World War II Database

Contributor: C. Peter Chen

ww2dbaseIn May 1940, the keel for the third Yamato-class battleship was laid down at Yokosuka Naval Arsenal in Yokosuka, Japan. Similar to her sister battleship Yamato and Musashi, her construction was a closely guarded secret, and the dockyard was surrounded by tall fences. No photographs were taken during the construction to ensure security. In mid-1941, her construction was temporarily paused as the Japanese Navy prepared for war. In 1942, the loss of four fleet carriers at the Battle of Midway prompted Japanese naval leadership to convert Shinano, about 45% complete at the time, into a fleet carrier in an attempt to replenish the lost naval aviation strength. The conversion was oversaw by Vice Admiral Keiji Fukuda of Kampon, or the Japanese Navy Technical Department. When she was completed in Oct 1944, she became the largest carrier in the world; her full-load tonnage would not be surpassed until the arrival of the US Navy Forrestal-class carriers in the 1950s. Due to the threat of air attacks on Yokosuka, she was ordered to move to Kure, Japan to complete her fitting-out; Fukuda requested a delay of this move, citing that her watertight compartment doors had not been completed and other issues, but the request was denied. She departed in the evening of 28 Nov 1944, carrying about 2,500 men on board along with 6 Shinyo special attack boats and 50 Ohka special attack rocket aircraft; she was escorted by three destroyers, Isokaze, Yukikaze, and Hamakaze. At 2100 hours, merely three hours after leaving port, she was spotted by USS Archerfish under the command of Commander Joseph Enright; Shinano also detected USS Archerfish and began zig-zagging. At 0305 hours in the morning of 29 Nov 1944, USS Archerfish began to move into an attacking position, but one of the Japanese destroyers moved toward the submarine and forced Enright to dive. Nevertheless, Enright would catch an opportunity to attack shortly after, firing six torpedoes at 0315 hours. While Shinano's armored flight deck could withstand the impact of 1,000-pound (454-kilogram) bombs, the largest used by US Navy carrier bombers at the time, these torpedoes, four of which hit, would destroy her. The first hit destroyed the refrigerated areas and one of the empty aviation gas storage tanks, the second flooded the outboard engine room, the third destroyed the No. 3 fireroom, and the fourth flooded the starboard air compressor room, magazines, and ruptured the starboard oil storage tank. Captain Toshio Abe did not realize the scale of the damage and maintained speed in order to outrun the submarine before a second attack run could be commenced, but within minutes the carrier would suffer a 10-degree starboard list. Counter-flooding ordered by Abe corrected the list to 7 degrees, but damage control efforts continued to be inadequate. When dawn broke, the starboard boiler room flooded completely, and the list increased to 20 degrees, and further counter-flooding efforts would fail. At 0745 hours, she lost all power. At 0850 hours, Abe ordered Hamakaze and Isokaze to take Shinano in tow toward nearby Cape Ushio for beaching; the towing attempt failed as tow cables snapped, attributed to the over-weight carrier due to the state of flooding. At 1018 hours, Abe ordered the carrier, now suffering a 30-degree starboard list and beginning to show the inevitability of capsizing, to be abandoned. She capsized at 1057 hours. 1,435 were killed in her sinking, including Captain Abe; 1,080 survived. The news of Shinano's sinking was restricted, and the survivors were quarantined for several months to prevent the news from leaking.

ww2dbaseSources:
Dan van der Vat, The Pacific Campaign
Nihon Kaigun/Combinedfleet.com
US Navy Naval History and Heritage Command
Wikipedia

Aircraft Carrier Shinano Interactive Map

Photographs

Shinano Operational Timeline

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7.  C. Peter Chen says:
8 Feb 2013 08:27:24 AM

Thanks Wade, we will make corrections you suggested.

10.  C. Peter Chen says:
20 Nov 2017 07:52:14 AM

Jaybox Holmes: Your nit picking is very much appreciated. The correction has been made!

13.  Alan Chanter says:
18 Jul 2022 07:21:18 AM

When Commander Enright told his story about sinking a Hayatake-class carrier, some people were more than sceptical. The American codebreakers believed they had identified all the remaining Japanese carriers and knew of their probable whereabouts. Although an earlier reconnaissance of Tokyo Bay had disclosed a previously unknown carrier nearing completion, US Navy intelligence believed Shinano to be a cruiser. It was therefore taken for granted that a cruiser had been converted into an aircraft carrier. But Enright made a drawing of the carrier which he had sunk and was therefore credited with sinking a 28,000 ton carrier. It was not until after the war that the US Navy discovered that Archerfish had, in fact, sunk the 70,755 ton carrier Shinano, about which the codebreakers had known nothing.