[4] Cammell Laird built Oropesa at Birkenhead, launching her on 9 December 1919[2] and completing her in September 1920.

[1] They drove her twin propeller shafts via single reduction gearing,[1] giving her a cruising speed of 14 knots (26 km/h).

Oropesa's maiden voyage began from Liverpool on 4 September 1920, taking her to Rio de Janeiro in Brazil and Buenos Aires in Argentina.

[2] In May 1921 PSNC chartered Oropesa to Royal Mail Lines, for whom she worked the Hamburg – Southampton – New York route.

[8] On 2 December 1939 Oropesa left Halifax, Nova Scotia with Convoy HXF 11 bound for Liverpool.

[9] The next day, about 70 nautical miles (130 km) out of port she and the steam turbine cargo liner Manchester Regiment collided.

50 of the latter's crew were transferred to Oropesa and Manchester Regiment was taken in tow, but the cargo ship foundered and sank with a number of deaths.

[4] On 16 January 1941 at 03:56 hrs Oropesa was southeast of Rockall in the Western Approaches when the German Type VIIC submarine U-96, commanded by Kptlt.

Oropesa did not sink immediately, so U-96 waited and at 04:40 hrs fired another torpedo, but that malfunctioned and went in circles.

The next morning the submarine struck in the Western Approaches again, sinking SS Almeda Star and killing all 360 people aboard.