Understanding the history of warship classification can be a rather mind-boggling affair. The trouble is that after the 1850s time never stood still as far as the development of naval technology went. It was a time of leaps and bounds in terms of what new weapons and steam propulsion could achieve and this meant that what suited a specific type of ship in one decade no longer applied after the introduction of newer ships by the next decade. It didn’t help that on occasion the bureaucrats in the Admiralty liked to get a little creative with ships receiving designations such as “dispatch vessels” and “torpedo cruisers” whose roles weren’t as clear cut as their classification might imply.
The term “cruiser” itself was termed as a result of new technology creating new types of ships. Cruisers were effectively an amalgamation of two previous types; the steam corvette and the steam frigate. Cruisers in the Royal Navy were a classic example of this muddling over classifications and realizing this the Admiralty eventually settled on three distinct types of cruisers arranged in first, second and third classes. This was more than simply the Admiralty stretching its bureaucratic muscles. Having vessels fit in to categories helped identify the role in which it would be intended to carry out and thus determine the requirements to naval construction yards. Again this depended on what the designations represented at the time of design and it was not uncommon for vessels to be reclassified under a new classification as time went on. Nevertheless opinion still played a big part in determining what was what.
The first-class cruiser represented the high end of the scale. These were the largest cruisers and were expected to operate in far off waters protecting the empire’s trade routes from commerce raiders, a role known as guerre de corse, and alternatively engage in the role itself when the opportunity presented itself. In terms of capability the first-class cruisers were second only to battleships.
Typically a first-class cruiser would have an armoured belt along the hull to protect from shells fired along the broadside and an armoured deck to protect from shells landing from above having been fired from a gun set to a high elevation. They would not generally be as well protected as a battleship however and the first-class cruiser would be expected to use speed and agility to escape the pursuit of a capital ship. That being said first-class cruisers would be expected to operate as part of the battlefleet providing support for the bigger guns of the battleships when the distance closed.
Like in battleships, first-class cruisers were often designed with mixed caliber weapons and thus suffered the same drawbacks in terms of targeting and logistics. One of the first vessels to receive the classification was HMS Shannon launched in 1875. The Shannon displaced around 5,500 tons and was armed with two 10inch main guns and a secondary armament of seven 9inch guns. The vessel was also fitted with a ram, something that had become quite fashionable in the middle part of the 19th century but very quickly became outmoded. Aptly demonstrating how quickly the size of cruisers in this category grew within twenty years first-class cruisers had reached around 15,000tons such as in the Blake-class of 1895.
Second-class cruisers were generally smaller than the first-class cruisers usually displacing between 3,000 and 7,000tons although there were examples that were positioned either side of these figures. Second-class cruisers didn’t have the protection of first-class cruisers and often lacked an armoured belt. Instead key sections of the ship received armoured protection such as the main machinery so that the vessel could still sail away from an unfavorable action. Once again there was some confusion as to what constituted this type of cruiser and there were a handful of ships that had the size and firepower of a first-class cruiser but had the lower protection of a second-class cruiser. In these instances, due to their size, the ships were classified as first-class cruisers.
Second-class cruisers were expected to primarily operate in the protection of trade routes but unlike the better armoured first-class cruisers they weren’t also expected to operate with the main force in big fleet actions. They were however expected to use their speed for reconnaissance purposes; travelling ahead of the main force to locate the enemy and then report back. When the first ship to be categorized as a second-class cruiser, HMS Iris, was launched in 1877 it was one of the fastest ships in the world being capable of achieving an enviable 18.5knots under trials.
The third-class cruisers were generally similar to second-class cruisers but were much smaller with the largest only reaching 3,000tons. They too had protection primarily centered on key components but their size meant they lacked the fuel for long distance operations and generally operated in home waters or from overseas garrisons. Naturally they were often less well armed than their first- and second-class brothers.
As well as the traditional trade route protection, guerre de corse and reconnaissance roles there were a number of third-class cruisers that had more specialized roles. These included vessels such as the Archer-class which displaced just over 1,000tons and was intended to protect the main fleet from the emerging threat posed by torpedo boats, a role which would eventually give way to the first destroyers. Another common role for third-class cruisers was that of flotilla leader for small formations of destroyers. The cruiser would carry the destroyer flotilla commander (Captain “D”) and his small staff who would direct and coordinate the small force’s operations which would often consist of convoy escort or enforcing a blockade line.
Technology and bureaucracy continued to advance as the 20th century dawned. While the older cruisers remained in service and often retained their classifications they were now starting to fall out of use. First-class cruisers eventually morphed in to Admiral Fisher’s battlecruiser concept which were as large as battleships but not as well protected. The requirements for what constituted a second- and third-class ship changed as armoured protection, power and weaponry improved and so cruisers fell in to two categories; heavy cruisers and light cruisers which generally carried out the roles of a second- and third-class cruiser respectively albeit with much better performance.