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Dutch Harbor


Digital relief map of Unalaska

U.S. Army


Dutch Harbor (166.54W 53.895N), located on Unalaska Island, was the largest settlement of the Aleutian island chain.  Unalaska itself is a large (67 miles or 108 km long), irregularly shaped mountainous island. The small civilian population was primarily Aleuts with an admixture of Russians.

Although the naval station was first established in 1903 and development of Fort Mears began in 1940, the port had only primitive facilities in late 1941. By early 1942 there were at least four 187,500 gallon (709,800 liter) fuel storage tanks, and fuel storage capacity had grown to 7.3 million gallons (27.5 million liters) by May 1943. Unalaska had so little level land that construction of an airstrip was considered impractical. Instead, construction had begun on nearby Umnak Island, which had some flat terrain but no decent anchorage. Supplies had to be transported by lighter from the anchorage at Makushin Bay (167.106W 53.742N).

Dutch Harbor was bombed on 3 June 1942 by  Japanese carrier aircraft to cover the invasion of the western Aleutians.  A total of 15 A6M Zeros, 12 D3A Vals, and 9 B5N Kates were launched from Ryujo and Junyo, but the weather was miserable, and only six Zeros and six Kates actually reached the harbor. The raid was detected by the radar on seaplane tender Gillis, which was anchored in the harbor, spoiling any element of surprise. The bombs missed the oil storage tanks but hit several buildings in Fort Mears. A report of American destroyers north of Unalaska prompted the Japanese to lauch all their remaining aircraft, 9 Zeros, 6 Vals, and 6 Kates plus four seaplanes from the escorting cruisers, but all except the seaplanes turned back in the terrible weather. The seaplanes were jumped by P-40s from Umnak and one was shot down. Total Japanese losses were a Zero, a Kate and two seaplanes, while the Americans lost a Catalina flying boat shot down by the attackers as they approached the harbor. An American counterstrike against the Japanese force scored no hits.

A second attack the next day by 15 Zeros, 11 Vals, and 6 Kates was more accurate, destroying four new 6,666-barrel fuel oil tanks and puncturing a nearby diesel oil tank. Nevertheless, overall damage was modest and did not put the base out of operation. The returning aircraft were jumped by P-40s of 11 Fighter Squadron from Umnak at their rendezvous point over west Unalaska, and the Japanese lost four aircraft. A fifth was lost operationally.

The Japanese believed that an entire division was based here and were surprised to find that the garrison was not more than 5000 men. Consideration was briefly given to invading Dutch Harbor instead of the western Aleutians, but the defeat at Midway and the unexpected presence of the fighter base on Umnak caused Hosagaya to abandon the idea.

Weeks later, a Japanese Zero lost during the raid was recovered almost intact on a nearby island, which allowed American aeronautical experts to thoroughly analyze the design, devise appropriate tactics for Allied fighters to counter the Zero, and refine some features of the Hellcat, which was then in the prototype stage.

References

Garfield (1965)

"Interrogations of Japanese Officials" (1945; accesssed 2011-12-5)

Morison (1951)

Rottman (2002)

"The Aleutians Campaign" (1993; accessed 2011-12-5)

Willmott (1983)



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