The USS Cyclops was built in Philadelphia; she was 540 feet long and 65 feet wide. The ship was a Proteus-class collier and could carry 12,500 tons of coal while making 15 knots with her twin screws. When the United States declared war on Germany and its allies in April 1917, support ships such as the Cyclops fell under the command of the Navy. The administrative change greatly affected the crew of these support ships. Instead of being run by civilians, the officers were now members of the Naval Reserve Force.
The Cyclops' final mission was to transport 9,960 tons of coal from her home port in Norfolk, Virginia, to Rio de Janeiro, Brazil, and bring back 11,000 tons of manganese ore. She departed on 9 January 1918 and arrived in Rio on 28 January, where she stayed for two weeks unloading and loading cargo. On 15 February, 309 souls departed for Bahia, Brazil, the only scheduled stop before Baltimore, Maryland. Two days later, at 1800 on 22 February, the ship embarked for Maryland; she was expected to arrive on 13 March. The last known location of the Cyclops was an unplanned stop made at Barbados on 3 March, with 1,800 nautical miles (nm) to go on a 4,844 nm journey.
