SPACESHIPS
ANNIHILATOR BATTLESHIP
On the Annihilator battleship, the usual laser broadsides of Imperial battleships have been abandoned in favour of two huge turret-mounted cannon. Known as Annihilator cannon, these massive weapons fire huge shells armed with powerful explosive warheads. The shells are fired at high velocity and then accelerated even further under propulsion from fast-burning plasma rockets. When they hit their target, their sheer speed and mass is enough to tear through even the armoured hull of an interstellar warship. A fraction of a second later their warheads explode and inflict devastating damage.
In essence, two huge mass drivers that fire missiles. You can see for yourself
here. Once fired at high speeds, they burn some more fuel to increase their speed further.
Most interesting is that their speed gives them the power to "tear through even the armoured hull of an interstellar warship."
Yet, "a fraction of a second later their warheads explode and inflict devastating damage", which clearly indicates that the projectile survives the impact well enough for the explosive warhead to deal damage.
The projectile's own engine could either be a fission or fusion drive, or simply running on the super charged plasma the Goliath collects.
Here's an example of a futuristic plasma engine, the Mini-Helicon, running on nitrogen, producing contained plasma and channeling it out for propulsion.
http://nextbigfuture.com/2009/02/mit-mi ... space.html
http://www.wired.com/wiredscience/2009/ ... mathruster
http://www.sciencedaily.com/releases/20 ... 221524.htm
Now, about the warhead.
No matter what's inside, the projectile itself is not flying anywhere near relativistic speeds, otherwise no projectile could penetrate any hull only to detonate fractions of a second later.
It also stretches the limits of hypervelocity impacts. A sudden impact would vaporize the projectile without giving it a chance to penetrate the hull under the form of a perfectly working ticking bomb.
The impact is akin to an immense deceleration, and it would require insanely strong materials to support the stress. Obviously variants of tungstens would be completely vaporized with low fractions of such speeds.
A velocity of 10 km/s would be a good guess, and perhaps already
too high.
Still, a thousand tonnes projectile travelling at 10 km/s would have a kinetic energy of 5 terajoules. That may be a tad low, but the main goal of the projectile is not to explode on the hull, but actually go through it.
With around 1 e8 kg.m/s of momentum, that's nothing to scoff at anyway.
A speed of 100 km/s would provide a KE of 5 PJ, but I just don't see how the hell the projectile is supposed to survive the impact to explode inside the ship, unless the armour is ridiculously thin.
Still,
here be an interesting paper about earth-penetrating weapons, rods and hypervelocities.
I'd quote a bit here:
It is straightforward to show, however, that the maximum penetration depth is severely limited if the missile casing is to remain intact. One can make reasonably accurate estimates of the penetration depth based on the well-developed theory of "long-rod penetration." The fundamental parameter R is the ratio of the projectile ram pressure to the yield strength of the material. The target material yields, and penetration occurs, when R is greater than one. For a steel rod to penetrate concrete, the minimum velocities for penetration is about one half a kilometer per second (1100 miles per hour). For ductile materials, the kinetic energy lost from the penetrator can deform the target and dig out a penetration crater.
Fundamentally, however, the depth of penetration is limited by the yield strength of the penetrator — in this case, the missile casing. Even for the strongest materials, impact velocities greater than a few kilometers per second will substantially deform and even melt the impactor.
An earth-penetrating nuclear weapon must protect the warhead and its associated electronics while it burrows into the ground. This severely limits the missile to impact velocities of less than about three kilometers per second for missile cases made from the very hardest steels. From the theory of "long-rod penetration," in this limit the maximum possible depth D of penetration is proportional to the length and density of the penetrator and inversely proportional to the density of the target. The maximum depth of penetration depends only weakly on the yield strength of the penetrator. For typical values for steel and concrete, we expect an upper bound to the penetration depth to be roughly 10 times the missile length, or about 100 feet for a 10 foot missile. In actual practice the impact velocity and penetration depth must be well below this to ensure the missile and its contents are not severely damaged.
That said, the bore is large, so the projectile is not going to be small either. It may be the equivalent of a small ship ramming into a bigger one. Technically, enough of the missile's mass at the front could melt before the warhead, is located in the rear, would be threatened by the heat. Then the tail of the missile would enter the hole its head put into the target's superstructure.
Actually, considering the size of the ships and the size of the cannons, there's little reason to believe that the plating is thicker than the missile is longer.
This could mean the projectile could easily pierce it, or even perhaps go through its entire superstructure.
The turret mounting allows the Annihilator captain to bring his weapons to bear on all sides - only ships directly behind the Annihilator are safe from attack. The cannon can also be fired as the turret is being rotated - where a laser broadside has to concentrate its fire, the Annihilator cannon can pick out separate targets for attack. This is especially effective against smaller ships when a single shot from an Annihilator cannon can destroy the target.
Smaller ships targeted by one of these massive cannons are destroyed in one hit. When you look at the picture, notably the Stalwart ships, it's not surprising at all: An annihilator barrel is longer than an escort ship!
This would give an idea of the strength of said ships.
Another thing to point out is the recoil. The Annihilator couldn't count on its main engines to counter act the sudden recoil of the guns if they were to fire at an angle from the ship's length axis.
The source doesn't address this.
CASTELLAN SHIELD SHIP
The Castellan is a battlefleet support ship. Its role is to provide other warships with the vital defence they need to be able to close with the enemy and bring their weapons to bear.
The Castellan shield ship is built around a single huge shield generator. Most warships have a number of shield generators each projecting a short-range field in one direction. The Castellan shield emanates from the ship in every direction and is powerful enough to extend its protection to any spaceship close to the Castellan.
When the Castellan shield is hit by enemy attacks, the shield generator absorbs the energy of the attacks, preventing them from damaging their targets. This causes a gradual build-up of power in the shield generator and only the close attention of its Adeptus Mechanicus custodians prevents it from exploding.
Eventually, however, the power build-up becomes so great that unless the generator is shut down it overloads and ruptures in an almighty explosion that literally rips the Castellan apart from the inside. This sends out a vast fireball which engulfs the area that was under the shield's protection and can destroy the spaceships which were accompanying the Castellan for its protection.
In battle, the Castellan's Captain must constantly assess the dangers of leaving the shield running or shutting it down to dissipate the energy build-up. If he shuts the shield down too often, he fails to benefit the other ships around him with the Castellan's protection. If he waits too long, he jeopardises those very ships he's meant to be defending.
Odd that no one thought about mounting a Big Gun on this baby. When you can blast nearby ships when 'sploding, you'd probably like to channel that energy into a tube pointed at your enemy. Dunno, that seems rather obvious, really.
It is a rather original design, where the shield exclusively absorbs the energy instead of deflecting it, and must be shut off for said energy to be vented out rapidly, somehow, because it otherwise keeps it, and clearly the system doesn't have the capacity to swap input and output at a whim. This means even for a structure dedicated to shielding only, a low radiation (the output to get rid of the pied up energy) when the device is turned on.
One would logically think that a system that's based on the absorption of nasty energy is supposed to be some exclusive and rather exceptional (as rare) tactical gain.
COBRA DESTROYERS
Cobra Destroyers usually act in support of battleship squadrons. When a Gothic battleship, for example, arrives in a system, its supporting Cobra squadrons are deployed to patrol the individual planets and moons. Their speed and mobility make them ideal craft to pursue and engage the sub-stellar spaceships of pirates, smugglers and rebels. For although they are small in comparison to the mighty battleships they accompany, Cobra Destroyers still vastly overawe and outgun all but the very largest of sub-stellar spaceships.
That's said and fixed. Cobra destroyers completely overclass even the heaviest sub-stellar combat ships, which would have had the ability to trade FTL engines for more reactor room or weapons.
This would imply that even the bigger ones are very, very small in comparison.
It fits with my point earlier on, about the awe that strikes inhabitants of planets when an Imperial warship arrives.
Cobra Destroyers are among the fastest warships in the Imperial Fleet. In battle, they operate in large squadrons, moving in tight formation into close contact with the enemy before firing their lasers or their destructive vortex torpedoes.
Even in large formations, Cobra squadrons can make tight turns, allowing them to sweep around an enemy's flank or move directly through his fleet, turn and launch a second wave of attacks from the rear. If the enemy turns to face the Cobras, he runs the very real risk of leaving himself open to attack from the rest of the battlefleet.
Cobras outmaneuver the heavier ships, fast enough to harass them and make targeting choices hard.
DICTATOR BATTLESHIP
The Dictator is probably the most unusual battleship to be built at the great Jovian shipyards. It is designed specifically for close assault and is used to board, and often dismember, enemy spaceships.
The gigantic power claws of a Dictator can move with frightening speed to grab an enemy spaceship and rip it out of formation. Even if they fail to take hold, the massive force of the Dictator's claws can severely damage an enemy ship, tearing through its hull and crushing or pulling off huge sections of a ship's superstructure, engines or weapons.
An enemy ship that is firmly grabbed by the Dictator's claws is dragged onto the Dictator's huge boarding drill that bites deep into the unfortunate ship's innards. Once the drill has crunched through an enemy's hull and torn its path of destruction deep into the interior of the ship, hundreds of vast reinforced hatches swing open and the Dictator's crack assault teams pour out and take the battle into the very heart of the enemy ship.
If the first assault of the boarding action isn't successful and the enemy resistance appears to be strong, the Dictator captain may order his troops back to their own ship. He'll then use the Dictator's mighty power claws to twist and tear and crush the enemy ship. Smaller ships may be literally torn in two by the Dictator - larger ships may be disembowelled by the terrible saw-toothed drill.
Sometimes a ship will manage to break free, firing its engines at maximum power to loose itself from the Dictator's iron grip. But this is a desperate manoeuvre, often crippling the escaping ship as huge sections of its hull are torn off in the attempt.
The design is really nice and funny. I can imagine what it would have been to use it in-game.
That said, I'm not sure about the "battleship" part, safe perhaps a reference to a massive amount of armour. After all, it's a very close range ship, and there are practical limits to how far its claws can extend, so it has to be very well defended and armoured to get close to another enemy ship.
All in all, it gives a weird idea of the ranges at play. Eventually, the Dictator (a concept entirely ditched in BFG, becoming a
Lunar-class) would need to complete, essentially, a ramming maneuver.
Minus the speed.
It has to close on its enemy, but must come in slow enough not to crash into it. This does mean the targeted ship cannot evade. The Dictator would be an idiotic concept if your average warship could pull accelerations up in the hundred gees at least.
Eventually, this monster of an issue would be tamed with the suggestion that exceptionally powerful tractor beams are used here. Unfortunately, they are not mentioned, and the concept itself belongs to Space Fleet.
DOMINATOR BATTLESHIP
The Dominator comes from the same family of ships as the Tyrant and Emperor. It is armed with the awesome inferno cannon. This massive cannon is mounted along the entire length of the Dominator's hull. The huge shells are loaded at the rear of the ship in a cavernous chamber positioned above the roaring fury of the Dominator's plasma drives.
Each inferno cannon shell is the size of a tall building, its warhead packed with explosive. The shells are moved from the ship's magazine on great tracked transport vehicles that crawl along echoing tunnels down the length of the ship. The shells are loaded by powerful winches, guided by an army of engineers whose prayers ring through the chambers. As the huge breech closes, the gun crews leave the chamber - no man could withstand at short range the awesome concussion produced as the shell is fired.
The shell accelerates down the long barrel of the cannon, reaching a searing velocity that hurls it out into space. The whole ship shudders with the recoil of the cannon - indeed, it is constructed with massively reinforced bulkheads and hull supports to withstand the powerful shockwaves.
When the shell detonates it releases a ball of radioactive fire that forms a sphere of destruction kilometres across. Not only the cannon's target, but any ship close to it receives a deadly blast of intense heat, energised particles and huge jagged shards of shrapnel larger than most sub-stellar spaceships.
The inferno cannon is affectionately known as the Planet Buster by a Dominator's crew because it is often used in planetary assaults to rain fire down on enemy cities. A single shell is powerful enough to destroy all but the largest cities, leaving only flattened ruins around a crater many hundreds of metres deep. When an enemy planet learns that a Dominator has entered the star system, it is rare for a complete and unconditional surrender not to follow swiftly.
Truly, the ship is the most powerful of all, but the procedure to load a shell and the way it has to be aimed means it's best used as a sniping ship against the enemy's main warships. A look at the game rules shall reveal if this cannon is intended to one shot any enemy ship or not.
This massive cannon is mounted along the entire length of the Dominator's hull. <- huge, lengthy, accelerator. The ship probably uses the engines to compensate for the acceleration. You can appreciate the
immense size of the cannon.
Each inferno cannon shell is the size of a tall building, its warhead packed with explosive. <- it's probably several tens of meters long, and it uses explosives, but later we're told it produces "radioactive fire." Go figure. Fizzling out near-fission materials?
Interestingly, this may also imply a ship size of a kilometer, more or less.
I must say that the sentence finishing with "explosive" alone seems odd. You'd expect explosive firepower, or explosives, with an s you know. The meaning could change a lot.
As the huge breech closes, the gun crews leave the chamber - no man could withstand at short range the awesome concussion produced as the shell is fired. <- crew dies if they remain anywhere close to the section where they loaded the shell. What a curious thing. It would suggest the recoil system is not fully encased, and the sudden compression of air can reach lethal psi overpressures.
The shell accelerates down the long barrel of the cannon, reaching a searing velocity that hurls it out into space. <- clearly became the Nova cannon later on, but at this time, with no hint of near to c ejection speed. And what about the searing velocity? Does it imply that the metal, due to the stress or friction, is brought close to the heat of fusion of its respective elements?
And the rest...
The "sphere of destruction kilometres across" either is another exotic containment system, or refers to the atmospheric effect. It's a planetary assault weapon, so we could go with the scientifically accurate option, but then it presents a vacuum context, with nearby space ships.
Now, it is a shell filled with explosive material, fired at a high speed at a planet. Basically, it is suggested that it will penetrate the ground before exploding. This could mean the crater is gouged by the explosion of the reactants, starting somewhere beneath the surface, which increases the craterization. However that's almost pointless, considering the speed and the fact that the major cratering factor will be the mass of the shell itself, as the momentum would provide a greater penetration into the ground.
The design wouldn't make sense if the mass and speed alone would be more destructive than the "warhead packed with explosive", which we would understand as the speed is not so awesome after all.
What about the effects on the ground?
Asteroid impacts generally remain the better method for the making of large craters, on bodies with a noticeable gravity.
So let's use
this simulator.
We'll take a not too large asteroid (60 meters wide), but pick some high density (20 tons per cubic meter, slightly more than depleted uranium) and assume an impact at 90° degrees. Purely vertical.
The biggest problem is the speed, but once again, it's a weapon packed with explosives, and that turns out to be absolutely pointless at speeds where asteroid vaporize themselves when hitting the ground.
Code: Select all
Your Inputs:
Distance from Impact: 1.00 km = 0.62 miles
Projectile Diameter: 60.00 m = 196.80 ft = 0.04 miles
Projectile Density: 20000 kg/m³
Impact Velocity: 10.00 km/s = 6.21 miles/s
Impact Angle: 90 degrees
Target Density: 2500 kg/m³
Target Type: Sedimentary Rock
Energy:
Energy before atmospheric entry: 1.13 x 10^17 Joules = 27 MegaTons TNT
The average interval between impacts of this size somewhere on Earth during the last 4 billion years is 1.4 x 10^3 years
Atmospheric Entry:
The projectile lands intact, with a velocity 9.9 km/s = 6.15 miles/s.
The energy lost in the atmosphere is 2.24 x 10^15 Joules = 0.53 MegaTons.
Major Global Changes:
The Earth is not strongly disturbed by the impact and loses negligible mass.
The impact does not make a noticeable change in the Earth's rotation period or the tilt of its axis.
The impact does not shift the Earth's orbit noticeably.
Crater Dimensions:
Transient Crater Diameter: 1.96 km = 1.22 miles
Transient Crater Depth: 0.694 km = 0.431 miles
Final Crater Diameter: 2.45 km = 1.52 miles
Final Crater Depth: 0.523 km = 0.325 miles
The crater formed is a simple crater
The floor of the crater is underlain by a lens of broken rock debris (breccia) with a maximum thickness of 243 m = 796 ft.
At this impact velocity ( < 12 km/s), little shock melting of the target occurs.
With a speed of 10 km/s, we get a depth of 523 meters. So we have several hundred meters there. The source doesn't say tens of hundreds of meters deep, or alternatively thousands of meters deep. This would be within acceptable parameters, and don't forget that the projectiles wouldn't be round, but lengthy. The KE would therefore be multiplied a few times, and penetration would likely be increased, if the article about hypervelocity rods is anything to go by.
Changes of speed don't add many meters to the depth.
Meanwhile, in space, the weapon clearly suffers from the same problem as the Nova Cannon, although there is no implied relativistic speed: the "fireball" (or blast in BFG) would overshoot a target, especially since it's packed with explosive and that there are limits to how fast the expanding matter can move. There would not be any "sphere" to speak of.
That said, let's be clear here. The Inferno Cannon was the most conventional in mechanics, and yet an awesome weapon the Imperium could mount on its mightiest ships. But it was truly enormous.
In the end, we are still far from the glittering super numbers touted as facts and conservative, supposedly from indisputable interpretations of other random pieces taken from modern 40K literature.
