Acasta-class turbine and framing experiments

The Navy ordered twenty Acastas, later the K class, using a common Admiralty design alongside shorter, narrower builder specials. An order of twenty ships in one programme could equal another navy's entire destroyer force. The scale of the order sustained competition between Parsons and Brown-Curtis machinery while leaving room for experiments such as cruising diesels and semi-geared turbines. Curtis even sent engineers to John Brown and commissioned turbines to investigate how Brown improved its designs. The comparison distinguishes skill in originating machinery from skill in refining it, while stressing that Curtis's own turbines were already good. John Brown was content to profit from refining another company's design, giving it a commercial reason to continue that work. Hull construction was another field of experiment: William Denny's Ardent tested longitudinal framing. In this account, Ardent's framing is credited with establishing Royal Navy destroyer practice until the later J class, which followed the 1936 Tribals. Three 4-inch guns, a two-pounder pom-pom and two single torpedo tubes gave the ships a useful fleet armament while the Navy gained experience with machinery and structure.