[2] She had paddle wheels and her coal-powered[2] two-cylinder side-lever engine (from Robert Napier) had a power output of about 740 indicated horsepower with a coal consumption around 38 tons per day.[3] On her maiden voyage, starting on 4 July 1840, she made Halifax, Nova Scotia, from Liverpool, England, in 12 days and 10 hours, continuing on to Boston, Massachusetts.The cargo included 600 tons of coal; mail due across the Atlantic; livestock for food and milk; and cats to control the rat population.[4] Her first homeward run from Halifax to Liverpool was made in just under 10 days at an average speed of about 11 knots (20 km/h), setting a new eastbound record which lasted until 1842.[8] The funding and first crossing of Britannia were key plot elements in a Warner Brothers film released in 1941 as Atlantic Ferry in the U.K., and Sons of the Sea in the U.S.