USS Vulcan (1884) was an iron-hulled, schooner-rigged screw steamship acquired by the U.S. Navy for use as a repair ship during the Spanish–American War.
Chatham—an iron-hulled, schooner-rigged screw steamship constructed at Philadelphia, Pennsylvania, by the American Shipbuilding Co.—was completed in 1884 and acquired by the Navy on 2 May 1898 from the Merchants' and Miners' Transportation Co., of Baltimore, Maryland. Renamed Vulcan, the erstwhile merchantman underwent a metamorphosis to the Fleet's first repair ship. She was equipped with machine tools, forges, and foundries, and a large supply of widely varied stores. A large force of skilled mechanics rounded out her versatile crew. Commissioned on 31 May 1898 at the Boston Navy Yard, with Lt. Comdr. Ira Harria in command, Vulcan soon sailed for the Caribbean.
After preceding via Newport News, Virginia, she arrived at Guantanamo Bay, Cuba, on 1 July in time to be present during the North Atlantic Fleet's bombardment that day of the Spanish forts at Aquadores. The ship served in Cuban waters for the duration of the brief war with Spain and performed yeoman service. On one occasion, while out on nightly patrol, her picket boat, commanded by Naval Cadet Louis G. Miller, drew some 200 shots from Spanish troops ashore. The Spaniards' fire—which the launch spiritedly returned—was ineffective; and all hands returned safely to the ship.
On 3 July, the American Fleet met and soundly trounced a Spanish squadron off Santiago, Cuba. Almost as soon as the smoke of that battle had cleared, the American Navy began making plans to salvage the Spanish vessels. Vulcan performed salvage work on the heavily damaged Spanish ships Infanta Maria Theresa and Cristobal Colon.