On September 11, 1923, the Luanda Railway ordered six 2-6-0T tank locomotives from Hudswell, Clarke & Co. of Leeds for a price of £2,030. They left the works on February 15, 1924 and carried the works numbers 1515 to 1520. Painted in dark blue, they got the running numbers 21 to 26. The drivers measured three feet and half an inch and the cylinders had a diameter of 13 and a stroke of 18 inches. The cylinders and the valve gear were both mounted on the outside. Weight in working order was nearly 27 tons. Their side tanks ran along the full length of the boiler and racks for the storage of fire wood were mounted on top of the tanks in front of the cab.