State of the art battleship armament in the late 19th century involved a mix of large and small caliber weapons. It was believed thatthe higher fire rate of the smaller weapons would make up for their lack of penetrative capacity. Indeed, some argued that large armored ships with small weapons (armored cruisers) could defeat battleships by saturating them with fire. However, developments in optics and improvements in gun accuracy at the beginning of the twentieth century began to tilt the balance towards heavier guns. The increased accuracy meant that ships could engage and expect hits at previously unimagined ranges. Moreover, the high rate of fire of smaller guns was mitigated by the fact that it was difficult to acquire the range by splashes when there were so many splashes around the target. Indeed, the presence of smaller weapons made it more difficult to get hits with larger guns. In 1904, the Japanese and the Americans began thinking about “all big gun” ships, which would carry a larger main armament at the expense of the secondary weapons. Satsuma, laid down in 1905, was designed to carry 12 12″ guns, but ended up carrying 4 12″ and 12 10″ because of a shortage of 12″ barrels. The slower Americans didn’t
lay down South Carolina until December 1906, about the time that Dreadnought was commissioned.
In October 1905 John “Jackie” Fisher became First Sea Lord. Fisher was, in an organizational sense, a committed revolutionary. He retired many of the older ships and set others to reduced commission. His vision of the Royal Navy centered on a new kind of ship, the battlecruiser, that would have the speed and armament to either destroy or run away from any potential foe. This was a bit too radical for the Admiralty, and he was forced to compromise on a new design for a battleship, to be called Dreadnought. Dreadnought would be slower, but more heavily armored, than the battlecruisers that Fisher wanted. Nevertheless, Fisher pursued the construction of Dreadnought with all enthusiasm. Dreadnought, like Satsuma and South Carolina, would be designed to carry a single main armament of large guns, rather than the mixed armament of previous ships.
But Fisher wanted more than big guns. What distinguished Dreadnought from South Carolina or Satsuma was the decision to use turbines instead of reciprocating 
engines, resulting in a higher speed, faster cruising, and less vibration. It was this contribution that helped make Dreadnought a revolutionary design. Neither the Americans nor the Japanese had envisioned their new ships as part of a fundamental break with the past. USS South Carlina was built onto the hull of a Connecticut class pre-dreadnought with what amounted to a re-arranged armament. She could have (and indeed this was the intention) operated at the head of a squadron of pre-dreadnoughts without difficulty or embarassment. Dreadnought, on the other hand, rendered the previous battleships of the world obsolete at a stroke. Carrying a large number of heavy, long range guns and having a higher speed than any contemporary meant that she could destroy extant battleships at range. Later battleships would have to be modelled upon Dreadnought; thus, she gave her name to a type of warship. “Dreadnought” is a name that the Royal Navy has used throughout it’s history, with the 1906 version being the sixth to carry the moniker (a Dreadnought served with Nelson at Trafalgar). It’s interesting to consider what modern battleships would have been called if another ship had preceded Dreadnought. I doubt, for example, that the navies of the world would have come to call their ships “South Carolinas”. Satsuma has a decent ring to it, but the Japan is probably too remote for the name to catch on. Dreadnought was followed on the slips by HMS Bellerophon and HMS Temeraire, neither of which, I suspect, would have become popular.
HMS Dreadnought was commissioned in December 1906 (accounts vary as to whether on the 3rd, 6th, or 11th of the month). She displaced about 18500 tons, could make 21 knots, and carried 10 12″ guns in five twin turrets. The British didn’t believe that superfiring turrets would work (and, in their defense, superfiring experiments in American battleships had yielded poor results), so arranged the turrets one fore, two aft, and one on each wing. This gave Dreadnought an eight gun broadside and six gun head on fire in either direction. Dreadnought was armored on roughly the same scale as the Lord Nelson class pre-dreadnoughts (although ironically the construction of Lord Nelson and Agamemnon was so delayed by the concentration on Dreadnought that they weren’t commissioned until 1908). She was Jackie Fisher’s baby. Fisher began stockpiling material for Dreadnought before finalizing the design, and delayed all other construction to accelerate her completion. Laid down in October 1905 (five months after Satsuma), she was launched in February 1906.
Dreadnought served as flagship of the Home Fleet until 1912, eventually being replaced by newer and larger ships. Her construction forced the navies of the world to reinvent their own battleship designs, with the result that Dreadnought remained the most powerful ship in the world for only a brief period of time. She missed Jutland while in refit, and served for a while as flagship of a fleet of pre-dreadnoughts intended to deter German bombardment of the English coast. On March 18, 1915 she rammed the German U-29, thus becoming the only battleship to ever sink a submarine. Although she returned to the Grand Fleet in March 1918, she was placed in reserve when the war ended, and scrapped in 1923. She survived First Sea Lord Jackie Fisher by three years.
