Keeping the guns and magazines together forward and the engines aft made the armoured citadel more compact, saving weight under the treaty displacement limit. The layout also placed cooler engine rooms and other spaces between the magazines and the hottest boiler rooms, reducing the thermal burden on propellant and shells. Nelson and Rodney did not need G3 speed because Hood and the Renowns could continue to perform the fast-capital-ship role. This division of labour let the new battleships spend scarce displacement on protection and heavy guns instead of machinery. The unusual silhouette was therefore the visible result of magazine safety, armour economy, and fleet-level role allocation working together.
Chapter · 1:37:24-1:40:38
Why Nelson concentrated its main guns forward
The Nelson class's all-forward armament reduced the armoured length, separated magazines from the hottest machinery spaces, and accepted lower speed because other ships covered the fast role.