Japanese aircraft carrier Shinano
Shinano underway during her sea trials in Tokyo Bay
| |
History | |
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Japan | |
Name | Shinano |
Namesake | Shinano Province |
Builder | Yokosuka Naval Arsenal |
Laid down | 4 May 1940 |
Launched | 8 October 1944 |
Completed | 19 November 1944 (for trials) |
Fate | Sunk by the submarine USS Archerfish, 29 November 1944 |
General characteristics | |
Type | Aircraft carrier |
Displacement |
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Length | 265.8 m (872 ft 2 in) (o/a) |
Beam | 36.3 m (119 ft 1 in) |
Draught | 10.3 m (33 ft 10 in) |
Installed power |
|
Propulsion | 4 × shafts; 4 × geared steam turbines |
Speed | 28 knots (52 km/h; 32 mph) |
Range | 10,000 nmi (19,000 km; 12,000 mi) at 18 knots (33 km/h; 21 mph) |
Complement | 2,400 |
Armament |
|
Armor |
|
Aircraft carried | 47 |
Shinano (信濃) was an aircraft carrier built by the Imperial Japanese Navy (IJN) during World War II, the largest such built up to that time. Laid down in May 1940 as the third of the Yamato-class battleships, Shinano's partially complete hull was ordered to be converted to an aircraft carrier following Japan's disastrous loss of four of its original six fleet carriers at the Battle of Midway in mid-1942. The advanced state of her construction prevented her conversion into a fleet carrier, so the IJN decided to convert her into a carrier that supported other carriers.
Her conversion was still not finished in November 1944 when she was ordered to sail from the
Design and description
One of two additional Yamato-class
Construction and conversion
As with Shinano's half-sisters
In December 1941, construction on Shinano's hull was temporarily suspended to allow the IJN time to decide what to do with the ship. She was not expected to be completed until 1945, and the
In the month following the disastrous loss of four fleet carriers at the June 1942 Battle of Midway, the IJN ordered the ship's unfinished hull converted into an aircraft carrier. Her hull was only 45 percent complete by that time, with structural work complete up to the lower deck and most of her machinery installed. The main deck, lower side armor, and upper side armor around the ship's magazines had been completely installed, and the forward barbettes for the main guns were also nearly finished. The navy decided that Shinano would become a heavily armored support carrier[8]—carrying reserve aircraft, fuel and ordnance in support of other carriers—rather than a fleet carrier.[9]
As completed, Shinano had a length of 265.8 meters (872 ft 1 in)
Machinery
Shinano's machinery was identical to that of her half-sisters. The ships were fitted with four geared
Flight deck and hangar
Shinano was designed to load and fuel her aircraft on deck where it was safer for the ship; experiences in the Battles of Midway and the Coral Sea had demonstrated that the existing doctrine of fueling and arming their aircraft below decks was a real danger to the carriers if they were attacked while doing so. Much of Shinano's hangar was left open for better ventilation, although steel shutters could close off most of the hangar sides if necessary. This also allowed ordnance or burning aircraft to be jettisoned into the sea, something that the earlier carriers could not do with their enclosed hangars.[8]
The carrier's 256-meter (839 ft 11 in)
Unlike the British carriers, Taihō and Shinano had unarmored sides to their hangars. For stability reasons, the latter only had a single hangar that was 163.4 by 33.8 meters (536 by 111 ft), with a minimum width of 19.8 meters (65 ft) aft, and had a height of 5 meters (16 ft 6 in). The forward area of the hangar was dedicated to maintenance and storage facilities. Aircraft were transported between the hangar and the flight deck by two
The ship's organic air group was intended to consist of 18 Mitsubishi A7M Reppū (Allied reporting name "Sam") fighters (plus two in storage), 18 Aichi B7A Ryusei ("Grace") torpedo-dive bombers (plus two in storage), and 6 Nakajima C6N Saiun ("Myrt") reconnaissance aircraft (plus one in storage).[8] The remainder of the hangar space would have held up to 120 replacement aircraft for other carriers and land bases.[9]
According to Lynn Lucious Moore's "Shinano: The Jinx Carrier" (US Naval Institute Proceedings, February, 1953) the steel flight deck was covered with a thin, shock-absorbent latex-sawdust compound.[15]
Armament
Shinano's primary armament consisted of sixteen 40-caliber 12.7-centimeter (5 in) Type 89 dual-purpose guns in eight twin mounts, two at each corner of the hull.[13] When firing at surface targets, the guns had a range of 14,700 meters (16,100 yd); they had a maximum ceiling of 9,440 meters (30,970 ft) at their maximum elevation of 90 degrees. Their maximum rate of fire was 14 rounds a minute; their sustained rate of fire was around eight rounds per minute.[16]
The ship also carried 105
Four Type 94 high-angle
Armor
The ship's original waterline armor belt thickness of 400 millimeters (15.7 in) was retained only where it had already been installed abreast the magazines, and reduced to 160 millimeters (6.3 in) elsewhere. Below it was a strake of armor that tapered in thickness from 200 millimeters (7.9 in) to 75 millimeters at its bottom edge. The flat portion of the armor deck over the machinery and magazine spaces, ranging from 100 to 190 millimeters (3.9 to 7.5 in), was retained, and the sloped portion that angled downward towards the bottom of the main armor belt was 230 millimeters (9.1 in) thick. Large external anti-torpedo bulges below the waterline provided the main defense against torpedoes, backed up by an armored bulkhead extending down from the belt armor; the bulkhead was intended to prevent splinters from piercing the main hull and, though not watertight, was backed by a second one which was. The joint between the upper and lower armor belts was weak and proved to be a serious problem when struck by torpedoes.[20]
Even though Shinano's avgas tanks were protected by armor that could resist a 155-millimeter (6.1 in) shell, the IJN attempted to isolate the tanks from the rest of the ship with a cofferdam. However the investigation into the loss of Taihō had revealed that her avgas tanks had sprung leaks after she was torpedoed. The resulting fumes then penetrated the cofferdam and exploded. Therefore, the IJN thought it prudent to fill the empty spaces between the tanks and the cofferdam with 2,400 metric tons (2,362 long tons) of concrete to prevent any fumes from escaping.[14]
Launching
The ship was originally scheduled for completion in April 1945, but construction was expedited after the defeat at the Battle of the Philippine Sea in June 1944 as the IJN anticipated that the United States would now be able to bomb Japan with long-range aircraft from bases in the Mariana Islands. The builder was unable to increase the number of workers on Shinano and could not meet the new deadline of October. Even so, the pressure to finish as quickly as possible led to poor workmanship by the workforce.[21]
Shinano's launch on 8 October 1944, with Captain Toshio Abe in command, was marred by what some considered an ill-omened accident. During the floating-out procedure, one of the caissons at the end of the dock that had not been properly ballasted with seawater unexpectedly lifted as the water rose to the level of the harbor. The sudden inrush of water into the graving dock pushed the carrier into the forward end, damaging the bow structure below the waterline and requiring repairs in drydock. These were completed by 26 October.[21]
Commissioning and sinking
Departure from Yokosuka
On 19 November 1944, Shinano was formally commissioned at Yokosuka, having spent the previous two weeks fitting out and performing sea trials.[22] Worried about her safety after a U.S. reconnaissance bomber fly-over,[22] the Navy General Staff ordered Shinano to depart for Kure by no later than 28 November, where the remainder of her fitting-out would take place. Abe asked for a delay in the sailing date[23] as the majority of her watertight doors had yet to be installed, the compartment air tests had not been conducted, and many holes in the compartment bulkheads for electrical cables, ventilation ducts and pipes had not been sealed. Importantly, fire mains and bailing systems lacked pumps and were inoperable; even though most of the crew had sea-going experience,[24] they lacked training in the portable pumps on board.[25] The escorting destroyers, Isokaze, Yukikaze and Hamakaze, had just returned from the Battle of Leyte Gulf and required more than three days to conduct repairs and to allow their crews to recuperate.[26]
Abe's request was denied, and Shinano departed as scheduled with the escorting destroyers at 18:00 on 28 November. Abe commanded a crew of 2,175 officers and men. Also on board were 300 shipyard workers and 40 civilian employees. Watertight doors and hatches were left open for ease of access to machinery spaces, as were some
Attacked
At 20:48, the American submarine
At 02:56 on 29 November, Shinano turned to the southwest and headed straight for Archerfish. Eight minutes later, Archerfish turned east and submerged in preparation to attack. Enright ordered his torpedoes set for a depth of 10 feet (3.0 m) in case they ran deeper than set; he also intended to increase the chances of capsizing the ship by punching holes higher up in the hull. A few minutes later, Shinano turned south, exposing her entire side to Archerfish—a nearly ideal firing situation for a submarine. The escorting destroyer on that side passed right over Archerfish without detecting her. At 03:15 Archerfish fired six torpedoes before diving to 400 feet (120 m) to escape a depth charge attack from the escorts.[31]Four torpedoes struck Shinano, at an average depth of 4.27 meters (14 ft 0 in).[27] The first hit towards the stern, flooding refrigerated storage compartments and one of the empty aviation gasoline storage tanks and killing many of the sleeping engineering personnel in the compartments above. The second hit the compartment where the starboard outboard propeller shaft entered the hull and flooded the outboard engine room. The third hit further forward, flooding the No. 3 boiler room and killing every man on watch. Structural failures caused the two adjacent boiler rooms to flood as well. The fourth flooded the starboard air compressor room, adjacent anti-aircraft gun magazines, and the No. 2 damage control station and ruptured the adjacent oil tank.[32]
Sinking
Though severe, the damage to Shinano was at first judged to be manageable.
A half-hour later, Shinano was making 10 knots with a 13-degree list. At 06:00 her list had increased to 20 degrees after the starboard boiler room flooded, at which point the valves of the port trimming tanks rose above the waterline and became ineffective. The engines shut down for lack of steam around 07:00, and Abe ordered all of the propulsion compartments evacuated an hour later. He then ordered the three outboard port boiler rooms flooded in a futile attempt to reduce the carrier's list. He also ordered Hamakaze and Isokaze to take her in tow. However, the two destroyers displaced only 5,000 metric tons (4,900 long tons) between them, about one-fourteenth of Shinano's displacement and not nearly enough to overcome her deadweight. The first tow cables snapped under the strain and the second attempt was aborted for fear of injury to the crews if they snapped again. The ship lost all power around 09:00 and was now listing over 20 degrees. At 10:18, Abe gave the order to abandon ship; by this time Shinano had a list of 30 degrees. As she heeled, water flowed into the open elevator well on her flight deck, sucking many swimming sailors back into the ship as she sank. A large exhaust vent below the flight deck also sucked many other sailors into the ship as she submerged.[36]
At 10:57 Shinano finally capsized and sank stern-first at coordinates (33°07′N 137°04′E / 33.117°N 137.067°E), 65 miles (105 km) from the nearest land, in approximately 4,000 meters (13,000 ft) of water, taking 1,435 officers, men and civilians to their deaths. The dead included Abe and both of his navigators, who chose to go down with the ship. Rescued were 55 officers and 993 petty officers and enlisted men, plus 32 civilians for a total of 1,080 survivors.[22] After their rescue, the survivors were isolated on the island of Mitsuko-jima until January 1945 to suppress the news of the carrier's loss.[37] The carrier was formally struck from the Naval Register on 31 August.[22]
Post-war analysis of the sinking
Post-war analysis by the U.S. Naval Technical Mission to Japan noted that Shinano had serious design flaws. Specifically, the joint between the waterline armor belt on the upper hull and the anti-torpedo bulge on the underwater portion was poorly designed, a trait shared by the Yamato-class battleships; Archerfish's torpedoes all exploded along this joint. The force of the torpedo explosions also dislodged an I-beam in one of the boiler rooms, which punched a hole into another boiler room. In addition, the failure to test for watertightness in each compartment played a role as potential leaks could not be found and patched before Shinano put to sea.[40] The executive officer blamed the large amount of water that entered the ship on the failure to air-test the compartments for leaks. He reported hearing air rushing through gaps in the watertight doors just minutes after the last torpedo hit—a sign that seawater was rapidly entering the ship, proving the doors were unseaworthy.[41]
See also
- List of ships sunk by submarines by death toll
- Shoki Fukae (Japanese actor who played villains in movies and TV show. One of the surviving crew members. He was rescued after drifting for 12 hours at the time of sinking. )
Footnotes
- ^ a b Enright & Ryan, p. xiv
- ^ Enright & Ryan, p. 2
- ^ Silverstone, p. 336
- ^ Garzke & Dulin, pp. 74–75
- ^ "Yokosuka City Historical Materials Room - July 1, 2020" (PDF). 1 July 2020.
- ^ "Imperial Flattops". www.combinedfleet.com. Retrieved 20 November 2023.
- ^ Garzke & Dulin, p. 75
- ^ a b c d e Garzke & Dulin, p. 78
- ^ a b c d Chesneau, p. 185
- ^ Jentschura, Jung & Mickel, p. 55
- ^ Preston, p. 91
- ^ a b c d Brown, pp. 32–33
- ^ a b c Brown, p. 32
- ^ a b c Garzke & Dulin, p. 79
- ^ "Shinano: The Jinx Carrier". U.S. Naval Institute. 1 February 1953.
- ^ Campbell, pp. 192–193
- ^ Campbell, p. 200
- ^ Stille, p. 51
- ^ Campbell, p. 216
- ^ Garzke & Dulin, pp. 79–80
- ^ a b Garzke & Dulin, p. 80
- ^ a b c d e f Tully
- ^ a b Enright & Ryan, p. 25
- ^ Holtzworth, pp. 26–27
- ^ Garzke & Dulin, pp. 83–84
- ^ Enright & Ryan, pp. 31–32
- ^ a b c Garzke & Dulin, p. 82
- ^ Enright & Ryan, pp. 19–20
- ^ Enright & Ryan, pp. 21, 29
- ^ Enright & Ryan, pp. 66, 94–101
- ^ Enright & Ryan, pp. 141–143, 150–158, 161
- ^ Enright & Ryan, pp. 159–160
- ^ Enright, Joseph (1 May 1987). "The Sinking of a Supercarrier". Washington Monthly.
- ^ Enright & Ryan, pp. 162–165
- ^ Enright & Ryan, pp. 172–175
- ^ Enright & Ryan, pp. 185–198
- ^ Enright & Ryan, p. 213
- ^ a b Blair, pp. 779–780
- ^ Czarnecki, Joseph (2002). "What did the USN know about Yamato and when?". NavWeaps.com. Retrieved 19 July 2020.
- ^ Holtzworth, pp. 26–28
- ^ Enright & Ryan, p. 164
References
- ISBN 1-55750-217-X.
- Brown, David (1977). WWII Fact Files: Aircraft Carriers. New York: Arco Publishing. ISBN 0-668-04164-1.
- Campbell, John (1985). Naval Weapons of World War II. Annapolis, Maryland: Naval Institute Press. ISBN 0-87021-459-4.
- Chesneau, Roger (1995). Aircraft Carriers of the World, 1914 to the Present: An Illustrated Encyclopedia (New, Revised ed.). Annapolis, Maryland: Naval Institute Press. ISBN 0-87021-902-2.
- Enright, Joseph F. & Ryan, James W. (1987). Shinano!: The Sinking of Japan's Secret Supership. New York: St. Martin's Press. ISBN 0-312-00186-X.
- Garzke, William H. & Dulin, Robert O. (1985). Battleships: Axis and Neutral Battleships in World War II. Annapolis, Maryland: Naval Institute Press. ISBN 978-0-87021-101-0.
- Holtzworth, E.C., Commander (January 1946). "Reports of the US Naval Technical Mission to Japan: Ship and Related Targets – Article 2: Yamato (BB), Musashi (BB), Taiho (CV), Shinano (CV)" (PDF). United States Navy. Archived (PDF) from the original on 18 October 2013. Retrieved 6 December 2023.
- Jentschura, Hansgeorg; Jung, Dieter & Mickel, Peter (1977). Warships of the Imperial Japanese Navy, 1869–1945. Annapolis, Maryland: United States Naval Institute. ISBN 0-87021-893-X.
- Preston, Antony (1999). The World's Great Aircraft Carriers. London: Brown Books. ISBN 1-897884-58-3.
- Silverstone, Paul H. (1984). Directory of the World's Capital Ships. New York: Hippocrene Books. ISBN 0-88254-979-0.
- Stille, Mark (2007). USN Carriers vs IJN Carriers: The Pacific 1942. Duel. Vol. 6. Oxford, UK: Osprey Publishing. ISBN 978-1-84603-248-6.
- Tully, Anthony P. (2001). "IJN Shinano: Tabular Record of Movement". Kido Butai. Combinedfleet.com. Retrieved 16 June 2013.
External links
- Two plans of the ship have been located in the National Archives and Records Administration files and are available for download at [1] Archived 1 November 2021 at the Wayback Machine and [2] Archived 1 November 2021 at the Wayback Machine.