The structure of the hull was Tanaita (shelf boards) structure using sawn timber as the component of Kawara (the components for the bottom of a ship), instead of the ones hollowed from a tree trunk, L-shaped strong components called Omoki for both sides and several layered Tanaita reinforced by many Funabari (beams fitted horizontally between the planks on the hull of a ship to withstand water pressure).
船体構造は木を刳（く）り貫いて造られる航（かわら：船底部）の部材（刳船部材）を板材に置き換え、両角に重木（おもき）というL型の丈夫な部材を用い、数枚の棚板を重ね継ぎして、多数の船梁（ふなばり）で補強した、棚板造りの構造であった。