SS Shin'yō Maru
|Name:||Clan Mackay (1894-1913)
Tung Tuck (1924-1937)
Chang Teh (1937)
Shinyō Maru (1941-1944)
|Operator:||Clan Line (1894-1913)
Adelaide Steamship Company (1913-1924)
Unknown, Shanghai (1924-1937)
Unknown, Greece (1937-1941)
Daiko Shoji (1941-1944)
|Fate:||Sunk on 7 September 1944|
|Class and type:||Cargo steamer|
|Tonnage:||2,634 gross register tons (GRT)|
|Length:||84.9 m (279 ft)|
|Beam:||12 m (39 ft)|
|Propulsion:||Triple expansion engine|
|Speed:||13.5 knots (25.0 km/h)|
Shinyō Maru (真洋丸?) was a Japanese cargo steamer during the Second World War. She was one of the hell ships, used to transport prisoners of war. She had served under a number of other names under a long career.
She originally was named the SS Clan Mackay, built on the River Clyde for the Clan Line. She sailed with them until sold in 1913 to the Adelaide Steamship Company, which renamed her Ceduna. She was again sold in 1924 to a company in Shanghai which renamed her Tung Tuck. She was renamed Chang Teh in 1937, and was sold to Greece later that year. She sailed for her new owners under the name Pananis, until seized by the Japanese at Shanghai in 1941 and renamed Shinyō Maru.
The Allies intercepted a message about the Shinyō Maru and, thinking it was carrying enemy soldiers, the USS Paddle attacked it on September 7, 1944, off the coast of Mindanao. There were 750 American prisoners of war aboard. Some Japanese guards shot prisoners as they struggled from the holds or were in the water; 688 died when the ship sank, leaving only 82 survivors; 47 of 52 Japanese guards died.
A December 1944 annotation in US military records indicates an intelligence failure helped contribute to the mistargeting of the Japanese transport ship filled with US POWs by the US submarine. "[A] note was added to the message of September 6 that Fleet Radio Unit Pacific (FRUPAC) interpreted as ""SHINYOO MARU (750 troops for Manila via Cebu." In pencil was written: "FRUEF (31 Dec '44) gets 750 Ps/W"! FRUPAC misinterpreted this crucial part of the message with fatal consequences."
- John J. Morrett, Soldier-Priest (1993). Also see 
- Victor Mapes, The Butchers, the Baker: The World War II Memoir of a United States Army Air Corps Soldier Captured by the Japanese in the Philippines (2000)
- Charles Vance Claybourn, The Claybourn Genealogical Society 
- American POWs on Japanese Ships Take a Voyage into Hell. The Shinyō Maru: An Explosion, and Survival, for Some POWs, Prologue Magazine, Winter 2003, Vol. 35, No. 4. Retrieved 28 March 2010.
- Roster of Allied Prisoners of War believed aboard Shinyō Maru when torpedoed and sunk 7 September 1944, 82 survivors 667 deaths. Source dated 2006. Retrieved 28 March 2010.
- 船舶輸送艦における遭難部隊資料（陸軍） - IJA report about military transport ship losses in WW2
- Hell ship survivors embrace 'miracle'. The Florida Times-Union, 8 September 2000, accessed 1 January 2011.