A twin-screw torpedo boat (length 135 feet, beam 14 feet; trial speed 24 knots) fitted with two 1,500 indicated horsepower (total) triple-expansion engines, built by Messrs. Yarrow and Co., Poplar, for the British Government, was armed with one stem torpedo tube, two broadside tubes and five quick-firing Hotchkiss guns. The engine-room was protected by coal bunkers and fitted with Yarrow's patent stokehole, a contrivance which allowed the furnaces to be isolated if the vessel was holed. The vessel was the largest and fastest torpedo boat built at that time for the British Government. The trials of a new large torpedo boat the Ariete (length 147 feet 6 inches, beam 14 feet 6 inches, draught 4 feet 6 inches: trial speed 26.18 knots) built by Messrs. Thornycroft and co. for the Spanish Government were also conducted on the same day as those of the boat built by Messrs. Yarrow and Co., Poplar, for the British Government.