What are current calcs for the 40k weapons

[Ford Prefect]

EDIT: Actually, strictly speaking I wouldn't even really call .99c close to lightspeed, but to be honest it's basically irrelevant.

[Darth Hoth]

.99 c? When last I heard, it was "near light-speed" or similar vague phrasings. Are there new sources that I am unaware of?

Every statement is 'close to light speed' 'something approaching the speed of light' etc etc. I'm fairly sure that the Battlefleet Gothic rulebook actually says 'at lightspeed', which was the first source I've ever read on the matter. I don't think saying that it's .99c is exactly controversial, given that is, in fact, 'close to the speed of light'' while .9c really isn't.

Technically anything over .5 c could be called "close" to lightspeed, depending on interpretation.

Note that this is NOT me saying that that number is likelier or making any claim to such effect, but I disagree that such a vague statement "obviously" means .99 c.

Anyway, thank you for the clarification.

[Black Admiral]

Nova Cannon velocity hasn't ever been given a specific number, just rather general statements ("close to light speed" (BFG Rulebook), "near light speed" (Shadow Point), "something close to the speed of light" (Cadian Blood) & "close to light speed" again (The Chapter's Due)).

(well, there is the mention of 5,000kps as Nova Cannon muzzle velocity in Warriors of Ultramar, but I think that can be discounted, being explicitly contradicted by TCD in the same series - less than 2% thereof is not "close to light speed" unless you're a moron)

[Eleventh Century Remnant]

First an admission to Darth Ruinus; I can't track the source of that 1.46E25 W figure down, not past the fact that it's in my own notes. Presumably it got there from somewhere, and my memory is telling me that it was a very old style line drawing with that figure explicitly stated, the one with the YT shilouette shown next to the muzzle for scale, but it hasn't shown up in the older revisions of that Wookiepedia page.

Worse, scaling from the reactor bulb fails to come up with anything of the sort, 65,450 m3 on a ten second firing cycle doesn't even give one petaton assuming comparable power densities to the ISD main reactor. I think it's right, but I've lost the evidence, so until and unless it turns up, have to retract that one.

Necessary but embarrassing bit out of the way, weapons other than nova cannon?

[Connor MacLeod]

First an admission to Darth Ruinus; I can't track the source of that 1.46E25 W figure down, not past the fact that it's in my own notes. Presumably it got there from somewhere, and my memory is telling me that it was a very old style line drawing with that figure explicitly stated, the one with the YT shilouette shown next to the muzzle for scale, but it hasn't shown up in the older revisions of that Wookiepedia page.

Worse, scaling from the reactor bulb fails to come up with anything of the sort, 65,450 m3 on a ten second firing cycle doesn't even give one petaton assuming comparable power densities to the ISD main reactor. I think it's right, but I've lost the evidence, so until and unless it turns up, have to retract that one.

Necessary but embarrassing bit out of the way, weapons other than nova cannon?

Near As I could figure: The EGW&T (but not the NEGW&T) mentioned the W-165 output nearly 4x the energy of the KDY-150, and could (IIRC) penetrate an ISD's shields in multiple hits. Work off of shielding/armor/durability in some way and one might get a calc of some kind if you figure out how many KDY-150 bolts it takes to overload an ISD's shields.

One possibility: the "canon" output for the ISD-1 reactor was used as a baseline, possibly by extrapolating either the possibile dissipation rate or how much power might need to be allocated to shields (thinking that much energy has to be overcome or something, I dunno.) and then working between the Planetary turbolaser and ion cannons from there. I suppose if you guess at heat sink ability as well (total energy absorbed) for an ISD you could work that out too.

I should point out that the NEGW&T says that that planetary turbolaser is the most powerful and long ranged "single" laser aside from a few superweapons and the Death sTar. Something that the heavy TL from the ROTS ICS might take exception to (unless that somehow is semantically NOT a TL or a beam weapon or something.) Nevermind the range thing (which is contraidcotry with a number of other sources)

[Connor MacLeod]

Nova cannon calcs: I thinkit would be worth reminding people that there's quite a bit of diversity to draw on here. Some 'nova cannon' in novels aren't really projectile cannon the way they are mentioned in BFG. They seem to fire an energy beam (but are still powerful weapons.) Examples include the Space Wolf novels, the third Word Bearers novel, etc.

Even the projectile weapons vary. The one in Hellforged seems od (you slam together two weird heavy metal spheres and it somehow powers the projectile to high velocity. Although that weapon is also implied to be hideously overbored). There's the "Warriors of Ultramar" nova cannon projectile moving at 5000 kps, which is a different one, and I think now probably has to be differentiated. Whether or not the breech diamater is still of any value or not, I dont know (and the breech thing has a number of problems I've still yet to work out anyways. Not like it's the sole determinant of projectile diameter anyhow). Anyways, the WoU Nova cannon is probably in its own category as well (same with its warhead.)

Other sources (like Cadian blood, etc.) probably mesh up best with the BFG nova cannon, but even there I should point out that there is no reason to assume one size fits all. We know nova cannons need the starship's engines to counter recoil (although how much recoil is up for debate) but that alone tells us that "cruiser scale" and "battleship scale" nova cannons ought to be differet (different size engines, different masses, etc.) After all we know OTHER weapons systems (torpedoes, lances, etc) scale up as well (bigger torps for Battleships, for example.) So even there you need at (least) two calcs.

Velocity seems to be a constant there, so that means the mass changes. Macor cannons can be from a few tons to several hundreds (or possibly a few thouand) tons. That sets a lower limit on nova cannon projectiles. Bombardment cannons (similar to nova cannon) are 5x massive than macro cannon. Torpedoes (also implied elsewhere to be similar to nova cannon in terms of size/diameter) say 10x. The broad inference here is that nova cannon projectiles could be thousands of tons or so (within an order of magntiude either way). Something as massive as a modern aircraft carrier is possible (may even be needed for some calcs).

It is worth noting that conservatively, one should assume Nova cannon consume ALL the power the ship uses. But realisticalyl it wont - we know that the engines have to have similar power levels just to counter recoil, and we never have seen or heard of other weapons being depowered when firing a nova cannon, so the Nova cannon outputs only represent part of the overall weapon's reactor output. If anything, they may provide a benchmark to tell us just how roughly powerful the other weapons on the ship are (lances, weapons batteries, etc.) although how closely that applies is still somewhat vague (it could be over a duration, for example.)

The calcs themselves? Well that depends on whether you're asking me for what I think, or what the evidence can show. My belief leans towards 40K being around SW level of firepower (which IMHO means petaton range) based on my own analysis, but that isnt the same as what it COULD be. In theory you could argue 40K firepower as gigaton range teraton range, or petaton range. Hell you probably could go higher (I never really cared to bother trying to work it higher than somewhere in petaton range.. that's insanely high enough for 40K.) Most people I know tend to settle just for teraton range at that so for whatever common opinion is worth.

Anyhow, the evidence itself has enough leeway for the possibility of lower yields, and anyone making firepower claims is well advised to keep that in mind when debating (The same should be true with Star wars firepower. Far too many people mindlessly just assume a certain firepower level without actually digging, even though there's still a fair bit of variation and problems associated there. The ICS did not "fix" everything, or hell even most things.)

Ground firepower.. is a whole nother story.

[IvanTih]

Does power to level a city refers to some vast hive city?I am confuse since cities in 40k are know to be extremly large.

[Darth Hoth]

If it just says "city" without further qualifiers, I would take it as meaning an "ordinary" city, unless there was something in the context to indicate that it was referring to a hive. By using conservative assumptions, I make my position less vulnerable to attack, while still leaving room for higher-end estimates. But that is just my personal preference, others might have other ideas.

[LionElJonson]

If it just says "city" without further qualifiers, I would take it as meaning an "ordinary" city, unless there was something in the context to indicate that it was referring to a hive. By using conservative assumptions, I make my position less vulnerable to attack, while still leaving room for higher-end estimates. But that is just my personal preference, others might have other ideas.

In the Rogue Trader adventure Lure of the Expanse, there are stats for the city-ships of Zayth, which are described as being the size of hives; they've got 75 Hull Integrity, 3 Void Shields, and 16 Armor. A typical Lunar-class Cruiser has 75 Hull Integrity, 20 Armor, and 2 Void Shields. Both possess approximately equal armament (two macrocannon batteries doing 1d10+2 damage per hit, up to six hits each).

So, 40k Hive Cities are probably quite resilient if properly designed with defense in mind, especially since the Zaythian hive-ships are basically giant, walking land-battleships, and a proper hive wouldn't need to waste space on locomotive systems or the systems needed to power them, and I don't think Titans or their Ordinatus buddies would be able to do much damage to one.

[Connor MacLeod]

City can mean anything, so it's not a reliable benchmark and even if its a big city levelling it doesnt need alot of energy (megaton range nukes we have today could easily devastate many cities, nevermind kiloton range stuff.) If you're going to use big hive cities (which we know get to continent size) as some sort of argument you're just better off going with "continent destroying" referneces anyhow since they are just as common and prone to sound more impressive. (although those have problems in and of themselves as well so their usefulness is debatable.)

[IvanTih]

I assume that 40k firepower(for IOM) lies in gigaton to teraton range.Does anyone agree with me.