Shimose powder

Shimose powder (下瀬火薬, Shimose kayaku) was a type of explosive shell filling developed by the Japanese naval engineer Shimose Masachika (1860–1911).

Shimose was born in Hiroshima Prefecture and was a graduate of Tokyo Imperial University as one of Japan’s earliest holders of a doctorate in engineering. In 1887 he was hired by the Imperial Japanese Navy as a chemical engineer, and in 1899 was appointed head of a research unit to develop a more powerful type of shell filling for use by naval artillery.[1]

Shimose developed a new explosive based on Picric Acid used by France in the form of Melinite and by Britain in the form of Lyddite. Picric Acid has an instability problem when in contact with iron or other heavy metals, so the French mixed it with Collodion and the British mixed it with Dinitrobenzene and Vaseline to form each compound for the stability in gun shells. On the other hand, Shimose coated the inside of a shell with unpigmented Japanese Lacquer and further sealed with wax to prevent the powder from becoming in contact with the metal shell. Because it was undiluted, the explosive generated more heat and blast speed than any other high explosive available at the time.[2] Shimose Powder, with its compound treated as top secret, was adopted by the Imperial Japanese Navy from 1893, not only for naval artillery but also for naval mines, depth charges and torpedo warheads. It played an important role in the Japanese victory in the Russo-Japanese War of 1904 to 1905.[3]