Why a sound cruiser design became obsolete so quickly

The ships met their immediate late-1890s requirements but had little protection against rapid technological change. They offered respectable guns and protection, yet their low speed and roughly 3,400-nautical-mile cruising radius supplied no lasting advantage as newer cruisers appeared. Contemporary British and American triple-expansion cruisers could already achieve higher speeds, so the absence of turbines does not fully explain the problem. The class also lacked a distinctive feature that stayed useful after its original mix of qualities became ordinary. Conversion to training ships after only five or six years of maximum utility reflected lost combat and prestige value rather than an inherently bad original design. A design tailored to immediate requirements may leave too little margin for the next tactical and technological change.