and determined to “hit ‘em where they ain’t.”

The Japanese fleet was divided. Yamamoto was at Truk with the battle line, but Ozawa and Kido Butai were enroute from Japan with their newly worked-up air groups and the newly commissioned fleet carrier Taiho, the latter still with workmen aboard fixing the minor problems of her hurried working-up cruise. The IJN had rushed almost every pilot in the training pipeline into service and scraped up a mix of old and new aircraft for them to fly, but Ozawa’s decks were nearly full. However, both Yamamoto and Ozawa were keenly aware that those pilots, planes, and carriers were all Japan would be able to field for a year or more. Between the two forces, Yamamoto had with him every carrier except a few escort carriers, every battleship and battlecruiser, every heavy cruiser, and most of the remaining light cruisers and modern destroyers left in the IJN. Yamamoto was fully aware of this, but far from confident, writing in a private letter: “I have every confidence that Combined Fleet will do all in its power to defeat the enemy, and every hope that I will do all in my power as their commander, but I fear that only Divine intervention can bring us victory.”

Yamamoto sortied from Truk even as the USN launched its first air strikes against Kwajalein. His plan was to draw the US attention with his force, then have Ozawa surprise them from the northwest.

OrBat

IJN
Battle Force (Yamamoto)
CV Ryujo, Ryuho, Hiyo (80 A6M, 30 D3A, 20 B5N)
CVS Mizhuo, Nisshin (32 F1M, 8 E13A)
BB Yamato, Musashi, Shinano, Nagato, Ise, Hyuga, Fuso
BC Kirishima
CA Mogami, Kumano, Myoko, Haguro, Aoba, Kinugasa, Furutaka, Kako
CLTT Oi
CL Agano, Naka, Kiso, Jintsu, Yahagi, Oyodo
11 DD

Carrier Force (Ozawa)
CV Akagi, Kaga, Shokaku, Zuikaku, Taiho (150 A6M, 60 D4Y, 40 D3A, 50 B6N, 50 B5N)
CVL Zuiho, Shoho (30 A6M, 20 B5N)
CVS Chitose, Chiyoda (32 F1M, 8 E13A)
CA Tone, Chikuma
CL Sendai, Yubari, Yura, Noshiro
9 DD

USN

TF 51, Carrier Force (Halsey)
CV Lexington, Yorktown, Saratoga CV9, Ticonderoga CV16, Bataan CV10, Bunker Hill, Concord CV11, Princeton CV18, Belleau Wood CV12 (324 F6F, 216 SBD, 108 SB2C 162 TBF)
CVL Independence, Enterprise CVL23, Hornet CVL24, Wasp CVL25, Ranger CVL26, Intrepid CVL28, Franklin CVL27, Hancock CVL29, Adams CVL30 (216 F6F, 81 TBF)
BB Iowa, New Jersey
CA Salt Lake City, Pensacola, Louisville, Chicago, Indianapolis, New Orleans, Minneapolis, San Francisco, Baltimore, Boston, Houston CA70, Quincy
CLAA Atlanta, San Diego, Oakland, Reno
CL Cleveland, Columbia, Denver, Santa Fe, Birmingham, Mobile, Wichita CL81, Miami
63 DD

TF 55, Battle Force (Spruance)
CVE Sangamon, Suwanee, Chenango, Santee (72 F6F, 48 TBF)
BB South Dakota, Indiana, Massachusetts, Alabama, North Carolina, Washington, New Mexico, Idaho, Colorado, West Virginia, Pennsylvania, Arizona
CL Philadelphia, Nashville, Phoenix, Honolulu, St. Louis, Helena
45 DD

TF 53, Amphibious Force (Turner)
Did not participate in the naval battle

IJN USN
8 CV* 9 CV
2 CVL 9 CVL
4 CVS 4 CVE**
7 BB 14 BB
1 BC
10 CA 12 CA
1 CLTT 4 CLAA
10 CL 14 CL**
20 DD 108 DD**
610 A/C*** 1,227 A/C***

*Using the term somewhat loosely; for example Ryuho could carry a group a third the size of a US fleet carrier, and Hiyo could only make 25kts.
**Not counting units in the Amphibious Force, which did not participate in the naval battle.
***Not counting floatplanes on surface combatants.

Note: I’ve decided to apply author’s prerogative and make USN carrier naming conventions what they should have been in my sole opinion. Yes, I realize this isn’t all that likely, but all alternate-name ships will appear with hull numbers so you can mentally replace them with OTL’s names if you wish.

Yamamoto’s plan was based on hope, but Halsey’s was based on something much more dangerous: false confidence. US intelligence had carefully analyzed Japanese carrier flight operations and losses to date and was highly confident that the Japanese would be unable to supply their seven known carriers with full air groups until at least July. The Japanese were assumed to know the strength of the US carrier force in at least rough terms. Putting these two pieces of information together, the Japanese were expected to hold their remaining fleet in reserve until they could fight under heavy air cover.

Halsey, accordingly, held much of his air strength in reserve and launched extensive searches until his initial attacks revealed only minimal Japanese air power was deployed in the Marshals. Thereafter, he used his air power to pound every target in the chain, hoping to ensure that the Japanese would be unable to bring forces from other islands to contest Kwajalein.

The US force was also, for the first time in a major operation, unsupported by a submarine picket line. While these had varied in strength, at least a few boats had always been present and were expected to provide warning of any large fleet approach. While Halsey was aware the picket line did not exist (due to their value in commerce raiding), it is generally accepted that he was subconsciously expecting there was a backup to his limited air searches that did not in fact exist.

Halsey’s sole preparations for an enemy fleet presence thus consisted of operating his carriers west of Kwajalein and ordering his battle line to keep armor-piercing shells aboard and be ready to move at high speed on an hour’s notice.

On May 19th, an E13A from Chitose located the US fleet and radioed a contact report. It was shot down, but mis-identified as a flying boat by the fighter that made the kill. Such a contact did not imply the presence of enemy ships, and Halsey was not even informed.