Turning off the Tap:
Bombing Japan's Oil Refineries and Storage Centers

By Bob Hackett

Japanese Home Islands

© Bob Hackett 2014
Revision 1

By 1944, as outlined in my preceding six Special Features, American air attacks on Southeast Asian oil refineries and storage facilities under Japanese control, combined with air and submarine predation on shipping, had effectively cut off the flow of crude oil to the home islands.

The Imperial Navy (IJN) was Japan’s largest consumer of fuel oil. In July 1944, the situation had become so desperate that the oiled-starved navy was forced to take such measures as cutting a hole in the bottom of sunken battleship MUTSU’s hulk and pumping out 580-tons of fuel oil for use by their ships in Operation Take ("Bamboo"). In the latter part of 1944, the IJN's naval aviation fuel situation had become so desperate that it beganinvestigating the possibility of extracting aviation fuel from pine roots.

By 1945, most of Japan's naval and merchant fleet was rusting on the bottom of the Pacific Ocean; nevertheless, Japan stubbornly soldiered on. Now, her urgent need was for aviation gasoline for fighter aircraft to defend against increasing raids by American Boeing B-29 “Superfortress” heavy bombers that in March 1945 had fire-bombed and destroyed most of Tokyo and threatened the Emperor in his Imperial Palace. Aviation gasoline was also needed to power Japan’s final weapon, their “kamikaze” suicide planes.

Japanese Homeland Oil Fields

Even in 1945, Japan's relatively small number of domestic oil fields was still capable of supplying unrefined product to the refineries. In the beginning of that year, proven domestic oil field reserves amounted to 17,977,000 barrels (755,034,000 gallons). During the first half of 1945, the oil produced at 4,277 operating oil wells on Hokkaido and Honshu amounted to 739,600 barrels (31,063,200 gallons).

Oil Refineries and Storage Centers

In 1945, the Utsube River Oil Refinery, located about 2 miles SE of Yokkaichi on the north side of the Utsube River, was ranked first as a center of Japanese aviation gas production. The installations included facilities for synthetic oil refining (estimated at 37 per cent of synthetic pr6duction), natural oil refining, production of tetra-ethyl lead (estimated at 25 per cent of total Japanese production) and extensive oil storage.

In 1945, the Kudamatsu Plant of the Nippon Oil Company, located WSW of Kure and about 5 miles SW of Tokuyama on the Inland Sea, was considered to be the fourth largest oil refinery in Japan and had an estimated annual refining capacity of 2,500,000 barrels and a cracking capacity of 666,000 barrels. It had an estimated storage capacity of 200,000 barrels.

The Maruzen Oil Refinery, Shimotsu, located near the south entrance to Osaka Bay was an important refinery and oil storage center for the IJN. It produced aviation gas, lube oil, gasoline and fuel oil and had extensive oil storage facilities for the Navy for both crude oil and refined product.

The Nippon Oil Refinery located in the Amagasaki water-front area was considered one of Japan's most important refineries, having a capacity of 2,000,000 barrels and a storage capacity of about 1,000,000 barrels. The synthetic plant was estimated to produce 200,000 barrels annual1y.

In 1945, the Nippon Oil Refinery at Tsuchizaki, located five miles NW of the city of Akita, processed crude oil from the fields around Akita, the largest natural petroleum producers in Japan. In 1944, the annual crude capacity was estimated at 1,320,000 barrels. This capacity increased in importance since it was not dependent on imported petroleum.

Synthetic Oil

In the 1920s, the IJN undertook experimentation with synthetic fuels. Synthetic oil was produced from domestic coal, coal tar and oil shale via an industrial chemical process and refined into gasoline and other petroleum products. The bulk of the coal came from domestic mining. While the United States naval blockade and mining operations were very effective in preventing oil shipments from reaching Japan, synthetic oil could be produced on the Home Islands.

Despite production problems significant quantities of synthetic oil were produced. Synthetic oil production from May to August 1945 was 21,845,250 gallons.

The Ube Coal Liquifaction Company in Ube, Japan was capable of processing coal into hydrocarbon stock destined for conversion into gasoline and other needed products. The company was credited with the capacity to produce 475,000 barrels of synthetic oil, about 1/3 of Japanese home-island productlon. The plant most probably obtained coal from undersea mines located about a mile south.

United States Army Air Force’s (USAAF) Strategic Bombing

Left- World War 2 Twentieth Air Force Patch; Middle-315th BW B-29 over Northwest Field, Guam; Right-315th Bomb Wing Patch

BrigGen (later LtGen) Frank A. Armstrong, Jr's 315th Bomb Wing (Very Heavy), based at Northwest Field, Guam, Marianas of the USAAF's Twentieth Air Force, was tasked by MajGen (later Gen/CSAF) Curtis E. LeMay to destroy Japan’s domestic oil refining capacity and oil storage facilities. The wing's B-29 heavy bombers were fitted with the advanced AN/APQ-7 Eagle radar that allowed targets to be accurately located at night.

Between June 26 and August 14, 1945, the 315th Bomb Wing carried out fifteen night precision bombing attacks against Japanese oil refineries and inflicted heavy damage upon the petroleum industry. During these attacks it destroyed six of the nine targets attacked for the loss of four B-29s.

The 315th Bomb Wing conducted its first attack against the Utsube Oil Refinery at Yokkaichi on the night of 26 June 1945. The 33 B-29s crossed the target in a steady, single-file stream and dropped 222.8 tons of bombs by radar on the refinery that was almost obscured by heavy cloud cover. Antiaircraft fire was meager and inaccurate. 13 enemy aircraft were seen, but no attacks were made. The raid destroyed or damaged 30 percent of the facility. Many of the vital portions of the refinery were hit and seriously damaged. However, the refinery had not been knocked out and another mission was needed to complete the job. No aircraft were lost, but one 16th Bomb Group B-29B ran low on fuel and landed at Iwo Jima.

On the night of 29/30 June 1945, thirty-two B-29s dropped 209 tons of bombs by radar on the Nippon Oil Company refinery at Kudamatsu with fair to excellent results. About 19 enemy fighters were seen. Six were identified as twin-engined, probably IJAAF Kawanishi Ki-45 “Nick” or IJNAF Nakajima J1N1 "Irving" night fighters, two as single-engined, one as an IJAAF Kawanishi Ki-61 “Tony” single-engined fighter and ten were unidentified. No attacks were made. NoB-29s were lost.

Ki-61 “Tony”, J1N1 "Irving" and KI-84 “Nick” fighters

During the night of 2-3 July 1945, 39 315th BW B-29's dropped 297 tons of bombs by radar on the Maruzen Oil Refinery at Minoshima. Eleven enemy fighters were seen. Three were identified as twin-engined, three as single-engined and five were unidentified. No attacks were made. No aircraft were lost. Reconnaissance photos showed only 5 percent of the plant was destroyed. Consequently, a follow up strike was scheduled. No B-29s were lost.

On the night of 6/7 July, the 315th attacked the Maruzen oil refinery a second time. 59 B-29's dropped 441.5 tons by radar on a totally obscured target. Enemy fighters made several attacks; some seemed to try to ram the Superforts. Photo reconnaissance on 11 July showed 95 percent of the plant had been destroyed. No B-29s were lost.

(Maruzen Oil Refinery - Destroyed [USAAF Photo])

On 9/10 July 1945, 61 B-29's dropped 468.7 tons of bombs on Utsube Oil Refinery at Yokkaichi with poor results. Ten to 15 enemy fighters made three attacks. No B-29s were lost, but two landed at Iwo Jima.

On 25 July 1945, President Harry S. Truman ordered atomic bomb attacks on Japan to begin as soon as possible. The next day, at Potsdam, Germany, near Berlin, the Allies (United States, United Kingdom and China) broadcast the Potsdam Declaration" that called for the unconditional surrender of Japan, or the alternative of its prompt and "utter destruction".

On 28 July 1945, in Tokyo, Prime Minister Admiral, the Baron, Suzuki Kantaro (14)(former CO of TSUKUBA) announced that Japan would ignore the Potsdam Declaration.

On the night of 5/6 August 1945, 106 B-29's dropped 938 tons of bombs on the Ube Coal Liquefaction Company facility and destroyed almost 100 percent of the synthetic fuel refining units and destroyed or damaged 80 percent of other structures. 25 to 35 Japanese fighters were sighted and made one attack. No aircraft were lost, but five landed at Iwo Jima.

By 6 August 1945, Japan continued to ignore the Potsdam Declaration, so at 0815, Colonel (later Brig Gen) Paul W. Tibbetts, piloting a 509th Composite Group B-29 "Superfortress" named "ENOLA GAY" dropped the 15-kiloton yield "Little Boy" uranium atomic bomb on Hiroshima.

Left: Little Boy" being loaded on "ENOLA GAY" Right: "Fat Man" plutonium atomic bomb

The Final Week of Hostilities

On 8 August 1945, Moscow declared that from 9 August 1945, the Soviet Government would consider itself to be at war with Japan.

On 9 August 1945, Japan stubbornly continued to ignore the Potsdam Declaration, so at 1101, Major (later Brig Gen, ANG) Charles W. Sweeney's B-29 "BOCKSCAR", of the 509th Composite Group's 393rd Bomb Squadron, dropped the 21-kiloton yield "Fat Man" plutonium atomic bomb on Nagasaki. That same day, Soviet Far East Forces, comprising 80 divisions of 1.5 million men, invaded Japanese-held Manchuria (Manchukuo).

Left and Center: Atomic bomb mushroom clouds over Hiroshima and Nagasaki. Right:-Emperor Hirohito

On 10 August 1945, fearful that the next atomic bomb would completely obliterate Tokyo and the Imperial Palace, Japan offered to accept the Potsdam Declaration, if Emperor Hirohito was allowed to remain head of state. Two days later, the United States announced it would accept the Japan's surrender and that the Emperor could remain in a ceremonial capacity.

At 1020, 14 August 1945, at a conference of his most senior military officers, the Emperor noted that with the enemy's use of atomic weapons and Soviet entry into the Pacific War, not even Vice Admiral Onishi Takijiro 's (40) Special Attack (Kamikaze) forces could stop them. Later, the Japanese announced the Emperor had decided to accept the Potsdam Declaration's terms and end the War, effective the following day.

Finally, on the night of 14/15 August 1945, six days after the atomic bombing of Nagasaki, BrigGen Armstrong led the raid on the Nippon Oil Refinery at Tsuchizaki near Akita, 300 miles north of Tokyo on the West Coast of Japan. In the longest nonstop B-29 mission from the Marianas (3,650 miles), 132 B-29s dropped 953.9 tons of bombs on the refinery. No enemy fighters were seen. No aircraft were lost. Huge fires and dense smoke covered the refinery as the 315th's crews turned to start the long journey to Northwest Field. [1]

Before the last 315th B-29B landed at Guam on the morning of 15 August, the war was over. President Truman had announced the unconditional surrender of Japan, and the returning crews heard the news over their radios. The 315th had inflicted the final bombing damage to the Japanese Empire with the last bombs away at 0339 hours, 15 August 1945

At noon, 15 August 1945, at the Imperial Palace, the Emperor announced Japan's surrender that was broadcast by radio all over the Japanese Empire.

Author's Note:
[1] BrigGen Armstrong had the distinction of leading the first and last USAAF strategic bombing missions of World War II and the longest and final heavy bombing raid in the war, as well as leading the first USAAF mission to attack Germany.

Some of the chronology and general information on this page is a composite of entries excerpted from:
"Missions of the 315th Bomb Wing, Very Heavy, in World War 2", Larry Miller, 2006
“Were There Strategic Oil Targets In Japan In 1945?”, Dr. Emanuel Horowitz, Air Power History, Volume 51 No 1, Spring 2004

-Bob Hackett