Japanese Battleship Musashi - Design and Construction

Design and Construction

Musashi was the second of the Yamato-class battleships designed by the Imperial Japanese Navy in 1937. Musashi and her sister ships were built to be capable of engaging several opposing capital ships simultaneously, as a method of compensating for Japan's inability to industrially match the United States Navy. With each of the Yamato class battleships displacing well over 70,000 long tons (71,000 t), it was hoped that the firepower of Musashi and her sister-ships could offset American industrial power.

In consideration of Musashi's projected mass, the construction slipway was fortified, nearby workshops were expanded, and two floating cranes were constructed from scratch. The keel of Musashi was laid down 29 March 1938 at Mitsubishi's Nagasaki shipyard, and was designated "Battleship No. 2". Throughout construction, strategically placed warehouses and several large hanging blinds made of hemp rope weighing 408 t (450 short tons) prevented outsiders from viewing construction. The deceptions were so successful that the American Consulate—located across the bay from Musashi's construction site—was unaware of her existence during the construction.

Launching the Musashi presented its own special set of issues. The ship's 4 m (13 ft 1 in) thick launch platform, made of nine 44 cm (17 in) Douglas-fir planks bolted together, took two years to assemble (from keel-laying in March 1938) because of the inherent difficulty in drilling perfectly straight bolt holes through four meters of fresh timber. The problem of slowing and stopping the massive hull once inside the narrow Nagasaki Harbor was addressed by attaching 570 t (630 short tons) of heavy chains divided evenly between each side of the hull to create dragging resistance in the water. Finally, the launch, like the ship itself, had to be concealed from prying eyes; the most important means of accomplishing this was a citywide air-raid drill staged on the launch day to keep everyone inside their homes. Musashi was successfully launched on 1 November 1940, coming to a stop only 1 m (3 ft) in excess of the hull's calculated 220 m (720 ft) travel distance across the harbor. The entry of such a large mass into the water caused a 120 cm (3 ft 11 in)-high tsunami, which propagated throughout the harbor and up the local rivers, flooding homes and capsizing small fishing boats. Musashi was fitted out at nearby Sasebo, with Captain (later Vice Admiral) Kaoru Arima assigned as her Chief Equipping Officer.

Towards the end of fitting out, the ship's flagship facilities, including those on the bridge and in the admiral's cabins, were subjected to change orders stemming from Combined Fleet's desire to have the ship equipped as the flagship of the Commander-in-Chief, as the Yamato was too far along for such changes. These alterations, along with improvements in the secondary battery armor, pushed back completion and pre-handover testing of the Musashi by two months, to August 1942.