Prewar experiments fed the M-class production programmes

The argument for prewar experimentation culminates in the accelerated building described from late 1913. Admiralty M-class destroyers and the Thornycroft, Yarrow and Hawthorn Leslie variants, including Yarrow's second M-class batch, drew on lessons from the earlier programmes. The Navy had accumulated comparisons of machinery and hull designs that could inform successive wartime orders. Those results reduced the need for fresh design studies when wartime requirements changed. A large group of yards already knew how to build destroyers, making those orders easier to translate into ships. Some familiar hull forms may also have been retained because they fitted the yards' previous construction experience.