Spinning the shipbuilding department out as Tama Shipbuilding (1937)

What the trading house’s ledger could not measure

Calling this a spin-off to fit the wartime system misses the core of the judgement. A proposal to abolish the shipbuilding department already existed inside Mitsui & Co. in the 1920s, and against a record in which operating profit was booked only in the 1921 and 1924 financial years between the founding and the early Showa period, there was little reason to keep carrying it as one division of a trading house. That Mitsui & Co. nevertheless set it up as an independent company rather than closing it can be attributed to assets that barely show in a trading house’s books: the superiority of the diesel ship proven with the Akagisan Maru, and the manufacturing and sales licence obtained from Burmeister & Wain.

It would, however, be too easy on the external conditions to read independence as the source of stable results. The improvement around 1937 coincided with a surge in shipping and with government subsidy. Three years after separation the company was designated a navy-controlled works, and it went on to mass-produce even midget submarines; the period in which it could choose its own business on its own economics was not long. Where separation told was rather after the war. Closing five plants to concentrate on Tamano alone, and recovering through planned shipbuilding, was possible because it held its plant and its people as an independent company, not as a division of a trading house.