Following the passage of the Merchant Marine Act of 1920, the Standard Oil Company of New Jersey placed orders for over a dozen new tankers with several shipyards in the United States.
As the new law provided companies with tax benefits in exchange for investment in American shipbuilding, Standard Oil decided to use this opportunity to significantly increase and modernize their fleet.
[4] As part of such effort, three tankers of approximately 15,000 deadweight tonnage each were ordered from the Federal Shipbuilding Company.
A. Moffett Jr. was the last of these three vessels (the other being SS Walter Jennings and SS E. T. Bedford), and was laid at the shipbuilder's yard on 23 July 1920 (yard number 50) and launched on 14 July 1921, with Mrs. James A. Moffett, Jr., wife of one of the directors of the Standard Oil Company of New Jersey, being the sponsor.
[5][6] The ship was shelter-deck type, had two main decks and was built on the principle of longitudinal framing providing extra strength to the body of the vessel.
The tanker had a cargo pump room located amidships equipped with two main pumps of the horizontal duplex type capable to process approximately 4,500 barrels of oil per hour from ten double main cargo tanks constructed throughout the entire length of the vessel[7] with a total capacity to carry approximately 5,015,388 US gallons (18,985,310 litres; 4,176,184 imperial gallons) of oil.
In addition, the ship had four cofferdams spread throughout the vessel for dry goods storage or to separate her fuel from both cargo and boiler rooms.
She was also equipped with wireless apparatus and submarine signal system, and had electrical lights installed along the decks.
[13] Upon discharging her cargo, the vessel sailed back to the United States, and arrived at New Orleans on September 26, thus successfully completing her maiden voyage.
[18] The tanker arrived at San Pedro on her first visit to the West Coast on March 21, where she loaded 15,000 tons of oil and sailed for New York on April 1.
[22] The refit was completed at the Tietjen & Lang Plant at Hoboken, New Jersey of the Todd Shipbuilding Company.
Moffett Jr. collided with the US Coast Guard patrol boat USCGC Rush in Ambrose Channel in the fog, sinking the cutter.
Moffett Jr. would complete 43 voyages, carrying 4,671,829 barrels of oil between ports mainly along the Gulf of Mexico and the Northeast United States.
A. Moffett Jr. sailed out of Baltimore, destined[29] to Port Arthur[30] before joining a convoy at Lynnhaven Roads on the 26th.
Two days later, at 2:30 AM damage to two engine pistons was reported to the bridge with the recommendation of leaving the convoy for port repairs.
At midnight on 7 July she was 3 miles (4.8 km) southwest of the Tennessee Reef in the Florida Straights when a torpedo from German submarine U-571[31] hit the port side of the empty number two tank at 12:15.
A second torpedo hit near the number 8 tank on the port side at around 12:35 AM, causing a major list to form.
At 2:30 AM an aircraft flew overhead, followed by USCGC Nike and the US Coast Guard Reserve manned civilian vessels Mary Jane and Southbound[33] which arrived to rescue survivors.
After being floated by the Merritt-Chapman & Scott Company tug Willett,[35] she was stripped of the donkey boilers, steam condenser, various auxiliary units, pumps, fitting, and valves[34] followed by the hulk being sold for scrap in 1943.