SS Walnut was a refugee ship converted from a British minesweeping Tree-class trawler which carried Baltic refugees from Sweden to Canada in 1948. The refugees' arrival at Pier 21 in Halifax, Nova Scotia led to a controversy which played an important role in shaping Canada's postwar refugee policies. Initially entering service during the Second World War as HMS Walnut, the trawler was sold for commercial purposes following the war. Converted for use as a cargo ship, the vessel retained the name Walnut until 1959 when sold and renamed Keta. The ship was broken up in 1976. Design and description Tree-class trawlers were designed to displace 545 tons standard and 770 tons at deep load. They were long overall with a beam of and a draught of . They were powered by a one-cylinder boiler providing steam to one vertical triple expansion engine. This drove one shaft creating and giving the ship a maximum speed of . The ship could carry 183 tons of coal. The Tree class was armed with one QF 12-pounder (76 mm) gun, three 20 mm Oerlikon anti-aircraft guns and 30 depth charges. The trawlers had a complement of 40. Royal Navy service Walnut was laid down on June 15, 1939 as HMS Walnut (T103) by Smiths Dock Company at South Bank, Middlesbrough with the yard number 1031, one of 20 s built for the British Royal Navy. Walnut was launched on August 12, 1939 and completed on December 13, 1939. Walnut belonged to a group of ten minesweepers commanded by New Zealanders in the 24th and 25th anti-submarine and minesweeping flotillas, protecting convoys on the east coast of Britain where they faced numerous German air and sea attacks. Walnuts commander, Gordon Bridson, received the Distinguished Service Cross for his performance while in command of Walnut. By the end of 1946, Walnut was one of only two Tree-class trawlers still in service with the Royal Navy. Both were sold in 1948. Refugee ship Walnut was first purchased by the Swedish firm Stem Olson and converted to a coastal cargo ship. In September 1948 the ship was purchased by a group of refugees from several Baltic countries who pooled their life savings to form a company called "Compania Maritima Walnut S/A". The refugees had fled to Sweden after the Soviet occupation of the Baltic republics. The uncertainty of their status in Sweden and fears that they would be