Not being weighted by massive external armor, the Reina Regente is unusually light in proportion to her bulk, and in consequence it has been rendered possible to supply her with engines of extraordinary power. They are of the horizontal triple expansion type, driving twin screws, and placed in separate water-tight compartments. The boilers, four in number, are also in separate compartments. Well above the water line there are two auxiliary boilers, which were supplied by Messrs. Merryweather, London, and are intended for raising steam rapidly in cases of emergency. These boilers are connected with all the auxiliary engines of the ship, numbering no fewer than forty-three. The engines have been designed to indicate 12,000 horse power, and on the trial, when they were making 110 revolutions per minute, they indicated considerably upward of 11,000 horse power, the bearings all the while keeping wonderfully cool, and the temperature of the engine and boiler rooms being never excessive. The boilers are fitted with a forced draught arrangement giving a pressure of 1 in. of water. In the official run she attained a speed equal to 21 knots (over 24 miles) per hour, and over a period of four hours an average speed of 20.72 knots per hour was developed, without the full power of the engines being attained. The average steam pressure in the boilers was 140 lb. per square inch. In the course of some private trials made by the builders, the consumption of coal was tested, with the result that while the vessel was going at a moderate speed the very low consumption of 14 lb. of coal per indicated horse power per hour was reached. The vessel is capable of steaming 6,000 knots when there is a normal supply of coal in her bunkers, and when they are full there is sufficient to enable her to steam 13,000 knots. The Reina Regente will be manned by 50 officers and a crew of 350 men, all of whom will have their quarters on the main deck. Among her fittings and equipment there are three steam lifeboats and eight other boats, five of Sir William Thomson's patent compasses, and a complete electric light installation, the latter including two powerful search lights, which are placed on the bridge. All parts of the vessel are in communication by means of speaking tubes. In order to enable the vessel to turn speedily, she is fitted with the sternway rudder of Messrs. Thomson & Biles. This contrivance is a combination of a partially balanced rudder with a rudder formed as a continuation of the after lines of a ship. The partial balance tends to reduce the strains on the steering gear, and thereby enables the rudder area to be increased without unduly straining the gear.