Laforey-class armament, geared turbines and new builders

The Laforeys developed the Acasta design with longer, narrower hulls and clipper bows. At about a thousand tons, they were roughly four times the displacement of the original Daring, Havoc and Ferret types. Three 4-inch guns and two twin 21-inch torpedo mountings increased the armament available to a fleet destroyer. Two pom-poms provided anti-aircraft armament, with alternatives described as 37 mm (one-and-a-half-pounder) or 40 mm (two-pounder) guns. Their stated performance included at least 29 knots and a range of 1,720 nautical miles at 15 knots. Parsons used Lucifer and Leonidas to argue for geared turbines in place of direct drive, subcontracting their hulls to Hawthorn Leslie. Thornycroft and White remained prominent in the pursuit of speed, while some ships received Brown-Curtis turbines even though John Brown did not build ships in this class. William Beardmore's new yard at Dalmuir also entered destroyer production with four ships, extending the industrial base.