Japan developed Shinshu Maru in the 1930s and kept the ship's role quiet. It was probably the first landing ship dock to be built, and it carried smaller landing craft in a form recognizable in modern amphibious ships. Allied intelligence concentrated on Japanese carriers, submarines, and cruisers, with far less attention paid to amphibious auxiliaries. Britain and the United States therefore knew too little about the ship to copy it, so their wartime dock-ship projects grew from parallel prewar studies and operational needs. Postwar amphibious design combined lessons from the Japanese and Allied lines of development.
Chapter · 2:32-6:09
Shinshu Maru and the landing ship dock lineage
Why Shinshu Maru was probably the first landing ship dock, yet Allied wartime dock ships developed without directly imitating the Japanese design.