War-emergency R-class destroyers developed from the Royal Navy's existing programme. The navy expected even emergency ships to remain useful for a long time, so continued development mattered alongside quick construction. An active design and production programme was easier to adapt rapidly than a completely new start. The work already underway supplied arrangements that otherwise had to be established during the emergency.
Notable Point · 35:59-36:35
Existing destroyer programmes speed wartime expansion
Wartime destroyer expansion benefits from an established design and construction programme that can be adapted quickly.