From Hell Ship to the Depths: The Tragic Tale of the Toyama Maru

by Jenny Chan

The sinking of the Toyama Maru, a Japanese troop transport ship, on June 29, 1944, marked one of the deadliest maritime disasters of the war. Before its catastrophic end, this vessel also served a darker purpose—as a "hell ship," carrying prisoners of war under brutal conditions, including a harrowing voyage to Narumi Camp in Nagoya. Let’s explore the haunting story of the Toyama Maru, a ship that bore witness to both human suffering and a tragic finale in the Nansei Shoto.

A Ship Built for Peace, Requisitioned for War
The Toyama Maru began its life far from the battlefields of World War II. Laid down on August 4, 1913, at the Mitsubishi Dockyard & Engineering Works in Nagasaki, the ship was launched on March 20, 1915, and completed just three months later. At 445 feet long, with a beam of 58 feet and a gross tonnage of 7,089, the Toyama Maru was originally built for the Nippon Yusen Kaisha (NYK) Line, a prominent Japanese shipping company. In its early years, it served commercial routes, including European ones during World War I, transporting food and ammunition. For nearly two decades after, it plied routes like Kobe to Surabaya, living a relatively quiet life.
But as World War II loomed, the Toyama Maru’s purpose shifted. In January 1941, the Imperial Japanese Army requisitioned the vessel, assigning it Army No. 782. It became a troop transport, ferrying soldiers across the Pacific to support Japan’s campaigns in places like the Philippines and Singapore. Yet, its role extended beyond moving troops—it also became a "hell ship," a term used for Japanese vessels that transported Allied prisoners of war (POWs) under inhumane conditions.[1]
The Hell Ship Era: Voyage to Narumi Camp
During the war, the Toyama Maru was pressed into service as one of Japan’s notorious hell ships, carrying POWs in cramped, unsanitary, and brutal conditions. These vessels were unmarked, making them targets for Allied submarines, and the treatment of prisoners aboard was often horrific—starvation, disease, and abuse were rampant. One documented voyage saw the Toyama Maru transporting POWs to Narumi Camp, a prison camp in Nagoya, Japan, where captives were forced into labor for the Japanese war effort.
The journey was grueling. Hundreds of POWs were packed into the ship’s holds, often with little ventilation, minimal food, and scarce water. Temperatures soared, and dysentery and malnutrition claimed lives before the ship even docked. Upon arrival, survivors were marched to Narumi Camp, where they faced backbreaking labor in factories, building war materials under harsh oversight. The Toyama Maru’s role in this brutal transport cemented its grim legacy, a stark contrast to its peacetime days of carrying passengers and cargo.[2]
Many survivors later described the experience as worse than imprisonment itself — a floating prison where death was an ever-present companion.

The Fateful Final Voyage
On June 27, 1944, the Toyama Maru set out on what would be its final mission, departing Kagoshima Bay for Naha City, Okinawa, as part of Convoy KATA-412. Aboard were over 6,000 men, primarily from the Japanese 44th Independent Mixed Brigade, along with a dangerous cargo of gasoline stored in cans in the lower holds. These troops were intended to bolster defenses on Okinawa, a critical stronghold as the Allies closed in. The convoy, consisting of 11 other ships, sailed into the Nansei Shoto, a chain of islands south of Japan’s main islands, unaware of the danger lurking beneath the waves.
On the morning of June 29, 1944, off Taira Jima, the U.S. submarine USS Sturgeon (SS-187), under the command of Lt. Cmdr. Charlton Lewis Murphy, spotted the convoy. At 7:30 a.m., the submarine fired four torpedoes at the Toyama Maru. Three struck their target: two hit the bow, igniting the gasoline and engulfing the ship in flames, while a third slammed into the midship, breaking the vessel in half. The explosions and fire were catastrophic, and within a minute, the Toyama Maru sank beneath the waves at approximately 27°47'N, 129°05'E.
A Devastating Loss
The human toll was staggering. Estimates of the number aboard vary, with some reports suggesting over 6,000 troops and crew, while others place the figure closer to 4,000. Of these, only about 600 survived, rescued by the convoy’s escorts. The loss of life—potentially 5,400 or more—ranks the sinking of the Toyama Maru among the worst maritime disasters in history, particularly for ships sunk by submarines. The exact number remains uncertain, as Japanese records were destroyed at the war’s end, leaving the true scale of the tragedy lost to time.[3]
The troops of the 44th Independent Mixed Brigade, intended to strengthen Okinawa’s defenses, were almost entirely wiped out. This loss weakened Japan’s ability to reinforce the island, which would later become the site of one of the war’s bloodiest battles in 1945. The USS Sturgeon, meanwhile, earned a degree of infamy for this attack, with its commander, Lt. Cmdr. Murphy, later receiving a Navy Cross for his actions during the patrol.

Murphy’s report on Toyama Maru sinking

A Legacy of Loss and Suffering
The Toyama Maru’s story is a haunting dual narrative—of a hell ship inflicting misery on POWs and a troop transport meeting a fiery end. Its voyage to Narumi Camp exemplifies the cruelty endured by prisoners, while its sinking underscores the relentless danger of wartime seas. Unlike the Tōya Maru, a train ferry that sank in a typhoon in 1954 with over 1,150 lives lost, the Toyama Maru’s demise was a direct result of combat, highlighting the brutal submarine warfare of the Pacific Theater. Today, no major memorial marks its resting place, and its story remains less known than other wartime disasters. Yet, for the families of the thousands lost—soldiers and POWs alike—the pain lingers, a silent echo beneath the waves.
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1. "Toyama Maru." Combined Fleet , www.combinedfleet.com/Toyama_t.htm . Accessed June 5, 2025.
2. "Toyama Maru." MaritimeQuest Daily Event Archive, 29 June 2005, www.maritimequest.com/daily_event_archive/2005/june/29_toyama_maru.htm . Accessed June 5, 2025.

3. "Warship Wednesday, Mar. 30, 2022: Jesse James of the Java Sea." Last Stand on Zombie Island, 30 Mar. 2022, https://laststandonzombieisland.com/tag/toyama-maru/ . Accessed June 5, 2025.

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