Magos wrote:Feedback and / or quotes more than welcome. It isn’t proof read, so any amendments there are also appreciated. Let me know what you think.
Since you ask here are my initial thoughts. I hope they help inform and cultivate your work.
Issues I misunderstood/couldn't find source:
*Speed of macrocannons
* Shell size in relation to type of macrocannon
* Engagment ranges/ time to intercept
* 20th century nukes required 20 megatons to "destroy" a city
*Ramming speed
* Size of fleets in battlefleet gothic
General issues:
* One shouldn't construe being the size of something to weighing the same especially two radically differnt items designed for completely alternate tasks Ie a Macroshell and a tank/ Land Raider
* I'm not sure of the logic assuming "kilo-tonne" is its weight as opposed to its explosive yield. We afterall talk of nukes by their explosive payload not their total mass of reactant.
*Not to dwell on it but requiring 20 megatons to destroy a city seems over enthusastic. Hiroshima was quite effectively destroyed with 16 kilotons. As well as far as I know the Castle Bravo test was the US's most powerful nuclear detonation and it was A) typicaly estimated at 15 megatons and B) a complete and unexpected accident. Further launch delivery systems like the
peacekeeper relied on numerous small yield warheads of maybe total count of 3 megatons.
* If macroshells have warheads it makes calculating mass and therefore kinetic energy problematic. A warhead is lighter than a corosponding solid block of the same dimensions obviously.
*I'm not sure of the logic of extrapolating from a troop transport to try and guess a warship's mass. They are two radically different vehicles which, at best, use the same base material. Further if canon masses exist they would have authority over any such speculation.
* I can not concur that this "The area between the two ships was saturated with energy as enough firepower to level a city was
unleashed across it. Execution Hour" is sufficent to estimate the passage of mere seconds. If further passages contain hard and fast details which can bookend the quote that would be something but as is the passage is quite vague.
*This "The weapons carried by some ships are powerful enough to reduce whole cities to plains of radioactive
glass. Battlefleet Gothic" I would argue is incongruent with your argument presented since it implies that only "some" ships are "powerful enough to reduce whole cities to plains of radioactive glass" with their weapons. Perhaps the full context of the quote makes it plainer it is talking about special weapons carried aboard some ships but as read seems to be a general statement on ship's firepower rather than a special class of "big guns".
* I feel I most note that in this"Running almost the complete length of the battleship, the starboard and port batteries were capable of
unleashing an incredible amount of firepower, easily enough to cripple even the largest warship with a
single barrage, or lay waste to entire continents if she entered the upper atmosphere of a rebellious
planet. Imperial Glory" the single barrage is attached to the largest warships not the "lay waste to entire continents" part. There is no reason one must assume a solitary barrage would "lay waste to entire continents".
* I would suggest this "We can infer that when no timeframe is given, and a ship is said to be capable of levelling
continents, we are talking about an extended ‚barrage‛, because of the gathered data and actual
case studies on planetary bombardment." much like your city destroying estimate is making too big an assumption on too limited a pool of evidence, in both cases one example, that is vague or open to interpetation.
* While this is rather straight forward "A mighty Repulsive-class Grand Cruiser with powerful reactors and heavy armour in sloping facets of
adamantine and ceramite scores of meters thick, the vessel carried a weight of armament and ordinance
that could reduce a continent to ruins with a single salvo. Black Crusade" "ruin" does not require or demand setting everything on fire across a continent. Indeed "ruin" could entail long term issues such as loss of infastructure to primary or secondary effects of this salvo. There is also the issue on if this salvo is all aimed squarely togather or if this hypothised salvo is spread out maximizing its destructive potential.
* This "It would be possible to manufacture a missile of any size: from a weapon a little larger than a normal
rocket shell, to one capable of wiping out a city, province, or continent. Rogue Trader" would qualify as a theoritcal possibility. One whose plausbility would have to be determined by the verse in question. By itself the quote does not mandate that such a weapon exists at all.
Additional firepower examples:
*"A plasma bomb is a large missile typically used by or against spacecraft. They are also used for planetary sieges. The missile energises at launch, converting into a mass of seething plasma - each missile becomes a ball of boiling energy sufficient to melt a city-block. As it converts to plasma, the missile divides into 6 fragments, this enables the plasma to spread out and saturate its target. A target under plasma attack becomes a blazing inferno which only the very fortunate survive." Rogue Trader
"A nova cannon is a huge weapon, normally
mounted in the prow of a ship so that the recoil it
generates can be compensated for by the vessel’s
engines. It fires a projectile at incredible velocity,
using graviometric impellers to accelerate it to
close to light speed. The projectile implodes at a
preset distance after firing, unleashing a force
more potent than a
dozen plasma bombs." BFG rulebook
Implying a Nova Cannon shell has the rough equivilent firepower to melt 12 city-blocks.
"" The torpedo wave's target had been the two largest rok-fortresses in the enemy fron tline. The roks were massive, one of them easily over eight kilometres from tip to tip, and possibly as many as four kilometres across. Eight torpedoes s truck it, the remaining six finding the other one. Normally, it might have taken several dozen torpedo strikes to destroy targets this large. Not today, however. Today the Imperium warships were using new ordnance: so called "rock-buster torpedoes", specially designed for the task at hand.
" shadow point page 83
Simply put a 8 by 4 KM asteriod is not going to stand up to multi-gigaton abuse. Plugging it in
here for a diameter of 8000 gives 2.4 gigatons for cratering energy assuming nickel-iron. Further :
"The Drachenfel's lance batteries gored into the sides of another rok, blasting away or vaporising hundreds of tonnes of
soft, porous rock." Shadow point page 93
So 2.4 gigatons would be a very generous over estimate for dozens of torpedo strikes.
"Nothing in our inventory would even come close to doing the job, but an astropathic message to the nearest naval unit would bring a task force here within weeks,
and a flotilla of battleships ought to be enough to level the continent. A couple of barrages from their lance batteries would be enough to excise this cancer, however deeply it was buried.
Of course the planet would be rendered uninhabitable for generations, but no one in their right mind would be willing to set foot here once the necron presence was known in any case, so the question was moot." Caves of ice page 166-167
Showing Cain believes a flotilla of battleships, however 40k defines such, are needed to level the continent rather than a solitary or lesser ships. Bracketing continent ruining firepower within the Imperial Navy.
" In the distance I can just about make out a sally port of Coritanorum. Two gatehouses flank a big armoured portal dug into an outcrop of rock from the
mountain into which most of the citadel is dug. It's that
mountain that makes it so easy to defend, rendering it impervious to all but the most sustained and concentrated orbital bombardment." Last Chancers 13th legion
"'Admiral Becks, your plan is totally unacceptable' the wisened warmaster said, smoothing the folds in his long black trench coat. 'It is impossible to reduce Coritanorum from orbit.'
'Nothing is impossible to destroy, Warmaster Menitus' the fleet admiral replied with a smug grin creasing the leathery skin of his hawk-like face. 'It may take a decade of bombardment, but we can annihilate that rebellious fortress and everyone in it.'
"Last Chancers 13th legion
An example of a very tough, dug in fortress and its resistence to orbital bombardment.
* Special thanks to as always to Mr. Oragahn for compiling examples in easy to locat segments
EDIT: Special hat tip to Mith for this gem:
Rogue Trader core rulesbook 2009 wrote:Macrobatteries from the main armament of most ships, filling the braodsides of vesseles with rank upon rank of gigantic weapons. Each require a crew of dozens, if not hundreds, to operate. Whether they fling kilo-tonne warheads across the void or roast their targets with high-intensity energy, macrobatteries fire in volley.
So it does appear to be talking of yield rather than total weight.