The torpedo-boat destroyer Havock (length 180 feet; beam 18 feet 6 inches) was fitted with two inverted-vertical triple-expansion engines (3,500 indicated horsepower (total) operating on steam supplied at 180 pounds per square inch by two marine locomotive boilers; armament: one 18-inch bow torpedo tube, two 18-inch torpedo tubes on a turntable aft, one 12-pounder quick-firing gun forward, two 6-pounder quick-firing guns, one on each side, and one 6-pounder quick-firing gun at the stern.