Kawasaki Aircraft Akashi Plant

The Kawasaki Aircraft Industries Akashi Plant was a massive integrated aircraft manufacturing complex located in Akashi, Hyogo Prefecture, approximately 12 miles west of Kobe. It was the company's largest facility and the headquarters of its engine division. Construction began in 1938 on approximately 1.82 million square meters of flat farmland acquired in the Hayashi-Sakizaki area, chosen for its proximity to the existing Kobe works, excellent rail access, and expansive terrain. The first buildings were completed in the summer of 1940, and by September 1941 the plant had produced its first complete aircraft.

The Akashi Plant's most critical role was the production of the Kawasaki Ha-40 liquid-cooled inverted-V12 engine, a licensed version of the German Daimler-Benz DB 601. The first Japanese-built DB 601A, designated Ha-40, was completed at Akashi in July 1941. This engine powered the Kawasaki Ki-61 Hien ("Flying Swallow"), known to the Allies as "Tony" — the only mass-produced Japanese fighter aircraft of the war to use a liquid-cooled inline engine. The Hien's streamlined design enabled superior speed and diving performance compared to radial-engine fighters, though the Ha-40's reliability problems, particularly with superchargers and cooling systems, plagued production throughout the war.

The division of labor between Kawasaki's facilities meant that the Akashi Plant focused on engine manufacturing while the Gifu Plant handled airframe assembly. Between 1940 and 1945, Akashi produced approximately 11,000 engines, of which roughly 30% were the water-cooled type for the Hien. By December 1944, the workforce had grown to approximately 38,000 workers, including mobilized students, women, and older laborers.

The plant's strategic importance made it a prime target for the US XXI Bomber Command. On January 19, 1945, a force of B-29 Superfortresses from the Marianas (62 aircraft over the target according to Akashi City's records) struck the facility in what was the first major air raid on Hyogo Prefecture. While US intelligence initially estimated 38% of buildings damaged, Japanese records revealed the true destruction was catastrophic — over 90% of the plant was destroyed, and more than 320 people (322 by the city's tally), including mobilized students, were killed in the approximately 30-minute attack. Kawasaki effectively decided to shut down the facility.

The destruction of the Akashi engine plant had immediate strategic consequences: with no Ha-40 engines available, 275 completed Ki-61-II airframes at the Gifu factory were converted to accept the Mitsubishi Ha-112-II radial engine, creating the improvised but surprisingly effective Ki-100 fighter.

The plant was targeted again on June 9, June 22 and June 26, 1945. After the war, Kawasaki Heavy Industries rebuilt on the same site. Today the Akashi Works produces motorcycles, general-purpose engines, industrial robots, and jet engines. A memorial cenotaph within the factory grounds commemorates the air raid victims.