A man who spent the war in a Hokkaido plant tasked with offsetting Japan’s petroleum shortages with man-made oil said he felt the nation’s enemies were “incommensurably rich” in the key resource.

The government built a plant to make coal oil in Takikawa, Hokkaido, in 1941. Shigeo Kokubun was hired the following year and ran the coke furnaces where coal was burned to generate gas, which was then liquefied into oil.

Since the technology had been developed by Germany, four German engineers were stationed at the plant, along with elite Japanese engineering graduates from top-notch universities, he said.

The furnaces were about 5 meters wide and as tall as a three- to four-story building. Operation required delicate heat adjustments because the quality of the gas varied with the temperature.

Due to the carbon monoxide content, it was not uncommon for workers to collapse from leaks, said Kokubun, who once did so himself. It started using canaries as gas detectors, but they died quickly, he said.

With a staff of around 1,500, the plant was the biggest employer in town, he said. Since the facility was deemed critical to national policy, employees often had an advantage in food rationing and even had access to sake near the end of the war.

Responsible for filling tanks with gas, Kokubun did not know whether oil was being successfully produced or how it was used. But he was proud to be working for the country.

Kokubun was drafted in June 1945 and fought Soviet soldiers in Karafuto, now Sakhalin, in the Russian Far East. During battle, he was surprised to see lots of Soviet planes flying over day after day but no Japanese aircraft, attributing it to Japan’s acute shortage of oil.

“I thought Japan couldn’t continue fighting,” he said.

The Hokkaido plant in fact was unable to operate at full capacity due to a shortage of materials. It was supposedly using three furnaces, but one was never built.

Japan was never able to cover its oil shortage with man-made oil, Kokubun said.