Advances in Iron Manufacturing Technology in the West

The peak for tatara manufacturing was the period from the end of the shogunal and domainal government to the early years of the Meiji Period (1868-1912). At this time the technology of the West flowed into Japan, and Japan's domestic conditions became unstable. The period when tatara manufacturing was at its height was simultaneously one in which the threat of Western iron was growing, and the tatara began its decline.

The middle of the 19th century was also a time in which a revolution in iron manufacturing had also taken place in the West. The blast furnace had been invented along the Rhine River basin in the 14th century, and pig iron was being made to produce guns and bullets. Gradually, the fuel used changed from charcoal to coal, and finally coke. With the invention of the steam engine at the end of the 18th century and the start of the Industrial Revolution, the volume of production from a blast furnace jumped to 6,000 tons per day. The paddle method of the mid-19th century was replaced as a succession of revolutionary technologies appeared, including the Bessemer converter furnace method, in which pig iron is efficiently converted into steel (1856), the Siemens-Martin open-hearth process (1864), and the Thomas process (1870, also called the Basic Process), which made it possible to remove phosphorous. Through these developments, iron making in Western Europe had already moved from a focus on manual labor to an industry capable of mass production.

Crucible steel was used as the high-quality steel needed for knives and swords. Making it called for dissolving the Swedish wrought iron used as the main ingredient in a crucible, together with a carburizing agent. Accordingly, in Western Europe as well as Japan, iron and steel (hagane) were created using different manufacturing processes. This is because steel would be used for “special steel,” for such things as swords and weapons where its quality would be especially valued, while iron was used as a general construction material, for which the emphasis would be on quantity and economic value. “Swedish steel” has been used approvingly as a synonym for quality. Special steel shifted from crucible steel to being manufactured in the newly invented arc furnace (1900), emerging as an industrial product.

Western-Style Iron Making in Japan

At a time of rising international threats, such as the Opium War (1839-1842) in China and the coming of Commodore Matthew Perry's “Black Ships” to Japan in 1853, reverberatory furnaces were built by the more enlightened daimyo with the goal of manufacturing cannon and shells to defend the nation. The domains where this was done included Nabeshima (located near the modern Fukuoka in Kyushu), Satsuma (the southern part of Kyushu), and Mito (Ibaraki, northeast of modern Tokyo). The Tokugawa government also accepted a proposal from Egawa Tarozaemon to build a reverberatory furnace at Izu Harayama on the Izu Peninsula. Pig iron manufactured in tatara was used as the source of iron for these reverberatory furnaces. In 1858, Oshima Takato, a warrior from the Nanbu domain (northern Honshu), built a Western-style blast furnace in Kamaishi (located in today's Iwate Prefecture) in order to supply pig iron for the Mito reverberatory furnace. However, because the manufacturing methods were old—such as c the use of charcoal as fuel and of water-powered bellows—it never attained economic profitability, and eventually was shut down in 1880. Supply shifted to the Kamaishi Mine Tanaka Ironworks operated by Tanaka Chobei, who established the first coke-based ironworks technology in Japan in 1894.

The Reverberatory Furnace at Izu Harayama (photo provided by the Industrial Tourism Bureau, Harayama-cho Town Office)

In 1897, the Imperial Diet approved a bill calling for the construction of a state-operated steel and iron manufacturing plant. The result was the state-owned Yawata Steel Works, built in 1901 using German technology. This marked the start of Japan's true modern steel industry. However, it was 1905 before the plant was operating smoothly, and the plant only became profitable in 1910.

The Decline of Tatara

The arsenals of the Imperial Army and Navy were the pathbreakers for modern Japan's steel manufacturing technology. The manufacture of crucible steel using tama-hagane and hocho iron from Izumo and Iwami (western Shimane Prefecture) began at the Tokyo Naval Arsenal in 1882, while acid open-hearth furnaces to produce armor plating, gun barrels, and other military items were constructed at the Yokosuka Arsenal in 1890, and at the Kure Arsenal in 1892. The Imperial Army began manufacturing tool steel and bullets with crucible steel at the Osaka Arsenal in 1889. Imports of Western steel since the start of the Meiji Period grew to five times (approximately 50,000 tons) the amount of steel and iron produced in Japan, and the volume rapidly increased with the Sino-Japanese (1894-95) and Russo-Japanese (1904-05) Wars.

Tatara production could not keep pace with the rapid rise in demand, while domestic Western-style production was not yet fully developed. The San'in region tatara blacksmiths made every effort to adopt Western technology and streamline, but their operations proceeded slowly. Seeking new markets, they strove to produce steel for the army and navy, and were able to increase their sales through the 1900s. However, the financial slump that followed the Russo-Japanese War, and the opening of the Yawata Iron and Steel Works made it inevitable that the tatara disappear. A few years after the First World War, the fires finally went out at the last remaining tatara in 1925.

The import and production of Western iron in the Meiji Period, and the decline of Japanese iron and steel

(NOTE) Japanese iron, Japanese steel; produced in the Chugoku region Domestically produced Western iron, Domestically produced Western steel; Production at Kamaishi and Yawata using Western-style iron-manufacturing methods

The Revival of the Tatara

In the Showa Period (1926-1989) and the start of the World War II (1931-45), there was demand for military swords and for a brief time tatara, such as the Yasukuni and Murakumo tatara in the Chugoku mountains, experienced a revival, but ceased operations immediately after the war. In 1970, fearing that the tatara iron-manufacturing technology would disappear forever, a tatara restoration experiment was begun under the direction of the Iron and Steel Institute of Japan, but this was not an effort aimed at reviving the tatara. However, in 1977 The Society for Preservation of Japanese Art Swords (Nittoho), with the support of the government's Agency for Cultural Affairs, built the Nittoho tatara in response to the increasing scarcity of the Japanese steel used to produce Nihonto. The Nittoho tatara is operated during the winter, providing tama-hagane for swordsmiths everywhere. The tatara have again come back to life.

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