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Posts Tagged ‘types’

Sci-fi starship types and doctrine

Posted by picard578 on March 1, 2018


Space combat is very different from naval combat as in World War II. Ships and fighters alike can maneuver in three planes. Sublight maneuverability has major impact on space combat – only a spinal gun mount can penetrate the shields of a similarly-sized warship. Maneuverability is limited by ship’s size, mass and structural integrity – smaller and lighter vessels are more agile and maneuverable. Because ship’s mass has major impact on agility, ships are built as small and light as possible for the role. However, when it comes to linear sublight acceleration, small vessel having an advantage is not given.

Sensors can be either sublight or FTL. FTL sensors have massive advantage in range – measured in light years. However, they are not capable of identifying ships except through their hyperspace signature – a ship remaining at sublight velocities is basically unknown. A ship moving through hyperspace can be easily identified, but even so reliability of identification depends on range. Ships cannot be engaged while in hyperspace, but must be intercepted and brought to realspace for combat. This typically requires advantage in cruise speed, or a well timed top speed burst. Presence of hyperspace inhibitors has also given rise to “pincer” tactic, wherein a ship that has caught enemy in hyperspace inhibitor field calls in reinforcements. These ships then only calculate hyperspace vector, with no exit point, relying on inhibitor field to bring them back out into realspace, significantly reducing calculus time required.

Nature of hyperdrive also has impact on ship design. Energy requirements for entering hyperspace and maintaining any given speed depend on ship’s physical size, mass, energy output and hyperdrive rating, but relationship is not entirely linear. As a result, smaller and lighter ships are typically faster than larger ships of similar overall shape. Transport ships tend to have lower cruise speeds because of increased mass, as well as using smaller, cheaper and more economical hyperdrives optimized for low-energy cruising at low to moderate speeds – larger hyperdrives tend to be disproportionately more expensive. Warships tend to be of elongated design due to need to provide maximum coil gun length and armour while keeping overall mass as well as target profile to minimum.

Hyperdrive has two settings – cruise speed and maximum speed. Cruise speed can be maintained for as long as ship has reactor fuel, while maximum speed can be maintained for a maximum of four hours before hyperdrive overheats and forces a twenty-four hour stop. Since energy expenditure for any given speed scales with size and mass, and fuel capacity also scales with size and mass, this means that ships of different sizes have similar endurance. However, square-cube law and the increased danger of being hit in combat means that heavy ships tend to sacrifice sublight and hyperspace mobility alike in exchange for increased firepower, shielding and armour. Result is that larger and heavier ships have reduced speed, range and endurance, and in general mobility must be traded off against combat power. This has led to colloqial classification of line warships into two main types: line warships or ships of the line, whose main purpose is to engage enemy ships in combat (battle missions), and cruisers, whose main purpose is to patrol friendly territory as well as hunt for enemy merchantmen during the war (cruising missions). Even so, larger warships may still be overwhelmed by smaller ships if said ships are too big to be affected by point defenses – that is, bigger than a fighter. As a result, they always operate with escorts, especially close to planetary bodies which may prevent engagement at maximum range.

Commercial traffic is extensive – a single industrial planet may be using resources from not only its own system, but also a dozen systems surrounding it, depending on rarity of specific materials – especially those required for high technology applications such as hyperdrive. This traffic naturally gives opportunities to pirates. Partly for protection, partly for efficiency, partly to avoid gravitational effects and anomalies which may affect speed and partly to escape (hyper)space monsters, much of commercial traffic is concentrated along well-travelled lanes.



Small craft can be divided into three basic types: air superiority (F), ship attack (B) and ground attack (A). These classifications can be further subdivided into types as described below.


Torpedo Bombers (TB)

Torpedoes are dangerous, but only at close to point blank range. At longer ranges, they get easily shot down by shipboard point defences, and even at close range large volume of fire is needed to get past the PDS. As a result, torpedoes are normally carried exclusively by light ships, such as destroyers, frigates and corvettes, which are light enough to avoid capital ship’s main gun while still large enough not to be bothered by extensive point defense systems. If close-range combat is deemed unavoidable, external torpedo launchers may be fitted to cruisers and battleships.

Torpedoes are also carried by bombers from carrier’s air wing. On its own, however, carrier’s wing would stand no chance against a battleship or a cruiser group – and even a lone light cruiser would cause massive casualties in a fleet carrer’s wing, or completely wipe out light carrier’s wing in most conditions. What is more, carrier’s fighter wing has no way of preventing enemy ships from escaping. While carriers do have hyperspace inhibitor onboard, a large fleet carrer would get gutted by a battleship even from the outside limit of inhibitor’s range, and a cruiser might easily either close the range or escape before it is destroyed. Light carriers’ hyperspace inhibitors are similarly range-disadvantaged compared to cruiser’s main gun.

As a result, torpedo bombers are used only in major fleet engagements. They engage after the light ships had already closed the range with enemy fleet, using confusion, electronic jamming and debris ever present in battle to mask their approach. Debris present significantly reduces ability of ships to detect bombers, and even if bombers are detected it can still significantly hamper the effectiveness of point defense systems by masking their fields of fire. These conditions allow bombers the opportunity for an effective attack. Even so, heavy casualties are to be expected.


Interceptor (P)

Interceptors are designed for defending fleet from enemy attack craft. Due to conditions where bombers actually become useful, they do not need to have long-range engagement abilities. Rather, firepower and sublight maneuverability are the key. As a result, most interceptors do not carry missiles, but rather rely on guns for destroying enemy small craft. They can also carry a small number of short-range missiles.


Attack (A)

These craft are designed for close air support for ground troops. As a result, they tend to have a gun and heavy armour, as well as ground attack munitions. Newer models are also shielded, protecting them from airburst weapons such as proximity shells and proximity-fuzed SAMs. Only direct hits by kinetic and HEAT rounds presend serious threat to such aircraft.




Battleship (BB)

Battleships are the heaviest, largest and most powerful warships in service. They are designed to destroy enemy warships and planetary defences. To do so, they focus on firepower and protection at the expense of mobility. Battleships rarely operate alone. Any mission where battleship is present will also see its screen of escorts come along with it to provide scouting, reconnaissance and protection against harrassing attacks. Typical battleship is 800 or more meters in length. Typical cruise speed is 10 light years per hour for old battleships and up to 15 light years per hour for new battleships. As M51 galaxy is 60.000 light years in diameter, fast battleship needs 4.000 hours or 167 days (5,6 months) to go from one side of the galaxy to another (Earth units).

Battleships are used as command ships for battle groups, fleets, large planetary assaults and landings.


Battlecruiser (BC)

Battlecruiser is a battleship intended for cruising missions. Due to their expense and relative lack of need for so powerful convoy raiders, battlecruisers tend to be few in number compared to battleships. Defining characteristics of battlecruiser are heavy firepower, high cruise and top speeds, high sublight maneuverability for a ship its size, relatively weak shields and armour of a light cruiser. This allows them advantage in maximum engagement range even against battleships. However, since even battlecruiser’s hyperspace inhibitor field has much shorter range than effective range of a battleship’s gun, allowing battleship to execute a quick hyperspace jump to engage, attack against a battleship of same generation is typically suicide. Where range advantage truly comes to bear is convoy interdiction: battleships are too valuable to regularly escort convoys, meaning that a battlecruiser can destroy it with impunity. If a battleship is present, battlecruiser’s higher speed typically allows it to safely retreat – although there is always a risk, no matter how small, that battleship, if properly positioned, will destroy battlecruiser before latter manages to retreat into hyperspace. Battlecruiser is 800 or more meters in length. Typical cruise speed is 15 light years per hour for old battlecruisers and 23 light years per hour for new battlecruisers.


Fleet Carrier (CV, CVL)

Fleet carriers are large, typically battleship-sized ships whose main purpose is carrying and operating aircraft. They have to have cruise and top speeds adequate for operations with the battle fleet. Typical carrier has a flight deck and several hangar decks. Although designs with more than one flight deck are not unknown, need to provide safe landing for fighters means that flight deck is typically taller than hangar deck, and thus only one is normally used. Further, flight deck ports at front and sides of the ship are a major vulnerability in a battle, and are so kept at minimum.

Fleet carriers carry various types of small craft for fleet combat and planetary assault alike. They are typically only used in planetary assaults, since in other circumstances enemy has little incentive to close to point-blank range where carrier’s fighters start being useful in ship-to-ship combat. Carriers can also provide sublight scouting for the fleet – while normally the job of frigates, fighters can better cover all various approaches in environments where sensory image is blocked and broken up, such as asteroid fields and dust clouds, some of which may block long-range sensors and limit the range of shorter-ranged ones. Lastly, they provide close air support and air cover for ground troops until such time that planetside air bases can be established. Fleet carriers are 800 or more meters in length, and have battleship-strength shielding as well as heavy armour, giving them same FTL speeds as battleships.

When needed, light carriers may also be deployed. They are less armoured and shielded than fleet carriers, as well as having reduced strike craft complement, but have improved sublight maneuverability and acceleration as well as higher cruise speed and endurance. As a result, light carriers may be deployed with cruiser groups on raids. They are between 400 and 800 meters in length.


Cruiser (CC, CL)

Cruisers are warships intended for cruising and patrol missions. They are a balance between speed – enabling them to catch enemy ships they can destroy and run away from stronger vessels, endurance – ability to stay on patrol for extended periods of time without resupply, and power – enabling them to stay in patrol area and drive away enemy raiders. Cruisers can operate independently, hunting for enemy convoys and merchant ships, or as a part of the fleet in which case they scout ahead, shadowing and reporting enemy warships. They are typically the largest warships carrying torpedoes.

Heavy cruisers are expected to provide escort for the battle fleet and screen for capital ships, as well as counter attacks by enemy cruisers and smaller vessels. As a result, they exchange cruise speed and endurance for increased firepower and protection. This, incidentally, makes heavy cruiser a ship of the line and not an actual cruiser. Heavy cruisers are 400 to 800 meters in length, but typical length is 600 to 800 meters.

Light cruisers are cruisers in the full sense of the word, focusing on performance in cruising missions. They thus sacrifice firepower and protection in exchange for cruise speed and endurance. They are typically both lighter and smaller than heavy cruisers, but some can be as large as largest of heavy cruisers. These are often informally called “large light cruisers”, a nickname that is sometimes used for battlecruisers as well. Numenorean navy, due to its emphasis on supply interdiction – particularly along hyperspace lanes – has very high number of light cruisers. During peacetime light cruisers serve in pirate supression and even scientific exploration roles. Light cruisers are 400 to 800 meters in length, but are typically between 600 and 700 meters.


Destroyer (DD)

Destroyers are smaller warships intended for escorting larger ships. They thus have reduced provisions for independent operations compared to what cruisers and battlecruisers have, and operate either with battle fleets or destroyer depot ships. They have a spinal gun as well as torpedo launchers. They also sometimes have mine laying and mine sweeping equipment, though this is uncommon due to low utility of mines in expanses of space. Main purpose of destroyers is to carry out torpedo attacks against enemy ships, and protect larger ships from similar torpedo attacks from other destroyers and torpedo boats. Consequently, destroyers often have point defense suite larger than what would be expected of ships that size. They are 200 to 400 meters in length.


Frigate (FF)

Frigates are destroyer-sized warships intended for long-range missions. They are basically sub-sized light cruisers, operaing in cruising role in situations and conditions when cruisers are too valuable, and also providing escort for light cruisers – much like destroyers escort battleships and heavy cruisers. Frigates are used as primary fleet scouts, commerce raiders and patrol ships. During peacetime they serve in policing and pirate interdiction roles. Frigates are 200 to 400 meters in length.



Corvettes are small, cheap ships. Their main roles are system patrol and fleet support, but are also used for convoy escort and show-the-flag missions. They are typically 100 to 200 meters in length. Unlike sloop however, they can be and are deployed with main battle fleet, providing support for larger warships.


Torpedo Boat (PBT)

Torpedo boats are small ships whose main armament are torpedoes. Their size and shielding make them far less vulnerable to enemy warships’ point defense systems compared to bombers, making them ideal for carrying out torpedo attacks against enemy ships. Much like destroyers, they have limited capacity for independent operations, making heavy use of support ships such as destroyer and torpedo boat tenders / depot ships. Normal size is between 50 and 60 meters, but some can reach sizes close to that of a corvette.



Escort ships can be divided into two main types: purpose-built warships, and modified civilian ships. In both cases however they are defined by their comparatively limited endurance, slow cruise speed and lighter armament compared to dedicated warships. These ships are only expected to escort transport ships between two friendly ports; fleet train is protected by dedicated warships due to need to actually keep up with the fleet. As a result, escort ships mostly expect to deal with pirates, and possibly enemy light units during the war – if heavy raiders are expected, important convoys will be escorted by full-fledged warships while less important ones will scatter. Escort ships neither have nor require provisions for long independent operations carried by line warships, and are typically built to commercial standards to increase production.


Escort carrier

Escort carriers are light carriers specialized in convoy escort. Unlike light fleet carriers, they have no requirement for high cruise speed or large fighter complement, making them much cheaper. Additional factor reducing the price is that they are typically built in commercial shipyards and to commercial standards. Their main purpose is defending against small one-man craft and modified civilian ships that most pirates use – fighters carried by an escort carrier would not be able to destroy any decently-sized warship on their own. Escort carriers may also carry additional provisions for smaller escort warships – destroyers and sloops.


Escort destroyer

Escort destroyers are destroyers specifically built for convoy escort. They are thus much slower in FTL than fleet destroyers, and are weaker in shielding, armour and firepower. They however have much better endurance, on par with frigates, and typically better maneuverability as well.



Sloop is a slower, less maneuverable small ship intended for escort. They are typically corvette or frigate sized, and in practice term „sloop“ or „sloop of war“ encompasses all escort ships smaller in size than escort destroyer.


Armed merchant cruiser

Armed merchant cruiser is a merchant ship comandeered by the Navy and equipped with weapons and shields rated above what merchant ships are normally allowed to carry. While typical merchant ship is not allowed to mount mass accelerators greater than 360 meters in length (frigate-sized), armed merchant cruisers may mount mass accelerators up to size of heavy cruiser guns. As a consequence, they are considered warships. They are intended for convoy escort and protection and thus have low hyperspace cruise speed. Some powers utilize modified merchant cruisers for merchant raiding. These are then known as auxiliary cruisers, and are provided with authorization („letter of marque“), making sure that crews will not be executed as pirates upon capture.




Logistics depot ship

Logistics depot ship is the centerpiece of Numenorean logistics system. Over two kilometers long, it combines the functions of a transport, cargo ship, mothership, maintenance and production center, and drop-off point. Onboard forge is capable of producing most parts that fleet needs (even heavy machinery parts and hull armour plates), as well as many supplies for ground forces. It also carries resource collectors, and is thus capable of mining asteroids, moons and planets for raw resources to produce necessary parts. If necessary, it can also distill water from comets. Due to its very slow speed and vulnerability to attack, it is typically left behind the lines with an escort, while transport ships carry supplies to the combat zone.


Destroyer depot ship

This ship is basically a smaller and faster logistics depot ship intended for supporting destroyers, frigates and torpedo boats in the area of operations. It provides maintenance support as well as crew relaxation facilities. They also carry specialized munitions required by smaller ships such as torpedoes. Depot ships also have foundry and forge, albeit sized for small ship parts instead of full-sized ones carried by logistics depot ships. As a result, they can accompany groups of light ships when same are operating behind the enemy lines for extended periods of time, thus removing need for a mass of specialized support ships that would unnecessarily increase group’s hyperspace signature.



Tanker is ship designed to carry liquids – fuel, machinery oil, water etc. They are typically fitted with heating systems to heat heavy oils and allow them to flow, as well as with steam smothering systems. Unlike generalist cargo ships, they have systems to allow deep-space replenishment of ships.


Passenger liner

Passenger liners are fast ships intended to transport people between destinations. Due to long travel times however, they are still fairly comfortable, though exact conditions depend on class. During the war, they are essential to quickly transporting large numbers of troops needed around the galaxy. Even small liners can transport upwards of 10.000 troops, albeit numbers are typically lower – down to 2.500 – on longer trips. Larger liners can carry up to 270.000 troops, which may go down to 65.000 on longer trips.

Some passenger liners are used as accommodation ships, receiving personnel from destroyed or heavily damaged ships. Accommodation ships are also used as barracks ships at advanced bases. Hospital ships are passenger liners modified to provide treatment facilities for soldiers and sailors in war zones. These are fully equipped hospitals capable of treating wide variety of injuries and ailments, and are also designed to provide logistical support to frontline medical teams and field hospitals.


General cargo vessel

These vessels have their own cargo-handling systems – lifts, booms and pulleys – and thus do not require shore facilities. Cruise speeds vary from 5 to 15 light years per hour. Cargo is typically carried in containers. As such, they have replaced bulk carriers entirely. Military-specification GCVs come in length of 225 to 1.800 meters, with beam of 40 to 325 meters, and height of 20 to 120 meters. Specified sizes are 225x40x20, 450x80x40, 900x160x80, 1350x200x100 and 1800x320x160 meters. Typical cargo loads for sizes are 30.000, 240.000, 1.920.000, 6.480.000 and 15.360.000 tons. Main purpose of GCVs is transferring materials from depot ships to fleet resupply points.


Heavy lift ship

Heavy lift ships are designed to recover and carry into hyperspace disabled ships. As such, they are typically built with expectation to handle battleships and fleet carriers. They carry disabled ships within semi-enclosed docking facility, which in some designs can be completely closed. Some larger heavy lift ships are also capable of carrying out repairs, serving as mobile space docks.


Orbital transport

Orbital transport is intended to transport cargo and personnel from orbiting ships to ground. Small orbital transports have length of 80 meters and can carry 1.200 passengers or 960.000 kg of cargo. Medium orbital transports have length of 120 meters, and can carry 2.500 passengers or 2.000.000 kg of cargo. Large orbital transports are 300 meters long, with capacity of 30.000 passengers or 24.000.000 kg of cargo.


Landing ship

Landing ship is a ship equipped with a dock and hangar bay designed to carry landing craft. Unlike aircraft carriers, they require no specialized maintenance facilities and are not expected to be anywhere near potential dangers. Consequently, they have large hangar bays capable of quickly launching large numbers of landing craft much more efficiently than an aircraft carrier would have been able to do, while still being cheaper and easier to produce than a carrier. They are used for landing operations and relief efforts.


Landing craft

Landing craft is a small type of vessel designed to quickly transport troops and supplies from ship to planet. As a result they have no FTL drive and are equipped with a bow ramp for quick embarkation, unlike orbital transports which cannot embark troops or cargo quickly and typically require docking facilities. Small infantry landing craft can carry only a single platoon. Larger infantry landing craft can carry a company of infantry, and are used to deploy support troops and equipment after beachhead had been established. Specialized vehicle landing craft are also used. Some landing craft are modified with guns, bombs and missiles to provide fire support before and during landing, as well as point defense against enemy artillery, missiles and aircraft.

Large landing craft are sometimes modified to serve as planetside barracks and command posts. Others are modified for various other Army uses, such as distilling ships or field hospitals.


Amphibious command ship

Amphibious command ship is a ship assigned to command large amphibious invasions, thus freeing capital ships to command fleets and battle groups. They have advanced communications equipment and extensive combat information spaces to be used by amphibious and landing forces commander. Such ships are typically converted passenger liners or landing ships instead of a specialist type.


General stores issue ship

These ships sail into rear areas and distribute general stores (canned goods etc.) to ships and stations. Once on station, they are resupplied by general cargo ships. They carry a heavy shuttle complement, and are used as resupply points for operations that are not large or important enough to warrant deployment of a logistics depot ship.


Combat support ship

Combat support / stores ships stow supplies and other goods for naval purposes, such as frozen, chilled and dry provisions, as well as ammunition, propulsion and aviation fuel, technical spares, general stores, fleet freight and personnel. They resupply from logistics depot ship or other supply ships before carrying supplies to the fleet. These ships are high-speed vessels designed for operations with the combat fleet. They are also equipped with more extensive medical and dental facilities than smaller ships can provide.


Repair ship

Repair ships are specialized for repairing damaged ships and equipment. Unlike destroyer depot ships they can service capital ships as well, but unlike logistics depot ships they can operate close to the fleet instead of staying at forward operating base. They are capable of repairing significant machinery failures and battle damage. Like depot ships, repair ship carries repair units, but in greater numbers and has greater selection of specialized repair units.


Hydroponics ship

Hydroponics ships are designed to provide fresh food and plants to help colonization and terraforming projects. Military hydroponics ships, also called botanical cruisers, are sometimes utilized to provide steady supply of fresh fruit and vegetables on long-term fleet deployments. Hydroponics ship can also include aquaponics system. In this system, excretements from fish are used to produce the nitrates used for plant growth. This helps keep the water clean for fish, as well as solving the issue of plant nutrition.



These ships are used by governmental structures other than military. As a result, they tend to be unarmed or lightly armed, and typically unarmoured with only shields for defense.



Cutters are small, short-ranged ships with weak FTL drive but excellent sublight acceleration and maneuverability. They are used for intra-system law enforcement. These ships are typically corvette-sized, but lack warship’s armour and powerful FTL drive. If needed, they can be used for system defense.



These ships are not used by military itself, but are used as classification for various types of ships used by mercenaries, privateers and pirates. Most of them are modified civilian ships. Sometimes these vessels are also used by PMCs to provide security for merchant ships. Privateers are given letter of marque which autorizes them to attack and capture or destroy enemy merchant ships, for which they are then given a bounty. In contrast, pirates attack any and all merchant ships and do not limit themselves by national boundaries or wartime.



Brigantines are light civilian transports, typically frigate-sized, modified with light weapons. As a result, they are fast and maneuverable for a ship of such size and type, but utterly incapable of dealing with anything more resilient than a torpedo boat or, at most, a corvette.



Chebecs are fast civilian ships, either fast transports or cruise liners, modified with coil guns, missile launchers, or both. As a result, they are fairy fast in both FTL and STL conditions, able to overtake most merchant ships. Depending on exact specifications, they may also be able to outfight some smaller escort ships, but they typically avoid any contact with naval vessels. These ships are not used only by privateers and such, but also by smugglers.



Galleons are large civilian transports modified with additional weapons. They are generally slow, but pirate types are typically modified for greater endurance. Bad maneuverability means that warships can generally easily outmaneuver them.



Mercenaries: this classification can be further divided by way of operations. Mercenaries proper operate as individuals or in small groups for pay.

Privateers: privateers are mercenaries which are hired by the state in time of war.

Pirates: pirates are individuals and groups which prey on merchant traffic for their own count. They are often, but not always, former privateers.



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Characteristics of aircraft types

Posted by picard578 on June 1, 2015

SIZE small (surprise, agility) large (range, missile load) medium-large (surprise vs range, weapons load) small-medium (surprise, agility vs endurance, weapons load)
NUMBER OF ENGINES single (agility, surprise, operating cost) twin (top speed) twin (damage tolerance) twin (damage tolerance)
COCKPIT/CANOPY TYPE bubble (situational awareness) sunk (drag reduction) sunk (drag reduction) bubble (situational awareness)
WING SWEEP moderate (maximum/cruise speed, turning performance, airfield perf.) moderate to high (high altitude performance vs maximum speed) low to moderate (low speed/altitude performance) none to low (low speed agility, airfield / low altitude performance)
WING LOAD low to moderate (agility) low to moderate (high altitude performance) high (gust sensitivity) low to moderate (low speed agility, airfield performance)
CREW 1 1-2 2 1-2
GUN CALIBRE 20-30 mm (firepower vs loadout) 25-30 mm (firepower vs loadout) 25-30 mm (firepower vs loadout) 25-30 mm (firepower vs loadout)
GUN TYPE revolver / linear action (response time) rotary (maximum rate of fire) rotary (maximum rate of fire) rotary (maximum rate of fire)
ENGINE TYPE afterburning turbojet / afterburning low bypass turbofan (speed, acceler.) afterburning turbojet / afterburning low bypass turbofan (speed, acceler.) afterburning turbofan (speed, endurance) nonafterburning high bypass turbofan (endurance)

NOTE: reason for selection of certain characteristics is explained in brackets. Aircraft that are intended for more than one of listed roles will have characteristics of several types.

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