Home Intro People Events Equipment Places Maps Books Photos Videos Other Reference FAQ About

World War II Database

Hiyo file photo [6845]


Ship ClassHiyo-class Escort Carrier
Laid Down30 Nov 1939
Launched24 Jun 1941
Commissioned31 Jul 1942
Sunk21 Jun 1944
Displacement24,150 tons standard
Length722 feet
Beam87 feet
Draft27 feet
Machinery6 Kampon water-tube boilers, 2 geared steam turbines, 2 shafts
Power Output56,520 shaft horsepower
Speed25 knots
Range11,700nm at 18 knots
Armament6x2x12.7cm dual-purpose guns, 8x3x2.5cm anti-aircraft guns, 6x130mm anti-aircraft rockets (post-1944)
Armor50mm belt
Aircraft48 operational, 5 in reserve


ww2dbaseHiyo was the lead ship of her class of aircraft carriers. She was originally laid down as the passenger liner Idzumo Maru by Nippon Yusen Kaisha (Japan Mail Steamship company), and was purchased by the Japanese Navy in 1940 for conversion into an aircraft carrier. Although originally destined for Carrier Division 1, upon completion she was assigned to Carrier Division 2, 3rd Fleet instead. On 12 Aug 1942, she became the flagship of Rear Admiral Kakuji Kakuta of Carrier Division 2. On 4 Oct, she departed for Truk, Caroline Islands in the Central Pacific, arriving on 9 Oct. Two days later, she departed for the Solomon Islands for what would become the Battle of Santa Cruz, but while operating off Guadalcanal on 17 Oct, a fire broke out in the generator room; with her speed down to 16 knots, she was sent back to Truk for repairs, thus missing the battle. Repairs began on 26 Oct, and on 13 and 27 Nov, while still under repair, American carrier aircraft attacked Truk, causing minor damage on Hiyo on both dates. On 30 Nov 1942, Captain Michio Sumikawa was assigned to the ship. On 5 Dec, she departed Truk, arriving in Kure, Japan on 11 Dec. Between 26 Feb and 4 Mar, she was in the drydock at Kure. On 27 Mar 1943, she was back in Truk. On 12 Apr, she was damaged by an air raid. On 17 May, she left for Japan as the Combined Fleet evacuated Truk, arriving at Yokosuka, japan on 21 May.

ww2dbaseOn 10 Jun 1943, while off Miyake Jima off southeastern Honshu, Japan, Hiyo was struck in the starboard side by two torpedoes from American submarine USS Trigger. The boiler rooms No. 1 and 2 were flooded, killing a great number of engineers and rendering the ship dead in the water. On the next day, cruiser Isuzu arrived to tow her to port, but by that time Hiyo had already restored partial power so that she could return to Tateyama on her own. After being moved to Yokosuka, she was repaired between 15 Jun and 15 Sep 1943; while under repair, her 48 aircraft were transferred to light carrier Ryuho. On 1 Sep, also while under repair, Captain Izumi Furukawa was assigned as her commanding officer.

ww2dbaseBetween Oct and Dec 1943, Hiyo ferried aircraft from Japan to Singapore, Truk, and Saipan of Mariana Islands. On 15 Feb, Captain Toshiyuki Yokoi took command of the ship.

ww2dbaseAt 1745 on 20 Jun 1944, while sailing with Junyo and Ryuho and covered by Nagato and Mogami, she came under attack by American aircraft during the Battle of the Philippine Sea. A bomb dropped by a dive bomber from USS Enterprise's Air Group 10 exploded above the bridge, wounding Captain Yokoi and killing most of the bridge personnel. Another bomb exploded on the flight deck. Soon after, six TBF Avenger torpedo bombers from USS Belleau Wood attacked her; two were shot down, but one of the torpedos dropped hit the starboard engine room. The engine room flooded, slowing her down. Fires were reported but were initially believed to be contained. The fire, however, led to an explosion in the port quarter, which ignited gas vapors in the entire rear of the ship. She began to settle by the stern with an increasing list to port. She sank at 1932. 247 men were lost, while 1,00 were rescued by destroyers, including Captain Yokoi.

ww2dbaseTo date, official Japanese reports still note that the cause of the final explosion that led to her sinking was caused by another American torpedo. This was due to Yokoi's post-battle report that noted so, probably in error.

ww2dbaseSource: Wikipedia.

Last Major Revision: Dec 2008

Escort Carrier Hiyo Interactive Map


Hiyo, date unknown

Hiyo Operational Timeline

31 Jul 1942 Hiyo was commissioned into service.
22 Mar 1943 Junyo and Hiyo departed Saeki, Hiroshima, Japan with Yugure, Hatsuzuki, Suzutsuki, and Kagero in escort.
27 Mar 1943 Junyo and Hiyo arrived at Truk, Caroline Islands with Yugure, Hatsuzuki, Suzutsuki, and Kagero in escort.
10 Jun 1943 Hiyo, Yugure, and Ariake deparated Yokosuka, Japan at 1400 hours. About 17 miles off Miyake Island at 1852 hours, USS Trigger fired six torpedoes at Hiyo, scoring two hits. In the darkness, at 1937 hours, Hiyo opened fire on Yugure while Yugure swept for the American submarine, killing two and wounding five. Yugure's No. 3 turret's shield was also damaged. Nevertheless, Yugure and Ariake would remain on anti-submarine patrols around Hiyo through the night.
11 Jun 1943 Isuzu, Ariake, and Yugure escorted Hiyo, damaged by USS Trigger on the previous day, toward Yokosuka, Japan.
12 Jun 1943 Isuzu, Ariake, Yugure, and Hiyo arrived at Yokosuka, Japan at 1030 hours. Torpedo-damaged Hiyo entered drydocks at Yokosuka Naval Arsenal for repairs at 1053 hours; her bottom scraped the bottom of the drydock while moving in.

Did you enjoy this article or find this article helpful? If so, please consider supporting us on Patreon. Even $1 per month will go a long way! Thank you.

Share this article with your friends:


Stay updated with WW2DB:

 RSS Feeds

Visitor Submitted Comments

1. daniela says:
10 Jan 2011 10:01:49 PM

very good
2. Anonymous says:
3 Oct 2013 09:53:52 AM

I realize my information is 70 years late in arriving. However, I do believe that the story is correct after reading about the Hiyo. John Day Slighton, Lt.JG Navy Cross winner, Told me this story and I have no reason to believe he made this story up. John said on the day he won his Navy Cross while making a torpedo attack on a Japanese Aircraft Carrier he accidently dropped a torpedo down the smoke stake of the ship which resuled in the ship sinking. This is a short version of his story. His wife is still living at 92 years old. If interested I can give you her name and address but not for the public viewing.

The captian of the Hiyo thought he was hit by a sub if a torpedo went down the smoke stake it would appear that he was hit by a sub. A dive needs to be made on this ship to determine if the explosion came from above or below the ship. I do believe you will find that Dr. John Slighton ,actually spelled SLIGHTOM, did not make this statement up. Why John never told anyone other than family and friends I don't know, but he was not a person to bragg.
3. Anonymous says:
3 Oct 2013 01:38:39 PM

For those that have not checked on the Hiyo, all research indicates that there were no submarines in the area when the Hiyo was sunk, this gives me more reason to believe that a torpedo could have been accidently droped down the stack of the Hiyo. Also, it appears the Caption of the Hiyo did make the correct observation of what happened he just never dreamed that the torpedo came down the stack rather than from a submarine. We will never know what may be the correct history of this battle unless at some time an exploratory dive is made on the ship to see what happened. As stated there was a gasoline explosion, but I thank it was detonated by a torpedo down the stack, dropped by John Slighton and the Yorktown. John said the torpedo stuck in the plane when he first released the torpedo, so he decided to fly over the deck and flap the plane down hard to release the torpedo on the deck and to his suprise when he leaned over he saw the torpedo accidently go down the stack instead. END OF STORY
4. Anonymous says:
14 Oct 2013 06:34:47 PM

I would like to apologize to this website and to anyone mislead by any article about Slighton. This situation did happen but not with this ship. This was my error.
5. Anonymous says:
25 Oct 2013 07:26:54 PM

When I made a retraction of my statement of John Slighton I was under the impression that the Yorktown was out of range to attack the Japanese fleet. However, since making this retraction I have learned that the Yorktown was actually 286 miles from the Japanese fleet . John Slighton left a DVD interview about this battle. In John's interview he stated that the Yorktown did dispatch a squadron to this battle. At mid point all but thee aircraft turned back only thee aircraft stayed the course Slighton was one of the three. Slighton was the only one of the Yorktown three aircraft that was not shoot down. Slighton was at this battle and it is possible that this may actually be the correct ship bases on what the captain of this ship has stated . I have listened to Slighton's interview he did not name the ship but he was at the battle with the Hiyo.
6. Anonymous says:
6 Jan 2015 07:30:06 PM

In most things I have read about the Hiyo I have not read anything about John D. Slighton and the Hiyo. However, if you read the citation for John D. Slighton for the Navy Cross which he received for his action in the battle with the Hiyo he is credited with two direct hit, and then leaving with two Japanese air craft after him which he was able to evaded and made a night landing on the aircraft carrier Princeton. Since this was late in the evening when Slighton made his attack on the Hiyo and it was late in the evening when this ship exploded maybe he really did drop a torpedo down the smokestack. In the Flying Magazine Oct. 1944 page 278 there is an article about John D. Slighton, Anna Illinois, being attack by three Japanese aircraft after he slammed a torpedo into the side of a Japanese aircraft carrier. This man was for real, but he did not bragg about what he did.
7. Anonymous says:
7 Jan 2015 07:13:06 AM

Looking at the information on the Hiyo and John D. Slighton I have no found any recorded information about the Yorktown's TBF Avenger's attack on this ship. However, if you look at the citation for John D. Slighton's Navy Cross which was issued for his action in this battle you will see he is credited with 2 direct hits. Also, in John's DVD it is very clear that his attack was on this ship. In his citation it states that he made 2 direct hits and left the battle with 2 Japanese aircraft attacking him. John evaded these aircraft and made a night landing on the USS Princeton. He said this was the first time he had ever made a night landing. If you look at Flying Magazine, Oct. 1944, page 278 you will see an article about John D. Slighton,LtJG,Anna Illinois. This article states that John D. Slighton was attack by three Japanese aircraft after he slammed a torpedo into the side of a Japanese Aircraft Carrier. Here again it does not give the date or the aircraft carrier. Slighton's attack was late in the evening, and the Japanese thought they may have a chance to save this ship, than all of a sudden it exploded. We can't prove that a torpedo did or didn't go down the smokestack, but could it be that his 2 hits may have been the final blow that sank this ship.

All visitor submitted comments are opinions of those making the submissions and do not reflect views of WW2DB.

Posting Your Comments on this Topic

Your Name
Your Email
 Your email will not be published
Comment Type
Your Comments


1. We hope that visitor conversations at WW2DB will be constructive and thought-provoking. Please refrain from using strong language. HTML tags are not allowed. Your IP address will be tracked even if you remain anonymous. WW2DB site administrators reserve the right to moderate, censor, and/or remove any comment. All comment submissions will become the property of WW2DB.

2. For inquiries about military records for members of the World War II armed forces, please see our FAQ.

Change View
Desktop View

Search WW2DB
More on Hiyo
» Kaneko, Tadashi

Event(s) Participated:
» Mariana Islands Campaign and the Great Turkey Shoot

» Japanese Aircraft Carrier Functions
» Japanese Aircraft Carrier Operational Status By Month
» Japanese Aircraft Carrier Specifications
» Japanese Aircraft Carrier Time Operational

Partner Sites Content:
» Hiyo Tabular Record of Movement

Escort Carrier Hiyo Photo Gallery
Hiyo, date unknown

Famous WW2 Quote
"You ask, what is our aim? I can answer in one word. It is victory. Victory at all costs. Victory in spite of all terrors. Victory, however long and hard the road may be, for without victory there is no survival."

Winston Churchill

Support Us

Please consider supporting us on Patreon. Even $1 a month will go a long way. Thank you!

Or, please support us by purchasing some WW2DB merchandise at TeeSpring, Thank you!