The USS Cyclops (AC-4) was a Proteus-class collier built for the United States Navy, launched on May 7, 1910, by William Cramp & Sons in Philadelphia, and commissioned on November 7, 1910. Designed to transport coal and later other heavy cargo, the Cyclops featured a robust construction typical of early 20th-century naval auxiliaries. The vessel’s specifications included a length of approximately 522 feet, a beam of about 65 feet, and a displacement of around 14,500 long tons when fully loaded. Her cargo capacity was significant, with a maximum of roughly 8,000 long tons, though she was overloaded during her final voyage. Throughout her service, Cyclops operated primarily along the U.S. East Coast, the Caribbean, and in Atlantic and South American waters. She supported the Atlantic Fleet, supplied ships in the Baltic during 1911, and played a role in the U.S. occupation of Veracruz in 1914–1915, where she coaled ships and assisted in evacuations. With the U.S. entry into World War I, she was commissioned as part of the Naval Auxiliary Service, joining a convoy to France in June 1917, before returning to U.S. waters. Later, she was assigned to the Naval Overseas Transportation Service, sailing to Brazilian ports to fuel Allied ships, carrying manganese ore essential for munitions. The vessel’s final voyage began on February 20, 1918, from Salvador, Brazil, bound for Baltimore with a cargo of manganese ore. Notably, she was reportedly overloaded, and her starboard engine was damaged, reducing her maneuverability. Despite these issues and a storm in the Virginia Capes area, Cyclops disappeared after leaving Rio de Janeiro on March 4, 1918, with no wreckage ever found. Her loss resulted in the deaths of 306 crew and passengers. The ship’s disappearance remains one of the greatest maritime mysteries of the 20th century, with theories ranging from structural failure due to cargo shifting or corrosion to storm damage, but no conclusive cause has been established. The USS Cyclops holds a significant place in naval history as part of the unsolved mystery of ships lost at sea without a trace.

This description has been generated using GPT-4.1-NANO based on the Vessel's wikidata information and then modified by ShipIndex.org staff.