The twin-screw torpedo gunboat H.M.S. Halcyon (length 250 feet, beam 30 feet 6 inches, draught 11 feet 3 inches; displacement 1070 tons), fitted with two 22-inch by 34-inch by 51-inch by 21-inch stroke triple-expansion marine engines developing a total indicated horsepower of 3,500, with steam supplied at 155 pounds per square inch by six marine locomotive boilers was built at the Devonport Dockyard and launched on the 6th of April 1894. The Halcyon was the third of five improved Sharpshooter class vessels built under the Naval Defence Act of 1889. It was proposed to arm the Halcyon with two 4.7 inch, and four 6 pounder quick-firing guns, and five torpedo tubes.