A strange sight at Espiritu Santo, 1943

Although I don't remember Dad ever mentioning it, he must have witnessed a curious sight over a few days in June 1943: A captured Japanese midget sub. On today's date, the USS Ortolan, a former minesweeper converted to a submarine rescue ship, arrived with the recovered enemy midget sub. Ortolan moored alongside the USS McKean, which was tied to the Vestal while undergoing repairs at Espiritu Santo.

Ortolan's Divers and crewmen securing sub
Source: Library of Congress

On May 7, the Ortolan recovered the scuttled "Type-A" midget sub-marine* off the northern coast of Guadalcanal, in Visale Bay. She towed the sub to Kukum Bay, Guadalcanal. Then on this date, she delivered the mini-sub to port authorities at Espiritu Santo, which is where Vestal's crew members got an up-close look.

50 Type-A's were built by Japan for use by the Imperial Navy during the war. Five of these 2-man midgets were used in the attack on Pearl Harbor on December 7, 1941. Eight of them were launched in the Guadalcanal Campaign. Three were captured after the attack on Sydney Harbor, Australia on May 30. Other mini-subs were recovered in Guam, Guadalcanal, and Kiska Island. However, most of the remaining 50 midgets are unaccounted for.

The Japanese launched 8 mini-sub missions during the Guadalcanal Campaign. The 46-ton, 24-foot midget subs were each armed with two 450 mm torpedoes in muzzle-loading tubes, 1 above the other on the port bow. The midgets were brought underwater “piggy-back” style on fleet I-class submarines and then deployed at night for attacks.

One of the U.S. ships torpedoed by a Japanese midget attack during the Guadalcanal Campaign was the cargo ship, USS Alchiba. The ship was beached in Tenaru Bay after the first hit on November 28, 1942, and then had the misfortune of being torpedoed a second time by another mini-sub. Alchiba was later repaired by Dad's ship, Vestal, and returned to war service.

Overall, the Japanese mini-sub operation netted poor results and only minimally disrupted the American naval operations at Guadalcanal.

USS Ortolan's crew standing on hull of raised midget sub
Source: Library of Congress

The mini-sub salvaged by Ortolan at Guadalcanal was displayed as part of a war bond effort in 1943-1944. It was brought to the Historic Ship Nautilus & Submarine Force Museum in Groton, Connecticut, where it has remained. It is only one of 5 Type-A midgets on display in the world. Another, one from the Pearl Harbor attack, is on display at the National Museum of the Pacific War, nearby in Fredericksburg, Texas.

*There is an engaging interactive 3-D model of Japan's WWII mini-sub produced by NOVA.

Sources: USS Vestal War Diary, June 1943; USS Ortolan War Diary, April-June, 1943; Midget Submarines in the Solomon Islands; Archaehistori.org