Japanese Plans and Operations

Written by Kevin Zucker (1971)

Tactical and Strategic Doctrine and Training
The Japanese plan for the war in the Pacific called for the assumption of the strategic defensive once certain vital areas were captured. The Allies were to be bogged down in a war of attrition against strong defences. Guadalcanal was at no time within the defensive perimeter established for this purpose. Japan actually discarded its plan to go to the defensive, and played the role it had intended for the U.S.

It is doubtful that the Allies' position in the Pacific would have been improved if Japan had given up Guadalcanal without a struggle. In effect, the U.S. invasion of Guadalcanal amounted to a dare — the Marines entrenched themselves on the island and waited for the Japanese to attempt to evict them from it. Neither U.S. nor Japanese planners realized until after the battle that the value of the island of Guadalcanal lay not in its size or location but in the fact that both sides were willing to commit large forces to gain undisputed control of it.

In formulating their plans, the opposing sides differed in content and procedure. The Japanese tended to formulate detailed plans, and stick closely to them. Their plans often called for close cooperation between large numbers of small groups of ships, relying upon coordination of movement. This lead to tactical inflexibility, which of course did not show up if the plan was good.

Similarly, if the size of the force was manageable, the Japanese commanders tended to do remarkable well.

Tactical training stressed small unit maneuvers and night combat, particularly so for the destroyers. This emphasis, along with the superiority of Japanese torpedo weapons systems, gave the Japanese a most potent, albeit specialized, force. Less than optimum results were obtained from forces which had not operated previously together, and in many cases the squadrons and divisions at Guadalcanal were reconstituted units with new ships taking the place of losses and transfers.

Fleet Operations and Organization
As the Order of Battle shows, the Eighth Fleet had 5 heavy and 3 light cruisers, 7 destroyers, 7 troop transports, 3 seaplane tenders, and 1 flying boat tender at the time of the U.S. invasion of Guadalcanal. Also under Eighth Fleet were 4 Naval Base Forces, 5 Special Naval Landing Forces, and about 20 torpedo bombers and 20 fighters. Also at Rabaul were 30 medium bombers and 20 fighters of the Eleventh Air Fleet and the 144th Infantry Regiment of the 17th Army.

This small force moved against the U.S. forces as soon as the invasion was discovered. A Naval Landing Force [the 5th Sasebo] was sent to Guadalcanal, the aircraft in the area began attacks against the Allied forces, and a cruiser force under Admiral Mikawa set out to destroy Allied shipping. The SNLF, meanwhile, was turned back by a U.S. submarine, and the 144th Infantry was sent to Papua.

The Japanese cruiser force handed a crushing defeat to the Allied covering force, sinking four and damaging one of the six cruisers in the area. They did not, however, attempt to attack the U.S. transports.

Because the U.S. controlled the airfield at Guadalcanal, the Japanese were at a distinct disadvantage in daylight naval operations. Their transports, being slow, were easy targets for U.S. aircraft. In order to overcome this problem, the Japanese began using destroyers to transport troops and supplies to the island.

Their missions were timed so that the ships would come into range of U.S. aircraft just at dusk, unload their cargo and perhaps shell the Marines' positions under cover of darkness, and leave aircraft range at dawn.

As soon as news of the invasion reached Japan, the major portion of the Combined Fleet made preparations to move to the area, with Truk atoll designated as its base. Once this move had been successfully made, the Japanese began to plan for a decisive battle against the U.S. carriers. Twice the Combined Fleet sortied from Truk with the aim of isolating the U.S. garrison on Guadalcanal, and both times they failed to do so.

Other sorties were carried out by Combined Fleet with intent to bombard the Guadalcanal airfield. Both cruisers and battleships participated in these bombardments. Although they were, on occasion, quite effective, they could not be sustained.

The Third Fleet was originally intended to be the carrier force, and the Second Fleet was to be the battle force, but, as the campaign wore on, these distinctions were forgotten. The Eighth Fleet, however, always bore the burden of supply force, and was specialized to this role. Based at Rabaul, with anchorages at Kavieng and in the Shortland Islands, the Eighth Fleet was almost constantly in action. Considering that supplies for perhaps 50,000 men had to be delivered at night by destroyer to an unfamiliar island with an enemy airbase on it, it is remarkable that, from August 7 to November 27 Eighth Fleet lost only seven destroyers.

The submarines of the Sixth Fleet did well in this campaign. They damaged one carrier and one battleship, and sank another carrier, all in a period of about two weeks. This, however, was about the extent of their accomplishments, the problem being that they concentrated on capital ships instead of transports. The endurance of the submarines was as follows I-15 Class — 90 days; RO-33 Class — 30 days; I-121 Class — 20 days; I-168 Class — 45 days; I-1 Class — 60 days. The vessels of Subron 6 [I-121 Class] were used as seaplane tenders.

The Order of Battle stops at November 27 because this was the week that Army aircraft began operating from Rabaul, and because the Japanese planners more or less gave up on Guadalcanal after this time — from this time on they began to think of the fighting on the island as a delaying action, and were reluctant to send reinforcements. In other words, the outcome had been decided, only the final figures were still in doubt.

Carrier Aircraft Complements
Although Japanese Naval Aviation establishment figures tended to run in multiples of seven and nine, for the purposes of approximation we have rounded off those figures, both here and on page 26, to the nearest ten.

Shokaku class ships, at this time, carried roughly 30 Type 00, 20 Type 99, and 10 Type 97 aircraft Ryujo and Hiyo class carried about 20, 10, and 10 while Zuiho would have 10 Type 00 and 10 Type 97.

These figures represent the general dearth of naval aircraft brought about by Japan's defeat at Midway only 62 days before the battle of Guadalcanal began. Japan's carriers at Guadalcanal operated, during this time, 15% to 30% below total aircraft storage capacity.


Japanese Aircraft Order of Battle
Eighth Fleet maintained at Rabaul 20 Type 97 'Kate' torpedo bombers and 20 Type 00 'Zeke' fighters. Reinforcement aircraft were supplied by Second, Third, and Eleventh Fleets. Eighth Fleet's air component was the 2nd Air Corps.

Eleventh Air Fleet also received 20 Type 99 'Val' light bombers on 9 October.

The Eleventh Air Fleet was composed of the 25th Air Flotilla, 14th and Tainan Air Corps and the 26th Air Flotilla [6th, Misawa, and Kisarazu Air Corps], the latter arriving during August. In addition, the Takao and the 3rd Air Corps arrived during early September, the Kanoya Air Corps arrived in mid-September, the 31st Air Corps arrived in mid-October, and the 253rd Air Corps arrived in late October.

In early November, the Tainan Air Corps was withdrawn, and HQ, 25th Air Flotilla was replaced by HQ, 21st Air Flotilla.

Special Naval Landing Forces
The SNLF were organized by the navy from naval personel. Several were organized at each of the four Japanese Navy Shipyards (Kure, Maizuru, Sasebo, and Yokosuka). About 10 of these units had been organized by the beginning of the war in December, 1941, and an equal number were organized in 1942. There were no standard establishment figures for the SNLF. As the situation required, more men might be added to one unit, or a unit might be split into two or more independent parts.

Generally speaking, the SNLF consisted of 500 to 1000 men each, with varying numbers of machine guns, mortars, and howitzers. The 3rd and 5th Kure, 5th Sasebo and 5th Yokosuka sent 2404 men to Papua, of which 1086 were casualties. These units also sent less than 500 men to Guadalcanal.

Along with the 11th-16th Naval Construction Units and the 80th — 85th Naval Garrison Units, the SNLF were often part of Naval Base Forces in the Solomons, which had been established at Guadalcanal—Tulagi, Shortland, Rabaul, and Kavieng.

Unit—Names of Ships—Arrival
SECOND FLEET: Vice Admiral Nobutake Kondo
Crudiv 4 Atago, Maya, Takao 21 August
Crudiv 5 Myoko, Haguro, Nachi 21 August
Batdiv 1 Nagato, Mutsu 21 August
Cardiv 11 Chitose, Kamikawa Maru 18 September
Batdiv 11 Hiei, Kirishima 21 August
Destroyer Squadron 4

Desdiv 2 Shiratsuyu Yudachi, Murasame, Harusame, Samidare 21 August
Desdiv 8 Arashio, Asashio, Michishio, Ooshio 21 August
Desdiv 9 Natsugumo, Asagumo, Minegumo, Yamagumo 21 August
—CL Yura 21 August
Desdiv 6 Akatsuki, Ikazuki, Inadzuma, Hibiki 2 October

THIRD FLEET: Vice Admiral Chuichi Nagumo
Cardiv 1 Shokaku, Zuikaku, Zuiho 21 August
Cardiv 2 Hiyo, Junyo 9 October
—Ryujo 21 Auqust
Batdiv 3 Kongo, Haruna 9 October
Crudiv 7 Suzuya, Kumano 21 August
Crudiv 8 Chikuma, Tone 21 August
Destroyer Squadron 10

Desdiv 4 Kagero Arashi, Hagikaze, Nowake, Urakaze 21 August
Desdiv 10 Akigumo, Kazegumo, Makigumo, Yugumo 21 August
Desdiv 17 Kagero Hamakaze, Isokaze, Maikaze, Tanikaze 14 August
—CL Nagara 21 August

SIXTH FLEET: Vice Admiral Teruhisa Komatsu
Subron 4 I-153, I-154, I-155, I-156, I-157, I-158, RO-33, RO-34 7 August
Subron 6 I-121,I-122,I-123 7 August
Subron 1 I-15, I-16, I-17, I-18, I-19,I-20,I-21,I-22, I-24,I-25,I-26 14 August
Subron 3 I-8, I-168, I-169, I-171, I-172, I-174, I-175 18 September
Subron 2 I-1,I-2,I-3,I-4,I-5,I-6,I-7 2 October

EIGHTH FLEET: Vice Admiral Gunichi Mikawa
—CA Chokai: Kavieng
Crudiv 6 Aoba, Furutaka, Kako, Kinugasa Kavieng
Crudiv 18 Tenryu,Tatsuta Rabaul
Destroyer Squadron 6

Desdiv 29 Kamikaze Asanagi, Oite, Yunagi, Kamikaze: Rabaul
Desdiv 30 Mutsuki Mochitzaki, Uzuki, Yuzaki, Mutsuki, Yayoi Rabaul
—CL Yubori Rabaul
Destroyer Squadron 2

Desdiv 15 Hayashio, Kuroshio, Oyashio 21 August
Desdiv 16 Hatsukaze, Amatsukaze, Yukikaze, Tokitsukaze 21 August
Desdiv 18 Shiranuhi, Kagero, Kasumi 4 September
—CL Jintsu 14 August
Destroyer Squadron 3

Desdiv 11 Fubuki, Murakumo, Hatsayuki, Shirayuki 28 August
Desdiv 19 Isonami, Shikinami, Uranami, Ayanami 21 August
Desdiv 20 Amagiri, Shirakumo, Yugiri, Asagiri 28 August
—CL Sendai 4 September
Desdiv 24 Umikaze, Kawakaze, Suzukaze 14 August
Desdiv 27 Shigure, Shiratsuyu, Ariake, Yuguri 16 October
Desdiv 31 Naganami, Makinami, Takanami 9 October
—CL Isuzu 9 October
Transports*—Rabaul: APs Nankai Maru, Myoko Maru, Yamafuku Maru, Yusukawa Maru, Kinai Maru, Kinryu Maru, Meiyo Maru
Rabaul: Flying Boat Tender Akitsushima

Rabaul: Seaplane Tenders Kiyokawa Maru, Soya, Nisshin
14 August: APs Boston Maru, Kagu Maru
14 August: Patrol Boats Nos. 1, 2, 34, 35
21 August: APs Asakayama Maru, Sado Maru
4 September: APs Hirokawa Maru, Lisbon Maru, Teison Maru
25 September: APs Azumasan Maru, Kyushu Maru, Naminoue Maru, Sasako Maru, Brazil Maru
2 October: APs Arizona Maru, Napra Maru, Brisbane Maru, Nako Maru, Canberra Maru, Kinugawa Maru, Shinanogwa Maru, Yamaouki Maru, Yamaura Maru