Dreadnought battleships, What are they?

With advances in gun laying and aiming, engagement ranges had increased from 1000 yards or less to 6000 yards or more over the previous few years, in part as a consequence of the devastating, but short-ranged firepower of the recently invented torpedo. This had caused a move away from mixed calibre armament, as each calibre required a different aiming calibration, something which unnecessarily complicated gunnery techniques. At longer ranges, the higher maximum rate of fire of the smaller calibres was negated by the need to wait for shell splashes before firing the next salvo. This negated the advantage of small-calibre guns; heavier weapons were no faster, but packed a much greater punch.

Partially as a consequence of this new philosophy, and partially as a consequence of its powerful new turbine engine, Dreadnought dispensed completely with the smaller calibre secondary armament carried by her immediate predecessors, allowing her to carry more heavy caliber guns than any other battleship built up to that time. She carried ten 12-inch guns mounted in five turrets; three along the centreline and two on the wings, giving her twice the broadside of anything else afloat. The first large warship equipped with steam turbines, she could make 21 knots in a calm sea, allowing her to outrun existing battleships (typical speed 18kts). Her armor was strong enough that she could conceivably go toe-to-toe with any other ship afloat in a gun battle and win.

Although there were some problems with the ship — the design's wing turrets strained the hull when firing broadsides, and the top of the thickest armor belt lay below the waterline when the ship was fully loaded — Dreadnought was so revolutionary that battleships built before her were afterward known as "pre-Dreadnoughts", and those following as "Dreadnoughts". Vessels built within a few years that were bigger and mounted more powerful guns were called "Super Dreadnoughts". In a stroke, Dreadnought had made all existing battleships obsolete; including those of the Royal Navy, which embarked on a programme of building ever-more-powerful Dreadnought designs.

National pride in the early 20th Century was largely based on how many of these ships a navy had, and details were published in the newspapers for the public to avidly follow; the naval arms race which Dreadnought sparked, especially between Britain and the young German empire, was to create powerful shockwaves. Whereas Germany before the commissioning of Dreadnought had been behind the British Empire by more than twenty battleships of the highest class, they were now behind only one.

Dreadnought was powered with steam turbines, which enabled her to sustain a higher maximum speed for longer, and with less maintenance than its triple-expansion engine powered predecessors. Being more compact, the turbines also allowed for a lower hull, which had the side-effect of reducing the amount of armour the ship had to carry. Although turbines had been used in destroyers for some years previously, Dreadnought was the first large warship to use them. As a consequence of the turbines, Dreadnought was actually slightly cheaper than the previous "Lord Nelson" class of pre-Dreadnoughts.