F3 balanced nine heavy guns, 28.5-knot speed, and room for later upgrades

F3 retained nine 15-inch guns while sacrificing four 6-inch secondary guns compared with F2, leaving deck space for later anti-aircraft weapons. Its 740-foot hull was longer than Nelson's 710 feet, though shorter than F2's 760 feet, with the beam held at 106 feet. Greater length at a constant beam could improve efficiency through the water, subject to hull shape and other design details. The main-battery arrangement also offered better forward firing arcs, with the advantages and risks of a more nearly bow-on approach. The layout appeared adaptable to an aft-facing aircraft catapult if independent operations created a need for aircraft.