Acheron-class competition and Yarrow specials

The 23 Acherons developed the Acorn design while John Brown and Thornycroft competed over machinery power and hull shaping as routes to speed. Some ships approached 35 knots. Alfred Yarrow subsidised the specials Firedrake, Lurcher and Oak so that the Navy could buy them at the same price as the other vessels. He wanted to demonstrate that a fast destroyer could also be strong and seaworthy. Their design target was 32 knots, while trials in differing weather supported an aggregate assessment of at least 33 knots; the assessment drew on the three ships' performance in different conditions. Commodore Keyes particularly valued the three ships, which served with distinction during World War I.