Rendsburg was one of three sister ships ordered by DADG in the mid-1920s -- the company's first motor vessels. All three were built at Hamburg shipyards: Vulcan-Werke completed Duisburg in July 1925 and Rendsburg in February 1926, while Blohm+Voss finished Magdeburg in December 1925. Rendsburg carried a pair of eight-cylinder four-stroke diesel engines driving a single propeller through hydraulic oil transformers and single-reduction gearing, a transmission system pioneered by MAN to allow high-speed diesel engines for marine use. Her twin engines produced 4,100 brake horsepower and pushed her to 13 knots. In 1926, DADG merged with Hamburg-Amerikanische Packetfahrt-Actien-Gesellschaft, better known as HAPAG, and Rendsburg continued her cargo runs under one of the world's largest shipping lines.

When war broke out in September 1939, German merchant ships scattered to neutral ports worldwide. Rendsburg took shelter at Tanjung Priok in the Dutch East Indies. On 10 May 1940, Germany invaded the Netherlands, and the Dutch colonial authorities seized every German vessel in their waters. Rendsburg became Toendjoek under the Dutch flag. Her second life was brief. In March 1942, as Japanese forces swept through the Dutch East Indies, the Dutch scuttled Toendjoek as a blockship to obstruct Japanese naval movements. She sank in shallow water, her hull settling into the seabed she had sailed over for years. Five months later, in August 1942, Japanese salvage crews refloated the vessel and gave her a third name: Tango Maru. Under the rising sun flag, the cargo ship entered the most terrible phase of her existence.

By 1944, Tango Maru was serving as what history remembers as a hell ship -- a vessel used by the Japanese military to transport prisoners of war and forced laborers under conditions of extreme deprivation. The people packed into her holds endured overcrowding, minimal food and water, and suffocating heat below decks. These ships carried no markings to indicate they held prisoners, making them indistinguishable from military transports to Allied submarines prowling the sea lanes. The term "hell ship" was not metaphor. Mortality rates on these transports were devastating, and those who survived described conditions that defied comprehension. Tango Maru carried approximately 9,200 people when the American submarine USS Rasher found her off the coast of Bali in 1944 -- about 5,700 troops and 3,500 Javanese rōmusha conscripted laborers and Allied prisoners of war. A torpedo strike sent the ship to the bottom in minutes, and at least 3,000 lives were lost -- prisoners and laborers whose captivity made them invisible to the submarine that killed them.

The name Tango Maru was not unique. At least two other Japanese ships carried it during the Second World War. One was the Talang Akar, a British-built, Dutch-owned tanker sunk in the Makassar Strait in November 1943 -- by the same submarine, USS Rasher. Another was a Japanese-built steamship operated by Nippon Yusen KK, destroyed by American aircraft in the East China Sea just five days after the Talang Akar went down. The waters of the Indonesian archipelago hold thousands of wrecks from the Pacific War, each one a compressed history of colonial trade routes, wartime desperation, and human lives caught between forces beyond their control. Tango Maru rests somewhere off Bali, a German-built hull bearing a Japanese name, filled with the remains of people who never chose to be aboard.