USS Trigger – the story of the loss and strategic effort to find the Yamato

 

The USS Trigger SS237 was lost with all hands, 89 crew, on March 28, 1945. The location was 32-16N, 132-05E, which is East of Kyushu.  See Exhibit A – goggle map.

 

Commander David Rickart Connole, my father, commanded the Trigger.

 

Summary of events

 

A. The initial part of the patrol

The Trigger departed Guam on March 11, 1945 and patrolled the area southwest of Kyushu and to the west of the Nansei Shoto chain of islands.

On March 18, 1945, Trigger sunk Tsukushi Maru #3 at 28-05N, 126-44E. On March 27, Trigger is credited for sinking the Odate at 30-40N, 127-50 E.

 

B. Forming a wolf pack to monitor and/or sink the battleship Yamato

 

On 3/26/45, Trigger was ordered to rendezvous with two other subs (USS Sea Dog and USS Threadfin) to form a wolf pack (known as “Earls Eliminators” after Earl Hydeman, CO of Sea Dog) with a rendezvous at 31-00 N, 132 E.  This location is SE of Kyushu to the East of the Nansei Shoto chain. The Trigger “hustled” about 250 miles on March 27 and March 28, presumably through Van Diemen Strait to get into position.

           

Although not shown in “public” USN historical records, but based on my deductions, the main purpose of forming this wolf pack was to seek out and sink the Japanese battleship Yamato, which was due to sortie from Bungo Suido anchorage to attack US forces that were landing on Okinawa.  If the subs could not sink the battleship, they could trail and report its location.

 

C.  Japanese preparations for Yamato’s sortie

In late March 1945, the Japanese were planning a sortie of the super-battleship Yamato to attack US forces that were attacking and landing on Okinawa.   The following was obtained from the website combinedfleet.com, which details Japanese ASW activities related to pending sortie by battleship Yamato from Bungo Suido:

 

http://www.combinedfleet.com/Mikura_t.htm

 

“27 March 1945
To provide anti-submarine cover for the planned sortie of super-battleship YAMATO and her escorts, ComKure Guard Unit's Rear Admiral Kiyota Takahiko (42) dispatches the 1st, 2nd and 3rd Sweeping Units to conduct an offensive sweep in Hyuga Nada and Osumi Channel. The surface units are supported by eight Magnetic Anamoly Dectector (MAD) equipped Aichi E13A1 Jakes and Kyushu Q1W1 Lornas from the Saeki Naval Air Group. MIKURA and CD-33 are detached from their unit to participate in the sweep, departing Saeki with the 3rd Sweeping Unit. CD-59 is the flagship. “

 

D. Going in harm’s way

 

            Not finding Sea Dog and Threadfin at the rendezvous point, Trigger evidently traveled about 85 miles north toward the entrance of Buigo Suido on the morning of March 28.  Unknowingly, Trigger was going in harm’s way…in close to shore and facing special ASW patrols.

That morning, Trigger was located by specially equipped (“magnetic analomy devices”) ASW airplanes just 50 miles off shore to the east of the city of Hyuga, and just south of the main channel of Buigo Suido.  These planes contacted the 3rd Sweeping unit (CD 59, CD 33 and Mikura), who came over to the area, dropped depth charges and sunk Trigger.

 

From http://www.combinedfleet.com/Mikura_t.htm

 

“28 March 1945
SW of Shikoku. At 1027, one of the ASW planes detects a contact and directs the 3rd Sweeping Unit to that area. After 1300, MIKURA, CD-33 and CD-59 and possibly others conduct several attacks on a submarine with Type 3 streamlined depth charges. After two hours, a large amount of oil and debris is sighted in the area of 32-16N, 132-05E. [1] “

 

 

D. Basis of Rick’s theory – the strategic reason for forming the “Find the Yamato” wolfpack

 

            1. In late March 1945, the Japanese were planning a sortie of the super-battleship Yamato to attack US forces that were attacking and landing on Okinawa.  This included setting up the ASW patrols.

 

2. With all these preparations, there had to have been a lot of radio communications.  Of course, the US Navy had been intercepting and decrypting Japanese navy messages for most of the war.  Thus, this Yamato sortie was obviously known to the US Navy command.

 

US Navy planners would address the strategic problem.  The primary goal was to protect the Okinawa landing forces, but additionally it was sink the Yamato (the last remaining Japanese capital ship).  The surface fleet (TF 58) participating in the Okinawa invasion would have been alerted.  A key part of the puzzle would be the timing of the Yamato departure from its anchorage in Bungo Suido, and US submarines would be the watchdogs.

 

3. As such, three submarines (Trigger, Sea Dog, Threadfin) in the general area were ordered from their assigned patrol zones to form the Earl’s Eliminator and watch for the Yamato departure.  Each of these submarines had to travel some distance, and quickly, to arrive at the wolf pack rendezvous point. The Trigger “hustled” about 250 miles on March 27 and March 28, presumably through Van Diemen Strait to get into position.

 

4. Wolf packs were generally formed for “high value” purposes…. to sink convoys or capital ships, support landings or lifeguard duty.

 

Since there was no other reported “high value” Japanese activity in the area and since there were no US Navy surface action in the area, the only reason for the wolf pack formation in this area south of Bungo Suido was to find the Yamato.

 

5.  Note: The Yamato departed Buigo Suido on April 6 and was sited by USS Threadfin, who reported the movement south toward Okinawa.  On April 7, hundreds of USN airplanes attacked and sunk Yamato.

 

 

E. More information needed.

 

To support the foregoing deductions, I am in search of the radio communications, decryptions, planning documents related to the “Find the Yamato” effort.   Additionally, I would like to locate the “tasking” orders from COMSUBPAC for the formation of the wolf pack (“Earl’s Eliminators”) in March 1945.  Alternatively, I am in search of oral histories of key staff commanders (e.g., Lockwood, Fife, Layton, Holmes) that would note the creation of the Earl’s Eliminators wolf pack.

 

 

F.  Background

 

The general location of the sinking of USS Trigger is generally known.  Two books tell the story of the loss and provide location information leading up to the sinking date:

            -Submarine Operations of WWII, by T. Roscoe, USNI, page 456-457

            -Submarine Losses of WWII, page 142

 

On March 28, 1944, submarines in the general vicinity heard depth charges and that “someone was taking a drubbing”.  A Japanese naval report indicated that a submarine was located, bombed and a large oil slick resulted.  The location was

32-16N, 132-05E, which is East of Kyushu

 

History of location reports (derived from the two books)

 

1. On March 18, 1945, Trigger sunk Tsukushi Maru #3 at 28-05N, 126-44E.  This is West of Nansei Shoto chain of islands.

 

2. On 3/24/45, Trigger ordered to patrol West of Nansei Shoto chain of islands between 29N and 31 N at the 100-fathom depth curve.

 

3. On 3/26/45, Trigger was ordered to rendezvous with two other subs to form a wolf pack at 31-00 N, 132 E.  This location is SE of Kyushu to the East of the Nansei Shoto chain.

 

4. In Roscoe’s account, it states that post war records credit sinking of Odate on 3/27/45 at 30-40N, 127-50 E, which is West of the Nansei Shoto chain

 

5.  If Trigger was West of Nansei Shoto on 3/27 at 30-40N, 127-50E, she would have had to travel about 240 miles to arrive at rendezvous point (31-00N, 132-00E).  However, the supposed Trigger sinking location (32-16N, 132-05E) is about 85 miles north up the coast of Kyushu. 

 

G. Japanese Records from combinedfleet.com

 

USS Trigger Loss

 

Information from combinedfleet.com about Japanese ASW activities related to pending sortie by battleship Yamato from Bungo Suido:

 

http://www.combinedfleet.com/Mikura_t.htm

 

27 March 1945
To provide anti-submarine cover for the planned sortie of super-battleship YAMATO and her escorts, ComKure Guard Unit's Rear Admiral Kiyota Takahiko (42) dispatches the 1st, 2nd and 3rd Sweeping Units to conduct an offensive sweep in Hyuga Nada and Osumi Channel. The surface units are supported by eight Magnetic Anamoly Dectector (MAD) equipped Aichi E13A1 Jakes and Kyushu Q1W1 Lornas from the Saeki Naval Air Group. MIKURA and CD-33 are detached from their unit to participate in the sweep, departing Saeki with the 3rd Sweeping Unit. CD-59 is the flagship.

28 March 1945
SW of Shikoku. At 1027, one of the ASW planes detects a contact and directs the 3rd Sweeping Unit to that area. After 1300, MIKURA, CD-33 and CD-59 and possibly others conduct several attacks on a submarine with Type 3 streamlined depth charges. After two hours, a large amount of oil and debris is sighted in the area of 32-16N, 132-05E. [1]

That afternoon, off Cape Toi, Kyushu. LtCdr John J. Foote’s USS THREADFIN (SS-410) encounters two kaibokan. Foote torpedoes and sinks MIKURA at 31-45N, 131-45E. All 216 hands are lost. The other kaibokan counter-attacks THREADFIN unsuccessfully. [2]

25 May 1945:
Removed from the Navy List.

Authors' Note:
[1] It is possible the submarine was Cdr David R. Connole’s USS TRIGGER (SS-237), lost with all 89 hands; however, no official report has ever been released with details of the date, place and cause of TRIGGER's loss.

[2] American and Japanese sources conflict. IJN records list both MIKURA and CD-33 as MIA since 28 March 1945. CD-65 witnessed carrier aircraft, most probably of TF 58, attacking a target in that area on that day. Therefore, some Japanese sources list MIKURA and CD-33 as sunk by carrier aircraft in the area of 31-45N, 131-45E. However, other Japanese sources, notably author/historian Kimata Jiro, support MIKURA's sinking by THREADFIN.

Thanks for assistance go to Dr. Higuchi Tatsuhiro of Japan.

-Bob Hackett, Sander Kingsepp and Peter Cundall