Leyte Gulf:
The Imperial Army's Carriers

Even though Classic Wargames aren't the usual 119694_avalanche Press products, we do hope to maintain our tradition of including unusual historical units, vehicles or ships in them.

Second World War at Sea: Leyte Gulf definitely follows in this path. Just as Bomb Alley has a German helicopter carrier and helicopter, so does Leyte Gulf boast not one but two sent to sea by the Japanese Army. That's correct — not the Imperial Navy, but the Army.

The Japanese services fought a nasty bureaucratic war throughout the period from the end of World War I until Japan's surrender in 1945. Japanese generals became disenchanted with what they saw as the Navy's inability and unwillingness to do enough to supply Army garrisons on isolated Pacific islands.

Akitsu Maru

They started by purchasing civilian freighters for use as transports, but by the middle of the war they had gone even further. The Army laid down a class of transport submarines to help run supplies to the islands, and to help protect its surface fleet it assigned a pair of amphibious assault carriers (themselves a radical concept) to escort duty.

These two ships, Akitsu Maru and Nigitsu Maru, had been laid down as passenger liners and converted to landing ships by the Army. They had stern doors for launching their 20 landing craft, and short flight decks as well.

Originally these had been intended to fly off aircraft that would then land at airfields captured by the landing forces. But by 1944, when these ships were commissioned, the Japanese Army was no longer doing much capturing. However, the Army had an aircraft available that could make full use of the short flight decks for take-off and for landing, and promised to show good qualities in anti-submarine warfare as well.

The Kayaba Ka-1

The Kayaba Ka-1 autogyro was based on an American design, imported to Japan in 1938. An autogyro is a hybrid of helicopter and airplane; while it has a rotor blade chopping overhead, it also has a propellor. Juan de la Cierva, a Spanish engineer, invented the concept and flew an autogyro over the English Channel in 1923. But the autogyro did not gain widespread acceptance.

The Army liked the craft's short take-off span, and especially it slow maintenance requirements. In 1941 production began, with the machines assigned to artillery units for spotting. These carried two crewmen: a pilot and a spotter.

In its ASW configuration, the spotter gave way to two depth charges. Ka-1 anti-submarine aircraft operated from shore bases as well as the two small carriers. They appear to have had one successful submarine sinking.

Had the Army and Navy been able to cooperate on the program, the Ka-1 could have been made devastatingly effective: the Navy had developed a precursor of what later navies would call "dipping sonar," perfectly suited to autogyro use.

American submarines eventually sank both of the carriers.

Mike Bennighof
October 2004