superfiring, presumably to keep the centre of gravity as low as possible and avoid the extra weight required for tall, superfiring barbettes. The designs were revised in October and split into separate battleship and battlecruiser designs. The battleship designs were given letters of the alphabet from L through N, with the use of triple or double gun turrets shown by 3 or 2 respectively. Both 'L2' and 'L3' had superfiring guns and the armour was reduced to a inclined waterline belt while the main armoured deck was thick ( where it sloped to meet the belt). They both had a designed speed of and had transom sterns. 'L2' displaced , but 'L3' was a thousand tons lighter. 'M2' and 'M3' followed in November and December and were very different from the earlier designs. 'M2' and 'M3' sacrificed fire directly astern by moving the rear turret(s) amidships in order to save weight by shortening the length of the armoured citadel. Compared to the earlier, more conventional, designs, 'M2' saved and 'M3' . More weight was saved by reducing the designed speed to and using only two propeller shafts, although it was thought that this would improve manoeuvering power over four smaller propellers. These changes saved for 'M2' and for 'M3' over their predecessors. A lengthened version of 'M3' was chosen for further development as N3 and approved in November 1921. Description Most noticeable of the N3 design was the concentration of the main battery forward of the bridge and machinery spaces. A related feature of the design was the tower bridge structure behind the first two gun turrets. This provided a better and more stable foundation for fire-control equipment, greatly improved accommodation and protection from the weather. The N3 battleships were significantly larger than their predecessors of the . They had an overall length of , a beam of , and a draught of at deep load. They would have displaced about , nearly double the displacement of the older ships. They had a complete double bottom deep. The ships would have had two geared steam turbine sets, each of which drove one propeller shaft, in two engine rooms forward of the boiler rooms. This allowed the funnel to be placed further aft and increased the ability of the rear turret to fire to the rear. The turbines would have been powered by small-tube boilers intended to produce a total of