To most Wargamers, these names are familiar: Akagi, Kaga, Zuikaku, Shokaku, Hiryu, Soryu. These formed the backbone of the aircraft carrier force that Japan started WWII with. If you are a grognard, then the names of the fleet carriers Hiyo, Junyo, Taiho, and Shinano are also well known. And if you grew up with Samuel Eliot Morison’s “History of United States Naval Operations in World War II”* you would know this force was supplemented with light and escort carriers Zuiho, Shoho, Hosho, Ryujo, Taiyo, Unyo, Chuyo, Ryuho, Chiyodo, Kaiyo, Shinyo, Chitose, Unryu, and Amagi. This was the complete list of commissioned Japanese carriers, and it was good.
Then many years ago, I read an article supporting the FGA’s game, “Eagle and the Sun” where the author claimed there were many more operational Japanese carriers than these. They were built and owned by the Japanese Army to support coastal and amphibious operations. I have 4 of the 5 magazines that FGA put out in the eighties, but have lost the one that had this article. My recent interest in the Peoples Liberation Army Navy acquisition of carriers made me think of those long lost carriers.
How is it that these assets come to be ignored by history? And more importantly, those missing and important elements that have been left out of all those wonderful games covering the war in the Pacific? Admittedly, these were not fleet carriers, but how many times have you played a Pacific game, where all the heavy carriers were out, and you were down to the lights? Having another three lights would make a big difference.
The Japanese Army and Navy almost never, if ever, cooperated together on any level. Basically, the Army was focused on the mainland, and the Navy, the Pacific. In the beginning of the war, Army divisions were used only with the larger land masses, while all the little islands were captured and maintained with Special Naval Landing Infantry. Historians, looking for Navy capital ships, wouldn’t think to check Army records. Army historians would note some “specialized landing craft” and not list them as carriers. People being people, only saw what they were looking for.
Not that the existence of these carriers went totally unnoticed, but most book writers do not go back original sources, but to sources in languages they can read. Almost every naval history writer of WWII either directly, or indirectly, is referring to Samuel Eliot Morison’s “History of United States Naval Operations in World War II.” This is known as to as “History repeats itself, historians repeat each other.” I may have lost that intriguing article, but now I have the World Wide Web.
The Imperial Japanese Army, like the United States Army, spent considerable intellectual capital working on the problem of landing, supporting and supplying a modern force upon hostile shores. After all, the onus of victory was on the Army. The Imperial Japanese Navy’s role was insuring the landing ships arrived, but the last 12 miles to the beach was the IJA’s problem. To that end, the IJA commissioned the construction of an LST, the Shinshu-Maru, which strongly resembles a modern US LST, which launched troop landing craft from gates on the ship. For scouting and bombing support, the ship was equipped with two aircraft catapults. There was no landing deck and the catapults were dropped before commissioning of the Shinshu, but the idea had taken hold with Army planners.
The army began to acquire and refit ships with aircraft capacity. During the early war, the Army had already converted the Kamakura-Maru, previously a 17,000 ton ocean liner, into a respectable 38 plane aircraft carrier. They also converted the 12,000 ton liners Akitsu-Maru and Nigitsu-Maru into 20 plane aircraft carriers. Later in the war, the Army commissioned the Yamashiro-Maru** and the Chigusa-Maru each at 12,000 tons, but could only handle 8 aircraft. And with undeserved optimism, the Army continued to acquire ships, and in early 1945, commissioned the 8,000 ton Kumano-Maru, with 37 aircraft, as well as the Shimane-Maru, and Otakisan-Maru, both with 12 aircraft.
The fate of these vessels was all well documented. Two were sunk by mines, several by submarines. One survived the war and was converted into a tanker. The original Shinshu-Maru, which was renamed Ryujo-Maru,*** was sunk at least 2 times and refloated and was used as late as 1944.
** Not to be confused with the IJN’s Battleship Yamashiro.
*** Not to be confused with IJN’s Aircraft Carrier Ryujo.