The Royal Navy stopped after three Indefatigable-type ships because its studies turned against the general-purpose dreadnought armoured cruiser. Low cost did not compensate for a design judged unsuitable for combat, including on distant stations. The arrival of 13.5-inch-gun ships made that compromise less attractive and pushed British construction toward the Lion line. Australia's Indefatigable was the last expression of that design branch before Fisher's wartime return. The halt followed a doctrinal rejection rather than a simple shortage of budget or yard capacity.
Notable Point · 2:58:37-2:59:07
Why the Royal Navy stopped with the Indefatigable class
Admiralty studies judged the cheap dreadnought-armoured-cruiser concept unsuitable for combat even on distant stations, prompting the shift toward the Lions.