The USS Tracer (AGR-15) was a Guardian-class radar picket ship laid down on December 24, 1944, as SS William J. Riddle under a Maritime Commission contract, and launched on January 31, 1945. It was acquired by the U.S. Navy on May 21, 1957, for conversion to a Radar Picket Ship at Charleston Naval Shipyard. It was commissioned on October 16, 1958, under LCDR. George S. Harrison’s command and served in the U.S. Navy until it was decommissioned on July 7, 1965. The construction and repair of Liberty ships relied extensively on asbestos-containing products such as boiler and steam pipe insulation, fireproofing material for bulkheads, brake linings in winches, and gaskets of valves and pipe fixtures. During its activity, the ship carried a complement of 138 men on board and it had the main missions in the Far East, Hawaii, Philippines, European and Mediterranean ports, Panama Canal, and San Francisco. For the services brought to the nation, the personnel of the USS Tracer qualified for the National Defense Service Medal.