This Gato-class submarine was laid down by the Mare Island Navy Yard and launched on October 22, 1941. She was sponsored by Mrs. Walter N. Vernou, commissioned on January 30, 1942 and commanded by Lt. Comdr. Jack H. Lewis.
Action in World War II
She first sailed to Hawaii on May 22, sailing to Midway Island before returning on June 9. She sailed to the Aleutians for a patrol of an area west of Cape Wrangell, Attu Island on June 26, though she contacted no enemy vessels.
Her second war patrol lasting from September 23 to November 8, saw her in Japanese home waters, making an attack on an enemy ship on October 8. Although that ship escaped after taking a torpedo hit, on October 17 she managed to sink Holland Maru. That night she was attacked by an enemy destroyer, but failed to sink her when one of her first torpedoes detonated prematurely. On October 20, she sank a 10,000-ton tanker with two torpedo hits. Four days later she made three observed torpedo hits on another tanker, though it eventually managed to escape.
Trigger conducted a combined minelaying and offensive patrol in waters surrounding the Japanese home islands from December 3, 1942 to January 22, 1943. While laying a minefield off Inubo Saki, Honshu on December 20, she saw a cargo ship pass her and later heard an explosion. Another explosion was later heard from the minefield.
On December 22, she made a surface attack of a ship, producing a hit which at last sight, had the vessel awash forward so far her screws were nearly out of the water. On December 31, 1942, she hit a cargo ship loaded with planes with two torpedoes. After diving to avoid a retaliatory attack, she could see no sign of the vessel. On January 10, 1943, she sank an approaching enemy destroyer with two torpedo hits.
On February 13, she left Midway to patrol off the Palaus. After two unsuccessful attacks, she made an attack on two freighters simultaneously on March 15. Hitting the lead ship twice with the first round and having to make another attack, she was eventually credited with sinking the Momoha Maru, a 3,103-ton cargo ship. She made an unsuccessful attack on a small freighter that night, watching one of her torpedoes circle around the ship and sail over her own engine room. On March 20 she made another attack on the lead ship of a convoy, scoring a hit which did not sink the vessel. She arrived at Pearl Harbor on April 6.
She returned for a patrol of the Japanese home waters from April 30 to June 22. On May 28, she scored a hit on a freighter off Iro Saki. The next day she made an unsuccessful attack on a small cargo ship. On June 1, she sank one of a pair of cargo ships. June 10 saw her make four hits on an aircraft carrier, which managed to limp back to Tokyo Bay, staying out of commission for almost a year.
Her sixth war patrol began on September 1, after a Pearl Harbor overhaul. Patrolling the East China Sea, on the 17th she hit a Japanese freighter with two dud torpedoes, though she was able to sink the 6,435-ton cargo ship the next day. September 21 saw the Trigger make an extremely successful attack on a convoy of three enemy tankers and three freighters protected by Japanese planes. At the end of three and one half hours, the submarine had sunk two tankers and a freighter for a total of 20,660 tons of enemy shipping. She returned Midway on the 30th for refitting and rearming.
Her seventh patrol brought her to the East China and Yellow Seas. On November 1, she made individual hits on a freighter and another enemy vessel before being sent below the waves during depth charges. She scored another hit on a freighter the next morning, later sinking the vessel with another round of torpedoes. Later that day, she destroyed a 7,148-ton transport with three torpedoes. After attacking a convoy on November 5, she dove to avoid retaliation, only to surface too early and suffer five near bomb misses.
On November 13, she sank a transport in a convoy of nine merchantmen and four escorts. On the 21st, she sank another cargoman with two torpedo hits. She returned to Pearl Harbor several weeks later, arriving on December 8, 1943. She left for the Truk-Guam shipping lanes and her eight war patrol on January 1, 1944. On the 27th, she had an encounter with a Japanese submarine, though no torpedoes were fired. Four days later she scored two hits on a coastal minelayer in a convoy, sending that ship to the bottom. She eventually managed to sink the 11,933-ton converted submarine tender, Yasukuni Maru. She returned to Pearl Harbor later that month.
Her ninth war patrol, beginning on March 23, saw her head to the Palaus again. On April 8, she encountered a convoy of around 20 large ships and 25 more escorts. As a destroyer charged towards her, she dove fast and sent four torpedoes at the vessel, hearing four explosions. Heavy depth charging damaged the submarine greatly, forcing her crew to make emergency repairs to the vessel with what they could find.
Meeting the Tang on the 14th, she exchanged information with the vessel and borrowed an air compressor the next day. On the 18th, the Tang delivered spare parts for the air compressor to Trigger, and continued on patrol. On the 26th, she fired six torpedoes at a convoy of six ships, observing four big explosions on each of a group of four bunched vessels. Two of those targets sank immediately. She then hit another group of ships with a successful torpedo shot shortly thereafter, and then made two additional hits on a damaged cargo ship. Minutes later she sank one escort n a group of three. During that attack, she sank a 11,739-ton passenger-cargo ship and heavily damaged two other cargo ships and a destroyer. She sailed to San Francisco for major overhaul before returning to Pearl Harbor.
She began lifeguard duty off the east coast of Formosa for bomber air strikes due on October 12. That morning, she rescued a pilot. On the 19th, she sighted a convoy, reporting the vessels even though she could make no attack. On October 30, she damaged a tanker, which was later sunk by two other American vessels. The next day she escorted the damaged Salmon to Saipan along with two other vessels, arriving on November 3. After departing a week later, she was ordered to return to Guam on November 17.
Her 11th patrol began on December 28 in the Bungo Strait-Kii Strait area. On January 3, she saw a torpedo pass by her starboard side and realized two days later, after returning to the same area, that she was being hunted. On the 29th, she closed for an attack on a convoy, though she had to dive to avoid a counter attack. She returned to Guam on February 3. March 22 saw her begin her 12th war patrol in the Nansei Shoto area. She sank a cargo ship and damaged another on March 18. On the 24th, she began patrolling west of the islands. On the 26th, she was ordered to join a wolf pack and replied with a weather report and nothing else. This was the last transmission received from the vessel. When she was not heard from by May 1, she was presumed lost.
Several vessels in the same area reported that on March 27, an attack produced many heavy explosions, presumed to be the Trigger. She was struck from the Navy List on July 1, 1945. For her World War II service, she received 11 battle stars and the Presidential Unit Citation for her fifth, sixth, and seventh war patrols.
Asbestos in Navy Ships
Although an essential component of the naval fleet, especially throughout conflicts of the last century, submarines also pose a lasting health risk to soldiers serving on them. However, these risks extend beyond the inherent dangers that existed while operating the vessels during military conflicts. Unfortunately, products containing asbestos were also common aboard submarines because of the material’s high resistance to heat and fire. Despite its value as an insulator, asbestos fiber intake can lead to several serious health consequences, including mesothelioma, a devastating cancer without cure. Furthermore, the enclosed environment of submarines put servicemen at an even higher risk of exposure. Current and former military personnel who came into contact with or served on submarines should seek immediate medical attention in order to detect possible health consequences associated with asbestos exposure.