The 28 cm SK L/40 was a German naval gun that was used in World War I and World War II as the main armament of the - and pre-dreadnoughts.
The 28 cm SK L/40 gun weighed , had an overall length of and a bore length of . Although designated as , its actual caliber was . It used Krupp's horizontal sliding-block, or "wedge", as it is sometimes referred to, breech design rather than the interrupted screw commonly used in heavy guns of other nations. This required that the propellant charge be loaded in a metal case (usually brass) which provides obturation, or sealing of the breech, to prevent escape of the expanding propellant gas. The 28 cm SK L/40 was the last large German naval gun to load all its propellant in a single case; later guns required a fore charge in addition to the main charge in the cartridge case.
The Drh.L. C/01 turret was used by the Braunschweig- and Deutschland-class battleships, one twin gun turret at each end. Its guns co