She had a single screw, driven by a three-cylinder triple-expansion engine made by John G. Kincaid & Company of Greenock.

[3] At the same time, the Pure Oil Co became the owner of Pennoil, which had belonged to the Pennsylvania Trading Company, AG.

[8] In 1916 the Standard Oil Company of New Jersey acquired her, renamed her Healdton, and registered her in New York.

[9] In Standard Oil service, the ship had "HEALDTON – U.S.A." painted in white capital letters several feet high, amidships on either side of her black hull.

[12] From Bergen she set course for Rotterdam along a safe channel that the Imperial German Navy had prescribed for neutral ships in the North Sea.

[13] At 20:15 hrs on 21 March she was 23 nautical miles (43 km) north by east of the Terschelling lightship off the Dutch coast, making 10 knots (19 km/h), when an explosion hit her port side amidships.

Her Master, Captain Charles Christopher, said that the boat was "cut from the tow line prematurely".

Dutch fishing trawlers saw the light from Healdton burning, but mistook it for the Aurora Borealis.

However, at 08:00 hrs the next morning the steam trawler Java sighted the sail of Number 2 boat, and went to investigate.

Germany denied sinking Healdton,[16][17] and declared that she was in a British prohibited zone when she was sunk.

[18] Imperial German Navy records do not show any U-boat in the vicinity when Healdton was sunk, whereas Royal Navy records show that the minelayers HMS Angora, Princess Margaret, and Wahine laid a minefield in that part of the North Sea on the night of 18–19 March.

Healdton left Philadelphia on 26 January, before Germany announced on 1 February that it was resuming unrestricted submarine warfare.

She was in Halifax when the United States Senate was debating the Armed Ships Bill, and Progressive Republicans led by Robert M. La Follette filibustered it.

She was crossing the North Atlantic from Halifax to Bergen when President Wilson ordered the defensive arming of US merchant ships after the bill had been talked out.

It did not change President Wilson's decision, but he added it to the list of incidents to present to the special session of Congress that he had called for 2 April.

And the 21 fatalities among her crew joined 15 who were killed when the cargo ship Vigilancia was sunk on 16 March.

On 6 April, Congress passed the motion by an overwhelming majority, and the US declared war on Germany.