1/700 Waterline Series - Aircraft Carrier Shoho

[Machine Translation] Since the end of World War I, the world's major powers have been competing to expand and build naval vessels, with the idea that "he who controls the seas controls the world. However, with the end of World War I, the United Kingdom was unable to bear the financial burden, and the United States and Japan found themselves in an untenable position due to their domestic circumstances. The Imperial Japanese Navy insisted on a 70% ratio against the U.S. and U.K., but was unable to obtain this ratio, and had to settle for a meager 60%. This placed great restrictions on battleships and aircraft carriers, and in the end the IJN was only allowed to possess four large aircraft carriers (Akagi, Kaga, Shozaku, and Zuikaku) and two medium-size aircraft carriers (Soryu and Hiryu). Naturally, the Imperial Japanese Navy was dissatisfied with this result. Therefore, the IJN took measures to envision in advance the diversion of large merchant ships, seaplane carriers, submarine carriers, and oilers to other types of ships. The Hihyo and Hayataka were converted from large merchant ships, and the Shoho and Zuiho were converted from other types of ships. Shoho was originally planned as an oiler Kenzaki and launched at Yokosuka Arsenal in June 1935. However, during the outfitting work, she was converted to a submarine carrier and completed as a submarine carrier in January 1939. However, due to the expiration of the London Disarmament Treaty in January 1941, she underwent another conversion in only two years, and was transformed into an aircraft carrier. Since she was originally a submarine carrier, construction progressed smoothly, and in January 1942, after one year of construction, she was reborn as an aircraft carrier with a flat deck. The flat deck was probably adopted to shorten the construction period by utilizing some of Kenzaki's bridge equipment. The name of the ship was changed from Kenzaki to Shoho in December, prior to its completion. Upon completion, the Shoho was immediately assigned to the 4th Air Squadron of the 1st Air Fleet. The Japanese forces launched a second-stage operation to prolong the war after the first-stage operations such as the attack on Hawaii in December 1941, the invasion of Singapore, and the Philippines went well. The first of these operations was Operation MO, the Port Moresby offensive aimed at blocking the U.S. and Australia. For this operation, a task force led by the first five naval vessels, Shozaku and Zuikaku, was deployed, and Shoho accompanied the fleet led by heavy cruisers such as Aoba and Kako of the 6th squadron to attack Port Moresby, in the role of providing umbrella air support. Shoho was accompanying them as an umbrella for air support. On the other hand, the U.S. Navy had deciphered the code and detected the Japanese fleet's plan to attack Port Moresby, and was waiting with a task force based on two aircraft carriers, Lexington and Yorktown. The location was in the Coral Sea, southeast of New Guinea. It was May 7, 1942. For the first time in history, a decisive carrier-to-carrier battle was to take place in this beautiful sea. First, the U.S. Navy took the initiative. The US Navy discovered a heavy cruiser-based attack force on one side of the Japanese fleet, which was divided into two groups, and since it was accompanied by the Shoho, it was judged to be a task force and attacked with all its might. Ninety-three thunderbombers were launched from Lexington and Yorktown, and all were concentrated on the Shoho. As a result, 13 bombs and 7 torpedoes hit the Shoho ( an astonishing number. This is comparable to the later Yamato and Musashi. Although the situation was different, when one thinks of the midway carriers that were disabled by only a few bombs, one can understand how they fought with their lion's share of strength. ), Shoho died in the beautiful emerald green sea after a short life of only three and a half months as an aircraft carrier. Meanwhile, the Japanese Navy launched a strike force around the same time, but only managed to destroy one destroyer, the oiler Neosho, which was misidentified as an aircraft carrier (and later sunk). However, after confirming the location of the enemy fleet through Shoho's noble sacrifice, the Japanese task force launched an all-out attack on May 8, sinking the Lexington and inflicting heavy damage on the Yorktown. However, the Japanese side also suffered damage from attacks by U.S. Navy aircraft, with the Shokaku being destroyed in mid-air. Both the Japanese and U.S. suffered heavy damage to their aircraft and damaged aircraft carriers, so the battle was not a thorough one, but the battle itself should be called a draw in favor of the Japanese. However, because the Shoho was damaged and the Zuikaku also lost an aircraft, four aircraft carriers had to be deployed to attack Midway in June, which was a distant cause of the loss of all four carriers. The loss of the Shoho was the first loss of an aircraft carrier in the Pacific War. (Actual aircraft data) At the beginning of the war, standard water capacity: 11,200 tons Flight deck length: 180m x 30.5m Waterline length: 201.43m Waterline width: 18m Main engine: Ro-type ship's main can 2 axles Speed: 28 knots Cruising range: 18 knots 7,800 nautical miles Armament: 12.7cm twin high-angle guns x Equipped with: Type 96 fighter, Type Zero fighter Type 21, 18 aircraft, 3 auxiliary aircraft, Type 97-3 attack aircraft, 9 aircraft

第１次世界大戦の頃より“海を制する者は世界を制す”とばかり世界の大国は海軍の拡張、建艦競争を競っていました。 しか し、第１次大戦の終結に伴い、まずイギリスが財政負担に耐えきれずに音を上げ、さらにアメリカ、日本も国内事情から無理な状況となり、アメリカが音頭を とってワシントン条約を、さらにロンドン軍縮条約を発効させるにいたります。 日本海軍は対米英７割を主張したものの入れられず、６割に甘んじなければなりませんでした。 このため戦艦、空母に大きな制限が加えられ、結局正規空母とし ては赤城、加賀、翔鶴、瑞鶴の大型空母４艦と蒼龍、飛龍の中型空母２艦の保有が認められたのみでした。 当然日本海軍としてはこの結果に不満でした。 そのため大型商船や水上機母艦、潜水母艦、給油艦などの他艦種よりの転用をあらかじめ想定しておくという方策がとられました。 飛鷹、隼鷹が大型商船からの改造例で、祥鳳、瑞鳳が他艦種からの改造例となります。 さて、祥鳳は当初、給油艦剣埼として計画され昭和10年(1935年)６月に横須賀工廠で進水しました。 しかし、艤装工事途中で潜水母艦への改造に着手、昭和14年(1939年)１月に潜水母艦として竣工しました。 しかし、折からロンドン軍縮条約が失効したため、昭和16年(1941年)１月わずか２年で再び改装工事に入り、航空母艦へとその姿を変容してゆます。 元々潜水母艦であったため工事は順調に進捗し、工期１年、昭和17年(1942年)１月に平型甲板を持つ航空母艦として生まれ変わります。 平型甲板としたのは剣埼の艦橋装備をある程度流用して工事期間の短縮を図ったものと思われます。 なお、完成に先立つ12月には艦名が剣埼から祥鳳へと変更になっています。 祥鳳は完成すると即日第１航空艦隊第４航空戦隊へと編入されました。 さて、日本軍は昭和16年(1941年)12月のハワイ攻撃、さらにシンガポール攻略、フィリピン攻略などの第１段作戦が順調に推移したため、長期持久を図るべく第２段作戦に着手します。 その手始めが米、豪遮断を目的としたポートモレスビー攻略作戦、MO作戦です。 この作戦には１航艦５航戦の翔鶴、瑞鶴を基幹とした機動部隊をあて、さらにポートモレスビーを攻略するための第６戦隊の青葉、加古など重巡洋艦を基幹とする艦隊に祥鳳が航空援護の傘を掛ける役割で随伴していました。 一方米海軍は暗号を解読して日本艦隊のポートモレスビー攻略の企図を察知、レキシントン、ヨークタウンの２空母を基幹とする機動部隊で待ちかまえていたのです。 所はニューギニア東南方海上、珊瑚海。 時は昭和17年(1942年)５月７日のことです。 この美しい海に歴史上始めて空母隊空母の決戦がおこなわれることになります。 まず、先手をとったのはアメリカ海軍。 ２つに分かれている日本艦隊の一方の重巡基幹の攻略部隊を発見、祥鳳が随伴していたためこれを機動部隊と判断して全力攻撃をかけます。 レキシントン、ヨークタウンから93機の雷爆撃機が発艦、すべてを祥鳳に集中したのです。 このため爆弾13発、魚雷７発が命中(驚くべき数です。 これは後の大和、武蔵と遜色ありません。 状況が違うとは言え数発の爆弾だけで戦闘不能になったミッドウエーの空母を思うといかに獅子奮迅の戦いをしたかが判ります。 )、祥鳳は空母としてはわずか３ヶ月半の短い生涯をエメラルドグリーンの美しい海に没してしまいました。 一方日本海軍は同じ頃攻撃隊を発進させるも空母と誤認した給油艦ネオショーを大破させ(後、沈没)駆逐艦１隻を撃沈したのみでした。 しかし、祥鳳の尊い犠牲により敵艦隊の位置を確認した日本機動部隊は、翌５月８日に全力攻撃を敢行、レキシントンを撃沈し、ヨークタウンにも大損害を与えたのです。 しかし、日本側も米海軍機の攻撃を受け翔鶴が中破する損害を被っています。 この戦いは日米双方とも搭載航空機に大きな損害をだし、また空母も傷ついたため徹底して戦果を拡大するには至りませんでしたが、戦い自体は日本優勢の引き分けと言うべきでしょう。 しかし、翔鶴が傷つき、瑞鶴も航空機を失ったため、６月のミッドウエー攻撃には４艦の空母で出陣しなければならず、それが遠因で、4空母すべてを失うはめになったことを思うと祥鳳の犠牲が充分活かされず悔やまれます。 なお、この祥鳳の損失は太平洋戦争における空母の損失第１号でした。 【実機データ】開戦時 基準排水量：11,200トン 飛行甲板長：180m×30.5m 水線長：201.43m 水線幅：18m 主 機：ロ式艦本式缶 ２軸 速 力：28ノット 航続力：18ノット7,800海里 兵 装：12.7cm連装高角砲×４門 25mm３連装機銃×４ 搭載機：96式艦上戦闘機及び零式艦上戦闘機21型 18機、補用３機 九七式三号艦上攻撃機 ９機