On 10 August 1904, at the Battle of the Yellow Sea during the Russo-Japanese War, the Japanese discovered that the armaments of their armored cruisers were outranged by those of the Russian battleships. The Japanese response was swift. While the war still raged they laid down new armored cruisers armed with 12-inch guns. The first, the Tsukuba, carried the same armament as contemporary battleships, was two knots faster than them, but had belt armor two inches thinner than most battleships’. The Tsukuba could be regarded as the first battle cruiser.
In March 1905 the U.S. Congress authorized the new “all-big-gun” Michigan-class battleships, while around the same time in Britain the design for the Dreadnought was being finalized. To complement their all-big-gun battleship, the British had designed an all-big-gun cruiser, which became the battle cruiser Invincible and her two sisters. This class carried eight 12-inch guns, had a designed speed of 25 knots, but carried an armored belt of only six inches. Although their specific role was not clearly defined, in general they were to conduct reconnaissance in force, be able to sweep aside enemy cruisers and support their own light cruisers, be employed in commerce protection on overseas stations, and finally be able to support the fleet as a fast wing, capable of outflanking the enemy line and pursuing the enemy as it fled.
The German conceptual model for their battle cruisers was different. Germany knew that it would always have fewer warships than its potential opponent, Britain, and therefore its battle cruisers were designed to be able to join the battle line as “gap fillers” after the fight had commenced. In a March 1909 article comparing battle cruiser development, a member of the Imperial German Navy’s information bureau, Korvettenkapitdn (Commander) Vollerthun, wrote:
In the type development of our grofien Kreuzers [battle cruisers] since 07, inspired by the English Invincible class, we have pursued more and more the qualities of a fast battleship with the intention of making the authorized number of large ships as far as possible also capable of fighting in the line. This approach with our grofien Kreuzers since 07 has given them a different character to the English, and has brought their displacement to that of the battleships.
To achieve this aim the German battle cruisers were much more durable than their contemporaries. They carried much thicker armor, spread over a greater area, and had smaller compartments and more of them. For example, the Derfflinger had 12-inch belt armor, the same as the British dreadnoughts of the Orion and Iron Duke classes. Nevertheless, class for class, the German battle cruisers carried guns of a slightly smaller caliber, but they were sufficient to do the job.
The one imponderable asset the German ships had—both battle cruisers and dreadnoughts—was their longitudinal torpedo bulkhead. Generally it ran the length of the citadel and was from 30- to 45-mm (1.2 to 1.8 inches) thick. The bulkhead proved very effective and prevented widespread damage or flooding on many occasions. The Moltke was torpedoed by submarines on two occasions, the Goeben struck two mines in December 1914 and three mines in January 1918, while the Seydlitz was mined once and torpedoed once. In each of these instances flooding was kept to a minimum, even when struck outside the area protected by the bulkhead, thanks to the battle cruisers’ subdivision into many compartments. On the other hand, multiple shell hits below the waterline far forward on the Lützow were the primary cause of her loss.
Therefore the German battle cruisers were extremely combat-capable ships, steadfast against shell fire, mines, and torpedoes. Korvettenkapitan Vollerthun succinctly summed up the differences between Royal Navy and Imperial Navy battle cruisers by terming the British ships “battleship-cruisers” and the German ships “cruiser-battleships”—indeed a farsighted and prophetic characterization.
To learn more read Mr. Staff's article from Naval History about the battle cruiser Lützow at the Battle of Jutland, click here.