Op I-Go to Iwo Jima

[rjl3]

I have just learned that some Japanese reinforcements to Iwo Jima including Tank Landing Ships were organized as Operation I-Go.

伊號輸送部隊

So far I have found information on I Go-1, -3, and -4.

I have not been able to find anything on I Go-2 (if it actually happened) or any larger numbers.

Does anyone have additional info on these I-Go convoys?

Ralph

[fontessa]

I have just learned that some Japanese reinforcements to Iwo Jima including Tank Landing Ships were organized as Operation I-Go.

伊號輸送部隊

So far I have found information on I Go-1, -3, and -4.

I have not been able to find anything on I Go-2 (if it actually happened) or any larger numbers.

Does anyone have additional info on these I-Go convoys?

Ralph

Operation I-Go 伊号作戦 was conducted by 11th Torpedo Squadron.
The ships involved are divided into the following four.
1st Transport Unit: CL Nagara, DD Fuyuzuki and DD Matsu
2nd Transport Unit: CL Kiso, CL Tama, DD Wakana and DD Hatsuharu
3rd Transport Unit: DD Hatakaze, DD Shiokaze and DD Yuzuki
4th Transport Unit: 4th Transport Ship (T-4, Equivalent to APD), T-104, T-152, T-153 (Equivalent to LSMs) and Transport Noto Maru

According to 11th Torpedo Squadron War Diary, the movements of ships involved were as follow.
1st Transport Unit
Nagara: Yokosuka 28 June 1944 - 30 June Chichijima 1 July - 2 July Yokosuka
Fuyuzuki: Yokosuka 28 June 1944 - 30 June Chichijima 1 July - 3 July Yokosuka
Matsu: Yokosuka 28 June 1944 - 30 June Chichijima 1 July - 2 July Yokosuka
2nd Transport Unit
Kiso: Yokosuka 30 June 1944 - 1 July Chichijima 2 July - 3 July Yokosuka
Tama: Yokosuka 30 June 1944 - 1 July Chichijima 2 July - 3 July Yokosuka
Wakana: Yokosuka 28 June 1944 - 30 June Chichijima 2 July - 3 July Yokosuka
Hatsuharu: Yokosuka 28 June 1944 - 30 June Chichijima 2 July - 3 July Yokosuka
3rd Transport Unit
Hatakaze: Yokosuka 28 June 1944 - 30 June Chichijima 1 July - 3 July Yokosuka
Shiokaze: Yokosuka 28 June 1944 - 30 June Chichijima 1 July - 3 July Yokosuka
Yuzuki: Yokosuka 28 June 1944 - 30 June Chichijima 1 July - 2 July Iwo Jima 2 July - 3 July Chichijima
4th Transport Unit
T-4: Yokosuka 29 June 1944 - 30 June Chichijima 1 July - 3 July Yokosuka
T-104: Yokosuka 28 June 1944 - 30 June Chichijima 2 July - 3 July Iwo Jima??? - ??? Yokosuka
T-152: Yokosuka 28 June 1944 - 30 June Chichijima 2 July - 3 July Iwo Jima ??? - ??? Yokosuka
T-153: Yokosuka 28 June 1944 - 30 June Chichijima 2 July - 3 July Yokosuka
Noto Maru: Yokosuka 28 June 1944 - 30 June Chichijima 1 July - 3 July Yokosuka

According to Senshi Sosho Vol.13, the reinforcement units below were transported to Iwo Jima with Operation I-Go.
20th Specially Established Machine Cannon Unit
21st Specially Established Machine Cannon Unit
Unnumbered Rocket Company
10th Independent Rapid-firing Battalion
11th Independent Rapid-firing Battalion
12th Independent Rapid-firing Battalion
3rd Battalion and Signal Unit / 17th Independent Mixed Battalion
I think the above units could be transported to Iwo Jima by only T-4, T-104, T-152 and T-153. I wonder why 1st - 3rd Transport Units went to Chichijima.

I have shown the position of “Ogasawara Futami” in the東松03 thread. Futami positioned / positions in Chichijima. That is;
Tokyo Prefecture > Ogasawara Islands (Administratively Ogasawara Village) > Chichijima > Ogasawara Village Government Office and Futami Port
Futami was very useful for the relay point for southern routes.

fontessa

[fontessa]

4th Transport Unit
T-4: Yokosuka 29 June 1944 - 30 June Chichijima 1 July - 3 July Yokosuka
T-104: Yokosuka 28 June 1944 - 30 June Chichijima 2 July - 3 July Iwo Jima??? - ??? Yokosuka
T-152: Yokosuka 28 June 1944 - 30 June Chichijima 2 July - 3 July Iwo Jima ??? - ??? Yokosuka
T-153: Yokosuka 28 June 1944 - 30 June Chichijima 2 July - 3 July Yokosuka

輸送艦.jpg (113.62 KiB) Viewed 1472 times

fontessa

[ijnfleetadmiral]

What I have for them:

T-4
Commanding Officers
(CEO) - LCDR KAWAHARA Masayori (Res.) - 10 May 1944 - 15 June 1944
LCDR / CDR* KAWAHARA Masayori (Res.) - 15 June 1944 - 4 August 1944 (KIA)

Navigators
(EO) - LT SASAKI Masaru (Res.) - 10 May 1944 - 15 June 1944
LT SASAKI Masaru (Res.) - 15 June 1944 - 4 August 1944

Chief Engineers
(EO) - LT KATO Masayuki (Res.) - 10 May 1944 - 15 June 1944
LT KATO Masayuki (Res.) - 15 June 1944 - 4 August 1944

T-104
Commanding Officers
(CEO) - LT MAEDA Tsuneo (Res.) - ??? - 25 May 1944
LT MAEDA Tsuneo (Res.) - 25 May 1944 - 13 December 1944

T-152
Commanding Officers
(CEO) - LT TAKESHITA Yoshimasa (Res.) - ??? - 25 May 1944
LT TAKESHITA Yoshimasa (Res.) - 25 May 1944 - 2 August 1944

T-153
(CEO) - LT ISHIDA Yasuo (Res.) - ??? - 15 June 1944
LT ISHIDA Yasuo (Res.) - 15 June 1944 - 25 March 1945
LT / LCDR AMANO Takaya (Res.) - 25 March 1945 - 1 April 1946

[fontessa]

11th Destroyer Squadron
Activated on 1 April 1943.
Deactivated on 15 July 1945.
Commanding Officers
RADM / RADM KIMURA Osamu 木村進 (40): 1 April 1943 - 20 November 1943 (11 C13072090400 / 20 C13072094500)
VACANT: 20 November 1943 - 15 December 1943
RADM / RADM TAKAMA Tamotsu 高間完 (41): 15 December 1943 - 1 July 1945 (1 C13072094900 / 11 C13072106100)
RADM / RADM MATSUMOTO Takeshi 松本毅 (45): 1 July 1945 - 15 July 1945 (11 C13072106100 / 10 C13072106400)
Staff Officers
(Head)
CDR / CAPT OKAMOTO Jiro 岡本次郎 (50): 1 April 1943 - 25 March 1945 (14 C13072090400 / 4 C13072104200)
CAPT / CAPT MATSUBARA Takisaburo 松原瀧三郎 (52): 25 March 1945 - 15 July 1945 (4 C13072104200 / 11 C13072106400)
??? / CAPT YOKOTA Minoru 横田稔 (51): ??? - 15 September 1945 (37 C13072107600)
(Gunnery)
LT / LCDR KOGA Yuko 古賀祐光 (41): 1 March 1944 - 15 July 1945 (14 C13072106400)
(Communications)
VACANT: 1 April 1943 - 1 August 1944
LT / LT ASONUMA Hirosato 阿曽沼広郷 (67): 5 October 1944 - 15 July 1945 (2 C13072101500 / 16 C13072106400)
(Engineer)
LT / LT SEKI Shigemi 関重美 (Eng.42): 1 April 1943 - 15 October 1943 (23 C13072090400 / 42 C13072093800)
LT / LT YAMAMOTO Sokichi 山本壮吉 (Eng.43): 15 October 1943 - 1 March 1944 (42 C13072093800 / 2 C13072096400)
LT / LCDR OSAKO Yoshikazu 大迫吉一 (???): 1 March 1944 - 20 February 1945 (2 C13072096400 / 35 C13072103500)
LT / LCDR YASUMIZU Minoru 安水稔 (???): 20 February 1945 - 15 July 1945 (35 C13072103500 / 20 C13072106400)
(TEMPORAL)
LCDR / LCDR OTA Kazumichi 太田一道 (59): 15 September 1943 - 25 November 1943 (38 C13072093000 / 42 C13072094500)

fontessa

[ijnfleetadmiral]

LT / LCDR OSAKO Yoshikazu 大迫吉一 (???): 1 March 1944 - 20 February 1945 (2 C13072096400 / 35 C13072103500)
LT / LCDR YASUMIZU Minoru 安水稔 (???): 20 February 1945 - 15 July 1945 (35 C13072103500 / 20 C13072106400)

OSAKO Kichiji 大迫吉二 (Eng. 45)
YASUNAGA Minoru 安永稔 (Eng. 47)

Other ships in the list:

MATSU
Commanding Officer: LCDR YOSHINAGA Gen (61)
Torpedo Officer: LT FURUTANI Teruji (70)
Gunnery Officer: LT FUNAHASHI Minoru (68)
Navigator: LTJG HASUHARA Toshiyuki (Res.)
Chief Engineer: LT NAGAYAMA Yoshikichi (Spec. Duty)

SHIOKAZE
Commanding Officer: LT YASUMOTO Shisei (65)
Torpedo Officer: UNKNOWN
Gunnery Officer: LTJG OTOMO YU (71)
Navigator: LTJG NISHI Motoi (Res.)
Chief Engineer: LTJG MIURA Zensuka (Spec. Duty)

HATAKAZE
Commanding Officer: LT TAKAYANAGI Chikamitsu (64)
Torpedo Officer: UNKNOWN
Gunnery Officer: LT ASATO Yoshio (70); relieved by LTJG WAKAMATSU Saburo (71) on 1 July 1944
Navigator: LT NAKANO Keijiro (Res.)
Chief Engineer: UNKNOWN

YUZUKI
Commanding Officer: LCDR MATSUMOTO Shohei (59)
Torpedo Officer: LTJG NISHIMURA Yukio (71)
Gunnery Officer: LTJG SHIRAKAWA Tamotsu (Spec. Duty)
Navigator: LTJG MIZUTANI Hiroyasu (71)
Chief Engineer: LT SHIIE Minoru (Spec. Duty)

HATSUHARU
Commanding Officer: LCDR NAGAKURA Yoshiharu (60)
Torpedo Officer: LT KAMEYAMA Takeshi (67)
Gunnery Officer: LT SHIRAISHI Norio (69); relieved by LTJG HIROSAKI Ryoji (71) on 1 July 1944
Navigator: LT OCHIAI Yutaka (Res.)
Chief Engineer: LT YAMAGUCHI Shigeto (Spec. Duty)

WAKABA
Commanding Officer: LCDR NINOKATA Kanehumi (59)
Torpedo Officer: LTJG TERABE Kineo (71)
Gunnery Officer: LT HATTORI Shinrokuro (69)
Navigator: LTJG AOKI Shikao (Res.)
Chief Engineer: LT TSUNEMI Tatsumi (Eng. 48)

FUYUZUKI
Commanding Officer: CDR SAKUMA Eiji (50)
Torpedo Officer: LT YAMATANI Masahiro (68)
Gunnery Officer: LT TSUGAI Akira (65)
Navigator: LTJG YAMAZAKI Kentaro (71)
Chief Engineer: LT YAMADA Hirokuni (Eng. 47)

TAMA
Commanding Officer: CAPT YAMAMOTO Iwata (46)
Executive Officer: VACANT
Gunnery Officer: LT ABE Hiroshi (64)
Navigator: LCDR TANIHARA Tatsuka (61)
Torpedo Officer: LT KIMURA Shichiro (Spec. Duty)
Chief Engineer: LCDR ASHIYA Takeo (Eng. 40)
Damage Control Officer: UNKNOWN
Surgeon: LCDR (Med.) SASAKI Tetsuya (1938)
Paymaster: LT (Sup.) KAMEI Nobuo (Pay. Aux. 5)
Communications Officer: LT TOKUNAGA Takehiko (69)

KISO
Commanding Officer: CAPT IMAMURA Ryonosuke (49)
Executive Officer: VACANT
Gunnery Officer: LT FUJIHIRA Takashi (65)
Navigator: LT HARADA Tamotsu (Res.)
Torpedo Officer: UNKNOWN
Chief Engineer: LCDR NAGASHIMA Suezo (Spec. Duty)
Surgeon: LT (Med.) TERASAKI Taira (1939)
Paymaster: LT (Sup.) SAKAMOTO Masaru (Pay. 28)
Communications Officer: VACANT

NAGARA
Commanding Officer: CAPT NAKAHARA Giichiro (48)
Executive Officer: VACANT
Gunnery Officer: LCDR KATSUWA Hisao (63)
Navigator: LCDR KOGURE Shoichi (61)
Torpedo Officer: LT SEKINE Osamu (67)
Chief Engineer: LCDR YOSHIDA Hisashi (Eng. 38)
Damage Control Officer: LT SEKINE Osamu (67)
Surgeon: LT (Med.) IDE Tamaru (1936)
Paymaster: LT (Sup.) OTSUKA Masayoshi (??)
Communications Officer: VACANT

[rjl3]

Thanks all for your informative responses.
Thank you Fontessa for the detailed information about the 11th Torpedo Squadron.

I have been incorporating this info with other sources I have available including the obvious Nihon Kaigun and TokusetsuKansen. At first I thought there were the typical conflicts with specific items between different sources but then I realized that the I-Go Transports did not have to align specifically with individual convoys. After much investigation I think that the I-Go movements were as follow. All dates conform with the various sources but the groupings into convoys looks different. The following are by convoy. Biggest differences are with I Go 3 and I Go 4:

I Go 1. Fuyutsuki, Matsu, Nagara. Yoko to Chichi and back.
I Go 2. Hatsuharu, Kiso, Tama, Wakaba. Yoko to Chichi and back.
I Go 3. Hatsukaze, Noto Maru, Shiokaze, T 4, T 104, T 152, T 153, Yuzuki.
Hatsukaze, Noto Maru, Shiokaze, T 4. returned Chichi to Yoko.
T 104, T 152, T 153, Yuzuki. Chichi to Iwo Jima. then Iwo Jima to Chichi.
I Go 4. T 104, T 152, T 153, Yuzuki Chichijima back to Iwo. then Iwo to Chichi.

I have dates for all of these which are in conformance with all sources.

Looks like June 44 was a very busy month for convoys to Chichijima. Besides the I Go convoys there were also:

3602. Yayoi Maru. others?
3606. original destination Saipan but stopped at Chichijima. 19 ships.
3609. 8 ships.
18 June. CD 24, T 103. (3618?)
25 June. CD 24, T 103, T 130. (3625?)
3628. 11 ships. arrived just in time to get wiped out by US carrier air with only 1 survivor.

As always I look forward to additional info, comments, and corrections!
Regards,
Ralph

[ijnfleetadmiral]

Convoy 3602 also included auxiliary storeship HOKKAI MARU.

Also:

NOTO MARU
This was an IJA transport, so I have no CO info for her. More than likely she was commanded by an unknown Merchant Captain.

T-103
Commanding Officer: LT KOIKE Sakae (Res.)

T-130
Commanding Officer: LT FUJIMOTO Shigeru (Res.)

CD-24
Commanding Officer: LCDR INOUE Junzo (Res.)

[fontessa]

T 104, T 152, T 153, Yuzuki. Chichi to Iwo Jima. then Iwo Jima to Chichi.
I Go 4. T 104, T 152, T 153, Yuzuki Chichijima back to Iwo. then Iwo to Chichi.

You seem to say that the ships above made two round trips between Chichijima and Iwo Jima.

According to the 11th Torpedo Squadron war diary, the details are;
June 26th: I-go Transport Unit activated
09:00 July 1st: Hatakaze and Shiokaze arrived at Chichijima
10:15 July 1st: 4th Transport Unit (Yuzuki, T-104, T-152 and T-153) arrived at Chichijima
Cargo and units movement from Yuzuki to T-??s
12;00 July 1st: Hatakaze and Shiokaze departed Chichijima for Yokosuka
04:30 July 2nd: 4th Transport Unit departed Chichijima
14:30 July 2nd: 4th Transport Unit arrived at Iwo Jima
19:15 July 2nd: 4th Transport Unit departed Iwo Jima
09:00 July 3rd: 4th Transport Unit arrived at Chichijima
09:55 July 3rd: I-go Transport Unit deactivated

The reinforcement units the below arrived at Chichijima on July 1st and departed there for Iwo Jima as the below;
20th Specially Established Machine Cannon Unit: July 16th
21st Specially Established Machine Cannon Unit: July 16th
Unnumbered Rocket Company: July 16th
10th Independent Rapid-firing Battalion: July 14th
11th Independent Rapid-firing Battalion: ???
12th Independent Rapid-firing Battalion: July 29th
3rd Battalion and Signal Unit / 17th Independent Mixed Battalion (I would like to delete it. I have missed.)

fontessa

[fontessa]

3606. original destination Saipan but stopped at Chichijima. 19 ships.

Convoy3606
Transports
美保丸 Miho Maru, 神鹿丸 Shinroku Maru (Hard to read), 杉山丸 Sugiyama Maru, 東天丸 Totem Maru, 淡路丸 Awaji Maru, 豊川丸 Toyokawa Maru. 甘井子丸 Kanseishi Maru
Escorts
DD: 松風 Matsukaze (F.S.)
TB: 千鳥 Chidori
Kaibokans: 壱岐 Iki, 天草 Amakusa,, 能美 Nomi
Subchasers: CH-16. CH-18
Auxiliary Minesweepers: 第7昭和丸 Showa Maru No.7, 第8昭和丸 Showa Maru No.8
Movements
Departed Tateyama Bay on June 6th
Sugiyama Maru was damaged by USS Whale’s torpedo attack on 7th.
She returned to Tokyo Bay with the escort of CH-18 and Showa Maru No.8.
Engine troubled Shinroku Maru returned to Tokyo Bay with the escort of Amakusa on 8th.
Matsukaze was sunk by USS Swordfish’s torpedo attack on 9th.
3rd Escort Fleet commander RADM Monzen Kanae (Monzen Tei) was KIA.
Escaped to Chichijima on 10th.
Comvoy3906 without CH-16. CH-18 Departed Chichijima on 14th,
Kanseichi Maru was sunk by USS Swordfish’s torpedo attack on 15th.
Showa Maru No.8 seems to have been sunk on 15th.
Arrived at Tokyo Bay on 17th.

3628. 11 ships. arrived just in time to get wiped out by US carrier air with only 1 survivor.

Convoy3628
Transports
志摩丸 Shima Maru (Sunk in Chichijima), 第8雲洋丸 Uinyo Mari No.8 (Sunk in Chichijima)､辰栄丸 Tatsuei Maru (Sunk in Chichijima)､昭瑞丸 Shozui Maru (Sunk in Chichijima)､大功丸 Daiko Maru (Sunk in Chichijima)､海光丸 Kaiko Maru and 第5利丸 Ri Maru No.5
Escorts
Mine Sweeper: W-25 (Sunk at Chichijima by U.S. carrier airplanes on July 4th)
Mine Layer 猿島 Sarushima
Unknown 3 ships
Movements
Departed Tateyama on 1944 June 29th
Arrived at Chichijima on 2 July 1944

fontessa

[Berend]

Convoy 3602: Auxiliary minesweeper No. 14 escorts the convoy part of the way.
Convoy 3628: 大功丸 Daiko Maru = 大功丸 Taiko Maru (1942)

Regards,

Berend.

[fontessa]

Convoy 3628: 大功丸 Daiko Maru = 大功丸 Taiko Maru (1942)

Berend.

Thanks!

fontessa

[rjl3]

Fontessa,

The round-trips to Iwo come from Tokusetsukansen:

19.06.28：（伊號輸送部隊第三輸送隊）横須賀～06.30父島06.30～06.30硫黄島07.01～07.01父島
19.07.02：（伊號輸送部隊第四輸送隊）父島～07.02硫黄島07.02～07.03父島

If the T Landing ships only did the I Go-4 July 2 trip, it seems there would not have been an I Go-3 except for transport to Chichijima only.
Don't know what to make of the fact that the earlier trip to Iwo, if there was one, is not mentioned in the 11th Squadron War Diary!

I suppose the first three I Go Movements could have been to Chichijima only and I Go-4 was the first trip to Iwo?

Regards,
Ralph

[fontessa]

3rd Transport Unit
Hatakaze: Yokosuka 28 June 1944 - 30 June Chichijima 1 July - 3 July Yokosuka
Shiokaze: Yokosuka 28 June 1944 - 30 June Chichijima 1 July - 3 July Yokosuka
Yuzuki: Yokosuka 28 June 1944 - 30 June Chichijima 1 July - 2 July Iwo Jima 2 July - 3 July Chichijima

The description of the war diary consisted of two parts - a movement summary table and daily detailed descriptions. The above was based on the former of which the picture is shown at the bottom.
According to the latter, the detailed movements are;
The 3rd Transport Unit (Minus Hatakaze and Shiokaze) namely only Yuzuki departed Chichijima at 0730 / June 30th.
Hatakaze, Shiokaze and T-103 departed Chichijima at 1330 / June 30th.
Hatakaze was ordered to engage the escort mission near Iwo Jima.
The arrival times of the above are not clear.
T-103 landed on Iwo Jima on July 1st.
Hatakaze and Shiokaze departed for Chichijima.
Where they arrived at Iwo Jima was not mentioned. I don't think they did.
Fuyuzuki and T-104 departed Chichijima for Yokosuka at 0150 on July 1st.
Hatakaze and Shiokaze arrived at Chichijima at 0900 on July 1st.
Yuzuki, T-104, T-152, and T-153 arrived at Chichijima at 1015 on July 1st.

伊号 移動履歴.jpg (66.26 KiB) Viewed 1201 times

fontessa