© 1998 Anthony P. Tully

Initial Command Structure:
Commanding Officer: Captain Beppu Akitomo.

21 December 1943:
Conversion from seaplane tender * to aircraft carrier begun 16 January 1943 completed at Yokosuka ten months after it began. Assigned to Northeast Area Force 2nd Base Air Force (AirFlot 51, 12th Air Fleet). Remains at Yokosuka.

29 January 1944:
Depart Yokosuka for Truk with ZUIHO, TAKAO, and destroyers TAMANAMI, WAKABA and HATSUHARU. However, cruiser TAKAO splits off later the same day, having been ordered to assist the torpedoed escort carrier UNYO, now making her way back to Yokosuka.

1 February 1944:
At sea, assigned to Mobile Fleet, to the newly organized Cardiv 3 with sister CHITOSE and the ZUIHO, as part of 3rd Fleet with the also newly 653rd Air Group assigned to Cardiv 3.

2 February 1944:
- Air recon shows Musashi, two carriers, five or six heavy and four light cruisers, and twenty destroyers among a flock of Marus at Truk. [Nagato,Fuso, and other ships had already left for Palau-Ugaki].[Carriers probably Junyo and Ryuho]. Tipped off by this recon, Koga orders the rest to leave Truk for Palau.[Carriers can not include Chitose, she is in Sasebo; not Junyo, still under repair in Japan; nor Ryuho, she is in the Inland Sea; . One is surely Zuiho, showing as present at Truk 3rd to 10th, the other Chiyoda, showing as having arrived apparently with Zuiho on the 3rd, and departs when she does].
3 February 1943:
Arrive at Truk.

10 February 1944:
Following invasion of Kwajalein, CinC Combined Fleet orders departure from Truk back to rear areas. Depart Truk in company with ZUIHO, HATSUHARU and WAKABA.

15 February 1944:
Arrived at Kure with ZUIHO carrying surviving units of ZUIKAKU air units.Captain Beppu relieved by Captain Jyo Eiichiro as commanding officer.

22 February 1944:
Depart Kure.

26 February 1944:
Arrive at Yokosuka.

1 March 1944:
Assigned to emergency plane shipment and reinforcement duty along with carrier RYUHO. CHIYODA departs Yokosuka for Saipan, escorted by INAZUMA and HIBIKI who remain with her throughout the month long roundabout voyage.

5 March 1944:
Arrive at Saipan, depart next day, arrive at Guam same evening.

8 March 1944:
Depart Guam, arrive Saipan same day.

10 March 1944:
Depart Saipan for Palau, with CHIYODA having embarked 201 Air Group for relocation to Palau.

12 March 1944:
Arrive at Palau.

15 March 1944:
Depart Palau.

19 March 1944:
Arrive Balikpapan.

21 March 1944:
Depart Balikpapan for Palau.

24 March 1944:
Arrive Palau.

27 March 1944:
Depart Palau back to Balikpapan.

29 March 1944:
Commander Kimura Gunji [52] appointed to command 653rd Air Group.

30 March 1944:
Arrive Balikpapan.

1 April 1944:
Depart Balikpapan for Davao.

3 April 1944:
Arrive at Davao.

5 April 1944:
Depart Davao for Kure.

10 April 1944:
Return to Kure.

11 May 1944:
After taking aboard aircraft of Air Group 653 on the 5th and 6th, departed Saeki for Tawi Tawi. Teamed with sister-ship CHITOSE, rendevoused with task force led by super-battleship MUSASHI, comprised of ZUIHO, JUNYO, HIYO, RYUHO, MICHISHIO, SHIGURE, and AKISHIMO.

12 May 1944:
Arrive at Okinawa temporarily, depart again.

16 May 1944:
Arrive at Tawitawi as part of the Mobile Fleet's assembling for "A-GO Operation" the defense of the Saipan/Marianas area.

22 May 1944:
Carried out take off and landing exercises with sister CHITOSE of their Air Group 653 in waters outside Tawi Tawi. Desron 2 screening.
Action:
- 1225 CHITOSE attacked by U.S. submarine PUFFER which fired six torpedoes. CHITOSE avoided some by hard right turn and some of the torpedoes prematured. CHIYODA astern takes course to clear the area. No damage is sustained by either carrier, but the exercises are cancelled and they returned to Tawi Tawi.

13 June 1944:
Depart Tawitawi for Guimaras, to escape the mounting submarine danger to the former, and respond to the attacks on Saipan on 11-12 June.

14 June 1944:
Arrive at Guimaras and begin taking on supplies.

15 June 1944:
"A-GO" Operation activated. Depart Guimaras with sister ship CHITOSE and rest of Mobile Fleet for the Battle of the Marianas (Battle of the Philippine Sea).

17 June 1944:
Sunrise: CHIYODA launched six B6N-Rs for search operations.

18 June:
Action:
- 1530 By order of Comcardiv 3 Obayashi Sueo CHIYODA launched 3 attack planes (to serve as pathfinders/guides), 15 Zeros as fighter-bombers, and 4 Zero fighters to attack enemy carrier fleet sighted at 1415 designated position `15-i. However, the attack is almost immediately recalled by radio command from Admiral Ozawa on TAIHO. One fighter bomber misses the deck and crashes into the sea on landing.

19 June 1944:
Launch air strikes in first day of the Battle of the Marianas. In the battle form part of the "Van Force" comprised of CHITOSE, CHIYODA, and ZUIHO screened by YAMATO, MUSASHI, HARUNA, KONGO, ATAGO, TAKAO, MAYA, CHOKAI, NOSHIRO, ASASHIMO, KISHINAMI, OKINAMI, TAMANAMI, HAMAKAZE, FUJINAMI, and SHIMAKAZE.

20 June 1944:
Air attack: At 1738 hit by one bomb on the flight deck aft, that started a moderate fire before it was extinquished. The bomb hit killed twenty men and wounded thirty, and destroyed two planes.

22 June 1944:
Anchor temporarily at Okinawa, depart next morning for the homeland.

1 July 1944:
Arrive Kure, enter drydock the next day for repairs.

9 July 1944:
Leave drydock, and remains in Kure for remainder of month.

3 August 1944:
Assigned to 2nd Diversion Attack Force. Remains in Inland Sea area.

20 October 1944:
Depart Oita with Ozawa's decoy Mobile Fleet (Third Fleet, CarDiv 3) for the Battle of Leyte Gulf. Force comprised of ZUIKAKU, ZUIHO, CHITOSE, CHIYODA, screened by HYUGA, ISE, OYODO, TAMA, ISUZU, HATSUZUKI, AKIZUKI, WAKATSUKI, SHIMOTSUKI, MAKI, KIRI, KUWA and SUGI.

24 October 1944:
Action:
- 1150 CHIYODA attack force launched. One aircraft plunges into the sea immediately after take-off.
- 1704 CHIYODA launched 3 fighters.
- 1813 CHIYODA recovered her aircraft.

25 October 1944:
Battle off Cape Engano:

WRITER's PREFACE: Because of the sad fact that no survivors of CHIYODA appear to have turned up post-war, the carrier's fate must be related as preserved by the observations of other ships and any messages exchanged. The reader must pardon the density of raw text. It is presented to allow maximum freedom of analysis.

Action:
- 0700-0730 Mobile Force assumes #4 Alert Cruising Dispotion.[Group 5 is ZUIKAKU, ZUIHO, OYODO, AKITSUKI, TAMA, WAKATSUKI, ISE, Group 6 is ISUZU, SHIMOTSUKI, SUGI, MAKI, HYUGA, and KIRI with CHITOSE and CHIYODA]. CHIYODA and CHITOSE steaming in parallel formation in rear of two circles, with CHITOSE on the starboard flank, CHIYODA the port.
- [0817-0855 First wave of planes from Task Force 38 attack.]
- 0824 CHIYODA and CHITOSE open AA gunfire. Most of enemy attacks CHITOSE which is heavily damaged and left slowing and listing to port.
- 0840 Destroyer SHIMOTSUKI on the port quarter succeeds in dispersing the attackers with accurate AA fire.
- 0925 CHITOSE announces she is dead in the water, operating on diesel power only, expected to last about five hours. Comcardiv 4 Matsuda orders CHIYODA to detach and speed up to head north to follow Ozawa's group. HYUGA and MAKI follow, leaving CHITOSE astern.
- 0937 Sister-ship CHITOSE is steeply listing to port and sinks stern first. Destroyer SHIMOTSUKI and cruiser ISUZU stop and begin rescue operations. As a result, the screen around CHIYODA thins more.
- 0942 HYUGA reports radar contact on a group of planes approaching from the south-southwest, range 60 kilometers.
- 0949 SHIMOTSUKI has to abandon rescue work at CHITOSE sinking site and move north, as a second wave of enemy planes is approaching to attack CHIYODA.
- 0956 CHIYODA's formation at this time CHIYODA in front with HYUGA on the starboard quarters; MAKI to port aft further back than HYUGA; SHIMOTSUKI coming up from the south to rear of MAKIN with ISUZU starboard nearly abeam of SHIMOTSUKI.
- 0959 Before SHIMOTSUKI and ISUZU can overtake from astern, CHIYODA comes under attack.
- 1000 Direct 500 kg bomb hit on the port quarter of the flight deck and series of damaging near-misses to starboard. Fires broke out and some magazines had to be flooded. Between the damage to the hull and the intentional flooding CHIYODA assumes a thirteen degree list to starboard. Due to loss of helm control from the bridge, CHIYODA has to resort to hand steering.
- 1008 ISUZU hit on No.2 turret by a small bomb.
- 1012 SHIMOTSUKI reaching the carrier sees CHIYODA listing to starboard and closes.
- 1016 CHIYODA's starboard engine room floods and stops. Soon after, the carrier goes dead in the water. SHIMOTSUKI and MAKI ordered to assist.
- 1018 CHIYODA dead in the water, HYUGA begins to circle her.
- 1025 SHIMOTSUKI commences also circling stalled CHIYODA at No.1 battle speed.
- 1050 CHIYODA notifies ComCardiv 4: "From now on, we are starting to navigate on one set [port] of engines only. All our signal lamps are out of commission---starboard engine room flooding; attempting to correct list."
- 1055 To the south, ISUZU is starting to rescue CHITOSE survivors.
- 1100 CHIYODA to ComCardiv 4: "Now unable to navigate on remaining engine."[1]
- 1105 AA action opened. The support ships are circling CHIYODA at speed in two layered clockwise circles; the outer has MAKI and SHIMOTSUKI, and the inner circle is the HYUGA. Fire checked on minute later.
- 1115 CHIYODA confirmed to HYUGA that she was unnavigable.
- 1120 SHIMOTSUKI ordered to head south and return to the rescue of CHITOSE survivors. Departs at full speed.
- 1155 HYUGA maneuvers to prepare to take CHIYODA in tow. But a moment later, given the obvious target the battleship-carrier makes, Matsuda reconsiders. At 1202 HYUGA orders CHIYODA to prepare for towing stations and for ISUZU to come tow CHIYODA. Then engaged in rescue ops at CHITOSE sinking location with SHIMOTSUKI, the ISUZU suspends that rescue and heads north to comply. The destroyer continues the rescue.
- 1218 ISUZU pulls in front of CHIYODA but is now notified that the carrier can't really help. CHIYODA's anchor windlass is inoperative. Jyo's crew asks ISUZU to provide a tow line. In response to inquiry whether can provide some towing movement, CHIYODA telegrams the cruiser that "engines on both sides unuseable."
- 1225 HYUGA calls off towing attempts as a third wave of enemy aircraft are detected approaching. [2]
- The third wave does not attack the small group for it continues north to go after ZUIKAKU and ZUIHO. But the disruption in the damage control work proves problematic. Fires and flooding had resumed while CHIYODA was drifting under the squall.
- 1239 SHIMOTSUKI leaves the place of CHITOSE's sinking and heads north to the stalled CHIYODA. MAKI does the same from the AKITSUKI rescue.
- 1245 Comcardiv 4 orders ISUZU to return to towing attempt with CHIYODA.
- 1317 ISUZU checks fuel. She reports to HYUGA only 400 tons left and therefore "even at 12 knots could not reach port if towing CHIYODA."
- 1320 HYUGA orders ISUZU: "Dispose of CHIYODA if need be."
- 1320 SHIMOTSUKI returns to vicinity of CHIYODA. HYUGA and MAKI circling the carrier. ISUZU continues making attempts to get into towing position.[3]
- 1340 ISUZU approaches CHIYODA.
- 1350 HYUGA and SHIMOTSUKI steam away from CHIYODA on due north course "to divert the enemy" while MAKI remains behind.
- 1414 Apparently it was decided CHIYODA could at least be towed a little distance more north out of the battle zone without seriously expending ISUZU's fuel. The light cruiser is again making preparations to tow CHIYODA when attacked by planes. One bomb hits the AA platform in front of the bridge. She is forced to switch to emergency steering.
- 1420 ISUZU again moves into possible tow position for CHIYODA but more aircraft are approaching and six minutes later she opens fire.
- 1431 With MAKI approaching from the south, ISUZU notifies of her steering casualty and that she is down to 400 tons of fuel and not able to tow CHIYODA.
- 1440 ISUZU advises MAKI that with her steering gear damaged she is maneuvering too erratically for transfer operations, and directs MAKI instead to remove CHIYODA's crew.
- 1525 MAKI replies that she is heading due north. ISUZU responds with warning to not "approach while we are on manual steering."
- 1540 ISUZU ordered by Comcardiv 4 to remove CHIYODA's crew and then scuttle the carrier with torpedoes. But this is also frustrated due to continuing danger from air surface attack. ISUZU advises "Starting back for CHIYODA now." However, only eight minutes later (1548) ISUZU sees AA bursts and smoke rising from CHIYODA's position on the southern horizon. It is too late: CHIYODA is coming under attack again. She reverses course.
- 1620 ISUZU sights ISE.

Sunk:
- 1624 CHIYODA attacked by gunfire of U.S. Navy Task Group 38.3 (four cruisers NEW ORLEANS, WICHITA, nine destroyers) surface forces, and stubbornly returns fire. They open fire at a range of 20,000 yards.
- 1640 CHIYODA is a mass of flames and giving off a towering column of black smoke.
- 1655 Hit repeatedly - CHIYODA rolled onto her starboard beam ends - hung there for a few moments - then settled bow down and disappeared. [2] Though scores of men are seen "swarming over her sides" as she heels over no survivors are permitted to be rescued. Thus, apparently Captain Jyo Eiichiro and the entire crew of probably about 970 officers and men perish (but see Note 3). (Position 18 - 37' N, 126 - 45 E')
- 1734 Correctly guessing that CHIYODA must have gone down by now under renewed enemy attacks, ISUZU decided to return to the scene and rescue any survivors thus cast adrift. She turns at 1747 and heads back south at full speed, signalling for MAKI to accompany her. However, MAKI is too damaged and overloaded both and at 1751 signals is down to 90 tons of fuel; ISUZU has to proceed alone. However, at:
- 1820 South-bound ISUZU encounters north-bound WAKATSUKI and HATSUZUKI with ZUIKAKU survivors. The cruiser signals for them to follow and the two destroyers make 180s and follow the cruiser. The pair soon pull ahead of the ISUZU
- 1853 HATSUZUKI suddenly comes under gunfire from the American surface force that sank CHIYODA.
- 1905 HATSUZUKI opens fire. Two minutes later ISUZU is straddled on either side of the bow. Radar indicates enemy is 24,500 meters to the south. Matsuda decides to retire and prepare torpedoes. ISUZU turns to course 320.
- 1940 ISUZU with WAKATSUKI in her wake retires to the north. All hope for rescue of both CHIYODA and HATSUZUKI crews is lost. [3]

20 December 1944:
Removed from the Navy list.

[2] - It is unknown if any of CHIYODA's crew transferred to other ships after she went dead in the water, but it is clear that the much of the crew remained aboard at action stations. On the other hand the assumption to date that none had the opportunity to transfer seems clearly mistaken. There was a window of time being prepared for towing when some transshipping may have taken place. It may be significant that Ikeda's loss register gives a figure smaller than her complement -- perhaps survivors removed prior were known to that work. (-Tully)

[2] The few accounts that mention it describe CHIYODA's final list and roll-over as to port, but she had been listing to starboard throughout, and close examination of the description makes it clear that the carrier's orientation has been confused. The final capsize was indeed also to starboard. This minutiae is only of interest insofar as it perstains to the damage below decks and effect of the shellfire. (- Tully)

[3] - There is indication that CHITOSE and CHIYODA's statutory complements actually decreased by 1944 due to desparate shortages of manpower. CHITOSE in 1943 is listed as having the following - Warrant Officers and above: 99; Petty Officers: 269; Sailors: 720. This gives a total of 1,088. Yet while figures for CHIYODA are not available, CHITOSE Action Report for Cape Engano shows she actually had only a total of 972 officers and men - Broken down this way: Warrant Officers and above: 77; Petty Officers: 234; Sailors: 657; Civilians attached to Navy service: 4. A similar reduced figure thus probably held for CHIYODA and not the 1,470 figure usually quoted.

Remarks:
Bob Hackett and Sander Kingsepp have posted a TROM covering CHIYODA's earlier career as a seaplane/midget submarine carrier on Sensuikan!