Durasteel

[sithlordfreedonnadd]

I've been wondering recently if anyone has tried to figure out how strong Durasteel is. i read somewhere that its 300,000 times stronger than steel but im not sure how accurate this is. I realize that it must be stronger than that because a turbolaser blast doesn't do an immense amount of damage to a ship and they have been shown to be thousands of times more powerful than modern day nuclear weapons. Modern Day nuclear weapons can generate heat in the tens of millions or even hundreds of millions of degrees Fahrenheit so turbolasers must easily be in the billions and durasteel melts under this heat but if it is too weak would not the entire ship be incinerated?

so this is my thinking please reply and if i have something terribly wrong please tell me

[Bottlestein]

^ Metal "strength" does not directly correlate with heat capacity, which is what is required to resist melting. For example, look up a list of titanium alloys. You'll see a titanium-aluminum alloy that has extremely high tensile strength (almost twice that of grade 12 titanium), and high heat capacity. Then, there's another alloy with higher tensile strength and lower heat capacity (IIRC it adds molybdenum or some such material to the titanium-aluminum alloy).

(In fact, these alloys are aerospace alloys designed for these properties in order to use in afterburner components for jet engines.)

The problem is since turbolasers concentrate the energy into a small area, and in the absence of atmosphere, we can't compare them to our "nuclear bomb - proof" materials which resist a nuclear blast in atmosphere, and at a much lower energy density.

For instance, in 1954, steel coated with graphite anti-ablators survived a 15 MT thermonuclear blast during the Castle Bravo test shot. However, the ablation from a turbolaser blast at different angles does not correspond to an isotropic one, as was the case here. So, we have to conclude the anti-ablators in Star Wars use mechanisms we don't understand (read: violate physical law). Alternatively, one could say that the crystalline structure of durasteel is so different that ablation isn't a problem, so it has not coating at all. Both scenarios will give you different heat capacities, but both cover what's seen in the films.

For an "off the cuff" calculation, heat capacity is linear with energy so if you take the heat capacity of graphite, you can use this type of formula:

"Heat Capacity" of Durasteel / Heat Capacity of Graphite = Energy calculated for Turbolaser / 15 MT

[takemeout_totheblack]

even if you go with 300kxsteel you come out with something that's pretty damn strong! Mechanical aspects aside, something with 300k the heat resistance of steel would be something like 18 petajoules per cubic meter for vaporization, that's a over 4 megatons! Considering starship armor is capable of withstanding a proximity blast from fusion missiles (AOTC:ICS) with only a bit of scoring to show for it, that number's probably not too far off.

What I want to know is why can starship armor durasteel withstand this punishment while vehicle armor is decidedly weaker? Suppose starship-grade duranium has 'neutronium' in it while lower grades don't?

[Adam Reynolds]

What I want to know is why can starship armor durasteel withstand this punishment while vehicle armor is decidedly weaker? Suppose starship-grade duranium has 'neutronium' in it while lower grades don't?

The primary reason for this difference is almost certainly one of weight. It has been stated in the AOTC ICS that starships that land, such as the Acclamator and Venator, are continuously using their repulsorlifts during the process. If an AT-AT used the same strength of armor as a starship, it would also be forced to use repulsorlifts while on a planetary surface, thus negating its primary purpose: breaching theater shields.

[takemeout_totheblack]

So the nuke-shrugging grade durasteel probably has neutronium, while an AT-AT or AT-TE have a neutronium-less version? So what would be the thresholds of the vehicle grade durasteel? Could we hazard a guess based on damage done by weapons we have numbers on?

[Adam Reynolds]

The best numbers I know of for ground weapons also come from the AOTC ICS, the LAAT/i's turreted blaster weapons are rated at 3E9 Joules or roughly a ton of TNT as are the similar weapons on a AT-TE. The beam weapons of the LAAT/i are significantly more powerful rated at 3E11 joules, or less than a hundred tons of TNT. The main weapon of the AT-TE fires variable yield shells so its effectiveness is unknown. The same is true for the missiles of a LAAT/i, however it is stated that they can fire missiles as powerful as 100 kilotons in a narrow cone. I would assume the Rebel defenses at Hoth have roughly the same firepower as the the beam weapons of a LAAT/i although their actual firepower is unknown. There was also a thread here a long time ago that rated AT-AT firepower in the mid to high kiloton range, possibly into the megaton range although there is doubt about the last figure.

This thread discusses the maximum firepower of an AT-AT:
http://bbs2.stardestroyer.net/Archive/v ... hp?t=10360&

[SeaTrooper]

So the nuke-shrugging grade durasteel probably has neutronium, while an AT-AT or AT-TE have a neutronium-less version? So what would be the thresholds of the vehicle grade durasteel? Could we hazard a guess based on damage done by weapons we have numbers on?

No, this is still durasteel, as seen when an AT-AT was hit by a Rebel artillery piece and there was a brief glow as the energy was conducted over a wider area and dissipated. Where the difference likely lies is in the OOMs between shipboard and ground based weaponry. In space, throwing around MTs, GTs and TTs (hopefully at considerable range) is much less of an own-goal problem than using KT-level weapons on a planetary surface. You don't want to shoot the bad guys and then go up yourself in the resulting fireball.

Frankly, even using KT-level weapons in ground combat is a seriously bad idea, and can only be supported if meant for targets a very long way from your own troops. Can you say 'Friendly Fire'?

[takemeout_totheblack]

Ok, then how can supposedly megajoule firearms even scratch said nuke-absorbing metal? Shouldn't they just dissipate harmlessly rather than making the big clouds of smoke we see in the OT? The fact that any vehicles are destroyed by what appears to be less-than-kiloton makes me lean towards the 'grades theory'.

[SeaTrooper]

Ok, then how can supposedly megajoule firearms even scratch said nuke-absorbing metal? Shouldn't they just dissipate harmlessly rather than making the big clouds of smoke we see in the OT? The fact that any vehicles are destroyed by what appears to be less-than-kiloton makes me lean towards the 'grades theory'.

Sure, which brings us back to adamskywalker's figures. I'm more than happy to run with those yields in-universe, but really wouldn't want to be anywhere near impacts coming from either side.

The clouds of smoke we see is either hull material being ablated, suggesting that energy-conduction and dissipation is not 100% efficient (as you'd expect) or, in the Falcons case, the burning of all the crap deposited on their hull. The OT and novels all noted how that ship leaked, was filthy with residues from stuff they'd picked up, and didn't Leia say something about needing shots after being on it? Plenty to burn off there.

Still, no matter how good durasteel is at energy-conduction, dissipation and resistance, you have got to expect some material to be burned off from a hit. Trying real hard to avoid the 100% efficiency fallacy here.

[takemeout_totheblack]

The clouds of smoke we see is either hull material being ablated, suggesting that energy-conduction and dissipation is not 100% efficient (as you'd expect) or, in the Falcons case, the burning of all the crap deposited on their hull. The OT and novels all noted how that ship leaked, was filthy with residues from stuff they'd picked up, and didn't Leia say something about needing shots after being on it? Plenty to burn off there.

Still, no matter how good durasteel is at energy-conduction, dissipation and resistance, you have got to expect some material to be burned off from a hit. Trying real hard to avoid the 100% efficiency fallacy here.

I wasn't saying it was 100% efficient, if it was then it wouldn't take any damage! I was saying that any metal capable of withstanding a proximity blast from what I assume is an anti-ship fusion missile with little more than scoring to show for it isn't going to to have any trouble with megajoule level blasters! Far less than 100% efficiency on that level would still be more than enough to harmlessly dissipate a 5-20 megajoule blast without any visible damage! Also, I was thinking less 'clouds of smoke from the MF', and more 'clouds of smoke from the brand-fucking-new Death Star during A New Hope'!
I know the Empire sunk a lot of money into building that thing, but I don't think they made the whole thing out of starship grade durasteel, leading me to believe that the internal structures were made from low-grade but still strong durasteel and duracrete.

[SeaTrooper]

Ha, yes! You don't want to be the contractor caught supplying sub-standard building materials to the Empire

[Bottlestein]

Actually - what is the cost benefit analysis that leads to 1 Death Star over however many ISD's, anyway?

The superlaser does the job quicker than a BDZ (assuming BDZ's take 24 hrs) - but once a planet's surface is unusable, there's no point blowing it up.

[Eleventh Century Remnant]

The Death Star, and later the Torpedo Spheres and various other strange superweapons, exist because it's not practical to bombard a shielded planet. Any even half- way decent set of planetary shields, for which there is the very real function of accident prevention for besides any military requirement, have so much area to radiate heat away with that any practical fleet would run it's fuel cells try trying to pound a way through.

Note any practical, not any possible fleet; from the EU it does seem to be possible to pound down the shields of a defended world, but it's a long, painstaking operation that requires serious force and involves stripping a large area of ships to provide it- to do it cleanly and suddenly, so that the journey time to the site is greater than the time spent in bombardment at least, for a first class shield system might mean stripping half the galaxy of ships of force.

Or there are always the usual tricks employed against a fortress in the pre- gunpowder era (which the situation reminds me of), infiltration, starvation, politics and treachery.

The Death Star's concentration of force that grants it the ability to just burn straight through the shields is a much cleaner and less fiddly solution, that avoids all kinds of opportunities for defensive action and public and political reaction until it's far too late.

Anyway, durasteel; how many different kinds, compositions and alloys of ordinary earth steel are there? Tens, possibly hundreds of thousands. It's a spectrum, not a point.

[DudeGuyMan]

This thread discusses the maximum firepower of an AT-AT:
http://bbs2.stardestroyer.net/Archive/v ... hp?t=10360&

Jesus Christ, what a terrible thread that was.

[Bakustra]

Hell, just look at the perspective you'd need to get the generator to be more than a mile across. All based on the assumption of 17.28 kilometers.

[DudeGuyMan]

At first I thought the giant flash as seen in the second panel of my impromptu comic strip was the "160 kiloton fireball" referenced in the linked thread. I was all ready to flip shit because it didn't even knock anyone over. Then I realized he was somehow actually ascribing the secondary explosion that took place several seconds later to the power of the lasers.

I don't want to excessively vulture some thread from 7 years ago but, since it was linked as presumably not-utterly-worthless evidence, it's worth raking over the coals a bit. How the hell did that post not get torn to shreds within the first page?

[Grandmaster Jogurt]

At first I thought the giant flash as seen in the second panel of my impromptu comic strip was the "160 kiloton fireball" referenced in the linked thread. I was all ready to flip shit because it didn't even knock anyone over. Then I realized he was somehow actually ascribing the secondary explosion that took place several seconds later to the power of the lasers.

If you're talking about what Darth PhysBod meant, he repeatedly stated that the second explosion seen is the reactor going off while the one you labeled as *piff* is the actual KT-level weapons blast.

Hell, just look at the perspective you'd need to get the generator to be more than a mile across. All based on the assumption of 17.28 kilometers.

Are you saying that the generator is a mile long, which needs a weird depth of field for it to be that far away, or that the generator being found to be a mile long is an iffy proposition? The latter is supported by the EU, which says that the reactor was built from the main reactor of a star battleship.

[DudeGuyMan]

Yeah, there's three stages to the hit. Flash, piff, and the kablooey seen from the cockpit. The flash didn't knock anyone over, and the kablooey was clearly the reactor itself going up. Sarcasm aside, the piff is a substantial explosion, but I have a hard time seeing it as being anywhere near 16 kilotons.

That's about the yield of the Hiroshima bomb, and it's going off in the middle of a field of snow and ice. You would expect to see a rather noteworthy and essentially instant effect upon the immediate surroundings.

[Batman]

Absolutely. If we ever saw the immediate surroundings. Oops-we don't. As for it not knocking anyone over-who would have there been for it to knock over? There's exactly zero Imperial or Rebel troops to be seen in the same frame as the shield generator, you know, and the position of the shield generator wrt the battle lines is, like, completely unestablished other than it can't be less than 17 km away?
I suspect you are severely overestimating the effects of a 16 KT event.

[Bakustra]

At first I thought the giant flash as seen in the second panel of my impromptu comic strip was the "160 kiloton fireball" referenced in the linked thread. I was all ready to flip shit because it didn't even knock anyone over. Then I realized he was somehow actually ascribing the secondary explosion that took place several seconds later to the power of the lasers.

If you're talking about what Darth PhysBod meant, he repeatedly stated that the second explosion seen is the reactor going off while the one you labeled as *piff* is the actual KT-level weapons blast.

Hell, just look at the perspective you'd need to get the generator to be more than a mile across. All based on the assumption of 17.28 kilometers.

Are you saying that the generator is a mile long, which needs a weird depth of field for it to be that far away, or that the generator being found to be a mile long is an iffy proposition? The latter is supported by the EU, which says that the reactor was built from the main reactor of a star battleship.

I'm saying halfway between the two. The depth needs to be wonky for it to be a mile wide, and the calc requires a one-mile wide generator. In addition, that reactor is underground. The shield generator itself is what's aboveground. So I doubt the calc right from its underpinnings.

Absolutely. If we ever saw the immediate surroundings. Oops-we don't. As for it not knocking anyone over-who would have there been for it to knock over? There's exactly zero Imperial or Rebel troops to be seen in the same frame as the shield generator, you know, and the position of the shield generator wrt the battle lines is, like, completely unestablished other than it can't be less than 17 km away?
I suspect you are severely overestimating the effects of a 16 KT event.

What are you saying? There have been a number of people who have argued against the units being kilometers. It could well be hectometers, which would put it at about 1 mile away from the generator. It could be made-up units.

[DudeGuyMan]

Oh boy, here comes Batman with his mindless reactionary defense and shitty posting. I don't think I've responded to a post of yours since I made an asshole out of you in the "Why can't R2 talk?" thread, so I guess I can spare a moment.

Absolutely. If we ever saw the immediate surroundings. Oops-we don't.

Jesus Christ, I just posted pictures. I know they had ever so clever speech balloons crudely painted in, but look at them. Specifically the third one. A supposed 16 kilotons of energy released instantly and directly onto a field of snow and ice, with nary a wisp of steam in sight. The shot persists for only a second, but that's more than enough time to notice the complete lack of effect.

As for it not knocking anyone over-who would have there been for it to knock over? There's exactly zero Imperial or Rebel troops to be seen in the same frame as the shield generator, you know, and the position of the shield generator wrt the battle lines is, like, completely unestablished other than it can't be less than 17 km away?

What the fuck? Look at the picture, dipshit. Specifically the first three where the big flash of light washes over rebel troops without even breaking their stride. Of course this flash and it's lack of effect have little bearing on anything, and were merely mentioned in passing reference to my own initial misunderstanding of the linked thread, but I suspect you just plain didn't understand what I was talking about but knew you wanted to disagree.

I suspect you are severely overestimating the effects of a 16 KT event.

More likely you're the typical sci-fi numbnuts who thinks everything under a kiloton is a firecracker. Here's a clue: The whole beam event looked like it had fuck-all effect upon the environment because the former was a special effect added in post-production (that no one was ever intended to spend more than literally 2 seconds looking at) while the latter was live action film. (Otherewise you would think that flash would at least cause the Rebel soldiers to pull up short or trip or something.) But suspension of disbelief, so there you go.

God, why did you even post?

[DudeGuyMan]

While I'm at it, what are the accepted wanktastic firepower stats for the rebels at Hoth? I bet they're at least as high! Maybe I'm "overestimating the effects of a 16kt event" but I was under the impression that the Hiroshima bomb could at least melt snow from 10 yards away. Curious how we see rebel artillery shots hitting AT-AT walkers in the shins and shit with zero observable effect upon anything anywhere. Where the hell did all that energy go?

[Thanas]

Wow, this is stupid. Vader wanted prisoners, there is no way he would have just nuked the base. The only thing we see with maximum firepower is the blast against the shield generator, for which we never see if it melts snow or not.

[DudeGuyMan]

Hoth isn't just snowy, it's completely covered in a frozen ocean according to Wookieepedia. We're talking about an event analogous to detonating an atomic bomb on the surface of a glacier. Bear with me because I'm no scientist, but I'm pretty sure that such an event would involve a massive and essentially instant release of steam which is conspicuously lacking here.

Also, is rebel artillery incredibly weak in comparison to AT-AT weaponry? Are the laser guns on snowspeeders an order of magnitude less powerful than those on an X-wing? I want to know how guys armed with nuclear-yield energy weapons managed to have a huge throwdown ground battle on top of a block of ice without us ever once seeing a giant sheet of steam rising from the ground.

[Thanas]

Hoth isn't just snowy, it's completely covered in a frozen ocean according to Wookieepedia. We're talking about an event analogous to detonating an atomic bomb on the surface of a glacier. Bear with me because I'm no scientist, but I'm pretty sure that such an event would involve a massive and essentially instant release of steam which is conspicuously lacking here.

That depends on the effects and construction of the shield generator in question and keep in mind that all we see is a huge fireball (though at least in the fireball I see some white stuff that might be steam, also there is steam in the screenshots you quoted).

Also, is rebel artillery incredibly weak in comparison to AT-AT weaponry? Are the laser guns on snowspeeders an order of magnitude less powerful than those on an X-wing? I want to know how guys armed with nuclear-yield weapons managed to have a huge throwdown ground battle on top of a block of ice without us ever once seeing a giant sheet of steam rising from the ground.

What artillery? The guns were probably weak because we know that Vader wanted prisoners and the rebels would probably not really like to nuke themselves by using heavy weaponry near the Imps, who are pretty close to them.

It is not like the rebels detected the Imperial landing zone and blasted it with their long-range heavy artillery, which by all accounts seems to not have been there.