Built by Harland & Wolff, Belfast as Yard Number 377, for Pacific Steam Navigation, Oronsa was launched on 24th May 1906 and delivered on 16th August that year. Her maiden voyage was on 13th September 1906. Designed as a cargo ship, she was 465 feet long, 7,907grt.
Under Captain Hobson, Oronsa left New York on 13th April 1918, as the lead ship in a convoy of 13 freighters heading for Liverpool, with a mixed cargo of sugar, nitrates and various metals. On 28th April 1918, she was torpedoed by German submarine U-91, Captain von Glasenapp, while some 12 miles off Bardsey Island, Wales. Three crew were lost in the explosion and sinking.