Possible reason for SD dorsal gun placement

[ect562]

People have often wondered why the Star Destroyer lineage (up until the Pellaeon-class of the EU at least) has the main guns placed in such a way so that they cannot be brought to bear on a single target easily. I think I remember Wong speculating that perhaps elevating the turrets over each other was structurally unsound, or providing power to the turrets meant they had to be arranged the way that they are.

I had another speculation:

Perhaps Star Destroyers were designed to fire in broadsides? Maybe the firepower of a broadside is more powerful than the combined main battery. In Revenge of the Sith, we saw that the Venator-class, in addition to the main battery, has "gundecks" of smaller turbolasers, similar to a sailing warship. I think it is likely that there are several of these gundecks spanning decks, so perhaps the smaller turbolasers on one side plus the main guns on a single side amounts to more firepower than all of the main guns together. I think it is worth nothing that the Venator that engaged Grievous' flagship in RotS chose to maneuver alongside firing broadsides, Age of Sail style, rather than dipping its bow down to bring its main guns to bear. Firing broadsides could also have the benefit of providing a smaller target profile to the enemy. Wookieepedia's article on Grand Admiral Thrawn shows a fleet formation with a labeled Star Destroyer battle line - perhaps an analogue to the Age of Sail's line of battle? Then again, we have no examples of formations being used in the movies, so this could just be a formation Thrawn used before the battle became a melee.

Thoughts?

[Eleventh Century Remnant]

Um, a near miss but no. Massed light guns don't add up to one big one, not without many more light guns than any ship short of the death star is able to mount- the existing figure for light turbolasers derives from the Acclamator's secondary armament as ICS stated, six megaton shot.

The DBY-827 is at the very least a multi- teraton weapon, based on the total output of the power plants of the Venators they're mounted on divided by the number of barrels it can be channelled through; 860 teratons per second, eight twin turrets.

That makes them 53.75 tt/sec weapons if the thing is intended to fight both sides, 107.5 tt/sec if only intended to fight one side. Not that this is a firm limit- the guns could be built to higher power ratings than that to take up the output of disabled turrets, and if they have any sense at all there will be factors of safety built in.

(For fanfic purposes I called the -827 a 70 teraton/shot weapon, basically because the tactical wrinkles, the detail devils made possible by a one and a half sided ship made interesting problems to write about, and it made a nice median between octuple 32's and twin 175's, but that's just me- the Imperial Starfleet's logic is going to be somewhat more grounded.)

Look at the tactics of turret warships of the ironclad and dreadnought eras; obviously not going to be an exact comparison, but it ought to give a baseline that we can then add considerations like "OK, line of sight (near or) lightspeed weapon, that's the ballistics out the window...what difference does ECM make?" to.

Essentially, it's all about fire arcs and range control. The main turrets are not too badly positioned for that- about as well as is consistent with the structural requirements for recoil, and the desire to not have multi-teraton power cables running through any more of the ship than absolutely necessary.

The fire arc needs to be enough to allow the firing ship to control the range, choose the target profile and aspect it wants to present, and the main turrets give about 120deg in two planes for that; the ship can fire amd manoeuvre, is loosely enough constrained to be able to dodge.

[Mr Bean]

Two major issues with your broadside theory

1. Space is 3d, by assuming a 10* dip you can engage targets in a 360* arch quite easily with only the conning town forming a blind spot. In space it's quite possible to roll on your back and rain fire down on a enemy ship. Quite impossible in the broadside is king wet navy days/

2. Targets are normally quite distant, close up engagements that let you use the SD's mass against it to shield part of it's armor against it.


Where I more image inclined I might throw up a few pictures of Star Destroyer's and their firing archs at various slight tilts and deviations. But trust me when I say both sides of the Dorsal turrets can target anything either can see by very slight movements at targets at standard SW engagement ranges.

[ect562]

I stand corrected!

[evillejedi]

One of the more recent Clone wars episodes (the one with the CIS spider commander) had Venators firing forward with down bow angles even though I believe the ship was slightly fattened in the show to allow it to fire forward anyway.

[ect562]

I thought that show would be totally lame but when I started watching it I was pleasantly surprised

[Night_stalker]

That could make sense as the big turrets do seem to be concentrated along the sides, but maybe it's because the inside of the ship is occupied by the hanger, reactors, storage spaces, and barracks for the 37, 085 crew onboard.

[j.eller]

Surely the best way for an ISD to saturate an enemy with as little damage by return fire is to tilt it's bow down about 45 degrees. That way all of the heavy guns can be brought to bear, (as well as the triple medium TLs). The reactor bulb is also protected from return fire by the body of the ship. Also gives the bridge a good view of whatever they're supposed to be killing.

I've always thought that the positioning of the guns is odd, and broadsides doesn't really make sense in space (as stated by Mr Bean)... perhaps, as they are biggest drain on the reactor in a battle it's more efficient to have them located close to it? I admit I know nothing about power transmission in capital ships!

[Pelranius]

Placing the main turrets closer to the reactors could also simplify the placement of back up power transmission systems.

[Sea Skimmer]

The logic or lack of logic in gun placement depends on what the Star Destroyer was designed to do. If it was designed primarily for fleet actions, then the arcs of fire of one ship aren’t as relevant as the arcs of a group of them combined. In that case a wall of ISDs would create a interlocking cross fire quite nicely, and the guns can continue to track crossing targets as the two walls of ships meet. Needing to be located close to the reactor seems like a given requirement, ICS shows so big massive power cables to size of some smaller modern warships feeding into them. But that wouldn’t rule out some other configurations as being possible on its own.

[Cykeisme]

Unlike modern cannons that are capable of all firing simultaneously without affecting the firepower of one another, all of a capital ship's directed energy weapons would likely be sharing a power source.

Perhaps each of the eight turrets, at its maximum power setting, is capable of putting out at least a quarter (or more) of the ship's power output; thus, it would be possible to direct all the ship's firepower on a target using only four turrets.