A torpedo boat (length 75 feet, beam 10 feet 6 inches, draught 3 feet; trial speed 17 knots), fitted with a 10-inch by 18-inch by 12-inch stroke, 275-280 horsepower inverted-vertical cross-compound condensing marine engine to prevent noise from the exhaust and escaping steam; operating at 470 revolutions per minute with steam supplied at 120 pounds per square inch by a locomotive boiler with a large grate and forced draught firing with an air pressure of 5 inches of water gauge in the boiler room obtained by a small fan running at 1,100 revolutions per minute driven by a small direct-acting engine and exhausting at 24.5 inches of mercury vacuum Armament 3 spar torpedoes. Built for an unnamed foreign Government by Yarrow and Co., Poplar.