Rakuyō Maru

In 1944, Rakuyō Maru became one of the most tragic and widely remembered of the Japanese Hellships. A Japanese passenger-freighter used to transport Allied prisoners of war, it sailed from Singapore in early September 1944 carrying about 1,318 British and Australian POWs bound for Japan. On 12 September 1944, while part of convoy HI-72 in the South China Sea, it was torpedoed by the American submarine USS Sealion, whose crew had no way of knowing Allied POWs were aboard. Hundreds of prisoners survived the sinking only to drift for days on rafts or wreckage before rescue by American submarines or Japanese vessels. Rakuyō Maru is remembered both for its catastrophic loss of life and for the extraordinary submarine rescue of some of its survivors.

Key facts

  • Type: Passenger-cargo ship (later used as POW transport)

  • Built: 1921 by Mitsubishi Shipbuilding & Engineering Co., Nagasaki

  • Tonnage: About 7,300 gross tons

  • Sunk: September 12, 1944, South China Sea

  • Casualties: Roughly 1,050 POWs killed

The Ship

Rakuyō Maru was a Japanese passenger-freighter later used in wartime convoy service. By 1944 it had been assigned to transport British and Australian prisoners of war from Southeast Asia toward Japan, where many were intended for forced labor. Like other Hellships, the vessel was not marked to indicate that it carried POWs, even though it was moving through waters heavily hunted by Allied submarines. In postwar memory, Rakuyō Maru became one of the most important symbols of the danger and cruelty of the Japanese POW transport system.

The Voyage

Rakuyō Maru sailed from Singapore on 6 September 1944 as part of convoy HI-72, carrying roughly 1,318 Allied POWs, generally described in public historical sources as British and Australian prisoners who had already survived captivity and forced labor in Southeast Asia. The ship’s route took it north through the South China Sea toward Japan. Conditions aboard were harsh, consistent with the broader Hellship experience: overcrowding, inadequate food and water, poor sanitation, and already weakened prisoners packed into transport holds under military guard. The voyage formed part of Japan’s larger POW transport system, which moved prisoners deeper into the empire for labor as the war turned against Japan.

The Attack or Loss

On the night of 11–12 September 1944, American submarines attacked convoy HI-72 in the South China Sea. USS Sealion torpedoed Rakuyō Maru, and the ship eventually sank with large numbers of POWs aboard. The attack was a lawful strike on enemy shipping, but because Rakuyō Maru was unmarked, the submarine had no way of knowing prisoners were on board. Many POWs escaped into the water on makeshift rafts or by clinging to wreckage, but rescue did not come immediately. Some Japanese vessels reportedly rescued Japanese personnel first and left many POWs in the sea. Four days later, USS Pampanito returned to the area and began rescuing survivors, joined by USS Sealion, USS Queenfish, and USS Barb.

Casualties and Survivors

The casualty totals for Rakuyō Maru vary by source, and that should be acknowledged openly on the page. The USS Pampanito historical account states that 1,318 POWs were aboard; 159 were rescued by the four American submarines—73 by Pampanito, 54 by Sealion, 18 by Queenfish, and 14 by Barb—and 136 more were later found to have been rescued by the Japanese, for a total of 295 survivors. That source therefore implies roughly 1,023 deaths. Other public summaries and memorial references give higher death totals, often because they count later deaths after rescue or use different reconciliation methods for those lost in the sinking and immediate aftermath. For that reason, Rakuyō Maru is best presented as a ship with a clearly catastrophic loss of life but with totals that require careful source-based explanation.

Legacy and Memorialization

Rakuyō Maru occupies a special place in Hellship history for two reasons. First, it was one of the great maritime POW tragedies of the war, with the loss of a very large number of British and Australian prisoners. Second, it produced one of the most remarkable rescue episodes in submarine history, when American submarines returned to search for survivors and brought dozens of emaciated POWs aboard. The survivor accounts from Rakuyō Maru later became some of the first direct testimony reaching Allied authorities about conditions endured by prisoners in Japanese captivity, including the Burma-Thailand railway. Today, Rakuyō Maru is remembered in archival records, survivor memoirs, museum collections, and continuing research into casualties, survivors, and the wider history of the Hellships.

Sources

  • Australian War Memorial, Second World War – Prisoners of the Japanese, Prison ships (Rakuyō Maru archival guide)

  • USS Pampanito, The Third War Patrol and POW rescue account

  • POW Research Network Japan, Rakuyō Maru

  • Imperial War Museums, The Sinking of Prisoner of War Transport Ships in East Asia

  • Australian War Memorial image record of Rakuyō Maru survivors

Related pages

  • Kachidoki Maru

  • The Philippine Hellship Convoys

  • Hellships Casualty Database

  • Hellships Survivor Records

  • Hellships Research Center

  • Hellships Researcher Guide