USS Achernar (AKA-53) was an attack cargo ship (a cargo ship designed to support amphibious warfare operations) of the United States Navy during World War II and after. For the invasion of Normandy it was the command post of General Omar Bradley, commander of the US First Army. She served as a commissioned ship for 19 years and 5 months. Construction She was laid down under a Maritime Commission contract on 6 September 1943 at Kearney, New Jersey by Federal Shipbuilding and Drydock Co., launched on 3 December 1943, named after the star Achernar, sponsored by Mrs. Adela Rogers St. John, acquired by the Navy on 29 January 1944, and commissioned on 31 January 1944. World War II service Following conversion and fitting out at the New York Navy Yard, Achernar held shakedown in the Chesapeake Bay. On 13 March, she arrived at Staten Island, New York – where she loaded cargo and embarked United States Army personnel for transportation to Britain travelling with Convoy CU-18. She arrived at Swansea, Wales on 30 March and spent the next two months transporting cargo and personnel between various ports in the United Kingdom in preparation for the Normandy invasion. On 1 June 1944, she was designated as First Army's headquarters ship. On 6 June, she steamed from Plymouth across the English Channel and anchored in her preassigned position in Baie de la Seine, France. For the next few days, she acted as a nerve center for troops fighting for a foothold in France. On 11 June, the First Army's headquarters disembarked, and Achernar returned to England. After a three-day respite in Plymouth, the ship moved to Rosneath, Scotland to take on the cargo and personnel of two construction battalions. On 19 June, she returned to Plymouth to load materials to repair damaged assault craft and, on 22 June, got underway for the assault area in France. While on station, she underwent several enemy air attacks. Achernar left France on 29 June to return to England and arrived in Plymouth on 1 July. On 5 July, the ship was ordered to sail as a part of Task Group 120.6, which was bound for the Mediterranean Sea to support the invasion of southern France. It arrived at Oran, Algeria on 10 July; then six days later sailed to Naples. After loading cargo there, she moved to an anchorage at Castellammare, Italy on 2 August.