The K3 and L3 studies show the scale of British ambitions before the final G3 and N3 proposals. Both are described with nine 18-inch guns and normal displacement around 50,000 tons. K3's battlecruiser requirement called for 30 knots, while the smaller L3 battleship was intended for 25 knots. The quoted L3 protection includes a 15-inch main belt inclined at 25 degrees, a nine-inch upper belt and eight-inch deck armour. Both designs are given 18-inch turret faces, supported by British presses and earlier Vickers experiments with plates of that thickness. If construction had proceeded before a later treaty, these ships or their smaller descendants would have left Britain with a substantially different fleet entering the 1930s.
Notable Point · 42:26-45:29
K3 and L3 combined nine 18-inch guns with different speed priorities
The larger British studies paired heavy armament with either battlecruiser speed or stronger battleship protection, backed by existing armour-manufacturing capacity.