Learning Pearl Harbor: What were Dreadnoughts?

When learning about the attack on Pearl Harbor, it's usually the battleships that get most of the attention, and a term that often comes up when describing these ships is "dreadnought," and even "super-dreadnought." So what exactly were the dreadnoughts?

The Origin of the Dreadnought

The only remaining dreadnought, USS Texas (BB-35), is now a museum ship

Though dreadnoughts played a major role in early 20th-century American naval warfare, this type of warship didn’t originate in the US Navy. The first ship with the attributes of a dreadnought was a part of the British Royal Navy. HMS Dreadnought was such a vast improvement over previous battleships that she inspired all subsequent models to follow suit.

One of HMS Dreadnought’s defining features was the implementation of an "all-big-gun" armament scheme. Essentially, rather than having a few large guns supporting secondary smaller guns, Dreadnought had 10 12-inch guns, accurate at much longer ranges.

The other defining feature of Dreadnought was that she used a steam turbine, which made her noticeably faster than older models.

Though "dreadnought" was largely used to describe the new model battleship and “pre-dreadnought” referred to older builds, by the time of the Washington Naval Treaty of 1922, the term had started to lose meaning, since all battleships followed the distinct design scheme.

Armament of the Dreadnought

Replacing short-range armament, HMS Dreadnought introduced a scheme that focused solely on big-guns of various calibers. While this mostly replaced the faster-firing secondary batteries, it provided battleships with the distance and strength needed to go toe-to-toe in open waters. With the introduction of larger guns, battleships could engage one another at greater distances, which pulled the emphasis away from rapid fire and placed it on improved accuracy.

Improvements to the long-range guns included a 12-inch mount that was able to fire at greater distances and at a higher rate of fire. From 1895 to 1902, even before the dreadnought armament scheme was conceptualized, 12-inch guns improved from firing one round every four minutes to firing two rounds every minute. Eventually, 12-inch guns became a standard on dreadnoughts

The First Dreadnoughts

First of the American dreadnoughts, USS South Carolina (BB-26)

In 1903, Japan became the first nation to lay down a vessel intended to utilize the “all-big-gun” design scheme. Ultimately, due to the financial strain of the Russo-Japanese War and limited supply of 12-inch guns, the final build ended up having a mix of 12-inch and 10-inch guns, and so these ships are considered "semi-dreadnoughts." Unlike Dreadnought, they were also powered by triple-expansion steam engines rather than steam turbines.

In 1910, the United States introduced its first dreadnought battleships: USS South Carolina (BB-26) and USS Michigan (BB-27).

Enter the Super-Dreadnoughts

HMS Orion, the first super-dreadnought

Though the dreadnought was a vast improvement over pre-dreadnought battleships, there were still tweaks to be made. Within five years of the commissioning of HMS Dreadnought, “super-dreadnoughts” started to enter into service. The first super-dreadnoughts were the British Orion-class, but the United States was quick to follow four years later with the Nevada-class, the US Navy’s first class of super-dreadnought battleship.

Earning them the label of “super” was a 2,000-ton increase in displacement and heavier 13.5-inch guns. All main armament was also placed along the ship's centerline and could fire well beyond the range of the 12-inch guns that had been standard on the original dreadnoughts.

All of the battleships at Pearl Harbor when it was attacked by the Japanese on December 7, 1941 were super-dreadnoughts.