Monday, 1 February 2016

Space Combat Part 2: Spinal, Broadside, and Turreted Weapons

Wherever nerds Science Fiction fans gather to debate the future of space warfare there are several debates that almost always pop up sooner or later, and which  seldom generate a consensus.    One of the most popular is the debate over fixed Vs turreted weapon mounts, with the fixed weapons divided into spinal mounts, and less commonly broadside mounts.  Related is the discussion over which of the three main direct fire weapons likely to be used in space combat - Laser, Particle Beam, and Kinetic - are most suited to each of the three mounting options.  In this blogpost I'm going to attempt a analysis of the specific strengths and weaknesses of each type of mounting, which weapon fits them best, and the tactical scenarios in which they offer the biggest advantages.  I'll also cover the worldbuilding needed to justify each option in your 'Verse.

The Spinal Mount

Definition: A weapon firing in a fixed forward arc, parallel to the direction of thrust, with limited elevation or traverse, and typically running through a significant portion of the spacecraft's length.

   Spinal or Keel mounted weapons are interesting because, unlike turrets or fixed weapons, they have no current real-world counterpart aside from fighter aircraft.  The sea going battleships that provide inspiration for many SF works used broadsides during the age of sail, and turrets in the era of Big Gun battleships, but a single forward firing weapon has never been used to my knowledge aside from a few submarines like the Surcouf, and that was neither common nor in line with the spinal mounts of SF.  If anything their closest analogy is the main gun of a turretless tank hunter.  Even that is a poor comparison given the role stealth plays in tank warfare, and the degree to which it is impossible in space.

   The rational behind the Spinal Mount is straightforward and pretty logical; the bigger the gun the better, right?  Most 'guns' in SF are in fact accelerators of some kind; railguns, coil-guns or gauss cannon, ram accelerators, and particle beams.  What this means is that muzzle velocity scales directly with the length of the weapon, rather than their being a optimum barrel length as their is with conventional firearms.  There are engineering limits, or those imposed by material science, but the highest theoretical velocity is as close to the speed of light as you can get.  A Spinal mount also translates the power of the weapon to the audience quite easily, especially when coupled with long recharge times and/or cool down.  The MAC guns of HALO and the Wave Motion Cannon of Space Battleship Yamato are pretty typical of this trope.

   There are a few disadvantages with the spinal mount, most of which revolve around the fact that the spacecraft must manoeuvre to aim the weapon.  Even if the finer adjustments are done internally rather than by the spacecraft's alignment it will still limit the speed that the spacecraft can edge widely separated targets.  It also means that if a enemy emerged unexpectedly from hyperspace the spinal mount might not have time to be oriented before it is destroyed.  Most spacecraft armed in this way are shown with only one main gun, with is a disadvantage if it breaks down or is disabled by enemy fire.  The spinal mount might well be a glass cannon, extremely dangerous, but needing other ships to contribute to its defence, especially if under attack by multiple enemy.

   While the time needed to aim, and the disadvantage of only being able to engage targets in the same direction at once are inescapable the problem of manoeuvrability may not be an issue.  A spacecraft equipped with a powerful gauss cannon, railgun, particle beam, or laser, will have plentiful electric power.  This can be used to power multiple thrusters distributed all over the spacecraft, rather than having them clumped together, and allowing acceleration in any direction.  With many fictional spacecraft the main drives are to large, expensive, or radioactive to allow this, but for more realistic low accelerations electrothermal or plasma based drives may do fine.

   The advantages are many.  A spacecraft can fit a larger spinal weapon than it could hope to fit into a turret, something likely to hold true for any size of spacecraft.  This is partially due to the fact that a turret has to turn, and so has limits on the mass and size of the weapon, and partially to the fact that recoil forces along the line of thrust can be absorbed by the thrust structure instead of by a complicated system of articulation.  This can also make the weapon more accurate as it will not have to cope with the vibration of turret articulation, or the fox in a unsupported barrel.  Greater muzzle velocity has the advantage of imparting a longer effective range on particle beam and kinetic weapons, helping to negate their inherent weakness.  Even if the energy they output is the same as a physically smaller weapon, the increased range will make them more effective at ranged combat, something there is likely to be a lot of in space.  And they do not need the cool down time shown in SF.  The most powerful might, but it should not be a surprise to find MAC gun like weapon with rapid fire capabilities. 

   Kinetic weapons benefit the most from a spinal mount as opposed to a turret or broadside since it helps to overcome their greatest weakness - low velocity.  Particle beams may also be common in this role since the long skinny shape of a particle accelerator fits the bill nicely.  Lasers on the other hand do not seem to be a good candidate.  Lasers do not benefit from having a longer physical shape, it is the diameter of the emitter that counts.  While there is an analogue - a spacecraft with a single massive mirror at the front - it has its own advantages and disadvantages, and does not really fit the description of a classic spinal mount.  Operationally it would be employed the same however, and have the advantage in rage over smaller turreted counterparts.

   It is this range benefit coupled with the low turning rate that define the use of spinal weapons.  They are the long ranged artillery of space.  If they can maintain range from the enemy the extra range might make them well right invulnerable, while if used in a defensive role that extra reach will fore the enemy to run a gauntlet of fire.  A battle between two of these spacecraft would be like a sniper duel - few tactics, with the one with the greatest accuracy coming out on top.  They would be at a disadvantage in any battle where there are multiple vectors of attack, or one that starts at close range. In a battlefield dominated by missiles they might not fare to well, but one that focuses on direct fire is likely to see them.

   The 'Verse that features spinal weapon can fall anywhere on the spectrum of scientific realism.  Given their long range and potential firepower it seems likely that any space force will have some in its ranks, and that they will form an important part of tactical doctrine.  One thing to note is that they become less attractive as the number and acceleration of ships increases as this brings out their weakness.  A jump drive that allows enemy to 'slip under the guns' as it were will also compromise them.  In any battle where missiles are unviable, massive firepower is needed from smaller ships, or the enemy will be engaged at extreme range a spinal mount is justified.  Another thing to remember is that a magnetic accelerator could be developed as a civilian cargo launcher on the moon, and repurposed as a weapon during a war, similar to in Heinlein's The Moon is a Harsh Mistress.  Even particle beams or lasers that fit the design requirements might be developed as part of beamed power stations.

The Turret

Definition:  A weapon or weapons mounted on or in an articulation that provides extreme ranges of traverse and elevation, as well as commonly housing the firing/loading mechanism and gun crew.

   The turret is one of the most common styles of weapon mounting in SF, and for good reason.  Nearly all wet navy guns are mounted in turrets, as are point defence weapons, and the main gun of tanks.  It was the invention and adoption of turreted main guns, along with the invention of the steam engine, that changed the face of ocean warfare forever.  A spacecraft armed with turrets can bring more of its weapons to bare on any enemy craft, and can do so regardless of its heading.  This is obviously important in a battle involving many spacecraft in close proximity, especially those capable of fairly pronounced manoeuvres and high acceleration.  Point defence weapons are far far more effective will a turret mount than without, allowing them to track incoming.

   There are two common mistakes with the representation of turrets in SF.  The first is the idea of a turret as a bolt on unit.  While this may be the case for smaller point defence units, it is almost never true of larger weapons.  Even the small gun turrets wet navy ships still use extend below the deck level, and old battleship turrets had more concealed than exposed.  The second issue is when turrets are placed in a position where the firing arc is limited by other turrets or by the hull of the spacecraft.  While the latter is to an extent unavoidable the former defeats the purpose of having a turret to begin with.  Yes, I'm looking at you Star Wars.

   Disadvantages of the turret are simple.  For any given weapon a turret to carry it will add complexity, mass, and power requirements to the design of the combat spacecraft, reducing the overall number that can be carried and increasing the cost.  Reduced accuracy can also be a problem due to vibration from the traverse motors, increased vibration in the flexible bearings, and flex in a unsupported barrel.  There amy also be a limit to the ammo that can fit in the turret, decreasing the overall firing rate.  Unique to spacecraft is the problem that recoil forces imparted on the spacecraft are not going to be constant, and will thus be harder to account for as they impact the trajectory of the whole craft.  

   Fundamentally turrets have a single advantage; they can be aimed independently of the spacecraft's orientation.  All the other advantages - reduction in number of guns needed to provide coverage in terms of point defence, ability to engage multiple targets in different directions etc are all derived from the former.  The advantage is most pronounced with point defence weapons, as they will face threats from many angles, and need to be able to track fast and close targets.

   Kinetic weapons are ideal for turrets given that unguided kinetics have short ranges, and it is in this envelope that turrets offer the biggest advantage.  Lasers also have a lot going for them.  Since the laser itself is likely to be in the main hull rather than the turret itself, with the beam reflected through a series of mirrors, there can actually be more turrets than the spacecraft can generate laser light for.  Whichever turrets are needed have laser directed into them, and the loss of a few to enemy fire is not such a disadvantage since the total energy output does not decrease.  Particle beams benefit the least.  This is both due tho their long skinny shape in most designs, and to the fact that bending a particle beam at any kind of angle will produce synchrotron radiation.  Tis could of course be overcome by having truely massive turrets or miniaturised particle beams.  In terms of point defence lasers are likely to be dominant given their accuracy at range, and the fact that a missile probably won't be too well armoured compared to a spacecraft.  Adaptive optics can also give point defence turrets quicker focusing and greater accuracy.  Kinetic point defence will be regulated to slower firing 'flak guns' that throw up a wall of shrapnel rather than targeting individual threats.

   Unlike broadside and spinal mounts turrets have the best chance of dominance in a softer SF 'Verse.  This is because they are best suited to short ranged, high relative speed combat where aim will have to be shifted quickly, and the spacecraft will be changing direction often.  They are also suited to battles where enemy spacecraft can emerge unexpectedly from hyperspace in any direction, and in which the spacecraft of both sides end up occupying the same volume of space.  Obviously force fields or shields help in this regard as they encourage ships to close to kinetic range where they can output more damage.  In a hard science 'Verse close quarters battles are unlikely as everyone will be seen long before they get into range, and with the ranges that are more realistic decrease the disadvantage of fixed weapons and emphasise range and accuracy.  Turrets will always be used as point defence installations however, so they will never be absent.  A lot of works also feature turret mounted kinetic guns as secondary weapons, like the Sulaco from Aliens; this is quite likly considering the relatively small size that kinetic weapons can have while remaining potent enough to be included.

The Broadside

Definition:  Weapons mounted at right angles to the direction of thrust, usually within the main hull of the spacecraft, and with limited traverse and elevation. 

   A fixed broadside battery is one of the most uncommon arrangements to be seen in SF, with turrets being far more common.  The only one that I can think of in visual SF is the gun deck aboard the Separatist ship at the beginning of Revenge of the Sith.  In written works the Black Fleet Trilogy by Joshua Dalzelle had what sounded like a fixed battery of laser weapons on the ship that acts as the setting for most of the first book, but it was never implicitly stated.  In the Honor Harrington books the beam weapons were, by memory, in broadside arrangement; a necessity imposed by the gravity drives used.  There are also the quite common examples in visual media where turrets are shown that would be unable to fire in any arc except that of a broadside.  Most of the turreted guns seen in the Star Wars movies fall into this category, with the Venator Class being a prime example.

   The scarcity of this arrangement is not unexpected.  With the prevalence of the 'Space is a Ocean' trope it is to be expected that a design philosophy that long ago gave way to turret armament should find little traction.  Where it is found it is most often for the visual effect, or because the work is intentionally trying to mimic the battles of the Napoleonic War transposed into space.

   There are not so many advantages to this type of design, and the conditions under which it become practicable are quite specific.  The main advantages are those shared by any fixed weapon mount.  Each weapon will mass less than an equivalent turret, and be simpler in construction.  It may be more accurate since it can be mounts straight to the spacecraft's structure via recoil absorbing mechanisms, reducing vibration.  Ease of access would also be a big factor, especially with advanced and perhaps temperamental weapons since turrets have never been known as spacious.  The weapon itself might also be more massive than a turret could cope with, or have a larger recoil force.

   Disadvantages are pretty obvious.  Limited traverse and elevation impose a greater need for manoeuvrability on the spacecraft, and run the risk that at close range or high traverse speed a more manoeuvrable target could stay out of the fire arc entirely.  This is partially avoided with lasers, since with adaptive optics they can have quite a good arc of fire without the actual emitter being articulated.  Since they cannot fire forward the spacecraft is at a disadvantage accelerating toward or away from a target, although this may not be a problem depending on the technology level of the 'Verse.  The broadside, and all fixed weapons, are at a disadvantage in a 'Verse where FTL can allow a enemy spacecraft to appear unexpectedly in any direction.  The need to rotate the entire spacecraft is going to slow down response times significantly compared to a turreted vessel.  Conversely the broadside is more attractive in a hard science 'Verse where you will always see the enemy coming.

   A broadside thus falls best into a 'Verse with fairly low accelerations and long engagement ranges.  It also becomes a lot more practical if the main offensive weapon is a missile attack from standoff range, especially if it is one involving tens or hundreds of missiles, and possible submunitions.  The ability to carry more weapons for the same mass than in turrets, coupled with the greater accuracy and potentially greater effective range would give the broadside ship a very good defence against missile spam attacks.  Against such an attack it is the volume, range, and accuracy of defensive fire that will stop your spacecraft from being ventilated by a hypervelocity penetrator, and in this regard the broadside holds the advantage.  Also, the greater the number of weapons, the more incoming can be targeted at once.

   Lasers or kinetic weapons would be the most practical.  Lasers would benefit from having many emitters, allowing more incoming to be targeted at once, and for kinetics it allows a greater overall rate of fire, important given their inaccuracy.  With kinetics it could also extend their offensive range by filling more space with metal than would be possible with fewer weapons and making it difficult to evade with low thrust levels; range would still be terrible compared to other weapons however.   Charged particle beams could interfere with each other, but a neutral beam wouldn't ave that issue.  The soft-kill ability of a particle beam might also prove handy against missile attacks; the beams could even be defocused to fill a huge volume of space with relativistic plasma, providing a potent radiation hazard for any incoming missiles.  But without exact numbers it seems impossible to give any of the three weapon types a clear advantage for broadside use; it depends doll on the details of the setting.

   Some of you might object to the idea that lasers are better with many emitters, and it is a common debate.  Do you use one emitter with longer range, or many smaller?  My reasoning is that in a 'Verse where missiles are a viable main offensive weapon they will broadly be able to fire enough missiles with enough submunitions that the extra range is not such a great advantage, more so since a accelerating missile at a half a light second or so is going to be phenomenally hard to hit, and could be travelling at a huge speed by that time.  In any case, a computer controlled array of smaller emitters can act as a single larger emitter to some extent, in the same way as many modern telescopes use mirrors composed of multiple segments.

   Although not strictly a 'broadside' a missile armed spacecraft might have its storage silos arranged in the same configuration to allow more rapid deployment.  With warfare based on missile spam the ability to unleash more missiles in less time might be the best chance at victory, and having the equivalent of a current VLS(Vertical Launch System) might be the ideal.  This could also look pretty cool visually while maintaining realism, so take notice Hollywood! 

  Well, there we go.  Part 3 is in the works, but no promises on how long it will take.  Anyone interested in a deeper discussion of this topic, along with the maths, can find a wealth of info on the Atomic Rockets website.  There is a lot there though, so this may be more helpful to someone looking at a overview of the subject.


  1. Is the torpedo launcher a spinal mount weapon?

    1. I mean, torpedo laincher on submarine, to be clear :p

    2. Not really. Since it can fire at any target in most of the forward hemisphere, the torpedo is a self contained guided projectile, and the launcher does not take up a significant length of the submarines hull it doesn't really fit the description.

  2. Great summary!
    On spinal mounts: one advantage of spinal mount weapons is that they can also double as the structural backbone of the ship, much like a modern skyscraper "hangs" off of its steel core, and it can take advantage of plumbing and accessways that would normally run the length of the ship in any case.
    As far as turrets go, turret rings are heavy and prone to jamming. Even a small laser or projectile hitting the thing can cause it to completely jam up. Likewise heat buildup during the normal cause of battle can cause the turret to seize. Also, a very good reason NOT to have them is that they increase cross-sectional size and are much harder to armour than the main hull (as well as providing a nice big path for damage to enter, in the case of laser turrets). I think having laser ports dotted all over the hull is what we're most likely to see.
    For broadsides, particle beams can be slewed out of their parts by magnetic fields which are generated internally. Heck, a few standoff mirrors would also work for lasers but are rarely seen in SF.
    Unfortunately, these don't scream "damage" as much as the Yamato's triple shock cannon turrets :P

    1. Most of that is engineering details, so its impossible to find a conclusive answer. Depending on the size of the turret it might only be one percent of the cross sectional area, not really adding to the profile, or it might be half as big as the main hull.
      With particle beams you don't want to bend them much or you get synchrotron radiation; it okay to do a few degrees for aiming purposes, but much more and you can loose a lot of beam energy, not to mention the hazard that the radiation could cause This is the reason that the old 'Star Wars' missile defence program used long skinny particle accelerators.

  3. The answer depends heavily on the nature of what you're shooting at is. If it is a shot hit - one kill environment, where opponents will always be seen well before entering weapons range and targeting is sufficiently accurate to hit reliably once in range, then the biggest spinal mount is the way to go. Broadsides would likely be the best fit in setting where ships peck each other apart only if the range remains long so arc remains less of an issue, making the Star Wars setting one where you would not want a broadside system. The biggest failing of a broadside system though is that in all likelihood in action at least half your guns will have no target but one other possible benefit is that it is the one where there is the best possibility of fitting weapons to ships not originally intended as warships.
    A turret system's main virtue will be flexibility. The ability to provide end on fire or broadside fire as required, which could mean than a turret equipped ship may be able to bring guns to bear on a single target than a broadside ship that nominally outguns it. Also while a turret is going to be bigger and heavier than a fixed mount, if positioned properly then it may work out lighter and smaller than having two sets of broadsides.
    Comments aside though good article.

    1. I suspect that the turret/fixed debate will only be decided by actually building combat spacecraft and using them operationally, although I hope Humanity has enough sense to avoid that. And any advanced space force would most likely include all weapons types within its fleet, or even on the same spacecraft.

    2. And the in meantime that within SF that the chosen layout makes sense within the setting.

  4. Splendid article as always! And I've some comments as always…
    First – why did you referred to coil-guns and gauss cannons as different things? Aren't they the same thing?
    With spinal mount the ship need to constantly change orientation to aim its gun; but the ship doesn't need thrusters for that. Flywheels can provide 'reactionless' method of rotation without the wasteful use of propellant and heavy powerful side thrusters.
    Currently satellites and spacecrafts use those things and future war spaceship could use it too.
    Since in space 'every gram counts' those flywheels could be more than just a dead weight; an indoor centrifuges, similar to what seen in Odessa 2001, be used to create artificial gravity for the crew for the long duration in space AND as a flywheels.
    Two are needed, perpendicular to each other and both are perpendicular to the ship's long axis in order to rotate the ship.


    1. I mentioned both coil-guns and gauss cannon because although they are the same thing some people might not one name and not the other. Sorry if it caused confusion.

  5. Interesting points as always!
    Something that you inferred about broadsides, but that I couldn't find written as such, is the ability for broadside ships to accelerate at a right angle for evasive manoeuvres. Against unguided or delta-V-limited projectiles (or even beams, at long enough range), this makes broadsides very interesting.
    In fact, we could even have horizontal warships, built around a "spinal", weapon with engines on the long side.

    A fourth type that is missing, though, is the "planar turret": a weapon that can rotate only on one axis.
    With a side axis, it could aim both in front, at the side or even possibly at the rear of the warship. This would allow to fire while accelerating toward the enemy as with a spinal mount, but also while evading as with a broadside, or even accelerating away as with a reverse spinal mount (a design I have never seen apart from weapons as repurposed engines, but that may be interesting).
    The downsides are the same as with turrets, complexity and smaller weapons, though less so with only one axis instead of two.

    Using the thrust axis instead would allow to turn the ship on itself to keep new parts of the armour exposed, which could be useful against lasers to give it time to cool down. The result may be more easily attained with broadside weapons in multiple directions, though.

    Another solution would be to have multiple thruster in a plane, or a planar thruster turret: the weapon would be fixed, but the axis of thrust could turn around. Again, a compromise between full thruster sphere and one main drive.

    1. The relationship between the angle of acceleration and the placement of fixed weapons is complicated enough that I'm saving it for its own post. I actually handn't thought of 'planar turrets'. It sounds like the arrangement used by the railgun turrets on the Sulaco, but with a better field of fire.

    2. For defensive purposes the Broadside Weapons are not only interesting for evasive manuevers while firing. A projectile which hits from the "prow" of your ship might penetrate through the whole length of it. A hit from the side only goes through your cross-section. So if you have a lengthy ship in direction of acceleration (which might be recommended due to structural resistance against hard acceleration by the Main Drive) flying at an 90 degree Angle towards the direction of your enemy might reduce the damage caused by hitting rounds. With Lasers this line of thought doesen't work of course.

  6. What would a giant spinal sized ball turret/gimbal mount with an engine on back be called?

  7. There's a particular reasoning for a broadside design that I've happened upon while playing around with my setting. Like most things, it's deeply tied to the assumptions at play, namely that laser combat occurs at ranges of up to multiple light seconds, and that, as you might expect, weapons capable of hitting that far are heavy and bulky. Beam optics tens of meters in diameter.

    Larger, even longer ranged weapons could be built, but light speed lag places limits on effective range against a maneuvering target. Against a more maneuverable ship your effective range is lower because their position is more uncertain. This makes maneuverability a vital concern.

    It occurred to me that for ships specialized for skirmishing at long range a spinal mount laser shouldn't be pointed forwards, but to the side. That way the ship can use its main engine to maneuver perpendicular to the target while keeping its spinal mount-equivalent weapon trained on it, with neither turrets or drastically vectored engines needed. The downside mentioned in the article, that the ship will be unable to thrust towards the enemy while firing, is significant here, and not all ships are built this way.

    I did some quick sketches to sort out some of the ideas in my head:

    This ship features broadside-mounted laser optics made up of many smaller elements. They can be fired in coherence against a ship target or split into multiple beams for missile defense. There's a main engine on either side of the ship for redundancy, (they can "notch" in a limited form of thrust-vectoring to keep flying on one) mounted in the middle. The rear half of the ship is a lightweight tensile structure hanging off the midsection. The spines are booms for various liquid radiator systems.

    Here's the ship next to a missile cruiser of maybe more conventional design: . They're products of very different in-universe design philosophies, but they're actually both cruisers of similar mass and performance. A laser-armed cousin of the missile cruiser would be shaped and sized similary, with a conventional spinal mount. The size difference between the two design directions is due to the fact that the laser ship here uses liquid hydrogen propellant while the missile ship uses much denser solid pulse units. As a consequence the laser ship is roughly 90% hydrogen by volume. The sheer mass of its propellant is what armors all the vital functions placed deep in the core.

    1. The sketches are pretty cool. With multiple element lasers I'm not sure that they even have to be in any given shape or arrangement which could allow for ships with very large effective mirror sizes while keeping the profile small. It is something I plan to do a post on in the future. The ultimate expression of your idea would be spacecraft with phased array lasers composed of smaller cells that can operate separately. Almost the entire surface could be an emitter in that case, making it hugely redundant.
      One other thing to this about when choosing between broadside and head on arrangements is the expected nature of incoming fire. With dumb-fire unguided weapons(and I include beams since they cannot correct their own course mid way to the target) that have a high chance of hitting and of doing massive damage then a small cross section and high random acceleration(the famed drunk-walk) is most important, favouring the head on designs. Missiles on the other hand will always aim for an intercept, so it is having a high relative acceleration, forcing them to expend fuel to aim ahead that is the best tactic. Depending on the scenario this is easiest achieved while accelerating at right angles to the flight path of the incoming missiles. I haven't done the math though, so I;m not a hundred percent sure.

    2. My understanding of this is very shaky but the impression I have is that the tighter the elements are packed and the more circular the array's shape the closer it behaves to one big element. There's always some losses in efficiency there.

      This is relevant:

      All I know is there are efficiency losses, I don't know how bad they are. It may well be an irregular shape would make up for them through sheer focusing power.

      Small profile and a broadside configuration could be combined with a banana-shaped ship! Like so: I figured a sail since it feels like it might spread the structural loads more nicely over its awkward shape. I've noted that it would be slow to turn, but I'm not sure now; it would probably depend on how big the sail and the separation between the sail and the ship is. It's certainly not to scale there, it's just a sketch of the general layout.

    3. That would look pretty cool too. I think that one thing often overlooked by people trying to create works of visual Science Fiction is that if you try to stay within the confines of physics but don't let it restrict your imagination you can end up with much better stuff than any Star Wars clone. The starship from Avatar was the best part of the movie for example, while the Sulaco from Aliens is mostly realistic and one of the most unique designs around(or was until people realised how cool it is).

  8. A rather useful blog entry since it not only describes what each weapon mount is but also what weapon types would benefit the most from such an arrangement and what kind of setting such a weapon mount would be most ideal.

    Though, personally, the broadside weapon mount arrangement would be the most difficult to justify due to its tactical inflexibility. Then again, with a similar system for a Laser Bank would make for quite the useful point defense system and especially with adaptive optics since there would be not need to mount them upon specialized turrets. Add in the fact that the emitters of the laser bank could even combine their effectiveness against harder targets and they're almost the ultimate space-born weapon system: Able to perform defensively and offensively when worked in concert. Certainly an idea to consider for my own combat spacecraft designs.

  9. 15th and 16th century oared galleys carried their cannon in forward-firing only arrangements, making them "spinal" weapons of a sort.

  10. What 'Unknown' said - spinal mounts were standard for Renaissance galleys. Pictures of early galleons (such as Henry VIII's 'galleasses') show that they also carried their heaviest guns firing forward. Their broadside guns were initially the secondary armament; only later did the broadside become the main punch.