in thickness. The barbettes for the 16-inch guns were intended to be 15 inches thick on the sides, tapering to closer to the centreline of the ship. Intended to resist the impact of a armour-piercing bomb dropped from a height of , the Lions deck protection was identical to that of the KGV class. It consisted of non-cemented armour over the magazines that reduced to over the machinery spaces. The armour continued forward and aft of the citadel at the lower-deck level. Forward it tapered in steps from five inches down to near the bow. Aft, it protected the steering gear and propeller shafts with of armour. Unlike the Germans, French and Americans, the British no longer believed that heavy armour for the conning tower served any real purpose, given that the chance of hitting the conning tower was very small, and protected the forward conning tower with only of armour. The underwater protection, also virtually identical to that of the KGVs, would have consisted of a wide three-layer system of voids and liquid-filled compartments meant to absorb the energy of an underwater explosion. It was bounded on the inside by the torpedo bulkhead. Both of the inner and outer voids were fitted with pumps to flood them with water to level the ship (counter-flood) in case she began to list. Over the length of the citadel, this system was found to be proof against of TNT during full-scale trials. The Lion-class ships would have had a double bottom with a depth of . Naval historians William Garzke and Robert Dulin believe that the design of the Lion class would have corrected some of the deficiencies of the KGVs with the notable exceptions of the too-shallow torpedo protection system, caused by limits of the existing infrastructure, and the limited endurance, both of which were addressed in the revised 1942 design. Their 16-inch main battery, although not the most powerful in the world, were superior to the earlier guns used in the s, and they "would have been the most powerful and fastest battleships to have served in the Royal Navy." 1942 design Construction was suspended shortly after the war began and the Admiralty took advantage of the time to refine the design in light of war experience in late 1941. The beam was increased to , the maximum width allowed by the locks of the Panama Canal, to increase the