The Allied merchant fleet suffered significant losses in the early years of the Battle of the Atlantic as a result of U-boat attacks. The Park Steamship Company was created by the Canadian government on April 8, 1942 to oversee construction of a merchant fleet to help replace the lost vessels and to administer the movement of materiel. This was part of a coordinated Allied effort that saw the construction of British, American and Canadian merchant ships using a common class of vessel known as the North Sands class (named after a beach near the J. L Thompson yard on the River Wear).
Source: Wikipedia: Park ship