This Balao-class diesel-electric submarine was built by the Mare Island Navy Yard of Vallejo, California. Originally intended to be named for a brightly-colored California kelpfish, the senorita, the Trepang was renamed on September 24, 1942 and launched on March 23, 1944. She was commissioned on May 22 of that year with three-time Navy Cross recipient, Roy Milton Davenport, in command. After shakedown out of San Diego, she left for Hawaii on August 15, 1944 to begin her combat service.
Action in World War II
On September 13, she began her first war patrol, prowling the waters south of Honshu. On September 30, she closed in on a group of ships and sank a 750-ton Takunan Maru freighter. On October 10, she made another attack, claiming a kill which in actuality did not occur. However, the next day she did sink the 1,000-ton Transport No. 105, despite the commanding officer’s belief that her four fired torpedoes had missed their mark.
On October 12, as the submarine cruised southwest of the Tokyo Bay entrance, she gave chase and landed hits on enemy vessels. Though Davenport believed he had damaged a Yamashiro-class battleship and had sunk a destroyer, Japanese records studied after the war did not verify either. She returned to the Marshalls for repair and a resupply of torpedoes. That patrol won Davenport a fourth Navy Cross.
On November 16, she got underway leading a wolfpack headed to the Philippines. On December 6, she spotted a group of ships approaching the Philippines, sinking two freighters quickly and damaging a third vessel. While coming about to deal a final blow to the damaged ship, she exploded. She then fired her remaining torpedoes at a fourth ship, which she claimed was sunk, though Japanese records again did not confirm this. The other ships in her wolfpack sank two other vessels. The Trepang, out of torpedoes, then sailed back to Pearl Harbor, arriving before Christmas. Davenport left the Trepang after this patrol to instruct at the Naval Academy.
Under the command of Comdr. Allen Russell Faust, the Trepang again sailed for Honshu, this time with the Piper SS-409, Pomfret SS-391, Bowfin SS-287 and Sterlet SS-392. The vessels made an anti-picket boat sweep past Nanpo Shoto, the eastern island chain south of Tokyo, to clear the lanes for the carriers of Task Force 58, which was about to strike the Japanese home islands to neutralize them during the assault on Iwo Jima. However, the Trepang encountered no enemy targets and had to settle for performing lifeguard duty. On February 24, 1945, she did sink the 875-ton freighter, Usuki Maru, and blew the bow off another small coastal vessel, though she had to retreat from antisubmarine vessels before she could finish off the damaged coastal vessel.
After returning to Guam in March, she sailed to the Yellow Sea for duty in dangerous stretches of shallow water. However, the submarine was extremely successful during this patrol, sinking a 1,000-ton landing craft, a 4,667-ton heavily laden freighter and Minesweeper No. 20. After leaving the Yellow Sea, she did lifeguarding for strikes on China and Tokyo before returning to Guam.
During her fifth war patrol, she first carried out lifeguard duties southeast of Tokyo Bay, rescuing two downed aviators her first day. While transferring these rescued pilots to the Tigrone, she received word of a B-29 Superfortress crew floating just seven miles from them. Arriving first, the Trepang picked up seven of the crew members, while Springer picked up the final man. While en route to rendezvous with the Devilfish, she sank a small freighter and hit it with her deck guns, around a dozen Japanese soldiers who jumped from the ship sat in the water, refusing to be picked up and taken prisoner. The Trepang left the men to drown.
Patrolling off the eastern coast of Honshu, in July she sank the lead ship of a three-ship convoy. After that attack, the Trepang felt the impact of two depth bomb explosions from a Japanese plane overhead that spotted her shadow. Both missed their mark and the submarine continued unscathed. Another lifeguard patrol followed, as she rescued a downed pilot from the airstrikes on the Japanese home islands.
After the War
Returning to Pearl Harbor for refit, there she witnessed the succession of events that led to the end of Japan’s involvement in World War II. After her refit, she sailed to San Diego, arriving on September 3, 1945. She was decommissioned on June 27, 1946 and placed in reserve at Vallejo, California’s Mare Island Navy Yard, remaining in reserve into the 1960s. Re-designated as an auxiliary submarine and classified AGSS-412 on June 11, 1962, she was struck from the Navy list on June 30, 1967 and sunk as a target on September 16, 1969. Trepang was awarded five battle stars and a Navy Unit Commendation for her service in World War II.
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.