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Defence Grid

Defence Grid

Submitted to the Imperial Department of Defence (DoD) following terrorist attacks against the Empire's orbital facilities, the Defence Grid is a series of modifications and upgrades to current systems to countermand efforts to destroy construction facilities.

The Defence Grid can be applied to any world with a global shield and/or a planetary turbolaser or ion cannons network. The cost was considered and approved as worthwhile by the Empire's High Command, which hopes to have the Grid implimented on all Imperial worlds with orbital facilities.

The first modification was to expand the sphere of a planetary shield network by several kilometres, allowing them to encompass any facilities (and low-orbiting ships) above a planet in their protective spheres. This means that no orbital station of yard, civilian or military, will be left defencless when the planet's shields are activated.

By increasing the number of surface-based generators, Imperial designers have allowed for the shields to retain their natural strength despite the increased load.

The second modification was to add several hundred additional cannons to a planetary defence network. These extra cannons are not powered independently, but each generator will now be able to provide power to one cannon. This means that, even if enemy forces attempt to "hide" behind orbital facilities, at least one cannon per network will be able to target and fire on them.

The third, and final, modification was to the planet's communication and sensor packages. Utilizing technology developed for the Dictator FCV, ground-based communications have been adapted to break through enemy jamming and transmit distress signals to the rest of the Empire. The sensor package has also been advanced to include several units adapt at picking up the presence of cloaked warships.

The system, while expensive to mantain, was deemed a worthy expense by the Empire and will be adapted to all worlds as soon as possible.

R&D Time: 20 Days (Dec. 7-27)
Plus ten days per planet (in a Construction Yard) to modify existing systems. New-built defences will have the new systems included within.

Comments

#16 8:38pm 12/12/03

Personally, Drayson, until we come up with specifications as to a TRF shipyard, it's hard for anyone to really say how what their shipyards look like. Everyone brings in their own perspective.



This is just my opinion but I would imagine the curvature of the planet as it extends to the northern hemisphere would have large part in providing a counterbalance to any line of sight advantage of multiple/secondary canon positions.

I know what you are trying to do Dray. I just don't think it can be accomplished in the manner you are proposing with the planetary weapons.

I like the idea with the shield tho.

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#15 3:03am 12/12/03

Heh!

Assuming that you don't plan to, uh, float planetary turbolasers up from the planet surface, no, thickness has no place here. From such distances the length/width of a yard is enough to obstruct planetary blasts.

My calculations do not include shipyard height whatsoever, anyway (aside from there being a 2-dimensional sheet).

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#14 2:43am 12/12/03

Then your ignorant.

Try this:

Go put a book on your table, and look at it from eye level. Place it so that the front cover is facing you, so that the book is as tall as it can get.

Now, put the book flat on its front cover, and look at it again from eye level.

In which position can you see more of what's behind the book?

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#13 6:50am 11/12/03

Uh...

[quote]I did a few calculations using the rough numbers Kas provided of an "average" scenario...

Planet Diameter: 48,575 km
Shipyard Diameter/Length(equal to width): 40 km
Shipyard-Planet Distance: 36,000 km
Shipyard-Ship Distance: 3 km

I drew up a couple of triangles in my head, the points of which: ship, shipyard center, shipyard edge; ship, planet center, planet edge. From there I used the above numbers with basic trigonometry to get numerical representations of both "upper" angles (one projected down and to the shipyard edge, the other projected down and to the planet edge).

The results? I pulled out the number 1.422 for the "shipyard edge" angle, and .593 for the "planet edge" angle. Therefore a ship positioned in the center of a square or circle - shaped shipyard is completely shielded when at 3 kilometers, even from hemispherical weapons.

(Note that if the height from shipyard to planet were reduced to 3,300, a "few thousand" km, the revised result for that half would be .634.)[/quote]
[quote](Note that I forgot to include the planet radius in the planet-to-shipyard distance. The increase, though, would just go to further decrease the to-planet angle, making the difference all the more clear.) [/quote]


You stated that a "few kilometer" increase is all that is necessary in shield height to surpass shipyard level; I was generous, then, in figuring that the closest a starship could get to a shipyard would be 3 kilometers.

My point? That under average circumstances, no, you [i]would not[/i] be able to fire upon a ship centered behind a shipyard. If a cannon from either pole must fire [i]through[/i] a shipyard to connect with a given ship, it wouldn’t be any easier for a cannon positioned elsewhere due to the geometry of a sphere.


The other comment was in response to this:

[quote]Assuming shipyards are massive blocks of steel, perhaps. But they're not.[/quote]

I fail to see what the material or thickness of a shipyard has to do with the targeting of a cannon that already has a clear shot, as you claim. Maybe these two factors would take effect if a cannon were required to fire through a shipyard to hit its mark, but otherwise, I don't see how you associate them with the stances you make.

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#12 3:41am 11/12/03

Uhh... yeah. Nowhere did it say we're firing [b]through[/b] a shipyard. The extra cannons allow all angles to be covered - and the shield means that a ship cannot get close enough to a shipyard to hide behind it.

So, again, wtf is your point?

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#11 10:56pm 10/12/03

Need to be walked through it...?


[quote](Kas) If you would be so kind as to draw your plan out on paper, you'll see that ships hiding directly behind a shipyard (up close) would be invincible from any cannon fire. You'd better rephrase this.

(Drayson) Assuming shipyards are massive blocks of steel, perhaps. But they're not. Also note that getting "up close" to a shipyard is no longer possible without running into a shield.[/quote]

[quote]The point is, since TNO yards orbit over the equator, a cannon in the Northern hemisphere could still target and attack an enemy ship, even assuming it did try and "hide" behind a yard.[/quote]


My point? That yes, it is possible for a ship to get "up close" enough to a shipyard as to be fully guarded, and were it targeted and fired upon [i]through[/i] the shipyard, the damage impact would be considerably buffered. In this case, I'll add, it would be better to fire from the equator, as both the overall and penetration distances wouild be reduced.

The relevant paragraph in your R&D implies, if not stated outright, that the extra cannons ensure a clear shot despite "shipyard hiding."

(Note that I forgot to include the planet radius in the planet-to-shipyard distance. The increase, though, would just go to further decrease the to-planet angle, making the difference all the more clear.)

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#10 7:20am 10/12/03

And again, wtf is your point?

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#9 6:01am 10/12/03

[quote]The second modification was to add several hundred additional cannons to a planetary defence network. These extra cannons are not powered independently, but each generator will now be able to provide power to one cannon. [b]This means that, even if enemy forces attempt to "hide" behind orbital facilities, at least one cannon per network will be able to target and fire on them[/b].[/quote]

And...

[quote]The point is, since TNO yards orbit over the equator, a cannon in the Northern hemisphere could still target and attack an enemy ship, even assuming it did try and "hide" behind a yard.[/quote]

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#8 5:56am 10/12/03

You're the only one talking about shooting at shipyards... wtf is your point?

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#7 4:55am 10/12/03

I did a few calculations using the rough numbers Kas provided of an "average" scenario...

Planet Diameter: 48,575 km
Shipyard Diameter/Length(equal to width): 40 km
Shipyard-Planet Distance: 36,000 km
Shipyard-Ship Distance: 3 km

I drew up a couple of triangles in my head, the points of which: ship, shipyard center, shipyard edge; ship, planet center, planet edge. From there I used the above numbers with basic trigonometry to get numerical representations of both "upper" angles (one projected down and to the shipyard edge, the other projected down and to the planet edge).

The results? I pulled out the number 1.422 for the "shipyard edge" angle, and .593 for the "planet edge" angle. Therefore a ship positioned in the center of a square or circle - shaped shipyard is completely shielded when at 3 kilometers, even from hemispherical weapons.

(Note that if the height from shipyard to planet were reduced to 3,300, a "few thousand" km, the revised result for that half would be .634.)


As for the material and thickness of the yard...

How thin could a 40 kilometer yard possibly be? Certainly not thinner than a smaller class of ship that a planetary turbolaser [i]still cannot pierce straight-through[/i]. Sure, the hull probably isn't of the same strength, but were a blast to puncture any hull two times over it'd be left with considerably less energy. I'm not even suggesting that the blast wouldn't be able to make it all the way; just that it would lose noticeable energy in the process.

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#6 4:05am 10/12/03

Your entire argument is based on the assumption that a shipyard is just a massive sqaure of steel.

More accurately, they're long, wide, and thin. Meaning that (with the additional cannons installed) one could still target the bridge of an ISD if it were directly behind a yard.

The point is, since TNO yards orbit over the equator, a cannon in the Northern hemisphere could still target and attack an enemy ship, even assuming it did try and "hide" behind a yard.

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#5 1:37am 10/12/03

[quote]Assuming shipyards are massive blocks of steel, perhaps. But they're not. Also note that getting "up close" to a shipyard is no longer possible without running into a shield.[/quote]

A blast would be weakened, however, if it had to pierce through a shipyard to reach its mark. Considering that a planetary turbolaser cannot fully puncture a shieldless warship (as in stream right through it), significant energy would be lost in doing so to a shipyard.

If you don't mind experiencing a penalty to the rate at which the cannon can damage ships, I don't either. Otherwise I just wanted that clarified.


Would a ship truly need to get too close to a [i]forty kilometer[/i] shipyard to evade fire? If you propose increasing the diameter of the shield by only a "few kilometers" on each side to extend passed outer-atmospheric stations, not much more of a shielded safe zone would be available; certainly not enough to compensate for the large body that a shipyard is.

Normally I wouldn't assume a shipyard to be that large, yet that number seems to have been a focus of other arguments.

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#4 3:16am 09/12/03

But Endor is not really a moon (as we think of them). It has gravity (and therefor) size enough to have an atmosphere and near-standard gravity... so it must be about the same size as Earth, no?

The Death Star was in geosync orbit, as well. Remember that it was protected by the shield, and therefor always had to be contained in that sphere as it rotated around the planet.

#3 5:56pm 08/12/03

The galactic standard I mentioned is Earth, our planet. The DS may have been able to orbit lower (a few thousand Km) because it's going around a moon.

The shipyards would have to be in geosynchronous orbit, more convenient for construction workers for it to be above one spot on the planet than constantly going around it. And it would cost less power-wise if it were at the height mentioned. Minimum power would have to be outputted to engines, etc, to maintain the orbit.

I can understand the bulb idea.

[quote] Sensor suites already located on Imperial warships, transplanted to the ground. But if it's more effort than that, I'll just remove the reference.[/quote]

I really would like more clarification on this, yes.

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#2 7:02am 08/12/03

[quote]Not several kilometers, several thousand kilometers. About 35,785 kilometers, to be exact. Probably more, as 35,785 is the height needed for geosynchronous orbit around a galactic standard planet, and you wouldn't want to be putting the shield right through your yards.[/quote]

Assuming a shield already projects into low orbit, and a yard sits in a high orbit, the shield projects outward only a few kilometres. And this in itself alters the shape of the shield - rather like a bulb before the shield comes back down to normal height. Projection height is programmed into a computer, which sets levels of ascent and descent, and the inreased power demand is met by a dedicated series of generators.

[quote]You will be projecting the shields at least 35,785 kilometers off the surface of the planet, probably around 35,700 more kilometers than they normally extend. I don't want to get into the math, but you can guess that the surface area that these shields will have to cover is going to increase exponentially. The earth is, after all, only 12,750 kilometers in diameter. You'll be stretching these shields from a diameter of around 13,000 kilometers to ... a rough guess of 84,150 kilometers in diameter. That's conservative.[/quote]

See above. And out of curiousity, what is a "Galactic Standard" planet and where do those numbers come from?

[quote]How many generators are you going to be adding.[/quote]

Enough.

I'll double check the Technical Commentaries later, but I would point out the projection of the Death Star shield in RotJ. I seem to recall a reference to the DS being either 800 or 2500 km from the moon, which is far lower than your 38 000 km. But I could be wrong.


[quote]If you would be so kind as to draw your plan out on paper, you'll see that ships hiding directly behind a shipyard (up close) would be invincible from any cannon fire. You'd better rephrase this.[/quote]

Assuming shipyards are massive blocks of steel, perhaps. But they're not. Also note that getting "up close" to a shipyard is no longer possible without running into a shield.

[quote]When a shipyard is not in the way, how many canons are you going to be able to use?[/quote]

[quote]These extra cannons are not powered independently, but each generator will now be able to provide power to one cannon.[/quote]

Perhaps this wasn't explained fully. New cannon emplacements are added, but not power plants. Therefor, only one cannon were batch will be able to fire. End result being that, lacking impediments, only one cannon per network will be able to fire. Though if said canon were to be destroyed, power could be shunted (with some effort) to a different emplacement.

[quote]Clarify.[/quote]

Sensor suites already located on Imperial warships, transplanted to the ground. But if it's more effort than that, I'll just remove the reference.

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