Wartime service
Orion's first voyage as a troopship was to Egypt, then to Wellington, New Zealand, to transport troops to Europe. She departed Wellington on 6 January 1940 and sailed in convoy for Sydney, Australia, to rendezvous with her sister ship Orcades, the convoy then sailing from Australia to Egypt.
On 15 September 1941, while part of a convoy carrying troops to Singapore, she was following the battleship HMS Revenge in the South Atlantic when the warship's steering gear malfunctioned and Orion rammed Revenge, the impact causing severe damage to Orion's bow. She continued to Cape Town, where temporary repairs were made and then continued to Singapore, where more permanent repairs were performed. The Japanese army was at this time advancing on Singapore, so Orion was called upon to evacuate civilians to Australia.
In October 1942 Orion was one of many former passenger liners which took part in Operation Torch, and made two voyages to North Africa, carrying over 5,000 troops each time. In 1943 her troop-carrying capacity was increased to 7,000, which with other vessels such as the USS West Point (former SS America) played a major part in the transportation of Allied forces.
On 17 December 1942 Orion set sail from Liverpool with 12th Corps and REME amongst others on board. It arrived at Freetown on 31 December 1942 and then Durban on 18 January 1943.
Her role as a troopship tapered off in the Pacific theatre, but she still ferried troops around at 5,000 a time. By the time she was released from service in 1946, Orion had carried over 175,000 personnel and had steamed over 380000 mi.
Postwar
Orion returned to Vickers Armstrong's yard in Barrow on 1 May 1946 to be refitted as a passenger liner. The refit took a year, and included a redesign to accommodate 546 First Class and 706 Tourist Class passengers.
She was the first Orient Line to make a postwar voyage to Australia, sailing from Tilbury on 27 February 1947. After that, her voyages included three cruises to the west coast of the US, including San Francisco, and voyages from Europe to Australia.
Orion was converted to a one-class ship, and her first voyage in that configuration began on 18 March 1958, taking immigrants to Australia from Tilbury.
In 1958, she was converted to carry 342 Cabin Class and 722 Tourist Class passengers on an independent schedule and, in 1961, she became a single-class ship carrying a maximum of 1,691 passengers, although the demand for sea voyages to Australia was declining.
Orion was retired in 1963, and left on her final voyage on 28 February 1963, sailing for Sydney, Australia, via Piraeus, Greece and Suez. She departed Sydney for the last time on 8 April via Melbourne and Fremantle, arriving back at Tilbury on 15 May 1963.
She was then chartered by Otto Friedrich Behnke GmbH as a floating hotel for the duration of the International Horticultural Exhibition in Hamburg, accommodating 1,150 guests. Orion arrived in Hamburg on 23 May 1963. The Exhibition ended on 30 September and, on 1 October, she left Hamburg for Temse, where she was broken for scrap at Boelwerf by Henri Spildooren and his team .
