The author will clarify the engine operation and its specifications of Hakki-Maru of Kaga clan that was the steamship introduced to Japan at the end of the Tokugawa period. Hakki-Maru was propelled by sails and a steam engine on Japanʼs coastline. The engine operation was relatively smooth under the calm weather, but some steam leaks of the boiler occurred mainly at the stormy weather. Though the boiler of Hakki-Maru was designed to generate steam pressures of 60 psi., the steam pressure was frequently less than 1/4 of the maximum working pressure. The repair of the engine required the help of a Shogunate engineer with a lot of operating experience. Hakki-Maru built in the United Kingdom and was equipped with a compound engine. Also it is highly probable that a combination of cylindrical boiler and surface condenser was equipped. These were developed to improve the efficiency of the engine but had been just put into practical use. The frequent breakdowns at Hakki-Maru were due to the installation of the latest equipment that required careful operation and maintenance. The steamship sold to Japan at the end of the Tokugawa period included not only old ones but also new one equipped with some cutting-edge technology. Since the steamship itself was the means of transportation, the latest technology onboard could quickly spread to the distant locations.
