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USS Trigger (SS-237)

USS Trigger (SS-237) patch

The USS Trigger (SS-237) was a Gato-class World War II era submarine.

The namesake of the USS Trigger is any of numerous deep-bodied fishes of warm seas having an anterior dorsal fin with two or three stout erectile spines.

The radio call sign of the USS Trigger was NAN-CHARLIE-CHARLIE-FOX.

On March 11, 1945, the USS Trigger, captained by Commander David R. Connole, left the submarine base at Apra Harbor on Guam on her twelfth and final war patrol.  Commander Connole was born on September 8, 1912, in Madison, Illinois.  He graduated from the United States Naval Academy in 1936 and then served aboard the Brooklyn-class light cruiser USS Boise (CL-47) for three years.  At the end of 1939 he completed the Submarine School at New London, Connecticut, and was assigned to the submarine USS Pompano (SS-181).  In September 1943, he became the commanding officer of the submarine USS Cuttlefish (SS-171), which served as a training vessel for prospective submariners at New London.  In December 1944, he was relieved by Commander Robert Kelly.  In March 1945, he was selected as the new commanding officer of the USS Trigger1

Commander Connole's operation order for the Trigger's twelfth patrol instructed him to hunt for enemy shipping in the Nansei Shoto Archipelago (Ryukyu Islands) area and to serve as a lifeguard during a scheduled carrier air strike on Okinawa.  On March 18, 1945, the Trigger reported she had made a seven-hour end-around attack on a convoy and had sunk a cargo ship.  The balance of the convoy fled westward.  ComSubPac knew the fleeing ships would head for a safe passage lane through a Japanese minefield.  Vice Admiral Lockwood therefore ordered the Trigger to shadow the escapees and locate the enemy's "safety lane."  On March 20th, the Trigger replied she had been held under by antisubmarine vessels for three hours after attacking the convoy and when she re-surfaced had been unable to regain contact on the escapees.  Four days later, ComSubPac directed her to patrol west of the Nansei Shoto chain, to avoid restricted areas, and to stay outside of the 100-fathom curve.  On March 26th, she was ordered to join the wolf pack Earl's Eliminators at a designated rendezvous point with USS Sea Dog (SS-401) and USS Threadfin (SS-410).  She sent a weather report that day, but never confirmed receiving the March 26th message.  The weather report was the last transmission received from the Trigger.  The pack was disbanded after the Trigger failed to acknowledge the message.  On March 28, 1945, a final message was dispatched giving the Trigger a new assignment and ordering her to acknowledge it.  No response was received.  On May 1, 1945, the Trigger was reported as presumed lost.  She was struck from the Navy list on July 11, 1945. 2

Loss Cause

On March 28, 1945, southwest of Shikoku, the Trigger was detected by Magnetic Anomaly Detector equipped reconnaissance seaplanes from the Saki Naval Air Group.  The aircraft directed antisubmarine surface vessels from the ComKure Guard Unit's 3rd Sweeping Unit to the area in the Nansei Islands (Nansei Shoto) area.  Beginning at about 1300 hours, at the geographic position 32°-16'N, 132°-05'E, the 3rd Sweeping Unit escort vessels Mikura, CD-33, and CD-59 conducted several attacks on the submerged submarine with Type 3 streamlined depth charges.  After about two hours, a large amount of oil and submarine debris was sighted on the surface.  The Trigger was the only submarine known to be operating in the immediate vicinity of the reported attack. 3

Edward L. ("Ned") Beach had served as an officer aboard the Trigger prior to his transfer to the USS Tirante (SS-420) as its new executive officer, in May 1944.  On March 28, 1945, while on patrol aboard the Tirante in the Yellow Sea, he recalled receiving a message on the FOX radio intercept schedule that brought welcomed news.  The Trigger had been ordered to join the Tirante in coordinated patrol in the East China Sea.  The Trigger was due to rendezvous with the Tirante that very night.  Beach and other former Trigger crew members aboard the Tirante looked forward to seeing their old home and friends again.  For the next three nights, Beach supervised radio calls to his old ship.

S 237 V S 420...K...S 237 V S 420...K...S 237 V S 420...K...I have a message for you...Trigger from Tirante I have a message for you...Trigger from Tirante...Come in please...

After three days of silence in response to their radio calls, Beach began to realize his beloved Trigger was gone.

There never was any answer, and deep in our hearts, after three nights, that was answer enough.  With your surface ships there are always survivors, messages, maybe a bit of wreckage.  They always operate together, so there is always someone who can later tell what happened.  With submarines there is just the deep, unfathomable silence.

We could visualize the sudden, unexpected catastrophe.  Maybe a Kamikaze plane.  Maybe a depth charge - a bull's-eye, after more than four hundred misses.  Maybe a torpedo, or a mine, or even - inconceivably - an operational casualty.

In some compartment they may have had a split second to realize that Trigger's stout size has been breached.  The siren screech of the collision alarm.  Instantly the angry water takes possession.  The shock has startled everyone in other compartments, and the worst is instantly obvious.

Almost immediately she upends.  The air pressure increases unbearably.  Everything loose or not tightly secured cascades down to the bottom, against what used to be a vertical bulkhead.  Some men have hung on where they were, but most are struggling around in indescribable confusion at the bottom of the compartment.  Instinctively all eyes turn to the depth gauges and watch as the needles begin their crazy spin.  Slowly at first, then faster and faster, they race around the dials.  The shallow depth gauges soon travel past their limits; finally jam against their stops on the second go around.  The deep-depth gauges and sea-pressure gauges soon afterward reach the limits of their travel.  Nothing can be heard except the rush of water, the groaning and creaking of Trigger's dying body, and the trapped, pounding pulses of the men.

Down, down, down she goes, to who knows what depth, until finally the brave ribs give way, the steel shell collapses, and Trigger's gallant spirit ascends to the Valhalla of ships, bearing with her the souls of eighty-nine loyal sailors. 4

A list of the personnel lost with the Trigger is maintained at

The Trigger received eleven battle stars for her World War II service and the Presidential Unit Citation for her fifth, sixth, and seventh war patrols.  The JANAC score for the Trigger is eighteen vessels sunk for 86,552 tons.  Her Alden-McDonald score is twenty-one vessels sunk for 113,374 tons and eight vessels damaged worth 48,179 tons.  Her SORG score is 25.3 vessels sunk for 173,900 tons and thirteen vessels damaged grossing 110,000 tons. 5

Also see:

USS Trigger (SS-237) First Patrol

Patrol Data and Captains for the USS Trigger (SS-237)

Patrol Duration
Rank & Name
1 Aleutians 26-Jun-42 to 18-Aug-42 CDR Roy S. Benson Pearl 6
2 Empire 23-Sep-42 to 08-Nov-42 Same Pearl
3 Empire 03-Dec-42 to 22-Jan-43 Same Pearl 7
4 Celebes &
Sulu Sea
13-Feb-43 to 06-Apr-43 Same Midway 8
5 Empire 30-Apr-43 to 22-Jun-43 same Pearl
6 East China
01-Sep-43 to 30-Sep-43 LCDR Robert E. Dornin Pearl
7 East China
& Yellow Seas
22-Oct-43 to 08-Dec-43 Same Pearl
8 Carolines 01-Jan-44 to 23-Feb-44 Same Pearl
9 Palau 23-Mar-44 to 20-May-44 LCDR Frederick J. Harlfinger II Pearl
10 Empire 24-Sep-44 to 23-Nov-44 Same Pearl 9
11 Empire 28-Dec-44 to 03-Feb-45 same Saipan
12 Empire 11-Mar-45 to Lost CDR David R. Connole Guam

JANAC Score for the USS Trigger (SS-237)

2 17-Oct-42 Holland Maru Cargo 5,869 32-21N, 132-04E
3 22-Dec-42 Teifuku Maru Cargo 5,198 34-52N, 139-49E
3 10-Jan-43 Okikaze Destroyer 1,300 35-02N, 140-12E
4 15-Mar-43 Momoha Maru Cargo 3,103 00-00N, 145-00E
5 01-Jun-43 Noborikawa Maru Cargo 2,182 35-02N, 140-14E
6 18-Sep-43 Yowa Maru Cargo 6,435 27-31N, 126-57E
6 21-Sep-43 Shiriya Tanker 6,500 26-27N, 122-40E
6 21-Sep-43 Shoyo Maru Tanker 7,498 26-27N, 122-40E
6 21-Sep-43 Argun Maru Cargo 6,662 26-27N, 122-40E
7 02-Nov-43 Yawata Maru Cargo 1,852 28-49N, 134-50E
7 02-Nov-43 Delagoa Maru Passenger-
7,148 28-55N, 134-43E
7 13-Nov-43 Nachisan Maru Passenger-
4,443 32-57N, 125-06E
7 21-Nov-43 Eizan Maru Cargo 1,681 36-40N, 125-31E
8 31-Jan-44 Nasami Maru Coastal
443 9-50N, 147-06E
8 31-Jan-44 Yasukuni Maru Converted
Submarine Tender
11,933 9-21N, 147-02E
9 27-Apr-44 Miike Maru Passenger-
11,739 8-20N, 134-53E
12 18-Mar-45 Tsukushi Maru
No. 3
Cargo 1,012 28-05N, 126-44E
12 27-Mar-45 Odate Repair Ship 1,564 30-40N, 127-50E
TOTALS     18 vessels 86,552 tons  

Alden-McDonald Score for the USS Trigger (SS-237)

2 05-Oct-42 Shinkoku Maru Cargo   3,991
2 17-Oct-42 Holland Maru Cargo 5,869  
3 20-Dec-42 Mitsuki Maru Cargo  3 3,893  MN  
3 29-Dec-42 Teifuku Maru Cargo  3 5,198  MN  
3 31-Dec-42 Shozan Maru Cargo   5,859
3 10-Jan-43 Okikaze Destroyer 1,215  
4 15-Mar-43 Momoha Maru Cargo 3,103  
4 15-Mar-43 Florida Maru Cargo 2,927  sh1  
4 20-Mar-43 Choan Maru Converted
5 28-May-43 Koshin Maru Tanker   975
5 01-Jun-43 Noborikawa
5 10-Jun-43 Hiyo Aircraft
6 18-Sep-43 Yowa Maru Cargo  3 6,435  
6 21-Sep-43 Shiriya Maru Tanker 14,050  
6 21-Sep-43 Argum Maru Cargo 6,661  
6 21-Sep-43 Shoyo Maru Tanker 7,498  
6 22-Sep-43 Gyoko Maru Cargo   6,854
7 02-Nov-43 Delagoa Maru Transport 7,148  
7 02-Nov-43 Chihaya Maru Cargo 7,089  
7 13-Nov-43 Nachisan Maru Cargo 4,433  
7 21-Nov-43 Eizan Maru Cargo 1,681  
8 31-Jan-44 Yasukuni Maru Converted
9 12-Apr-44 Unknown Sampan  3   50
9 27-Apr-44 Asosan Maru Transport 4,405  sh2  
9 27-Apr-44 Miike Maru Passenger-
9 27-Apr-44 Kasado Frigate   870
10 30-Oct-44 Takane Maru Tanker 3,340  sh3  
12 18-Mar-45 Tsukushi Maru #3 Cargo 1,012  
12 27-Mar-45 Odate Cable Ship  4 1,564  sh3  
  TOTALS 21 vessels sunk
8 vessels damaged
  Tons sunk
Tons damaged

sh1 = Shared credit w/ aircraft   sh2 = Shared credit w/ 242-Bluegill   sh3 = Shared credit w/ 182-Salmon & 392-Sterlet
3 = Probable   4 = Possible   MN = Struck mine laid by Trigger 10

SORG Score for the USS Trigger (SS-237)

Trigger SORG score report

SORG totals for Trigger
25.3 vessels sunk for 173,900 tons
13 vessels damaged for 110,000 tons

Updated Thursday, 25-Dec-2014 16:46:48 EST


1.  United States Submarine Losses World War II, p. 142-143.  Some of the biographical data for Commander Connole is from "The History of the USS Connole (FF-1056)," published online at (accessed October 1, 2011).  I note that this article has many errors, so I also used the patrol reports for the submarines referenced in the article.

2.  United States Submarine Losses World War II, op. cit.

3.  United States Submarine Losses World War II, op. cit.; Miller, Vernon J., "U. S. Submarine Losses," issue 44, p. 57-58; Hackett, Bob, and Sander Kingsepp and Peter Cundall, "IJN Escort Mikura: Tabular Record of Movement," published online at, 2006 (accessed on January 23, 2012).

4.  Beach, Edward L., Submarine!, p. 310-312.

5.  Japanese Naval And Merchant Shipping Losses During World War II By All Causes, Joint Army-Navy Assessment Committee, USS Trigger (SS-237), published online at (accessed September 29, 2011); Alden, John D., and Craig R. McDonald, United States and Allied Submarine Successes in the Pacific and Far East During World War II, Fourth Edition, see USS Trigger (SS-237), Attack Nos. 352, 368, 378, 391, 480, 481, 499, 505, 527, 670, 671, 683, 842, 851, 874, 1117, 1133, 1134, 1135.1138, 1249, 1250, 1254, 1255, 1308, 1325, 1575, 1576, 1810, 1811, 1812, 1819, 1865, 1866, 1867, 1869, 1870, 2967, 3703, 3704, 3733, 4754, 4755, and 4756; Submarine war patrol reports on CD, USS Trigger (SS-237), data collected by the Submarine Operations Research Group (SORG) in the report "Results of U. S. Submarine War Patrols Listed Alphabetically by Name of Submarine."

6.  The Trigger returned to Dutch Harbor on August 10, 1942, and then from August 12-18, 1942, sailed back to Pearl for refit prior to her second patrol.

7.  The Trigger returned to Midway for refit prior to her fourth patrol.

8.  The Trigger returned to Pearl.

9.  The Trigger returned to Saipan first per special orders from ComSubPac, sailed again to complete a special mission, and ultimately ended her tenth patrol at Guam.  Prior to beginning her eleventh patrol she sailed to Saipan for special repairs and began her patrol from there.  She returned to Guam after that patrol.

10.  Trigger laid Mark 12 mines on 20 December 1942 at 35°-44'N, 140°-56'E.