Standardized Terran Naval Classes

It is damned difficult to enforce a naval treaty regarding limits on naval buildup when nobody can agree on what is being limited. One would think a battleship is clearly different from a corvette, but create a treaty limiting battleships and suddenly corvettes become immensely large and heavily armed. It took too many years, but we have finally agreed on a system that will keep everyone accountable. At least, until some wiseass naval architect decides he knows a new way of doding the treaty's stipulations.
Anonymous delegate to the peace treaty following the Great Colonial War

ANNAPOLIS NAVAL ACADEMY
SECURITY: UNCLASSIFIED, FOR PUBLIC RELEASE
PREPARED FOR INFORMATIONAL RELEASE
COMPILED BY THE OFFICE OF SPACEBORNE NAVAL INTELLIGENCE
CREATED FOR THEORY OF INTERSTELLAR NAVAL TACTICS

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Given the delicate and often hostile nature of the various human governments, conflicts between them sprang up quickly and frequently, generally of a deep space naval nature. This led to naval buildups and developments becoming signs of hostility and increasingly cutthroat arms races. Following the Great Colonial War, it became clear to everyone involved that there needed to be a consistent form of regulation and limitation on naval development. The problem, historically, was that adding treaty limits to warship design and construction only increased motivation for designers and naval architects to devise newer and clever designs. If that were not the chosen course of action, a government would call a ship by a different name than the one limited by the treaty.

As a solution, the peace conference following the Great Colonial War established a standardized glossary of warship classes and guidelines for creating new ones to account for future technological developments. The goal was that all future naval treaties would rely on standardized naval classes to define what ships were covered and their limits, regardless of what a government or ship designer might call their project. There was some pushback, but in the end, the standardized classes became the standard metric for ship design, as much for having a set of consistent guidelines as it was political.

To ease the process, they streamlined the countless options available based on the size of the overall ship, armament, and armor thickness. That way, regardless of what role a ship fulfilled or what a government classified the ship as objective elements could be used. The three elements were easy to see and verify as an additional bonus. The delegates chose to skip the small craft for the treaty as they realized there was little point in defining and regulating ships that could only carry a single person. Instead, they focused on warships that required rather sizable crews and could carry heavy weaponry.

Rated Warships

The general dividing line between rated warships and unrated ships of war is the size of their armament. Warships are most frequently understood as ships designed and built for war, while ships of war are generally smaller vessels retrofitted with smaller weapons that fire solid, non-explosive slugs. The exception, however, is the monitor class of ship. For the most part, monitors are unregulated as for the ship's size and armament. It's only limitation is that a ship can only be a monitor if it does not possess a -Nth Dimensional Engine, nor the structural capacity to have one added.

Warships can carry and utilize naval guns- designed to be used in vacuum and fire explosive shells, either pre-loaded or ones requiring each component to be loaded separately. These are generally breech-loading, rifled guns that would rate as artillery in land-based armies. Smaller ones can utilize autoloaders, while the largest require teams of more than a dozen spacers, assisted by electro-hydraulics to load each component.

It is important to note that warships are categorized by the size of their guns rather than other armaments because they create the most structural stress, meaning vessels have to be designed to use them. Torpedoes, rockets, and their rarer guided missile cousins can be easily adapted to most large ships, making them less useful for regulating warship development.

Patrol & Escort Ships:

Despite not being what most people consider when they hear the term of warship, the types viewed as escorts are the ones most frequently encountered. They don't make up the bulk of most naval fleets but are the ones most likely to interact with civilian traffic. Frigates are commonly used to patrol trade routes and escort merchantmen, making them frequent sights on trade stations and in systems with extensive traffic while corvettes are frequently deployed within heavily populated systems for security.

• Corvette: Corvettes are the smallest vessels rated as warships, generally only carrying 3-inch guns of various calibers and rarely extending beyond 200 feet in length. They most frequently serve as in-system patrol vessels and pickets along the edges of fleets in places where pinnaces and scouts are deemed unlikely to survive long enough to report. On the frontier, however, many ingenious designers created corvette-sized carriers to act as the outermost screen of pickets and respond rapidly to crises. Initially considered unorthodox, it was quickly adopted by more developed polities as the effectiveness of a picket screen capable of transiting through -Nth dimensional space became apparent.
• Frigates: Larger than a corvette but smaller than a destroyer, frigates typically fall between 200 and 400 feet long. While destroyers generally start at approximately 300 feet long, leading to ambiguity, frigates are designed and built for long-term and independent actions. They can carry up to 4-inch guns by treaty and because larger guns require more space than frigate-sized vessels can spare. Their roles include escorting convoys, commerce raiding, scouting, diplomatic transports, harassing enemy systems, and countless other uses invented by creative captains and admirals.
• Destroyer: Starting at 300 feet in length, there is significant overlap between frigates and destroyers, but they can carry up to 5-inch guns and be up to 450 feet long. Unlike frigates, destroyers are not meant to operate independently and are designed to operate with a squadron or battlegroup. As a result, they are frequently outfitted for escort and screening. Their guns are generally designed and loaded for quick-firing action, with machine guns and autocannons to protect against small craft, torpedoes, rockets, and missiles. Within fleets, they also act as the primary scouts.

Cruisers

Despite the dichotomy of light, medium, and heavy cruisers, cruisers are considered a single category of ships based on the treaties following the Great Colonial War, with the various categories being determined by the size of the guns they carry as main armament. Length-wise, cruisers are classified as anything between 450 and 800 feet long. All cruisers are designed to operate alone for extended periods, muck like frigates, but rather than serving as escorts, cruisers often serve as anchors for strategic and political objectives, being both too valuable and too expensive to use for escort duty.

• Light Cruiser: The smallest of the cruisers, these are distinguished by having up to 6-inch guns. In most cases, the standard layout is three or four centerline turrets of 6-inch guns, with many smaller guns spread across the ship. Light cruisers are the most frequently deployed of the cruisers, being relatively cheap while still having the firepower to stand up against nearly all ships their rating or below. They are especially used on the borders of the Diskward Marches, where piracy is expected (and sometimes encouraged). Still, there are no military forces except the Knights-Stellarum that could pose a serious threat to a state. Other light cruisers are frequently used to lead destroyer formations and to act as heavy firepower within screening formations. Given the smaller space required for 6-inch guns, light cruisers can dedicate more space to increasing their speed, maneuverability, or other specialized functions. Generally, however, they are designed to prioritize speed and maneuverability.
• Medium Cruiser: The middle ground within the cruiser classes, medium cruisers can carry up to 7-inch guns, which begins to require significantly more space to utilize, meaning they sacrifice speed for more armor and heavier firepower. As a result, medium cruisers are the true generalists of the warship ratings and make up the bulk of the naval forces in human-settled space. Most ambitious governments own at least one cruiser, although, for many smaller governments, a single medium cruiser comprises the bulk of their naval strength. With their prevalence and overall adaptability, medium cruisers can generally fulfill any roles to which they might be assigned.
• Heavy Cruiser: Sacrificing the speed and adaptability of the other two cruiser types in favor of firepower, heavy cruisers carry up to 8-inch guns but still remain significantly faster than battleships and battlecruisers. These are often the flagships of fleets and midsize governments. Generally speaking, heavy cruisers are adapted or reconfigured into other roles the way that light and medium cruisers are. The investment in the armor and weapons necessary for a ship to warrant such a rating and remain competitive against other heavy cruisers is simply too high to repurprose.

Capital Ships

Generally considered the pride of their respective fleets, capital ships are a very broad category but generally include anything over 800 feet long or with armament larger than an 8-inch gun. The two most famous types of capital ships are the battleship and the spacecraft carrier, emblematic of two void-based warfare theories. Some argue that carriers made battleships obsolete, but given that range in space can be more-or-less infinite, there remains a strong argument for using battleships. Projectile-based weapons have a range dictated only by the quality of their targeting solutions and the accurate knowledge of the enemy's position and vector. The consensus is that these capital ships are the ones who can win, or even prevent, a war by their very presence existence and essentially neutralize the enemy's capacity to wage war beyond their planet if their capital ships were destroyed.

• Carrier: The largest of the capital ships, fleet carriers regularly exceed lengths of 1,000 feet, given the infrastructure requirements of deploying and maintaining a large force of smaller craft. Not all carriers are built to that size, with the bulk of the known existing carriers to be built on cruiser-sized hulls, but the number of craft they can deploy places them as a capital ship when they are smaller than the 800-foot limit of a cruiser. Versatility has become one of the primary justifications for the expenses needed to construct and field fleet carriers as it is relatively easy, compared to building new spacecraft, to change the composition of a carrier's aircraft. They have been used as central command ships, hospital ships, mobile bases, and attack ships. Theorists have argued that modern battleships and battlecruisers are too well armored following the Great Colonial War for small-craft weapons to have effects on, but this remains a contentious argument.
• Battleship: The battleship is the classic embodiment of the capital ship doctrine. With main guns having gone up to 18 inches and designers working on the possibility of 19-inch and even 20-inch guns, battleships can shatter small ships and even many planetary fortifications with a single salvo. Their armor is extensive and can easily reach two feet of armor. However, the amount of mass each battleship carries is enormous which makes both their speed and maneuverability highly limited while their cost to operate are, no pun intended, astronomical. They are, however, more or less unchallenged in the battlespace and have been used by the United Terran Governments to prevent wars from breaking out between colonies simply by the presence of a battleship nearby.
• Battlecruiser: A more recent development in the naval arms race, the battlecruiser seeks to make battleships more cost-effective and versatile, much like they did in the early 20th century. Often the same size as battleships and with guns almost as large, the battlecruisers sacrifice much of the armor in favor of speed and maneuverability. Battlecruiser designers hope to find the middle ground between cruisers and battleships. Still, the effectiveness of the design has not been truly tested, nor has the roles of a battlecruiser fully developed yet.

Smaller Craft

While not regulated by the treaties following the Great Colonial War, small craft have effectively been consolidated into several specific roles and categories based on their intended purpose. Given the small nature of these vessels, they are significantly more limited in their range, carrying capacity, and purpose than even the smallest of the warship classes. Note, however, that these are limited to naval vessels and do not include civilian ships, which can and often do break all regulations and categories.

Fighters

• Superiority Fighters: As the archetypal fighters, there remains some of the early romanticisation of superiority fighters despite their less than romantic name. Fundamentally, superiority fighters are designed to seize space superiority by eliminating the enemy's small-craft forces. They are dedicated dogfighters and fighter-to-fighter combatants, often being lightweight, lightly armored, and relatively lightly armed. Despite this and their frighteningly high casualty rates, the romance of the Knights of the Sky still lingers.
• Interceptors: Larger, faster, and more heavily armed than superioriy fighters, interceptors sacrifice much of their maneuverability in favor of pure speed and endurance. Rather than focusing on establishing battlespace superiority, interceptors focus primarily on the interception of bombers and large projectiles like torpedoes, bombs, and other stellar debris. Built to be heavier, they rarely engage in dogfights as they lack the evasiveness necessary to survive close in engagements, despite often being armed with rockets and autocannons designed to break through the armor of heavy and strategic bombers.
• Multirole Fighters: More of a catchall than a specific category, multirole fighters are any and all craft designed to have multiple purposes. Frequent examples include fighter bombers, fighter interceptors, scout fighters, and strike fighters. Generally, these crafts are designed to be general all-around with the ability to adjust the payload in accordance with the upcoming mission profile. As these are more cost-effective, more and more governments have begun transitioning to multirole fighters rather than dedicated specialists.

Bombers

• Light/Medium/Heavy Bombers: The role of bombers, regardless of their weight classification, is to deliver heavy ordnance to a specific target with more accuracy and reliability than can be delivered otherwise. These are built to target enemy ships in space and tactical-level planetary and station targets. Given the lack of gravity in space, many of these bombs have some sort of small propellant to begin their drop and some form of guidance system to try and keep them on target, generally via radio control. The vast majority of bombs, however, are unguided and are dropped and left to the original launch vector. The distinction between the three weight classes is defined by the amount of ordnance they can carry. Light bombers generally carry up to 1 ton of ordnance in various sizes, while medium bombers carry up to 15 tons of ordnance along a larger operational range. Heavy bombers generally carry up to 40 tons of ordnance and can have a significant operational range- perhaps even their own small -Nth dimensional drive, usually limited to one system. These bombers are usually designed for a tactical role in close conjunction with other forces, including fighter escorts, warships, ships of war, and ground assault forces.
• Strategic Bomber: Despite some original confusion between a heavy bomber and a strategic bomber, a side by side comparison reveals they operate on separate scales. Strategic bombers, at the smallest, carry 4 tons of ordinance, but most carry between 12 tons and 15 tons and have their own -Nth Dimensional engines equivalent to most interstellar civilian freighters. These bombers are not designed to operate as part of combined arms formations but instead go on long voyages to enemy-held territory to launch mass bombing raids against targets at the strategic level. As such, they frequently have heavy armor and defenses to help breach planetary defenses and protect against hostile fighters. Others, especially older ones, have been outfitted with autocannon and large caliber kinetic weapons to provide heavy weaponry support to ground-based forces.
• Torpedo Bomber: With the development of larger and more heavily armored battleships, it has become clear to bomber designers that they simply cannot build a bomber large enough to carry the number of bombs required to significantly impact a modern capital ship. As a result, designers began experimenting with transferring the antiship torpedoes from the warship mounts to small craft in order to better evade point-defense and interceptors. However, the nature of torpedoes and their slow launch speed make both the torpedos and the torpedo-bombers vulnerable to defensive fighter screens and interceptors, but a single effective torpedo hit can effectively remove, if not destroy, a warship. The risk-reward ratio on that remains undecided.

Other Craft:

There are countless numbers of other vessels, both civilian and military, in human-inhabited space. Most of them, however, do not fall under regular military use, making them outside the scope of this dossier. There are crossovers, however, as well as ones that do not fit neatly in any other category.

• Gunships: Too large to be a fighter but rarely carrying bombs, gunships fulfill the intermediary position between fighters and bombers, although they are not often used in direct fleet engagements, although some have been designed as point-defense and anti-fighter vessels, with flak cannons and radar jamming, or other types of support equipment that cannot be carried on fighters or bombers. Most gunships are used in close support of ground forces or as a backup to customs and law enforcement vessels.
• Couriers: Radio waves do not travel faster than light, but vessels can. That has developed into the practice of using couriers to carry messages at faster-than-light speeds as well as material that cannot. These come in both commercial, personal, and military designs but are generally built around a -Nth Dimensional Engine. Some are little more than a cockpit attached to the -Nth Dimension Engine, while others are freighters designed for speed. Couriers are rarely, if ever, armed and then only lightly, as only the fastest of ships can generally keep up with them.
• Reconnaissance/Scouts: The reverse side of the couriers are the scouts and reconnaissance craft. Rather than carrying things between systems, they go and look at them. These are generally divided between the recon and scout types of ships, with recon being more military and scouts being broader in purpose, but are often used for both. These ships are designed for long ranges, speed, and endurance, supporting sophisticated radar, radio waves, and photographic recorders. The largest and most sophisticated scout vessels are built and designed for the Cupertinan and commercial star surveyors who chart the frontier and discover new star systems.
• Assault Landers: While some argue that an orbital blockade more or less negates the need for planetary or station invasions, that was shown not to be the case during the Great Colonial War when blockaded, but otherwise unoccupied planets built massive siege guns that could be fired on warships in orbit and, in some cases, beyond. While such weaponry was crude and improvisational, the fact that it exists forced an entire reworking of system-level strategic doctrine when it came to the armed occupation of inhabited systems. Essentially, systems were no longer considered pacified while only blockaded. Governments quickly realized they needed effective and reliable means of transporting ground forces to the ground. Assault landers are large, heavily armored transports that carry infantry, armor, artillery, and logistical support. They're primarily armed, when armed, with machine guns and autocannons to clear landing zones and provide some basic cover.
• Boarding Pinnaces: Large ships cannot safely and reliably connect via their airlocks. As a result, the old practice of using a pinnace to transfer between vessels was revived. It quickly became apparent that pinnaces could be used for forceful and peaceful boardings. Boarding pinnaces with interior airlocks, drills, and blast-reinforced fronts were quickly designed. Primarily small craft for elite teams to establish a beachhead aboard an enemy vessel, some are large enough to carry platoons. They can also be used to deploy special operations teams to planetary surfaces or station targets, although they are not usually stealthy enough for infiltration.
• Q-Ships: Not entirely the same as a commerce raider, a Q-ship is a specially designed and built military ship disguised as a civilian vessel. Many are used as spy ships, but the most feared ones are those built as commerce raiders. They are warships that look like civilian vessels, making it very easy for them to launch ambushes against military targets. One particular clarification is that Q-ships are different from armed merchantmen or privateers, which are almost always ships of war that began their lives as civilian vessels before having weapons added. Q-ships are designed and built for war, making them warships. Some can even carry the guns of rated warships, although no Q-ship has ever been reported with anything larger than a four-inch gun.