The first-class torpedo boat No. 79 (length 125 feet, beam 13 feet, draught 5 feet 6 inches; speed 22.39 knots) built by Messrs. Yarrow and Co., of Poplar, for the Royal Navy was fitted with a 1000 indicated inverted vertical triple expansion marine engine operating 400 revolutions per minute on steam supplied at 140 pounds per square inch by a marine locomotive boiler.