Armored Cruiser - 1890s: Armored Cruisers in The Pre-dreadnought Era

1890s: Armored Cruisers in The Pre-dreadnought Era

The development of rapid–fire cannons in the late 1880s forced a change in cruiser design. Since a large number of hits at or near the waterline could negate the effect of water–excluding material used in protected cruisers, side armor again became a priority. Four inches was considered adequate. However, it had to cover not just guns and the waterline but also much of the hull structure in–between; otherwise, the equally–new high–explosive shells could penetrate and destroy much of the unarmored portion of the ship. Another development was the publication in 1890 of American naval strategist Alfred Thayer Mahan's book The Influence of Sea Power upon History. While Mahan emphasized the importance of battleships above all other types of warships in obtaining command of the sea, armored cruisers and large protected cruisers could still be used as second-class battleships to maintain control of the sea lanes and potentially as fighting units of a battle fleet.

The armored cruisers built in the mid– to late–1890s were often as large and expensive as pre-dreadnought battleships. They combined long range, high speed and an armament approaching that of battleship with enough armor to protect them against quick-firing guns, considered the most important weapons afloat at the time. Their speed was made possible due to another development, Case-hardened steel armor—first Harvey armor and then crucially Krupp armor. The higher tensile strength of these armors compared to nickel steel and mild steel made it feasible to put a light yet useful armor belt on a large cruiser. They saved further weight by not requiring a heavy timber backing, as previous armor plating had, to soften and spread the force of the impact from oncoming shells; 2.5 inches (64 mm) of teak to give a fair surface upon which to attach them was all that was needed. Moreover, this belt could also be much wider than previously, covering the center of the hull, where the ammunition and engines were located, from the main deck to five feet below the waterline. Steel bulkheads added strength to the hull, while armor as thick as the belt covered the guns and heavier protection surrounded the conning tower. With these improvements, the ships became more fully protected than was possible previously. They were also expensive to maintain at fighting strength as they required a greater number of stokers to feed the boilers than a battleship when steaming at flank speed.

The ideas presented by Mahan prompted French Admiral François-Ernest Fournier to write his book La flotte necessaire in 1896. Fournier argued that a fleet of technologically advanced armored cruisers and torpedo craft would be powerful and flexible enough to engage in a wide range of activity and overwhelm potential enemies. French naval and government circles embraced this ideal mutually and even advocates of battleships over cruisers admitted the latter's potential usefulness in scouting and commercial warfare. The result was the building of increasingly large armored cruisers. The Jeanne d'Arc, laid down in 1896, displaced 11,000 tons, carried a mixed armament of 7.6-inch (193 mm) and 5.5-inch (140 mm) guns, and had a 6-inch (152 mm) belt of Harvey armour over her machinery spaces. The 12,300-ton Léon Gambetta and 14,000-ton Edgar Quinet classes followed. With a speed of 22.5 knots, the Léon Gambettas were armed with four 7.6-inch (193 mm) guns in twin turrets and 16 6.5-inch (165 mm) in four single and six twin turrets and were protected by up to six inches (150 mm) of Krupp belt armor and nearly eight inches (200 mm) on their conning towers and turrets. The Edgar Quinets, slightly faster at 23 knots, were armed with 14 7.74-inch (194 mm) guns and carried up to 6.7 inches (170 mm) of armor on their belts, almost four inches (99 mm) on their decks and six inches (150 mm) on their turrets.

Britain, which had concluded as early as 1892 that it needed twice as many cruisers as any potential enemy to adequately protect its empire's sea lanes, responded to the perceived threat from France, Russia and, increasingly, Germany with a resumption of armored cruiser construction in 1898 with the Cressy class. At 21 knots, the Cressys were slower than the newer French cruisers. However, their 6-inch (152 mm) belt of Krupp steel was expected to keep out armor-piercing shells from a 6-inch (152 mm) quick-firing gun at likely battle ranges, while their two 9.2-inch (233.7 mm) and 12 6-inch (152 mm) guns offered comparable firepower. The 2500-ton weight of their belt armor was an improvement over the 1809 tons of the otherwise similar Diadem class and very similar to that of the Canopus class of battleships. The Cressys were the beginning of a rapid expansion in British cruiser construction. Between 1899 and 1905, seven classes of armored cruisers were either completed or laid down, a total of 35 ships.

Japan, which now received British technical assistance in naval matters and purchased larger vessels from France and Britain, began an armored cruiser program of its own. With the end of the First Sino-Japanese War in 1895 and the return under pressure from Russia (in what became known as the "Triple Intervention") of the Liaotung peninsula to China, Japan began a 10-year naval build-up program, under the slogan "Perseverance and determination" (臥薪嘗胆, Gashinshōtan) in preparation for further confrontations. The core of this 109-ship build-up was the "Six-Six Program" of six battleships and six (eventually eight) armored cruisers comparable to the British Cressy class.The Yakumo followed the basic pattern for these cruisers—on a 9,646 long tons (9,801 t) displacement, she carried four 7.99-inch (203 mm) and twelve 6-inch (150 mm) guns, was protected by a 3.5–6.7-inch (89–170 mm) main belt, 2.4-inch (61 mm) armored deck and 5.9-inch (150 mm) turret armor and steamed at 20.5 knots (23.6 mph; 38.0 km/h). They were considered a compromise between cruiser and battleship and were intended to augment capital ship strength in battle squadrons. This practice would persist until World War I.

The first United States armored cruiser, the USS Maine, was launched in 1889 but not completed until 1895 due to a three-year delay in the delivery of her armor plate. Armed with four 10-inch (254 mm) guns, mounted en echelon (with the fore turret sponsoned to starboard and the aft turret to port) to allow end-on fire for both turrets, and six 6-inch (152 mm) guns on broadside, she carried between 7 and 12 inches (178 to 305 mm) of belt armor and between 1 and 4 inches (25 to 102 mm) on her decks. However, Maine was laid down before Harvey or Krupp armor was available and could not benefit from the advantage in weight these much lighter armors offered. She was redesignated a "second-class battleship" in 1894, an awkward compromise reflecting that, at 16.45 knots, she was considerably slower than other cruisers and weaker than first-line battleships. Her destruction In Havana harbor in 1898 was a catalyst in starting the Spanish-American War.

Maine's immediate successors, New York and Brooklyn, launched in 1895 and 1896 respectively, carried thinner but newer armor than Maine, with 3 inches (76 mm) on her belt and 3 to 6 inches (76 to 152 mm) on her deck but better protected overall against rapid-fire weaponry. Their armor was comparable in thickness to that of Dupuy de Lôme but the French ship's armor covered a much greater area of the hull. The hull protection of both ships was superior to their main rival, the British Blake class, which were the largest cruisers at the time but had no side armor. Armed with six 8-inch (203 mm) guns, New York carried more heavy weapons than the French ship. Moreover, New York's builder diverged from the Navy blueprint by rearranging her boilers during construction; this allowed the installation of additional transverse and longitudinal bulkheads, which increased her underwater protection. Brooklyn was an improved version of the New York and Olympia designs, more heavily armed (with eight 8-inch (203 mm) and 12 5-inch (127 mm) guns) and with better sea-keeping abilities through the addition of a forecastle. After these two ships, the Navy concentrated on battleship construction until the Spanish-American War showed how cruisers could be "useful," in the words of General J. B. Crabtree, "and how desirable others would be."

Shortly after the war ended, the Navy laid down six Pennsylvania-class armored cruisers to take advantage of lessons learned and better control the large sea areas the nation had just inherited. Much larger than their predecessors (displacing 14,500 tons as compared to 8150 for New York), the Pennsylvanias "were closer to light battleships than to cruisers," according to naval historian William Friedman. They carried four 8-inch (203 mm) and 14 6-inch (152 mm) guns, 6 inches (152 mm) of armor on their belts, 6.5 inches (165 mm) on their turrets and 9 inches (229 mm) on their conning towers. Their deck armor was light at 1.5 inches (38 mm) for flat surfaces and 3 inches (76 mm) for sloped, a compromise made for faster speed (22 knots, compared with 20 knots for Brooklyn). Improved ammunition made their main guns as powerful as the 12-inch (305 mm) guns of the battleship Iowa and their use of state instead of city names, usually reserved for capital ships, emphasized their kinship.

The Spanish-American and First Sino-Japanese Wars proved instrumental in spurring cruiser growth among all the major naval powers, according to naval historian Eric Osborne, "as they showcased the abilities of the modern ships in warfare." The only time cruisers were seen in any of their traditional role, he continues, was as blockade ships during the Spanish-American War. More often, they were seen fighting in a battle line. They would not been seen in their designed role until World War One.

Even with all their improvements and apparent performance, opinion on the armored cruiser was mixed. The 1904 edition of the Encyclopedia Americana quotes an otherwise unidentified Captain Walker, USN, in describing the role of the armored cruiser as "that of a vessel possessing in a high degree offensive and defensive qualities, with the capacity of delivering her attack at points far distant from her base in the least space of time." The same source defines an armored cruiser as "a battleship in which the qualities of offense and defense have been much reduced to gain high speed and great coal capacity" and adds, "... there are many who hold that the armored cruiser is an anomaly, something less than a battleship and more than a protected cruiser, performing satisfactorily the duties of neither, with no special function of her own and lacking the great desideratum in warships, ability to fight in proportion to her great size and cost."