# What formations would stellar capital ships use?

The science fiction militaries of my latest project field large numbers of space faring battleship style capital ships.

Historical, combat formations have been dictated by the capabilities of the combatants: classical century infantry had limited mobility and range, so dense lines and blocks of troops were commonplace. Sailships used lines astern effectively focus the side mounted weapons of all the ships in combat. Modern armour is highly mobile and faces hard hitting weapons, so irregularly disperses its units to minimize the effect of hostile fire and facilitate rapid maneuvering.

What formations may be used in stellar combat where capital ships face attack from any direction with little to no forewarning, can take significant amounts of damage before going down, and can rapidly bring fire to bear on any vector?

Details of the scenario

Faster than light travel is readily available to all ships, but ships can neither fire from nor reliably detect targets at FTL speeds.

The battleships' primary role is to blaze away at other big ships from the longest possible range they can reliably hit their target. The battleships' weapons and sensor packages can be considered extremely precise, and the main cause of missed shots is that the propagation of weapon bolts (shall we just call them lasers for now?) are limited to the relativistic constant, c, which permits target ships to take evasive maneuvers. This puts a soft limit on effective range based on the target maneuverability.

A typical range for battleship combat is 300,000 km, but battles that relied on volume of fire, or luck, have been fought at ranges an order of magnitude higher.

Guided missiles and combat drones are frequently used to fight from ranges into several billion kilometers, but they're often rendered ineffective by the close range point defense weapons of capital ships.

More agile battlecruiser-cavalry style capital ships attempt to engage other capitals at point blank range to create and exploit breakthroughs, strike high value targets, and cause confusion. The battlecruisers carry dramatically more powerful weapons that are, inherently, limited to close ranges.

Capital ships are usually accompanied by smaller, less resilient escorts escorts which perform more specialized roles.

Thanks for you help, all you armchair generals out there!

Update

Thanks for the help so far.

Here are the requested clarifications:

• FTL in this universe can only be used to relocate, and renders the ship undetectable. FTL ships cannot fire nor be fired upon.
• Point defense weapons are cheap and can be used whenever unnecessary without blowing the budget.
• I'm going with anti-gemoetry weapons for the main battery; point defenses and close ins vary from ship to ship: Lasers, masers, mini-missiles, gravity-flank, and projectiles all appear in places
• FTL systems can be brought to readiness in under a minute, sometimes a lot less.
• Because of the ready availability of FTL, and that FTL travel co-incidentally renders the ship undetectable, units can rapidly deploy onto any attack vector, hence why little warning of attacks are available. Most combat is started by smaller groups as bait.
• FTL can be used in combat for a convenient escape or re-positioning.
• Crews are usually sentient AIs, hence a (ballpark) "one second at the speed of light" safe reaction time. The AIs have approaching equal rights, so generally aren't used in suicide attacks. Lone human pilots (even in capital ships) appear, but have AI copilots.
• Do your point-defense weapons have a significant cost in terms of money or physical resources? You describe them as 'lasers', which generally are generally treated as negligible cost in a sci-fi scenario, but it's always good to double check. Also, are railguns a part of your ships' arsenals? Dec 31, 2016 at 9:14
• For effective answers you need more parameters, such as e.g. the time it takes to prime FTL jump engines after a jump; shields y/n; laser, plasma, projectiles?; humans or AIs?; are comms still bound to light speed? Etc Dec 31, 2016 at 10:24
• If it takes 15 - 30 seconds to rig for FTL, you'll almost never see any serious combat in deep space. The weaker fleet would jump to safety before they could take any serious damage. The only way to force a battle would be to attack an immobile installation like a planet, where the defending fleet can't just jump to safety without abandoning the installation. Attacking a planet is a totally different ball game than deep-space combat, since there will be static defenses and both fleets can make assumptions about the enemy's positioning. Dec 31, 2016 at 11:34
• @user45623 Quite agree. The question implied rapid FTL deployment. Now that the OP has confirmed that, deep space combat will be nigh impossible. Unless the attackers can arrive, in FTL mode, with great precision and fire their weapons before the target vessels can escape. Dec 31, 2016 at 13:40
• @user45623 That's the idea, 456, that's the idea... They'll be a lot of baiting, deception, and non-lethal, basically pointless combat. The plot's setup to allow ships to escape before destruction in most circumstances. Thanks for the help. Jan 1, 2017 at 0:07

Combat formations are usually based on some or all of the following (inter-related) factors:

• Expected direction of the enemy
• Optimal firing arcs of the units in the formation
• Minimizing exposure to the enemy

Often we have a decent idea of what direction the enemy will be coming from, so we position our units so that their optimal firing arcs are roughly in that direction and try to maximize the number of our units that have a clear line of fire. If the area the enemy could be coming from is large, we also try to cover weak spots - if your tank can only fire straight forward, you'll want other units that can cover its sides or flanks.

We also try as much as possible to reduce our exposure, either by using cover or angling our units such that they present a minimal profile to the enemy (or by positioning them far enough apart that the enemy can't blow them all up with one shot). Usually there's some tradeoff between maximizing firing arcs and minimizing exposure - for example, most naval battleship designs get maximum firepower from broadsides, which also increases their exposure by presenting the largest possible profile to the enemy.

What formations may be used in stellar combat where capital ships face attack from any direction with little to no forewarning, can take significant amounts of damage before going down, and can rapidly bring fire to bare on any vector?

Much of the standard reasoning about formations goes out the window in the situation you describe. The enemy can always come from any direction, so there is no way to take enemy positioning into account in the choice of your formation. Combined with the general lack of cover in space, this prevents you from designing a formation that meaningfully reduces your units' exposure to the enemy. Your ships can almost immediately shoot in any possible direction, so optimal firing arcs are not a major consideration.

Realistically, the formations that your units use are going to depend on the specific ships involved and their strengths and weaknesses. You might position your toughest ships in a sphere or cylinder around your weakest ships. It's also very difficult to design a ship that can bring equal amounts of firepower to bear in any direction, so ships are likely to be positioned based on where their biggest weapons are located. We don't have enough information on the specific vessels in your fleets to provide suggestions in this area, however.

An alternative to discrete formations is cluster patterns. Say that your fleet has 5 heavy battleships and 15 light cruisers. You might split them into equally sized clusters, each with 1 battleship and 3 cruisers. The cruisers can provide supporting fire for, or take cover behind, the battleships as warranted by combat. An advantage of clustering that the clusters can move independently, which allows your fleet to respond to an enemy threat more fluidly than a strict formation. You can also adjust the makeup of your clusters (fewer and larger, or more and smaller) based on the enemy threat.

Based on the information you've provided and assuming most capital ships have similar capabilities, tactics and maneuvers are going to be the key factors in combat, not formations. You admirals are going to be focused on when and how to move their fleets, what ships make up each fleet, and how they use their weapons, rather than the specific positioning of the ships in relation to one another. Formations might come down to little more than establishing a minimum distance between the units in the fleet.

As an addendum, I find that in most cases, maneuvers make for far more interesting literature than formations. If your evil Imperial fleet chases a handful of Rebel ships fleeing for cover behind a plant, only to find a withering array of Rebel missile boats waiting in ambush on the far side, that will be a lot more memorable than a detailed description of the 3D formation a fleet is traveling in. You can also use situational formations, which are also often more memorable. For example, the battlecruisers form an umbrella around the badly damaged carrier as it dives towards the safety of the planetary shield.

tl;dr

• Given that the enemy can come from any direction, if your ships can fire in any direction with equal effectiveness, there isn't much use for conventional formations among ships of similar class.
• If your ships can fire in, or absorb fire from, any direction with equal effectiveness, they are boring. Redesign them to have weak spots. Then design your formations around protecting those weak spots.
• Cluster patterns are a good alternative to distinct formations
• Try to emphasize maneuvers and tactics, since these will probably have more significance in combat and also make for more interesting reading. (see a4android's answer)
• As an aside, from an economic standpoint I don't think it will ever make sense to field as large and expensive of a target as a capital ship unless shields are invented. Dec 31, 2016 at 11:29
• You, sir, are a boss. If I were wearing a hat, I would take it off. What you've said is exactly what I was looking for. Maneuver warfare and half kilometer spaceships crashing into each other it shall be...All the way! Many thanks. Would you like a commission into the admiralty? Dec 31, 2016 at 11:40
• Great, glad to help! Dec 31, 2016 at 11:41
• Definitely "emphasize maneuvers and tactics". Combat will lead to interesting & exciting reading. Both sides will have to out-tactic each other in spades. Thinking about this set-up I was tempted to write my own version. It could be fun! Dec 31, 2016 at 13:46
• Redesign them to have weak spots. Then design your formations around protecting those weak spots. An example of this are Star Destroyers from Star Wars. Their shape is optimized for getting as much firepower pointing forwards as possible, but at the expense of minimal firepower on their flanks and rear. As a result, they generally travel in groups of two or more, so that they can cover each others' flanks. May 12, 2020 at 20:17
• One lightsecond is too short for dodging. 300,000 km means that the two-way message lag is 2 seconds. Calculate how much acceleration you need to dispace the ship by one ship diameter in that time ...
• The description of battlecruisers sounds more like torpedo boats in WWI warfare or slightly earlier. Short-range weapon capable of killing capital ships, must break through the fire of the capital ships, cause confusion in addition to actual damage.
• Is there a role for escorts? Does it make sense to stop missiles/drones before they can get a clear sensor picture of the main formation? Otherwise the smaller specialists are not escorts.
• Good. Now calculate how much acceleration you need to reach Warp 1.5 in less than a minute. Dec 31, 2016 at 14:51
• @BillyS, if you look at the OP I don't think FTL works that way.
– o.m.
Dec 31, 2016 at 21:06

If "Faster than light travel is readily available to all ships, but ships can neither fire from nor reliably detect targets at FTL speeds.", then the obvious strategy involves fast attack and evasion at FTL speeds.

This does assume vessels are capable of precise manoeuvres at FTL speed. Locate enemy vessels, determine the distance, set your weapons, go to FTL, travel at FTL until you reach their location, drop out of FTL mode, arriving at your targets and blaze away in the hope that enough of your energy-bolts strike and destroy the enemy before they jump to FTL speed and run away. This does work better if you align your weapons where you believe prospective targets are situated.

Simply having fleets of capital ships blazing away at each other seems wasteful and inefficient. If your vessels have FTL drive systems, use them to advantage. In this set-up, the chances are combat will be effectively neutralized or extremely difficult to engage in if ships can move away undetected and unharmed at FTL speed.

This answer does assume when the OP says "Faster than light travel is readily available to all ships" that spacecraft can go to FTL quickly and easily. However, this doesn't seem to be unreasonable or a special case in this scenario.

NB: Energy-bolts sounds much cooler than plain old-fashioned lasers. Much more space opera too!!

The most important factor in any battle is knowing where your opponent is. If you don't know where they are you can't hit them, and you can't - effectively - prepare a defense. If you can know where they are before they know where you are you can effectively choose the field of battle.

Your FTL cycles are crazy fast, all the lazers, mazers and rail guns in the 'verse won't matter if one side has even a small edge with faster FTL jumps than the other. This is because you - with the faster FTL cycle - get to control battle field information, and therefor the battle.

e.g. Your scouts report a capital ship in orbit around a given world. Your capital ship can jump every 20 seconds, their capital ship jumps every 30 seconds.

1. So you jump 80 light-seconds away from the ship, you've 20 seconds to target (but you don't fire), then you jump again.
2. You jump to a different location 60 light-seconds away from the ship, use this position and 20 seconds to improve targeting information. The other ship still has no idea you're there, your information (literally your light) is still 40 seconds away from them.
3. You jump again to within 21 light-seconds of your target, you've 20 seconds to fire a volley of laser/maser/rail-gun rounds targeting FTL engines & sub-light thrusters. After 20 seconds you jump out of position. The first "information" they have on you is the barrage that hits them.

This assumes FTL travel is instant, if it's not just add the travel time to the steps above

Your arms race here isn't really about better weaponry, but about the time between FTL jumps (and the length of time each jump takes), the side with faster FTL (even if it's only a tiny difference), has battle field advantage.

FTL Movement

The ability that you are providing:

Stealth movement of a craft in a faster than light velocity is the biggest weapon someone could have. Now you are battling in who detects who first

The possibilities are huge just a few to take in consideration.

• You have the perfect guided missile: In the instant that you detect an enemy fleet, just deploy a few smaller autonomos crafts with those coordinates and make them explote like a thousands suns.

• Long distance doesn't matter, I detect a laser/railgun/missile being fired and automatic evasive maneuvers engage, the fartest the capital ship is from a battle easier to avoid his shots.

• Fleets would stay in FTL movement to remain undetected, then appear for a few seconds, unleash hell and disappear again.

Best Formation

The only formation that I could think would make any sense would be a random one. Fleets would enter and exit FTL at random points of space and time with semi coordination from a command center who will exist to avoid collision between ships.

The plan would be to produce as much noice as posible to avoid any meaningful detection.

I will assume you have both FTL communications and FTL travel, and this kinda breaks the whole space combat trope if both are allowed simultaneously on the battlefield.

• FTL travel

If you have both FTL-capable capital ships (huge costs) and FTL-capable small cheap frigates or shuttles, then load up your frigates with your choice of doomsday weapons like a massive boron-hydrogen fusion warhead, set them on autopilot, and use them as FTL missiles which are impossible to dodge. Or just use FTL missiles. These hit the target before it is aware they've been fired.

I guess this is why FTL is usually impossible inside a solar system's gravity well. Or it has a max warp speed. Or FTL jumps can be detected instantly due to fluctuations in the flummoxion fields.

• FTL communication

The problem of aiming a FTL missile at a target is that you need to know where the target is, however if it is moving and distant, speed of light creates a delay.

Thus, you shoot a large number of small cheap spy drones whose only purpose is to locate targets, and relay (via FTL comms) where they are to the FTL missiles primed for launch. With instant transmission of targeting info, you get a sure hit every time.

So if you want a nice space opera battle, FTL comms also need to be blocked, maybe with a flummoxion jammer doohickey. Or all the ships need to be ultra-stealthy.

• I guess this is why FTL is usually impossible inside a solar system I assume you mean "usually in works for fiction"? Sep 6, 2017 at 20:01
• Yeah, in works of fiction. It it's real, then sign me up! Sep 6, 2017 at 21:44

Defense becomes difficult with the high FTL cycle rate and "FTL invisibility".

If your FTL cycle rate is 30 seconds, and it takes you 5 seconds to acquire a target, appear 20 light seconds out from the target (1/2 the cycle rate + 1/2 the target acquisition time + 1 for safety). Acquire your target, fire everything, FTL out to a new position as soon as you can and repeat.

The target has a chance to spot you 5 seconds before the incoming rounds hit. Assuming they have time to look for you while they are trying to move out of the way (how far can a capital ship move in 5 seconds?), their return fire won't get to you until you are gone. That's even if they can find you since they have to search a spherical space. The longer it take for them to find you, the less time they have to get out of the way.

Alan Dean Foster's The Damned trilogy explores this type of combat (all be it with much shorter FTL cycle times). It is all done by computers. Space combat is very boring to read in this scenario (which is why the books focus on ground combat).

If you want ships to have to maneuver, I recommend some kind of FTL distortion wave that is detectable before the ships arrive.

You might also want to look at David Weber's Honor Harrington series or Steve Wamsley's Aurora game (and blog). Both the book series and the game have similar roots. The game blog has a lot of discussion about maneuvers and about the effectiveness of various weapons at range.

• Another possible reference is the last book in David Weber's Empire of Man series, titled We Few. It doesn't deal with the high cyclic rate FTL, but it does offer some useful insights about dealing with the lightspeed delay. May 12, 2020 at 20:20

Some basic ones:

The wall: Enemy sees the ships like you see a wall. Resolution depends on numbers and wall dimensions(that is valid for all other formations below as well). Offensive formation. Any of the ships can target any enemy ship, even the same, and the same is valid for enemies as well.

The book: Enemy sees ships like you see a book on the bookshelf. Defensive formation. As a ship is close to front line, the more the attacking options for it and the more the attacks it may accept as well. As a ship goes back away from front lines the choices get fewer but fewer enemy ships can target it as well. If ships have means of recharge or repair, this formation adds endurance, as damaged/shields down ships can move back and replaced by fresh ones.

The egg: Enemy sees ships like you see an egg. Pointed sphere from front, sphere from back, oval from sides. Perfect formation if you deal with 2+ enemy fleets, even of equal or close strength to yours, and do not want to break your fleet to smaller ones. Offers great offence and defense balance regarding ships you may target and ships targeted by enemy. Also offer quite lots of choice about how much firepower you unleash to each enemy fleet. Target enemy fleet at the front may get the most offence, other fleets around may get significant firepower as well and fleet(s) at back also get considerable firepower.

The ring: Looks exactly as a ring. How enemy sees it depends if the enemy is inside or outside the ring. This formation is used at 2 entirely different cases: Guerrilla tactics against a stronger fleet, and lay siege on a weaker fleet.

When used at guerrilla mode, only a part of the ring is inside fire zone and the ships keep moving doing circles. This effectively result wasted firepower for the stronger fleet, better chance to hit for the weaker fleet and increased endurance for the weaker fleet as ships go out of the combat arc to round in again may recharge and possible repair something. A highly defensive tactic, having a large number of ships unable to fire or get fired at regular intervals.

When used as encirclement method, attacker density may be very scarce. However maneuverability of the attacker in ring is much higher than the defender regardless defender's formation. Attacker certainly has high attacking options and the same is valid for defender as well, but this does not equally help both sides, instead the attacker is overwhelmingly in favor. This tactic however cannot be applied unless the defender is pinned down to location for any reason.