of her guns. Navies worldwide continued to build masted, turretless battleships which had sufficient freeboard and were seaworthy enough to fight on the high seas. The distinction between coast-assault battleship and cruising battleship became blurred with the Admiral-class ironclads, ordered in 1880. These ships reflected developments in ironclad design, being protected by iron-and-steel compound armour rather than wrought iron. Equipped with breech-loading guns of between 12-inch and 16 ¼-inch (305 mm and 413 mm) calibre, the Admirals continued the trend of ironclad warships mounting gigantic weapons. The guns were mounted in open barbettes to save weight. Some historians see these ships as a vital step towards pre-dreadnoughts; others view them as a confused and unsuccessful design. The subsequent of 1889 retained barbettes but were uniformly armed with guns; they were also significantly larger (at 14,000 tons displacement) and faster (because of triple-expansion steam engines) than the Admirals. Just as importantly, the Royal Sovereigns had a higher freeboard, making them unequivocally capable of the high-seas battleship role. The pre-dreadnought design reached maturity in 1895 with the . These ships were built and armoured entirely of steel, and their guns were now mounted in fully-enclosed rotating turrets. They also adopted main guns, which, because of advances in gun construction and the use of cordite propellant, were lighter and more powerful than the previous guns of larger calibre. The Majestics provided the model for battleship building in the Royal Navy and many other navies for years to come. Armament Pre-dreadnoughts carried guns of several different calibres, for different roles in ship-to-ship combat. Main battery The main armament was a main battery of four heavy guns, mounted in two centre-line turrets fore and aft. Very few pre-dreadnoughts deviated from this arrangement. These guns were slow-firing, and initially of limited accuracy; but they were the only guns heavy enough to penetrate the thick armour which protected the engines, magazines, and main guns of enemy battleships. The most common calibre for the main armament was , although some ships used smaller guns because they could attain higher rates of fire; British battleships from the Majestic class onwards carried this calibre, as did French ships from the class, laid down in 1894. Japan, importing most of its guns from Britain, used 12-inch guns. The United States used both and guns for most of the 1890s until the , laid down in 1899 (not the earlier of Spanish–American