from the bridge was improved by the addition of an open platform connected to the bridge wings. They had an overall length of , with a draft of and beam of . The ships were powered by two General Electric geared steam turbines that each drove one propeller shaft using steam provided by four Babcock & Wilcox boilers. The turbines produced which was intended to give the ships a top speed of . The destroyers carried enough fuel oil to give them a range of at . They were crewed by 9 officers and 264 enlisted men. Armament, fire control, protection and sensors The main battery of the Fletcher-class destroyers consisted of five dual-purpose /38 caliber guns in single mounts which were grouped in superfiring pairs fore and after of the superstructure. The fifth mount was positioned on the aft superstructure forward of the aft pair. The guns were controlled by the Mark 37 director. Their anti-aircraft battery depended on the availability of the weapons, but Johnston was built with ten Bofors guns in five powered twin-gun mounts and seven manually operated Oerlikon cannons. The forward pair of Bofors mounts were located forward of the bridge and the second pair were on platforms abreast the aft funnel with one mount on each broadside; the last mount was positioned between the aft superfiring pair of guns and the single mounts forward of them. Each mount was controlled by a nearby Mark 51 director. Four Oerlikons were located amidships, two on each broadside, and three were grouped in a triangle at the stern, next to the depth charge racks. The ships were fitted with two racks, each holding eight depth charges and adjacent to them were two storage racks with five depth charges each. Abreast the aft superstructure were six "K-gun" throwers, three on each side, with five depth charges. The destroyers were equipped with two quintuple rotating torpedo tube mounts for Mark 15 torpedoes. The Fletchers had only minimal armor that was intended to protect against shell splinters and fragments. The sides of the propulsion machinery compartments consisted of plates of special treatment steel (STS) while the deck above them consisted of STS. The "square bridge" ships like Johnston had the splinter armor of the bridge reduced from the 0.75-inch armor of the earlier "round bridge" ships to . Furthermore, the protective plating of the Mark 37 director was reduced from