Development of management of Tatara iron making at Oku-Izumo in Edo era

Abstract

Iron making by Tatara at Oku-Izumo developed from reopening in 1638 after prohibition of operation to becoming the center of iron production in Japan in the end of Edo era. The history of its management was studied from the stand point of countermeasure to environmental and economic problems, and quality of the product, in order to get the hints for the future iron and steel making. (1) Managers of tatara at Oku-Izumo held concurrently the manager of agriculture, forest and stock farming. As the results of the all-round management, social system of circulation was established, under cooperation with the administration. (2) The change of Tatara operation from 4 to 3 d in the first half of 19th century was trial and error for economical production system, and fixing of 3 d operation was interpreted as the flexible production system. (3) Superiority of Kera produced by Tatara process as the material for production of sword by forging was originated in un-uniformity. This suggests that conception surpassing the optimum of partial process is valid for cost down of quality assurance and the creation added value of the product in modern iron and steel making.