RMS Duchess of Atholl was one of a class of four steam turbine ocean liners built in Glasgow in 1927–29 for Canadian Pacific Steamships Ltd's transatlantic service between Britain and Canada.

In 1942 a U-boat sank her in the South Atlantic, killing four of Duchess of Atholl's crew, whilst 821 survivors were rescued.

[3] In 1926 Canadian Pacific ordered a set of four new 20,000 GRT cabin class liners for its North Atlantic service between Britain and Canada.

Duchess of Atholl was unique in being built by William Beardmore and Company at Dalmuir, but was otherwise similar to her sisters.

These developed a combined power output of 3,557 NHP and drove twin screws via single reduction gearing,[8] giving her a speed of 17.5 knots (32.4 km/h; 20.1 mph).

[14] When the Second World War broke out in September 1939 Duchess of Atholl at first continued her scheduled liner service between Liverpool, Montreal and Quebec, taking about eight days for each North Atlantic crossing.

[15] On 17 November 1940 Duchess of Atholl left Liverpool for Egypt with Convoy WS 4B, which went via Freetown in Sierra Leone and Cape Town in South Africa to Suez.

Duchess of Atholl embarked evacuees and left Suez on 12 January 1941 with Convoy SW 4B, which gave her escorted passage as far as Durban in South Africa.

She sailed via Freetown to Cape Town with Convoy WS 7, which happened to include her sister ship Duchess of York.

On 25 May 1941 Duchess of Atholl left Suez on her return voyage, and three days later she reached Aden where she joined Convoy SW 7 to Durban.

[18] From Durban she continued unescorted via Cape Town, crossed the South Atlantic and reached Trinidad on 14 July.

Duchess of Atholl left Diego-Suarez on 25 May and sailed unescorted back to Scotland, calling at Durban, Cape Town and Freetown before reaching the Clyde on 27 June.

Three days later Duchess of Atholl began her return voyage to the UK, sailing unescorted and calling at Durban and Cape Town.

[15] On 3 October 1942 Duchess of Atholl left Cape Town unescorted[15] for Freetown, from where she was to continue to the UK.

At 0921 hrs the U-boat fired a final torpedo, which hit Duchess of Atholl's starboard side near her foremast.

Captain Moore and his senior wireless officer threw all code books, classified documents and nine confidential bags of mail overboard before becoming the last personnel to leave the ship at 0945 hrs.

After abandoning ship the operators continued to send distress signals, and made contact with the wireless station on Ascension Island.

[1] From Ascension Island the ocean boarding vessel HMS Corinthian, a converted Ellerman Lines cargo steamship, put to sea to find the survivors.

[1] The Free French Flower-class corvette FFL Commandant Drogou escorted Corinthian to Freetown, where they arrived on 15 October.

Duchess of Atholl's survivors left Freetown on 18 October aboard the armed merchant cruiser HMS Carnarvon Castle, a converted Union-Castle passenger liner, which took them to Glasgow.