I was impressed. It was a pleasant read, lively and engaging, much unlike the pieces of fiction I encountered in WH40k sourcebooks in having an engaging POV and witty commentary (much of it in the form of footnotes) with some fairly subtle things that the narrator doesn't tell you, but are suggested by the text. I liked it. After some time, it occurred to me that I should probably take down a few technical notes.
Las-bolts from lasrifles put dents in sandbags. Conversely, sandbags are effective cover. This would obviously not be the case if lasrifles were very high energy weapons - something much more than a megajoule of thermal energy would put rather more than a dent in a sandbag.p15 wrote:To all intents and purposes they'd remained a distant threat, despite the occasional las-bolt putting a dent in the sandbags protecting us.
This heavily footnoted passage is interesting because it talks about typical combat range - which is something rarely talked about. This range is hundreds to thousands of kilometres.p61 wrote:Contrary to what you might see in an episode of Attack Run1, starships in combat seldom approach to within point blank range of one another, exchanging fire instead at hundreds, if not thousands, of kilometres. There are exceptions, of course; you have to get close to your target to launch boarding parties or knock out a fighter screen, not to mention ramming, which is a favorite Ork tactic.2 Even so, we were able to pick out the positions of the combatants as another lance or torpedo volley struck home, and once by a peculiar sensation of sickness and disorientation as space itself seemed to twist in the middle of my field of vision, sucking some luckless victim into the hell of the warp as its engine exploded.3
1. A popular holodrama of the 930s, about a squadron of fighter pilots in the Gothic War.
2. Indeed, the Brute-class vessel referred to earlier is build ('designed' being perhaps too alien a concept for the ork mindset) with precisely this form of attack in mind.
3. The ork Ravager Ardenuff, according to the final report of the commission previously cited. The name, incidentally, is an ork term most closely translated as 'battleready.'
This is from around the edge of the system in its cometary halo - a fair distance out, although fairly vague. Given the hypothesized radius of the Oort Cloud is around a light year, and the drive is sublight, this probably refers to a Kuiper-belt-like structure.p62 wrote:'How long would that take?" Jurgen asked.
I shrugged again, and retrieved the appropriate information after searching through our tiny craft's limited databanks. 'About three weeks,' I concluded.
This didn't sound too bad - it would have taken the troopship a little under half that to coast in from this far out on the fringes of the system, assuming it survived the engagement at all.
30-50 AUs is 4.5-7.5x10^12 meters. 3 weeks is 1.8x10^6 seconds. Half that is 9.1x10^5 seconds. The average velocity is possibly up to around 1% of lightspeed, so safe maximum velocity might be an issue. If we solve for a zero-zero intercept, that gives 0.6-0.9g average acceleration for the escape pod and 2-4g for the shuttle. A simple braking-to-zero from a high incoming velocity (the escape pod is fired off at high thrust initially) halves this (0.3-0.5 and 1-2). Actually, one odd footnote, which I forgot to copy down, is that Cain must have figured out how to turn on the artificial gravity, but didn't make note of it in his private memoirs - there's some description of the escape pod having been in free-fall right after launch.
This is a pretty similar line. The orks figured out how to force an Imperium ship out of warp prematurely and ambush it, so the Imperium responded by coming in from further out. Note that transit of days within the system is still expected.p67 wrote:Forewarned by astropathic messages, subsequent convoys were forced to drop out of the warp far further out than they otherwise would have done for fear of suffering a similar fate, running the gauntlet of sustained attacks for two weeks or more rather than the handful of days they would ordinarily be forced to endure.
A word on communications. This actually comes full circle in the last novel in the omnibus; Cain has just won a conflict against Chaos forces on the very same planet some decades later, and used an out-of-date astropathic message (that apparently dropped out of warp over fifty years late) that said an Imperium fleet was coming to save the day to cover up Necron activity.p260 wrote:'These situations are so fluid that all the news we had when we left Coronus will be completely out of date by now anyway.'
This was an interesting incident. The Chaos vessels emerged exceptionally close to the planet, a tactic that was repeated later; the debris from those later ships clogged up the geostationary orbits, so we have a good idea of the velocity that the enemy ships were using - just a few kilometers per second relative to the planet, by all appearances; less than escape velocity.p588 wrote:Both Chaos vessels had re-emerged from the atmosphere, and were now spinning away on an uncontrolled trajectory, no doubt melted to slag by their fiery passage through the superheated air.1
1. Actually, starships are a lot tougher than that; although both were now lifeless, and their outer hulls little more than featureless blobs of congealed metal, much of their internal structures remained intact. Both were boarded and inspected by Ordo Hereticus investigation teams after hostilities ceased, although I'm assured nothing of particular interest was found on either.
Nevertheless, the outer hulls of the first two capital ships the Chaos forces flung at the planet melted in the atmospheric run and everybody inside got cooked. This can be compared to the descent of the Invisible Hand, which was survivable (although possibly lower velocity) or an assortment of incidents in which the E-D's hull was superheated without melting or harming the interior. Several meters of adamantium doesn't provide the protection or resistance against thermal effects that several decimetres of tritanium do; tritanium has, in star-diving incidents, been heated to twelve thousand degrees without melting, a value impossible to reach with atmospheric re-entry at meteoric velocities.
What's further interesting, and which I thought I'd remembered to jot down, was that the debris of the second wave of Chaos ships was dangerous enough, as orbital debris, to force subsequent Chaos invaders to come out of warp outside geostationary orbit; this means that chunks of exploded warship, moving at orbital velocities, are sufficiently hazardous to nail intact warships.
Incredibly specific statement. Probably not actually that accurate, but we're talking 2.2-2.7 gigajoules if it is. The plasma cannon is mounted on one of several ogryn-sized servitors (i.e., 2.5-3m tall) that is built like a tank.p638 wrote:I dived behind the obelisk just as the plasma cannon recharged, and a searing bolt of star-stuff roared past the glittering lump of ironmongery, finally expending itself in the lake beyond. A thousand litres of water flashed instantly into steam, wreathing the whole scene in a chilling mist, which blocked out the sunlight as abruptly as a slamming door, and I began to think we might have a chance after all. It was a slim hope, but the artificial fog might just confuse the constructs' sensoria long enough for me to get the drop on them somehow, or at least get to safenty.
As far as I know, this is the single highest specific yield for a non-melta weapon used by an Imperium unit smaller than a Warhound, and also the highest yield shot that such a unit survived. Even melta yields are typically not clearly higher than this, although the efficiency of melta guns against heavy targets, both in this and other novels, strongly suggest that meltas are higher energy weapons than most of the heavy weapons the Imperium fields. (It is, of course, short range, uses volatile fuel for ammunition, and hard to use precisely.)
Here's what I mean by "built like a tank." Interestingly, Jurgen decapitates one with his melta gun. I seem to have forgotten to quote that incident, but that strongly suggests that the melta gun unleashes more raw energy than a plasma bolt from a machine 2.5-3 meters tall, built by the Imperium's most technologically sophisticated sub-faction.p639 wrote:I flung myself aside, seeking whatever refuge I could find behind the next face of the metal obelisk, just as another bolt of plasma hissed past, missing me by millimetres,1 and impacting against the chest of the construct I'd been fighting, with a satisfactory sizzle of vaporising metal and flesh. To my astonishment, however, the thing remained standing, although it was severely damaged. No matter, its internal systems were now clearly visible, and I drew back my chainsword, ready to strike at some vital component.
1. Clearly an exaggeration, as a plasma bolt passing that closely would have inflicted severe flash burns.
In general, these servitors should be able to throw around raw firepower not much less than a Dreadnought, and certainly could have been equipped with any of the weapons that a Space Marine could carry.
p684-5 wrote:Before I could reply, though, the sky turned white, all colour leached from it by a flare of harsh, actinic energy of almost inconceivable magnitude. Fortunately, the buildings of the city blocked any direct line of sight we might have had, or we would have been struck blind in an instant. A moment later the ground trembled, windows shattered, and a rain of debris pattered down around us, dislodged from the structures we drove between. Jurgen jammed on the brakes, butdecades of familiarity with his driving had left me prepared for this, and I kept my feet with relative ease.
'What the hell was that?' Kayla asked, slewing the second Salamander sideway, and crushing a parked groundcar under its tracks before coming to a half with its nose embedded in the plinth of a remarkably ugly statue of a remarkably ugly man, which disfigured the middle of the square we'd been passing through.
'Orbital strik, I said, having seen something similar on a few occasions before. 'Probably the lance batteries of a warship.'
p686 wrote:If nothing else, the wide gardens would offer our best chance of evading another orbital strike if I turned out to be wrong, as they were a long way from any tempting targets.
Orbital bombardment up close and personal. This is not more than a few megatons from 'probably the lance batteries of a warship.' Actually, given the apparently split-second gap in between the flash of light and the shockwave's arrival means that Cain and Jurgen aren't that many kilometres from the strike's center; we're really talking about a sub-megaton weapon. Note also that "wide gardens" are big enough to evade another orbital strike.p704 wrote:'Luckily for us, the debris belt forced the enemy flotilla into a low polar orbit rather than a geostationary one over the capital,' Julien said. 'The warships won't be in position for an orbital strike on these co-ordinates for about an hour. More or less.'
Lance batteries aren't necessarily especially high-yield weapons, but they are fairly dangerous ship-to-ship; the idea that it takes a warship to make a nuclear-scale strike is really, when you think about it, more important than the yield itself.
Point to consider: Whatever a melta is made of starts melting around a red temperature, not appreciably more than 1000 C or so. This means it isn't an exceptionally heat-resistant material by modern standards.p711 wrote:'Any moment now," I said, and my aide nodded, lining up his melta on the collapsing gate. It was glowing a deep ackenberry red by this time, the diamond hard composite softening like caramel, and the end must surely come soon.
Here we see the sandbags that featured earlier in the omnibus - successfully shielding against lasgun fire.p714 wrote:Two or three other troopers hovered behind him, and another couple, a bit quicker off the mark, were already sprinting for the dubious cover afforded by the smoking ruin of the pile of sandbags Jurgen and I had abandoned a few moments earlier. One went down, felled by our lasweapons, but his squad mate made it to safety, and began adding a little more to the hail of las-bolts aimed in our general direction.
p739 wrote:'Given them an edge," the familiar voice said cheerily. 'Tied an automatic targeter into the auspex array ofthe command one, with a vox-link to the rest. It's an unholy lash-up, given the time we had available, but it'll just have to do until we can burn the incense properly and recalibrate. If it works at all.'
This is a very interesting incident where a less-traditional techpriest uses the machines' inbuilt AIs quite effectively.p740 wrote:I never got the chance to complete the sentence, as the multi-laser in the turret fired, the miniature thundercrack drowning out everything, even the rising scream of the approaching shuttle engines. For a moment I thought the sound was echoing from the surrounding hills, then I realized the vox-relay had done its work despite the lack of incense, and the other five had fired too, almost simultaneously. Raising my amplivisor again I tried to focus on the approaching shuttles.
'A hit, by the Emperor!" I cried jubilantly, then corrected myself. 'No, two at least!' The outermost aircraft on either side of the formation were both losing speed and altitude, which made sense to me, as the Chimeras were ranged along each side of the valley, and the machine spirits, logical as ever, would simply have sought the nearest targets.
Further interesting is that managing to hit the incoming shuttles, using a battery of five Chimeras with multilasers, is the sort of feat that is worth praising the Emperor for.
Meltas can vaporize people. (This shouldn't be a surprise).p744 wrote:We took the traitors completely by surprise, a trooper in the uniform of a Perlian being reduced to a greasy stain by a blast from Jurgen's melta, while I accounted for a Madasan on the other flank with a single las-bolt.
Another incident in the final novel that was of some interest was that a single small Necron ship blew up a couple of Chaos capital ships.