May-August 1945: Starvation Grows

Mindfield MIKE briefing map, May 1945.

Overview:

By the midpoint of 1945, Operation Starvation was having a terrible effect on Japanese coastal shipping. Almost all of the major ports and straits of Japan were repeatedly mined, severely disrupting Japanese logistics and troop movements for the remainder of the war with 35 of 47 essential convoy routes having to be abandoned. Shipping traffic through the bustling port of Kobe declined by 85%, from 320,000 tons in March to only 44,000 tons in July. The US Twentieth Air Force flew 1,529 sorties and laid 12,135 mines in twenty-six fields on forty-six separate missions. Mining demanded only 5.7% of the 21st Bomber Command's total sorties, and only fifteen B-29s were lost in the effort. In return, mines sank or damaged 670 ships totaling more than 1,250,000 tons. In the five months prior to the end of hostilities, mines sank or damaged more shipping than any other agent including submarines or direct air attack by both Army and Naval forces. The Shimonoseki Straits and all important industrial ports were almost completely blockaded

The mining of Japanese waters proved to be so effective that the Japanese were forced to rely on smaller, nonstandard ships to assist in their desperate shipping efforts. Allied submarines were forced to resort to using deck guns on sampans and other fishing vessels which were too small for torpedo usage. Confirmed sinkings by allied submarines declined significantly during this time period. Some enterprising crews found different ways to create havoc when there were no ships to be sunk. The USS Barb in particular became particularly adept at this craft, surfacing and bombarding various coastal towns on numerous occasions. The sub's commander, Commander Eugene B. Fluckey, was already a Medal of Honor recipient for a daring mission off Japanese occupied China's coast. Going a step further, he created a demolition squad and launched the only wartime landing on Japanese soil, blowing up a train in the process.

Daring missions such as the USS Barb's can be directly attributed to a lack of targets for the US Navy's submarines to attack. Operation Starvation was strangling the Japanese homeland

Density comparison of mine vs submarine losses of Japanese merchant vessel losses in the waters surrounding the Japanese Home Islands. The panel depicts the littoral waters of Honshu, Kyushu, and Shikoku. May to August, 1945.

Expanded Legend:

U.S. aerial mines sink 183 Japanese mercahant vessels in and around the Japanese home islands as well as Korea. This represents a 321% increase over mine activity during the first four months of 1945, with most that activity occuring in March and April.
With expanded forward bases, the US takes the war to Japanese occupied Korea in an effort to cut off the flow of raw materials to mainlaind Japan. 21 merchant vessels are sunk in Korean coastal waters, with 62% of those sinkings occurring by mines.
In addition to skyrocketing US mine activity in the Kanmon Straits (see inset) carrier-based air attacks on Kure and the Inland Sea in late July and early August of 1945 result in the sinkings of 46 Japanese merchant veseels. This represents 48% of all merchant vessel sinkings by aircraft that year.

Briefing map of minfield LOVE, May 1945

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A 2,000 lb Mark 25 naval mine is loaded into the bombway of a B-29 Superfortress.

Members of the USS Barb pose with her battle flag at the conclusion of her 12th war patrol. Lacking sufficent targets off Japan due to Operation Starvation, the USS Barb bombarded the Japanese shoreline with rockets and even landed a demolition squad on the Japanese at Karafuto, destroying a train. Taken at Pearl Harbor, August 1945.

The 40mm deck gun on the USS Bergall (SS-320), a Balao Class submarine. Note the two Japanese flags on the gun's barrel, denoting two sinkings. These sinkings are more than likely not reflected in the totals surveyed for this project as they could have only been small sampans or other light craft. As the war drew to a close sinkings of this type became more common as the decimated Japanese merchant fleet turned to smaller craft due to losses and fuel shortages.

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Carrier-based air attacks on Kure and the Inland Sea caused the sinking of dozens of Japanese vessels. Although not included in the scope of this study, the large Japanese ship seen in this photograph is the battleship Haruna.