On 25/26 February 1947 Cardiff Queen was prepared for her launch, launched by Mrs Banks, Chairman of P & A Campbell, and moved to the fitting out basin of Fairfield Shipbuilding and Engineering at Govan. She was the second of four new paddle steamers proposed to be built for P & A Campbell's Bristol Channel and Sussex Coast operations in the aftermath of the Second World War. The first, Bristol Queen, came out the previous year having been built locally by Charles Hill and Sons at Bristol.
For their second paddle steamer Campbells sought tenders from Clyde shipbuilders Inglis and Fairfield. Inglis proposed a beefed up version of Waverley, which they were building for the LNER, with enhanced scantlings more suitable for the Atlantic swells of the Bristol Channel. Fairfield offered a modified version of Jupiter and Juno which they had built just before the war for year round work in the more exposed parts of the Lower Clyde working the winter service to Arran.
In the end the contract was awarded to Fairfield for a paddle steamer with the same beam and draught as Jupiter and Juno but 15ft longer to improve buoyancy and to be fitted out in the same style as Bristol Queen.
The idea of building four new paddle steamers turned out to be on the optimistic side with the second, Cardiff Queen, also being the last. She was though a fine vessel specifically built for sea going work which led Nick James, in his excellent book about the ship, to describe her as being "The ultimate coastal paddle steamer".