Rail gun "yields" in terms of kilo/megatonnes

[VR Jay Le Chardon]

There were theoretical weapons called "Rods from God" which were outlawed under the outer space treaty, a kinetic orbital bombardment weapon, based on the idea of launching a tungsten rod at a planets surface, whereby the impact would convert the kinetic energy into an explosion like an asteroid strike.

So in light of those weapons, has anyone ran kinetic energy calculations for the rail guns? Just thinking about Odyssey, ground striking from a ship, say an iEagle, with rail guns, would that be like a sniper rifle shot? Or would it be more akin to an RPG? Or maybe a tank shell? Or a tomahawk missile?

OR...

...given the nigh-on-luminal speeds of the projectiles, would they be in to the realms of nuclear weapons?

Any thoughts or insights would be much appreciated.

 

[Elpapo]

Rails are gifts from tunel. Praise it.

 

[Four Muffins]

We should probably test by hitting space leggers with rails, just to be sure.

 

[Achtung-Goomba]

We should probably test by hitting space leggers with rails, just to be sure.

Happy to volunteer, bonus points if I make orbit and you can volley me into the mail slot of an orbiting station.

 

[Dillon Fallon]

I thought this would probably be a reasonable approximation.

Relativistic Baseball

 

[Trollymctrollerson]

Now im curious if a railgun delivers more damage in MJ to a shield than it costs from the power distributor. Does it somehow create energy? It produces heat too. How many BTU of thermal energy are released from discharging one? To answer your question, just shoot it at rock in the asteroid field. Gravity would not add any meaningful velocity or kinetic energy over its useful range. Rods from god allow gravity to accelerate them for hundres of KM.

 

[Kamiyoda]

There were theoretical weapons called "Rods from God" which were outlawed under the outer space treaty, a kinetic orbital bombardment weapon, based on the idea of launching a tungsten rod at a planets surface, whereby the impact would convert the kinetic energy into an explosion like an asteroid strike.

So in light of those weapons, has anyone ran kinetic energy calculations for the rail guns? Just thinking about Odyssey, ground striking from a ship, say an iEagle, with rail guns, would that be like a sniper rifle shot? Or would it be more akin to an RPG? Or maybe a tank shell? Or a tomahawk missile?

OR...

...given the nigh-on-luminal speeds of the projectiles, would they be in to the realms of nuclear weapons?

Any thoughts or insights would be much appreciated.

Rods from god were bunker busters at best. No idea where people got the idea they were nuclear yield weapons, but thats a story for another time and not really on topic at all.

And the short and sweat answer is a big "???" for every weapon in ED. There is no concrete way to calc anything meaningful aside from either looking at the power requirements or looking at the physical damage done and extrapolating from that.

So the best I can give you without doing a massive deep dive into the lore again is this:

A stock class 2B Railgun needs about 5MW per second to fire constantly. The prototype railgun used by the American navy is somewhere around the ballpark of 25MW per second.

Guessing the projectile speed of ED railguns is pretty much impossible as from a gameplay standpoint they are just slow firing lasers with an unknown projectile size(And I highly doubt they are anywhere near reavalistic as that would break the setting in half over its already tenacious back).

But screw it, assuming the Railgun has a 5th of the power requirements of a modern day railgun, roughly the same speed and higher fire rate. With the projectile being about the size and mass of a 16 inch WW2 shell because that thing is YUGE, we are looking at roughly 1.4 megatons of TNT per shot.

Is this absolutely ridiculous? Yes. Does it fit the setting? Probably not. But the real answer is boring.

 

[gorankar]

Red Mist.

 

[VR Jay Le Chardon]

Happy to volunteer, bonus points if I make orbit and you can volley me into the mail slot of an orbiting station.

Paint a federation emblem on your space suit and I'll be sure not to miss

 

[Sublime]

I thought this would probably be a reasonable approximation.

Relativistic Baseball

Tenuous atmospheres only.. /s

 

[Bortas]

So in light of those weapons, has anyone ran kinetic energy calculations for the rail guns?

It's actually pretty easy to calculate... we just need the mass and speed of the projectiles. Do you have those handy?

 

[Eraden]

I don't think this game really has a good handle on reality where numbers are concerned. Consider if you will, the ability of ships in this game to dive into the atmosphere's of stars and even worse, get ridiculously close to neutron stars. A single modestly sized neutron star has enough energy to literally exceed the energy output of all of the major factions' navies by SEVERAL ORDERS OF MAGNITUDE. Yet our ships can turbocharge off of these monsters with little harm (assuming you do it right). You can see where I am going with this. If this kind of thing is permitted within this game, there is very little chance that railguns are going to get done properly. For starters, I seriously doubt the railguns in this game are throwing projectiles the size of the munitions of 20th century naval battleships. There is simply not enough room in the gun chamber for something like this. It's more likely to be a traditional tungsten railgun slug (rod) that is a few cm in diameter but very long. It will still have a hefty mass but not nearly as much as a 2 ton round. The amount of energy required to launch a slug of this size at hypersonic speeds (we are not talking relativistic, that is just plain idiotic), is ENORMOUS! It will do a lot of damage to whatever it hits but then again, it's being used against other ships that can happily cuddle up to stars, both alive and the zombie kind. At this point, you might just be better off turning off your thinking and enjoy the pretty pictures. Reality has left the building.

 

[Eraden]

Now im curious if a railgun delivers more damage in MJ to a shield than it costs from the power distributor. Does it somehow create energy? It produces heat too. How many BTU of thermal energy are released from discharging one? To answer your question, just shoot it at rock in the asteroid field. Gravity would not add any meaningful velocity or kinetic energy over its useful range. Rods from god allow gravity to accelerate them for hundres of KM.

That simply can't happen, Trolly. At least, not unless this game wants to throw out all pretense of being science fiction. The Universe is quite strict on this. There is no such thing as being able to create energy out of nothing. Perpetual motion machines not allowed. Strictly speaking, the amount of energy delivered to a shield from the impact, should be at BEST, equal to the energy imparted to the railgun slug. Realistically, there will be loss of energy due to a variety of inefficiencies in the process, so the energy delivered to the shield will be somewhat less than the energy imparted to the slug.

 

[Morbad]

So in light of those weapons, has anyone ran kinetic energy calculations for the rail guns?

I get zero.

Zero projectile mass (our fully modular railguns with internal magazines don't change mass when firing, so the 'projectile' logically has a mass of zero) times infinite velocity (or just under the speed of light if you want to get stingy) for hitscan, squared, still equals zero.

If we want to use the 20kg mass plasma slug consumes per shot, and still use a velocity close to the speed of light...well, you're looking at two orders of magnitude more energy than then 'relativistic baseball' below, because 20kg is about 134 baseballs worth of mass energy equivalent.

No idea where people got the idea they were nuclear yield weapons

Well, the smallest nuclear weapons have pretty meager yields. The W54 could go down to 10 tons (yes, just tons, no kilo) TNT equivalent. An old stove dropped from geosynchronous orbital altitude would probably outdo it.

Now im curious if a railgun delivers more damage in MJ to a shield than it costs from the power distributor. Does it somehow create energy?

Many weapons in ED seem to be more than 100% efficient, sometimes by huge margins. Anything with a DPE over 1 delivers more energy than it costs. This could be justifiable for weapons delivering explosive payloads, but not for kinetic energy weapons, lasers, or the like.

The huge efficient beam laser I'm so fond of does 51.3MW of damage and produces a thermal load of 4MW(?), for a total output of 55.3MW...while drawing 1.36MW from the power plant, and needing 4.5MW of cooling from WEP.

This apparent creation of huge amounts of energy from nothing is one of my main complaints about healing beams.

Then again, we don't really know for sure what unit is used for damage, or how our shields are even supposed to work...they are as fantasy as it gets.

That simply can't happen, Trolly. At least, not unless this game wants to throw out all pretense of being science fiction.

Elite: Dangerous has a plausible galaxy and a Newtonian physics engine (distinct from flight model, which has all sorts or magical forces and limiters strapped on top of that physics) for non-fixed objects, but that's where it's science ends, and it's never really pretended to do more.

 

[GoldenSilver484]

If taken at the face values as displayed and the fact shields are measured in megajoules, a C2 railgun hits with a force of 41.5 MJ.
For reference of the impact, one megajoule is the kinetic force behind a 1 tonne car traveling at 161km/h. (According to Wikipedia.)

It's completely believable as far as destructive power is concerned when compared to real life equivalents.
The 1200kg shell fired from the 406mm guns found on Iowa class battleships leave the barrel with 355 MJ of force (also Wikipedia), or 8.55 times harder than a C2 railgun.
Even a SRB oversized C4 PA, despite being the highest single shot alpha weapon we have, tops out at 225.7mj.

 

[Bigmaec]

This thread is very spacebattles.

 

[Ydiss]

No more than a sentence is required to conclude this thread: it's a game that's got magic shields in it.

I like discussions about science. But if we really like science then we should know that it's impossible to draw any conclusions using the scientific method when the hypothesis is based on Elite.

So, either talk science or talk game.

Science? Rail guns are magic (they don't apply to thermodynamic/relativistic rules).

Game?

The rail gun ends at 6km max and does no damage to a planet.

Both?

It's a game that's got magic shields in it, Jim.


/thread

 

[Kamiyoda]

This thread is very spacebattles.

Looks away suspiciously

I have no idea what you are talking about!
Hides Federal Corvette vs CR90 thread

 

[Rubbernuke]

Looks away suspiciously

I have no idea what you are talking about!
Hides Federal Corvette vs CR90 thread

Just don't do it. Step away from the vehicle sir.

 

[GloatingSwine]

So in light of those weapons, has anyone ran kinetic energy calculations for the rail guns? Just thinking about Odyssey, ground striking from a ship, say an iEagle, with rail guns, would that be like a sniper rifle shot? Or would it be more akin to an RPG? Or maybe a tank shell? Or a tomahawk missile?

If we assume that the quoted shield strength in MJ is the same unit we are used to, a class 2 railgun has ~3.5-4x the muzzle energy of a modern tank gun.