I’ve mentioned Aegis several times, but haven’t really explained what it is. As it, and systems like it, are very important parts of modern naval warfare, this is a gap I intend to rectify.

Aegis destroyer USS Wayne E Meyer at LA Fleet Week 2016¹

During WWII, navies realized that the increasing performance of airplanes, and the development of guided missiles, would render guns obsolete as air-defense systems. They began to develop missiles as an alternative, although none reached service before the mid-50s. The US 3T family – Talos, Terrier and Tartar – is a good cross-section of these early missiles. These early missiles had much greater envelopes than the guns they replaced, but they weren’t perfect by any stretch of the imagination. Targets were acquired by rotating radars, which would take several seconds to complete a search. Each missile required a dedicated illuminator to provide the signal it homed in on. Due to electronic interference, only two illuminators could be installed on each end of the ship.² Due to the limited accuracy of early missiles, two missiles were fired at each target, limiting a ship to no more than maybe 8 missiles in the air at once. In theory, it should be able to fire about two missiles/launcher/minute, but in practice it was usually limited by guidance channels. Long-range missiles might be able to get off 10 salvos/end, more normal systems about half that. So a heavy escort could kill maybe 20 targets, a normal one 5-10, assuming that the missiles actually worked.

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After the end of the American Civil War, the US quickly went from having one of the world's most powerful navies to one of the least powerful. From 1865 to 1882, Congress left the navy to rot, and the US was soon behind such naval giants as Chile and Brazil. In 1882, an advisory panel recommended the construction of new ships, including battleships in 1885. The resulting ships, Texas and Maine,³ were second-class battleships of the generation immediately proceeding the Royal Sovereign, with en echelon turrets. Texas had two single 12" guns, while Maine had twin 10" guns. The secondary battery was 6 6" guns, although American industry was not up to producing 6" QF guns at this point, so the guns were not quick-firing. Both had armor protection over only a limited area, and would have been very vulnerable to QF gunfire. They took almost 9 years from contract to completion, and were thus obsolete before they entered service. Because of this delay, and of their origins as second-class ships, they had little influence on later US designs.

USS Maine in Havana Harbor before the explosion

Congress was still being stingy with funding, and in 1889, just before leaving office, Representative John R. Thomas managed to pass an appropriations bill mandating the construction of an "armored cruising monitor" of his own design. This would have been a low-freeboard ship with a twin 10" turret forward, a 6" gun aft, and a 15" dynamite gun⁴ in the bow. Thomas was a lawyer, not a naval architect, and the new Secretary of the Navy, Benjamin Tracy, managed to kill it off before it could turn out to be about the most useless ship ever built for the USN.

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A battleship as built can be seen as the sum of the answers to a whole series of questions, ranging from the highest levels of national strategy down to the most mundane issues of how best to operate a large and complex pile of machinery. A full and comprehensive analysis of all of these questions and their answers for even a single ship would require a whole book (actually several bookcases in danger of structural collapse), but I'll attempt a high-level overview here.

The Austro-Hungarian fleet on maneuvers

The first major question that shapes a ship is "What do we want our fleet to do?" The answer is informed by the strategic situation and the resources available, because there's never enough money as we'd like. We've previously looked at the basics of naval strategy, and the broad choices available to a navy. But how do battleships fit into this framework?

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Many have proclaimed the obsolescence of the aircraft carrier in the face of modern weapons. I've previously discussed the threat to aircraft carriers from missiles, both cruise and ballistic, and why neither is as effective as some pundits have claimed. However, the last major threat, from the submarine, is probably the greatest danger to surface forces. Modern submarines can be divided into two categories, nuclear attack submarines (SSN) and diesel-electric submarines (SSK), with very different threat profiles.

USS Oklahoma City (SSN-723)

The SSN is probably the greatest threat to the carrier, and the only real competition for the title of the modern capital ship. It has the strategic and tactical mobility to hunt a carrier on the open sea, and unlike any other weapon, it has a reasonable chance of reaching a carrier undetected and unattacked. Only 6 navies⁵ currently operate SSNs, and only the USN operates more than a dozen.

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The Russian battleship program continued to churn out ships in the early 1890s, producing ships in the pre-dreadnought mold. As with their earlier efforts, the result was a mix of good, bad, and bizarre ideas.

Navarin

The first Baltic battleship of this type, Navarin, was a radical departure from the previous ships. At a time when the British were shifting to high freeboard, the Russians built their first low-freeboard turret ship. Navarin was armed with a pair of twin 12" turrets and eight 6" guns, and originated as an attempt to hold down costs by building smaller ships.⁶ Navarin's most notable feature was her four funnels, two pairs side by side. This quickly gave her the nickname "Zavod" (factory).

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An excellent article on the (British) MoD Civil Service

This comes from The Thin Pinstriped Line, one of the best places I know of for getting a look inside the guts of running a military.

An understanding of the basics of naval strategy is vital to making sense of the logic behind the construction of the battleship, and also to understanding naval warfare today. Modern naval strategy began with Alfred Thayer Mahan's seminal book The Influence of Sea Power upon History. He outlined how control of the sea had granted Britain victory over her enemies during most of the 18th century, and theorized that a power which could control the sea would have outsize influence over events on land. Events since then have borne him out.

Alfred Thayer Mahan

Even today, the sea remains the best way of moving large quantities of heavy objects about the globe. Over 90% of global trade goes by sea. Despite American airlift capabilities, any large-scale deployment of US troops would require equipment and supplies to be transported by sea. Two schools of thought have developed to deal with these basic facts: sea denial and sea control. Read more...

It's not uncommon to see articles proclaiming the doom of the aircraft carrier in the face of the threat from China or other powers. Fortunately, the authors of such articles rarely understand warfare that well. Finding the carrier in the first place is not that easy, and then you have to kill it. Last time, I discussed the threat from conventional cruise missiles. But the weapon most commonly touted as making carriers obsolete is the DF-21D Anti-Ship Ballistic Missile (ASBM). The theory is that due to its speed and ability to evade defenses, there’s no practical way to protect against it. As you might expect, the story is much more complicated and much more favorable to the carrier.

A DF-21D missile

The DF-21D first came to US attention in 2009, prompting concern in the navy and panic outside of it. Defense analysts and talking heads said that there was no defense against it. At the time, that was only partially true, and important context was left out. In certain circles, however, this was uncritically accepted and interpreted to mean that no defense against ASBMs was possible. One so-called defense expert even went to the point of claiming that no defense was possible against any weapon on a ballistic trajectory, including a Harpoon in pop-up mode.⁷ This is frankly absurd, as the same logic leads us to conclude that it's impossible to play the game of baseball. Read more...

In the late 1880s, the pieces came together to create a new type of ship that would dominate the seas for most of the next two decades. After 1906, these became known as pre-dreadnoughts. While all of the elements that made them up had been used on previous ships, the end result was to bring an end to the experimental ships and produce the largest fleets of armored capital ships ever seen.

HMS Resolution, of the Royal Sovereign class

As the 1880s drew to a close, Britain faced a serious challenge to her traditional naval dominance. For the previous two decades, the drain of fighting colonial wars had kept the Navy budget low, while other powers had built up their fleets. However, these wars had largely come to an end, and in 1889, the Naval Defence Act was passed, formally establishing that Britain would match the fleets of the next two greatest powers combined, and authorizing 10 battleships over the next four years.⁸

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Stability is one of the most important factors to consider when designing a ship, but it’s often overlooked in popular references. Staying upright is an important function of any ship, and insufficient stability resulted in the loss of Vasa and HMS Captain, as well as three destroyers during Typhoon Cobra. One key means of avoiding this fate in bad weather is to keep the ship's center of gravity low, which often restricts design and particularly modification, a notable case being the installation of light AA batteries during WWII.

HMS Captain

There are three important points in defining a ship’s stability. The first, two, the centers of gravity (CG) and buoyancy (CB), are the points through which all of the forces of a given type can be assumed to act. Naively, we’d expect the ship to be stable if the CG is below the CB, so any roll would produce a righting arm. While a ship with such characteristics would be stable, the vast majority of ships achieve stability through a different mechanism.⁹ Instead, ships take advantage of the fact that their form near the waterline causes the CB to move to the side that is more deeply submerged, creating what is known as a righting arm (GZ) and pushing that side back up. In normal operations we can assume that the CB is essentially ‘hanging’ from a point, called the Metacenter (MC), making it easy to find how much the CB has moved at a given angle of heel.

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