© 1999 Anthony P. Tully (revised 2007)
1 July 1942:
Conversion from NITTA MARU to an escort carrier begun at Kure, with Captain Okura
Tomasaborou assigned as fitting-out officer.
25 November 1942:
Conversion to an escort carrier completed at Kure, named CHUYO and assigned to Combined Fleet. Captain
Tomasaborou remains as commanding officer.
28 November 1942:
Arrive at Yokosuka, and enter drydock.
4 December 1942:
Undocked.
12 December 1942:
Depart Yokosuka for Truk on the first of thirteen voyages ferrying planes, supplies, and passengers.
Note: almost invariably the screen was the "workhorses" of Desdiv 7, the AKEBONO, SAZANAMI, and USHIO. When others
are present, they are mentioned.
18 December 1942:
Arrive at Truk; Depart 21 December back for Yokosuka.
26 December 1942:
Return to Yokosuka.
2 January 1943:
Depart Yokosuka.
8 January 1943:
Arrive at Truk, escorted by SHIGURE and ASAGUMO.
10 January 1943:
Depart Truk.
12 February 1943:
Arrive at Truk; 15th depart.
20 February 1943:
Arrive at Yokosuka.
28 February 1943:
Depart Yokosuka for Truk.
5 March 1943:
Arrive at Truk, departs on the 8th.
13 March 1943:
Returns to Yokosuka and remains there till the end of the month.
4 April 1943:
Depart Yokosuka with TAIYO and CHOKAI for Truk, escorted by HIBIKI, KUROSHIO, and SAZANAMI.
7 April 1943:
Stopover at Saipan; depart same day.
9 April 1943:
Late evening: Approaching Truk, the task force is attacked by USS TUNNY. But her torpedoes malfunction,
inflicting merely dents on TAIYO.
10 April 1943:
Arrive with TAIYO and CHOKAI at Truk.
16 April 1943:
Depart Truk with TAIYO escorted by SHIGURE and HIBIKI for Yokosuka.
17 April 1943:
Stopover at Saipan; joined by SAZANAMI, depart the same day.
21 April 1943:
Arrive at Yokosuka, depart again with UNYO and TAIYO, escorted by NAGANAMI and SHIGURE, for Truk on the 25th, arriving there on the 30th.
8 May 1943:
Depart Truk for Yokosuka.
13 May 1943:
Arrive with UNYO at Yokosuka, both carriers turn around and depart again for Truk on 24 May.
29 May 1943:
Arrive with UNYO at Truk.
5 June 1943:
Depart Truk accompanying UNYO for Yokosuka, arriving on the 9th.
8 June 1943:
Action:
- 2316 Task Force attacked by submarine from starboard flank. No damage; torpedoes prematured or missed.[Position: 31-30'N, 143-10'E. Attacker was USS SCULPIN SS-191. Fired four torpedoes at last carrier in column which was probably CHUYO. Submarine was using K-time 0016 9 June].
16 June 1943:
Depart Yokosuka with RYUHO and UNYO for Truk.
21 June 1943:
Arrive at Truk, depart to Yokosuka on 28 June, arriving with UNYO 2 July at Yokosuka.
10 July 1943:
Depart Yokosuka for Truk; arriving there on 16 July.
19 July 1943:
Depart Truk with RYUHO and UNYO for the homeland, arriving at Yokosuka on 24 July. A rest is now taken, the
ship remaining home through the end of the month.
9 August 1943:
Enter drydock at Yokosuka.
18 August 1943:
Undocked.
7 September 1943:
Voyages resume; depart Yokosuka with TAIYO for Truk. Arriving at Truk on 11 September.
21 September 1943:
Depart Truk with TAIYO for Yokosuka, escorted by SHIMAKAZE.
24 September 1943:
South of Yokosuka, TAIYO is hit by torpedo in starboard quarter from USS CABRILLA. Moderate
damage and a loss of a shaft is inflicted, and CHUYO has to take her in tow.
26 September 1943:
Return safely to Yokosuka with the damaged TAIYO.
27 September 1943:
Attached to Combined Fleet.
4 October 1943:
Depart Yokosuka for Truk, arriving on the 10th.
15 October 1943:
Depart Truk; returning to Yokosuka on 20 October.
27 October 1943:
Depart Yokosuka.
1 November 1943:
Arrive at Truk; depart on the 5th with ZUIHO for Japan.
10 November 1943:
Return with ZUIHO to Yokosuka.
15 November 1943:
Attached to Grand Escort Command.
16 November 1943:
Depart Yokosuka with ZUIHO and UNYO for Truk; arriving there on 21 November.
30 November 1943:
0530: Depart Truk via the North Channel for Yokosuka as part of a task force led by ZUIHO, and comprised also of UNYO and MAYA, and escorted by AKEBONO, SAZANAMI, URAKAZE, and USHIO. Aboard the CHUYO and UNYO are twenty-one and twenty POWs respectively from USS SCULPIN, sunk 19 November by YAMAGUMO. OTC command is CO heavy cruiser MAYA, Captain Kato.
Action:
- 1012 [1112-King time for sub] Warned by ULTRA the USS SKATE ambushed the force outside of Truk. Four torpedoes were fired apparently at one of the Taiyo-class carriers' starboard side but seemingly prematured just short of one. No damage received. SKATE reported thirteen depth-charges dropped in response.
2 December 1943:
Action:
- 2157 IJN [2257 K-time used by sub] Task forced attacked by USS GUNNEL. Aided by a zig toward, fired four torpedoes at the port side of the lead carrier - apparently ZUIHO -- on a 90 degree port track. They apparently missed but except for four explosions believed to be four depth-charges the Japanese do not appear to react.
3 December 1943:
Action:
- 1538 Task Force received warning of a submarine alert from Combined Fleet. (Undoubtedly one or more of the submarines reporting sightings had been overheard or observed)
- 2230 Fleet entered typhoon weather but does not alter course despite forty-fifty knots winds and very heavy seas. However, the submarine danger is considered sufficiently muted that they ceased zigzagging for seakeeping.
- At 2310, while the fleet is struggling through typhoon weather the CHUYO is hit by in port bow magazine by torpedo from USS SAILFISH (SS-192) in position: 32-30'N, 143-40'E. Though neither the magazine or the av-gas tanks forward of it are set off; a fire is started in the No.3 crew space above the impact and bow plates are torn. But the carrier is able to maintain headway. However, the shipping water forward lowers the bow and curtails speed.[Note 1] Kato on MAYA orders URAKAZE to guard CHUYO and the rest of the fleet to proceed with CHUYO to follow as best can. It seems these orders were not received. After first correcting some rudder malfunctions CHUYO had to follow the fleet at half-speed on her own as best she could.
4 December 1943:
- At 0455 is hit again by one or two torpedos of two fired which struck at the junction of the boiler room and port engine room in a second attack by SAILFISH. [Note 2] Chief Engineer Fujitsu Kichitaro and apparently all hands are killed by immediate inundation of the machinery rooms and boilers exploding. Carrier is stopped dead in the water down somewhat at the stern with a small port list and unable to navigate - position: 31-55'N, 143-40'E. Destroyers URAKAZE and SAZANAMI with cruiser
MAYA come to assist and make prepations for towing. Despite this aid, at:
- At 0842 the ship is again attacked and hit by one or two torpedoes in the port side that reportedly hit under the bridge. This was nearly the same spot as the first hit and the increased damage must have been great. Flooding massively, she now began to plunge sharply by the bow and heel to port. Captain Tomasaborou gave the order to lower the ensign and abandon the ship, but made clear he intended to go down with her.
Sunk:
- 0847 CHUYO plunged by the bow under the waves barely six minutes after being hit. As a result, loss of life was very heavy. Reportedly between crew and passengers nearly 3,000 were aboard at the time. Of these, Captain Tomasaborou and 513 officers and men were lost. One source says that more than 730 passengers went down with the ship, but the figure appears higher when considering how few survivors there were. A mere 130 men are picked up by URAKAZE with another 30 by SAZANAMI. Among the lost
twenty of the U.S. POWs from USS SCULPIN.Only one of the POWs survived to be rescued among the mere 160 survivors found by SAZANAMI and URAKAZE.[See Note 3]
5 February 1944:
Removed from Navy List.
Remarks:
First of four Japanese escort carriers to be sunk by U.S. submarines in the Pacific War.
Note 1: Prior accounts of CHUYO, including earlier versions of this TROM, spoke of the flight deck forward collapsing from the bow being shattered by the torpedo hit. However, this entire assumption derived from mis-identified photograph evidence that showed what was long alleged to be CHUYO dead in the water with a collapsed forward flight deck and missing prow, with a destroyer alongside. Supposedly this was URAKAZE and the view taken from the air just before she was struck a third time and sunk. Earler Japanese works had not yet caught this error and so the received record led to some understandable mis-interpretation of the evidence.
However Japanese historian Katsura Rihei convincingly demonstrated the photo is of sister-ship UNYO, which suffered precisely such bow damage and collapse in January 1944 after submarine attack. Furthemore, the final snapping of the bow occurred outside Yokosuka, where such photograph from the air could be taken. The destroyer is apparently KISHINAMI. As a final point, I might add the sketch of CHUYO before the third attack made through the periscope shows an intact bow. This can be considered tentatively supporting real-time evidence CHUYO had not lost her bow or flight deck, which accords with Japanese survivors correcting this point for Mr.Katsura.
Sketch of CHUYO about 0700 4 December 1943:
Note 2: Some Japanese writings recall just one hit in the second attack but the official reel record lists two, after correctly noting one earlier. It is intriguing to note that SAILFISH believed her second attack was on the target's starboard side and lists the attacks as a starboard track but the official reel TROM of the carrier CHUYO says "hit by two torpedoes from enemy submarine (port engine room)" in the second attack. This also incidentally tends to confirm the submarine's claim both were observed to hit. It is significant that the carrier had a modest list to port and was down by the stern when observed at length by the submarine prior to its third and final attack.
Note 3: It is unknown whether the figure of 737 passengers reported lost with 513 of CHUYO's crew includes the U.S. PoWs. If the figures do not, the actual number of passengers lost was 757 and the actual saved 161. The best evidence indicates it was URAKAZE that rescued George Rocek, the single SCULPIN survivor of the carrier's sinking. Incidentally, The Japanese and the lone American survivor agree CHUYO dramatically plunged by the bow while lurching sharply to port though the exact nature of the final damage remains unknown.
Translation of keys:
http://www.combinedfleet.com/Taiyo-CVE-caption-key-GranPrixShuppan.rtf
