 These kinds of improvements were extended to the wartime destroyer classes, despite the smaller hull volumes available.Later in the war, the war cruiser technology was applied to heavy cruiser hulls, creating the classes known as the New Heavy Cruisers.The new technology also made possible even heavier versions of existing "heavy" and "command" designs, such as the Heavy Command Cruisers and Heavy Battlecruisers (the latter of these were particularly important as Dreadnought replacements late in the war, with their DN-like command ratings of 10).